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Maillot C, Riquet D, Stubbe L, Bodnar JL, Houel N. Post-operative osteopathic manipulative treatment of Morel-Lavallee syndrome assessed using infrared thermal imaging: A case report. J Bodyw Mov Ther 2024; 39:447-453. [PMID: 38876667 DOI: 10.1016/j.jbmt.2024.03.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 02/01/2024] [Accepted: 03/12/2024] [Indexed: 06/16/2024]
Abstract
INTRODUCTION The Morel-Lavallee lesion (MLL) is a closed, degloving soft-tissue injury, wherein the skin and subcutaneous tissue are separated from the underlying fascia. This syndrome causes disruption of wound healing. Infrared thermography is a noninvasive and pain-free tool that can be used to evaluate scar and the influence of osteopathic manipulative treatment. OBJECTIVE To evaluate the influence of post-operative osteopathic manipulative treatment (OMT) of Morel-Lavallee lesions (MLL). METHODS During four osteopathic sessions on one volunteer patient, 28-year-old male, resulting in MLL of the left knee after motorcycle accident. The effects of OMT were assessed using an infrared thermal imaging camera and qualitative palpation examination of osteopathic dysfunction, scored on a scale of 1-4. RESULTS and discussion: Both scar and peri-scar area temperatures increased after OMT. The difference in temperature between the scar and the peri-scar area decreased after OMT. Increase in temperature was greater when the OMT was applied around the scar than when applied at a distance from the scar site. The palpation score for dysfunction of the MLL scar site decreased from 4/4 to 2/4 after the final session. CONCLUSION Several OMT sessions focusing on the MLL scar site appear necessary to obtain noteworthy results. OMT improved mobility and increased the temperature of the scar and the peri-scar area.
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Affiliation(s)
- Caroline Maillot
- Ecole Supérieure d'Ostéopathie, ESO Paris Recherche, Cité Descartes, 77420, Champs sur Marne, France.
| | - Damien Riquet
- Ecole Supérieure d'Ostéopathie, ESO Paris Recherche, Cité Descartes, 77420, Champs sur Marne, France; Université de Reims Champagne-Ardenne, PSMS, 51100, Reims, France.
| | - Laurent Stubbe
- Ecole Supérieure d'Ostéopathie, ESO Paris Recherche, Cité Descartes, 77420, Champs sur Marne, France; Université Paris Sud, Université Paris-Saclay, CIAMS,EA 4532, F-91405, Orsay, France; Université Paris Sud, Université d'Orléans, CIAMS EA 4532, F-45067, Orléans, France.
| | - Jean-Luc Bodnar
- Université de Reims Champagne-Ardenne, ITheMM, 51100, Reims, France.
| | - Nicolas Houel
- Université de Reims Champagne-Ardenne, PSMS, 51100, Reims, France.
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Caetano J, Rodrigues LM, Alves JD. What have we learned on pre, very early, and early systemic sclerosis microcirculatory pathophysiology? A scoping review. Autoimmun Rev 2024; 23:103540. [PMID: 38604463 DOI: 10.1016/j.autrev.2024.103540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/13/2024]
Abstract
OBJECTIVE Microvascular dysfunction is an early event in the pathogenesis of systemic sclerosis (SSc). The objective of this scoping review is to update the current information and the level of knowledge about the mechanisms of microvascular dysfunction in pre-SSc, very early diagnosis of SSc (VEDOSS) and early SSc. METHODS A PubMed® database search allowed us to include original data from full-length articles in English in which the main topic was microvascular dysfunction in pre-SSC, VEDOSS or early SSc. Data was extracted using a customized form. RESULTS In the present review 437 articles were identified, and 42 studies included, reporting data from a total of 1069 patients with pre-SSc, VEDOSS or early-SSc. Distinct mechanisms of microvascular injury were identified comprising, angiogenesis and vasculogenesis, cell surface proteins and adhesion, molecules expression, cytokines profile, inflammatory and oxidation pathways, and skin perfusion determinants. Most of the studies were conducted in early SSc, with a reduced number in pre-disease stages, in which the prompt recognition of specific mechanisms and biomarkers may allow targeted treatment to prevent disease progression. CONCLUSIONS Although different molecular expression patterns and signaling pathways related to microvascular dysfunction in pre-SSc, VEDOSS, and early SSc were identified, additional prospective longitudinal studies and combined work with functional evaluation of peripheral skin perfusion are needed.
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Affiliation(s)
- Joana Caetano
- CBIOS-Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1749-024 Lisbon, Portugal; Systemic Autoimmune Diseases Unit, Department of Medicine IV, Fernando Fonseca Hospital, 2720-276 Amadora, Portugal; Nova Medical School, 1169-056 Lisboa, Portugal.
| | - Luís Monteiro Rodrigues
- CBIOS-Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1749-024 Lisbon, Portugal
| | - José Delgado Alves
- Systemic Autoimmune Diseases Unit, Department of Medicine IV, Fernando Fonseca Hospital, 2720-276 Amadora, Portugal; Nova Medical School, 1169-056 Lisboa, Portugal.
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Nääv Ottosson J, Berggren JV, Tenland K, Bohman E, Sheikh R, Malmsjö M, Merdasa A. The effect of traction force on eyelid blood perfusion during closure of defects. Orbit 2024:1-7. [PMID: 38687914 DOI: 10.1080/01676830.2024.2335999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/20/2024] [Indexed: 05/02/2024]
Abstract
PURPOSE In oculoplastic surgery the eyelid tissue is frequently stretched in order to repair defects after tumor surgery. However, there is a paucity of research regarding how stretching affects eyelids. The purpose of this study was to gain insight into how traction force affects eyelid stretch as well as tissue perfusion, using a laser-based in vivo monitoring technique. METHOD Lower-lid pentagonal resections were performed in eight patients and a total of nine eyelids. The medial section of the eyelid was then stretched using a dynamometer up to a force of 2.3 Newtons (N), and eyelid stretching and blood perfusion were continuously measured using laser speckle contrast imaging. RESULTS Tissue perfusion decreased exponentially when eyelid tissue was stretched, with an initial sharp decline followed by a more gradual reduction. Perfusion approached zero at a force of approximately 2.0 N. The length of the eyelid increased with increasing force up to 1.5 N, after which there was only a very slight increase in length. CONCLUSIONS Eyelid tissue seems to respond to traction in a non-linear fashion, where the initial force results in the greatest eyelid stretching and reduction in blood perfusion. The results provide information on the effects of a large force for direct closure of large eyelid defects. Considering how quickly perfusion approaches zero, the high success rate of eyelid reconstruction surgery is likely a testament to the extensive vascularization of the periocular region.
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Affiliation(s)
- Jens Nääv Ottosson
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Johanna V Berggren
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Kajsa Tenland
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Elin Bohman
- Department of Clinical Neuroscience, Division of Eye and Vision, Stockholm, Sweden
| | - Rafi Sheikh
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Malin Malmsjö
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Aboma Merdasa
- Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
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Markwalder L, Gush R, Khan F, Murdoch CE, Krstajić N. In vivo laser speckle contrast imaging of microvascular blood perfusion using a chip-on-tip camera. iScience 2024; 27:109077. [PMID: 38375226 PMCID: PMC10875563 DOI: 10.1016/j.isci.2024.109077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/28/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024] Open
Abstract
Laser speckle contrast imaging (LSCI) is an important non-invasive capability for real-time imaging for tissue-perfusion assessment. Yet, the size and weight of current clinical standard LSCI instrumentation restricts usage to mainly peripheral skin perfusion. Miniaturization of LSCI could enable hand-held instrumentation to image internal organ/tissue to produce accurate speckle-perfusion maps. We characterized a 1mm2 chip-on-tip camera for LSCI of blood perfusion in vivo and with a flow model. A dedicated optical setup was built to compare chip-on-tip camera to a high specification reference camera (GS3) for LSCI. We compared LSCI performance using a calibration standard and a flow phantom. Subsequently the camera assessed placenta perfusion in a small animal model. Lastly, a human study was conducted on the perfusion in fingertips of 13-volunteers. We demonstrate that the chip-on-tip camera can perform wide-field, in vivo, LSCI of tissue perfusion with the ability to measure physiological blood flow changes comparable with a standard reference camera.
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Affiliation(s)
- Lukas Markwalder
- Systems Medicine, School of Medicine, University of Dundee, Ninewells Hospital & Medical School, DD1 9SY Dundee, UK
| | - Rodney Gush
- Moor Instruments, Millwey Rise Industrial Estate, Weycroft Avenue, EX13 5HU Axminster, UK
| | - Faisel Khan
- Systems Medicine, School of Medicine, University of Dundee, Ninewells Hospital & Medical School, DD1 9SY Dundee, UK
| | - Colin E. Murdoch
- Systems Medicine, School of Medicine, University of Dundee, Ninewells Hospital & Medical School, DD1 9SY Dundee, UK
| | - Nikola Krstajić
- School of Science and Engineering, Fulton Building, University of Dundee, DD1 4HN Dundee, UK
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Hu Y, Hu A, Song S. Photoplethysmography for Assessing Microcirculation in Hypertensive Patients After Taking Antihypertensive Drugs: A Review. J Multidiscip Healthc 2024; 17:263-274. [PMID: 38250310 PMCID: PMC10799628 DOI: 10.2147/jmdh.s441440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/09/2024] [Indexed: 01/23/2024] Open
Abstract
High blood pressure (BP) is a common disease and is associated with many chronic diseases. Measuring BP is essential for the treatment and management of many diseases, and therefore there is a growing need for a non-invasive, sleeveless and continuous BP monitoring device. With the development of technology, pulse waveform analysis using photoplethysmography (PPG) has become more feasible for evaluating BP. This study aimed to evaluate the changes of vascular elasticity and blood volume over time by using the characteristic parameters extracted by PPG. We reviewed the latest progress and literature on the observation of capillary network characteristics in hypertensive and non-hypertensive patients by PPG, the influence of different drugs on microcirculation characteristics in hypertensive patients with PPG, and further explored the key relationship between microcirculation and hypertension. We found that the PPG waveform produced by the fingertips of hypertensive patients is very different from that of healthy people, and the PPG waveform changes significantly during diastolic period after antihypertensive treatment. With the rapid development of medical technology, people can get more intuitive microcirculation image data, which provides beneficial help for the comprehensive understanding of hypertension.
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Affiliation(s)
- Yanchun Hu
- Department of Orthopaedics, the Fifth People’s Hospital of Jinan, Jinan, People’s Republic of China
| | - Anming Hu
- Taishan College, Shandong University, Jinan, People’s Republic of China
| | - Shenju Song
- Department of Nursing, the Fifth People’s Hospital of Jinan, Jinan, People’s Republic of China
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Yoo J, Cheon M. Dynamic blood flow imaging with 99mTc-hydroxymethylene diphosphonate as a therapeutic response marker in patients with Raynaud's phenomenon. Sci Rep 2023; 13:19751. [PMID: 37957209 PMCID: PMC10643549 DOI: 10.1038/s41598-023-47197-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 11/10/2023] [Indexed: 11/15/2023] Open
Abstract
We evaluated the predictive value of dynamic blood flow scintigraphy with 99mTc-HDP (hydroxymethylene diphosphonate) for therapeutic response in patients with Raynaud's phenomenon (RP). Eighty patients who underwent dynamic blood flow scintigraphy using the one-hand chilling method were enrolled. We analyzed the quantitative variables as the ratio of chilled fingers to ambient fingers (CAfinger), that of the chilled hand to ambient hand (CAhand), and that of chilled fingers to ambient palm (FPR) (CAFPR) at 15 and 30 s after 99mTc-HDP bolus injection. Total cumulative radioactivity counts for 180 s were obtained. We evaluated the clinical utility of these quantitative parameters with other clinical variables, including RP severity, therapeutic compliance, types of RP, and scintigraphic interpretation of findings in patients with RP. Fifty-two patients showed poor therapeutic response. There were significant differences between good- and poor-therapeutic responder groups in RP intensity (p = 0.003), CAfinger15s (p = 0.008), CAfinger30s (p = 0.002), CAfinger180s (p = 0.011), CAhand15s (p = 0.008), CAhand30s (p = 0.007), CAhand180s (p = 0.017), CAFPR30s (p = 0.004), and CAFPR180s (p = 0.002). After multivariate logistic regression analysis, only CAfinger30s (p = 0.002) had an independent predictive value of the therapeutic response. 99mTc-HDP dynamic blood flow scintigraphy could be helpful in predicting the therapeutic response in patients with RP.
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Affiliation(s)
- Jang Yoo
- Department of Nuclear Medicine, Veterans Health Service Medical Center, Seoul, South Korea.
| | - Miju Cheon
- Department of Nuclear Medicine, Veterans Health Service Medical Center, Seoul, South Korea
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Iqbal S, Bacardit J, Griffiths B, Allen J. Deep learning classification of systemic sclerosis from multi-site photoplethysmography signals. Front Physiol 2023; 14:1242807. [PMID: 37781233 PMCID: PMC10534001 DOI: 10.3389/fphys.2023.1242807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/18/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction: A pilot study assessing a novel approach to identify patients with Systemic Sclerosis (SSc) using deep learning analysis of multi-site photoplethysmography (PPG) waveforms ("DL-PPG"). Methods: PPG recordings having baseline, unilateral arm pressure cuff occlusion and reactive hyperaemia flush phases from 6 body sites were studied in 51 Controls and 20 SSc patients. RGB scalogram images were obtained from the PPG, using the continuous wavelet transform (CWT). 2 different pre-trained convolutional neural networks (CNNs, namely, GoogLeNet and EfficientNetB0) were trained to classify the SSc and Control groups, evaluating their performance using 10-fold stratified cross validation (CV). Their classification performance (i.e., accuracy, sensitivity, and specificity, with 95% confidence intervals) was also compared to traditional machine learning (ML), i.e., Linear Discriminant Analysis (LDA) and K-Nearest Neighbour (KNN). Results: On a participant basis DL-PPG accuracy, sensitivity and specificity for GoogLeNet were 83.1 (72.3-90.9), 75.0 (50.9-91.3) and 86.3 (73.7-94.3)% respectively, and for EfficientNetB0 were 87.3 (77.2-94.0), 80.0 (56.3-94.3) and 90.1 (78.6-96.7)%. The corresponding results for ML classification using LDA were 66.2 (53.9-77.0), 65.0 (40.8-84.6) and 66.7 (52.1-79.2)% respectively, and for KNN were 76.1 (64.5-85.4), 40.0 (19.1-63.9), and 90.2 (78.6-96.7)% respectively. Discussion: This study shows the potential of DL-PPG classification using CNNs to detect SSc. EfficientNetB0 gave an overall improved performance compared to GoogLeNet, with both CNNs performing better than the traditional ML methods tested. Our automatic AI approach, using transfer learning, could offer significant benefits for SSc diagnostics in a variety of clinical settings where low-cost portable and easy-to-use diagnostics can be beneficial.
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Affiliation(s)
- Sadaf Iqbal
- Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
- Northern Medical Physics and Clinical Engineering, Freeman Hospital, Newcastle Upon Tyne, United Kingdom
| | - Jaume Bacardit
- School of Computing, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Bridget Griffiths
- Department of Rheumatology, Freeman Hospital, Newcastle Upon Tyne, United Kingdom
| | - John Allen
- Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
- Northern Medical Physics and Clinical Engineering, Freeman Hospital, Newcastle Upon Tyne, United Kingdom
- Research Centre for Intelligent Healthcare, Coventry University, Coventry, United Kingdom
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Gopal JP, Vaz O, Varley R, Spiers H, Goldsworthy MA, Siddagangaiah V, Lock B, Sharma V, Summers A, Moinuddin Z, van Dellen D, Augustine T. Using Laser Speckle Contrast Imaging to Quantify Perfusion Quality in Kidney and Pancreas Grafts on Vascular Reperfusion: A Proof-of-Principle Study. Transplant Direct 2023; 9:e1472. [PMID: 37090123 PMCID: PMC10118345 DOI: 10.1097/txd.0000000000001472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 04/25/2023] Open
Abstract
The accuracy of intraoperative graft perfusion assessment still remains subjective, with doppler examination being the only objective adjunct. Laser speckle contrast imaging (LSCI) has been used to assess intraoperative blood flow in neurosurgery and in various surgical specialties. Despite its ability to accurately quantify perfusion at the microvascular level, it has not been clinically evaluated in kidney/kidney-pancreas transplantation for perfusion characterization. We aimed to evaluate the utility of LSCI and identify objective parameters that can be quantified at reperfusion. Methods This study was registered in ClinicalTrials.gov (NCT04202237). The Moor FLPI-2 blood flow imager was used in 4 patients (1 Simultaneous Pancreas and Kidney, 2 deceased, and 1 living donor kidney transplants) during reperfusion to capture reperfusion data. The following parameters were measured: flux (average speed × concentration of moving red blood cells in the sample volume), doppler centroid, total and valid pixels, valid rate, and total and valid area. Flux data were analyzed with Moor FLPI analysis software. Results The perfusion characteristics and flux images correlated with initial graft function. Conclusions LSCI is a safe, noncontact imaging modality that provides real-time, accurate, high-resolution, full field blood flow images and a wide range of flux data to objectively quantify organ reperfusion intraoperatively in kidney/kidney-pancreas transplantation. This modality could be used to develop a robust numerical quantification system for the evaluation and reporting of intraoperative organ perfusion, and aid intraoperative decision-making. Perfusion data could be combined with biomarkers and immunological parameters to more accurately predict graft outcomes.
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Affiliation(s)
- Jeevan Prakash Gopal
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- Department of General Surgery, The Queen Elizabeth Hospital King’s Lynn NHS Trust, King’s Lynn, United Kingdom
| | - Osborne Vaz
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
| | - Rebecca Varley
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Harry Spiers
- Department of Transplantation, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
- Department of Surgery, University of Cambridge, Cambridge, United Kingdom
| | - Matthew A. Goldsworthy
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Vishwanath Siddagangaiah
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Brian Lock
- Moor Instruments Ltd, Axminster, United Kingdom
| | - Videha Sharma
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
| | - Angela Summers
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- University of Manchester-Faculty of Biology, Medicine and Health, Division of Diabetes, Endocrinology and Gastroenterology, Manchester, United Kingdom
| | - Zia Moinuddin
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
| | - David van Dellen
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
| | - Titus Augustine
- Department of Renal and Pancreas Transplantation, Manchester University Hospitals NHS Foundation Trust, Manchester Royal Infirmary, Manchester, United Kingdom
- University of Manchester-Faculty of Biology, Medicine and Health, Division of Diabetes, Endocrinology and Gastroenterology, Manchester, United Kingdom
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Stockwell SJ, Kwok TC, Morgan SP, Sharkey D, Hayes-Gill BR. Forehead monitoring of heart rate in neonatal intensive care. Front Physiol 2023; 14:1127419. [PMID: 37082236 PMCID: PMC10110846 DOI: 10.3389/fphys.2023.1127419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/21/2023] [Indexed: 04/22/2023] Open
Abstract
Heart rate is an extremely important physiological parameter to measure in critically unwell infants, as it is the main physiological marker that changes in response to a change in infant condition. Heart rate is routinely measured peripherally on a limb with a pulse oximeter. However, when infants are critically unwell, the blood supply to these peripheries is reduced in preference for central perfusion of vital organs such as the brain and heart. Measurement of heart rate with a reflection mode photoplethysmogram (PPG) sensor on the forehead could help minimise this problem and make it easier for other important medical equipment, such as cannulas, to be placed on the limbs. This study compares heart rates measured with a forehead-based PPG sensor against a wrist-based PPG sensor in 19 critically unwell infants in neonatal intensive care collecting 198 h of data. The two heart rates were compared using positive percentage agreement, Spearman's correlation coefficient and Bland-Altman analysis. The forehead PPG sensor showed good agreement with the wrist-based PPG sensor with limits of agreement of 8.44 bpm, bias of -0.22 bpm; positive percentage agreement of 98.87%; and Spearman's correlation coefficient of 0.9816. The analysis demonstrates that the forehead is a reliable alternative location for measuring vital signs using the PPG.
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Affiliation(s)
- S. J. Stockwell
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
| | - T. C. Kwok
- Centre for Perinatal Research, Lifespan and Population Health, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - S. P. Morgan
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
| | - D. Sharkey
- Centre for Perinatal Research, Lifespan and Population Health, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - B. R. Hayes-Gill
- Optics and Photonics Research Group, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
- *Correspondence: B. R. Hayes-Gill,
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Guven G, Dijkstra A, Kuijper TM, Trommel N, van Baar ME, Topeli A, Ince C, van der Vlies CH. Comparison of laser speckle contrast imaging with laser Doppler perfusion imaging for tissue perfusion measurement. Microcirculation 2023; 30:e12795. [PMID: 36524297 PMCID: PMC10078364 DOI: 10.1111/micc.12795] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/29/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Laser-based tissue perfusion monitoring techniques have been increasingly used in animal and human research to assess blood flow. However, these techniques use arbitrary units, and knowledge about their comparability is scarce. This study aimed to model the relationship between laser speckle contrast imaging (LSCI) and laser Doppler perfusion imaging (LDPI), for measuring tissue perfusion over a wide range of blood flux values. METHODS Fifteen healthy volunteers (53% female, median age 29 [IQR 22-40] years) were enrolled in this study. We performed iontophoresis with sodium nitroprusside on the forearm to induce regional vasodilation to increase skin blood flux. Besides, a stepwise vascular occlusion was applied on the contralateral upper arm to reduce blood flux. Both techniques were compared using a linear mixed model analysis. RESULTS Baseline blood flux values measured by LSCI were 33 ± 6.5 arbitrary unit (AU) (Coefficient of variation [CV] = 20%) and by LDPI 60 ± 11.5 AU (CV = 19%). At the end of the iontophoresis protocol, the regional blood flux increased to 724 ± 412% and 259 ± 87% of baseline measured by LDPI and LSCI, respectively. On the other hand, during the stepwise vascular occlusion test, the blood flux reduced to 212 ± 40% and 412 ± 177% of its baseline at LDPI and LSCI, respectively. A strong correlation was found between the LSCI and LDPI instruments at increased blood flux with respect to baseline skin blood flux; however, the correlation was weak at reduced blood flux with respect to baseline. DISCUSSION LSCI and LDPI instruments are highly linear for blood flux higher than baseline skin blood flux; however, the correlation decreased for blood flux lower than baseline. This study's findings could be a basis for using LSCI in specific patient populations, such as burn care.
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Affiliation(s)
- Goksel Guven
- Department of Intensive Care, Erasmus MC, Rotterdam, The Netherlands.,Departments of Trauma and Burn Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands.,Department of Internal Medicine, Division of Intensive Care, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Annemieke Dijkstra
- Departments of Trauma and Burn Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands
| | | | - Nicole Trommel
- Departments of Trauma and Burn Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands
| | | | - Arzu Topeli
- Department of Internal Medicine, Division of Intensive Care, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Can Ince
- Department of Intensive Care, Erasmus MC, Rotterdam, The Netherlands
| | - Cornelis Hendrik van der Vlies
- Departments of Trauma and Burn Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands.,Trauma Research Unit Department of Surgery, Erasmus MC, Rotterdam, The Netherlands
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Späth M, Romboy A, Nzenwata I, Rohde M, Ni D, Ackermann L, Stelzle F, Hohmann M, Klämpfl F. Experimental Validation of Shifted Position-Diffuse Reflectance Imaging (SP-DRI) on Optical Phantoms. SENSORS (BASEL, SWITZERLAND) 2022; 22:9880. [PMID: 36560250 PMCID: PMC9783365 DOI: 10.3390/s22249880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Numerous diseases such as hemorrhage, sepsis or cardiogenic shock induce a heterogeneous perfusion of the capillaries. To detect such alterations in the human blood flow pattern, diagnostic devices must provide an appropriately high spatial resolution. Shifted position-diffuse reflectance imaging (SP-DRI) has the potential to do so; it is an all-optical diagnostic technique. So far, SP-DRI has mainly been developed using Monte Carlo simulations. The present study is therefore validating this algorithm experimentally on realistic optical phantoms with thread structures down to 10 μm in diameter; a SP-DRI sensor prototype was developed and realized by means of additive manufacturing. SP-DRI turned out to be functional within this experimental framework. The position of the structures within the optical phantoms become clearly visible using SP-DRI, and the structure thickness is reflected as modulation in the SP-DRI signal amplitude; this performed well for a shift along the x axis as well as along the y axis. Moreover, SP-DRI successfully masked the pronounced influence of the illumination cone on the data. The algorithm showed significantly superior to a mere raw data inspection. Within the scope of the study, the constructive design of the SP-DRI sensor prototype is discussed and potential for improvement is explored.
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Affiliation(s)
- Moritz Späth
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Alexander Romboy
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
| | - Ijeoma Nzenwata
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
| | - Maximilian Rohde
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Dongqin Ni
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Lisa Ackermann
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Florian Stelzle
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Martin Hohmann
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
| | - Florian Klämpfl
- Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen, Germany
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12
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Berggren JV, Stridh M, Malmsjö M. Perfusion Monitoring During Oculoplastic Reconstructive Surgery: A Comprehensive Review. Ophthalmic Plast Reconstr Surg 2022; 38:522-534. [PMID: 34919068 DOI: 10.1097/iop.0000000000002114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Knowledge of how blood perfusion is affected during and after reconstructive surgery is of great importance to predict the survival of grafts and flaps. When commonly used reconstructive procedures were developed a century ago, they were based on empirical observations of clinical outcome. METHODS This is a comprehensive literature review that summarizes the current state of knowledge regarding microvascular perfusion monitoring during oculoplastic procedures. RESULTS Over the years, a number of techniques for perfusion monitoring have been developed as an attempt to be more objective than clinical examination using traditional methods such as observations of skin temperature, turgor, color, smell, and capillary refill time. There are limited publications regarding microvascular perfusion monitoring during reconstructive procedures in the periocular area. Modern laser-based techniques have been attractive due to their noninvasive nature. CONCLUSIONS Today, modern, noninvasive techniques are available to monitor perfusion during and after surgery. This has increased our knowledge on the perfusion in common oculoplastic surgery procedures. A detailed understanding of how blood perfusion is affected will hopefully allow the improvement of surgical techniques for better clinical outcome.
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Affiliation(s)
- Johanna V Berggren
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Ophthalmology, Lund, Sweden
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13
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Ren Y, Senarathna J, Grayson WL, Pathak AP. State-of-the-art techniques for imaging the vascular microenvironment in craniofacial bone tissue engineering applications. Am J Physiol Cell Physiol 2022; 323:C1524-C1538. [PMID: 36189973 PMCID: PMC9829486 DOI: 10.1152/ajpcell.00195.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/07/2022] [Accepted: 09/27/2022] [Indexed: 01/21/2023]
Abstract
Vascularization is a crucial step during musculoskeletal tissue regeneration via bioengineered constructs or grafts. Functional vasculature provides oxygen and nutrients to the graft microenvironment, facilitates wound healing, enhances graft integration with host tissue, and ensures the long-term survival of regenerating tissue. Therefore, imaging de novo vascularization (i.e., angiogenesis), changes in microvascular morphology, and the establishment and maintenance of perfusion within the graft site (i.e., vascular microenvironment or VME) can provide essential insights into engraftment, wound healing, as well as inform the design of tissue engineering (TE) constructs. In this review, we focus on state-of-the-art imaging approaches for monitoring the VME in craniofacial TE applications, as well as future advances in this field. We describe how cutting-edge in vivo and ex vivo imaging methods can yield invaluable information regarding VME parameters that can help characterize the effectiveness of different TE constructs and iteratively inform their design for enhanced craniofacial bone regeneration. Finally, we explicate how the integration of novel TE constructs, preclinical model systems, imaging techniques, and systems biology approaches could usher in an era of "image-based tissue engineering."
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Affiliation(s)
- Yunke Ren
- Department of Biomedical Engineering, the Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Janaka Senarathna
- Russell H. Morgan Department of Radiology and Radiological Sciences, the Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Warren L Grayson
- Department of Biomedical Engineering, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland
- Translational Tissue Engineering Center, Johns Hopkins University, Baltimore, Maryland
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Arvind P Pathak
- Russell H. Morgan Department of Radiology and Radiological Sciences, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Biomedical Engineering, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Sidney Kimmel Comprehensive Cancer Center, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Electrical Engineering, Johns Hopkins University, Baltimore, Maryland
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
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14
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Aghabaglou F, Ainechi A, Abramson H, Curry E, Kaovasia TP, Kamal S, Acord M, Mahapatra S, Pustavoitau A, Smith B, Azadi J, Son JK, Suk I, Theodore N, Tyler BM, Manbachi A. Ultrasound monitoring of microcirculation: An original study from the laboratory bench to the clinic. Microcirculation 2022; 29:e12770. [PMID: 35611457 PMCID: PMC9786257 DOI: 10.1111/micc.12770] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 04/08/2022] [Accepted: 05/20/2022] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Monitoring microcirculation and visualizing microvasculature are critical for providing diagnosis to medical professionals and guiding clinical interventions. Ultrasound provides a medium for monitoring and visualization; however, there are challenges due to the complex microscale geometry of the vasculature and difficulties associated with quantifying perfusion. Here, we studied established and state-of-the-art ultrasonic modalities (using six probes) to compare their detection of slow flow in small microvasculature. METHODS Five ultrasonic modalities were studied: grayscale, color Doppler, power Doppler, superb microvascular imaging (SMI), and microflow imaging (MFI), using six linear probes across two ultrasound scanners. Image readability was blindly scored by radiologists and quantified for evaluation. Vasculature visualization was investigated both in vitro (resolution and flow characterization) and in vivo (fingertip microvasculature detection). RESULTS Superb Microvascular Imaging (SMI) and Micro Flow Imaging (MFI) modalities provided superior images when compared with conventional ultrasound imaging modalities both in vitro and in vivo. The choice of probe played a significant difference in detectability. The slowest flow detected (in the lab) was 0.1885 ml/s and small microvasculature of the fingertip were visualized. CONCLUSIONS Our data demonstrated that SMI and MFI used with vascular probes operating at higher frequencies provided resolutions acceptable for microvasculature visualization, paving the path for future development of ultrasound devices for microcirculation monitoring.
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Affiliation(s)
- Fariba Aghabaglou
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Ana Ainechi
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Haley Abramson
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Eli Curry
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Tarana Parvez Kaovasia
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Serene Kamal
- HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Electrical and Computer EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Molly Acord
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Smruti Mahapatra
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Aliaksei Pustavoitau
- Department of Anesthesiology and Critical Care, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Beth Smith
- Department of Radiology and Radiological Science, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Javad Azadi
- Department of Radiology and Radiological Science, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Jennifer K. Son
- Department of Radiology and Radiological Science, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Ian Suk
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Nicholas Theodore
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Betty M. Tyler
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Amir Manbachi
- Department of Neurosurgery, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,HEPIUS Innovation Laboratory, School of MedicineJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Electrical and Computer EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA,Department of Mechanical EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
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15
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Cumsille P, Lara E, Verdugo-Hernández P, Acurio J, Escudero C. A robust quantitative approach for laser speckle contrast imaging perfusion analysis revealed anomalies in the brain blood flow in offspring mice of preeclampsia. Microvasc Res 2022; 144:104418. [PMID: 35931124 DOI: 10.1016/j.mvr.2022.104418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 07/27/2022] [Accepted: 07/31/2022] [Indexed: 02/01/2023]
Abstract
Microcirculation analysis of the brain cortex is challenging because surface perfusion varies rapidly in small space-time regions and is bone protected. The laser speckle contrast imaging (LSCI) technique allows analyzing in vivo brain vascular perfusion generating a large amount of data that requires sophisticated data analytics, making researchers invest much effort in processing. Our research question was whether the reduced placental perfusion model (RUPP) of preeclampsia (PE) was associated with impaired blood perfusion in the offspring's brains. We aimed to develop a robust numerical approach that mainly consisted of applying a signal-processing tool for calculating optimal segmentation and piece-wise fits of the offspring's brain perfusion signals obtained from the LSCI technique. We combined this tool with the usual statistical analysis, implementing both in Matlab software. We performed brain perfusion measurements from offspring (five days postnatal, P5) of control pregnant dams (sham, n = 13) and of RUPP dams (RUPP, n = 7) using the Pericam® PSI-HR system at a basal condition and after thermal stimuli (warm and cold). We found that pups of RUPP mice exhibited significant differences in perfusion and vascular response to thermal stimuli compared to the sham mice. These differences were associated with high data variability in the Sham group, while in the RUPP group, perfusion looks "stiffer." Data also suggest sex-dimorphism in the vascular response since female pups in the Sham group but not male pups showed statistically significant differences in response to the warm stimulus. Again, this sex-related difference was absent in pups of RUPP mice. In conclusion, we present a robust quantitative approach for LSCI measurements that revealed anomalies in the brain blood flow in offspring of the RUPP model of PE.
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Affiliation(s)
- Patricio Cumsille
- Vascular Physiology Laboratory, Department of Basic Sciences, Universidad del Bío-Bío, Campus Fernando May, Av. Andrés Bello 720, Casilla 447, Chillán, Chile; Centre for Biotechnology and Bioengineering (CeBiB), University of Chile, Santiago, Chile.
| | - Evelyn Lara
- Vascular Physiology Laboratory, Department of Basic Sciences, Universidad del Bío-Bío, Campus Fernando May, Av. Andrés Bello 720, Casilla 447, Chillán, Chile; Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile
| | - Paula Verdugo-Hernández
- Escuela de Pedagogía en Ciencias Naturales y Exactas, Facultad de Ciencias de la Educación, Universidad de Talca, Chile
| | - Jesenia Acurio
- Vascular Physiology Laboratory, Department of Basic Sciences, Universidad del Bío-Bío, Campus Fernando May, Av. Andrés Bello 720, Casilla 447, Chillán, Chile; Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile
| | - Carlos Escudero
- Vascular Physiology Laboratory, Department of Basic Sciences, Universidad del Bío-Bío, Campus Fernando May, Av. Andrés Bello 720, Casilla 447, Chillán, Chile; Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile.
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16
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Antonova N, Velcheva I, Paskova V. Hemorheological and microvascular disturbances in patients with type 2 diabetes mellitus. Clin Hemorheol Microcirc 2022; 81:325-341. [DOI: 10.3233/ch-221393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: In the blood vessels the impaired hemorheological parameters in patients with type 2 diabetes mellitus (T2DM) could lead to elevated flow resistance, increased forces at the endothelial wall and to microvascular disturbances. OBJECTIVE: The aim of the study is to investigate the hemorheological variables and the changes of the skin blood flow responses to cold stress in T2DM patients. METHODS: The basic hemorheological parameters: hematocrit (Ht), fibrinogen (Fib), whole blood viscosity (WBV) and plasma viscosity (PV) were examined in 20 patients with T2DM and a control group of 10 healthy age and sex matched controls. The mechanisms of vascular tone regulation were investigated using the wavelet analysis of the skin temperature oscillations (WAST). The degrees of the microvascular tone changes were determined during a cold test in the endothelial (0.02–0.0095 Hz), neurogenic (0.05– 0.02 Hz) and myogenic (0.05– 0.14 Hz) frequency ranges. RESULTS: Significant increase of Fib and WBV in the patients in comparison to controls was found. The mean values of the amplitudes of the skin temperature (ST) pulsations decreased significantly during the cold stress only in the endothelial frequency range for the diabetic patients. CONCLUSIONS: The results of our study reveal parallel impairment of the blood rheological parameters and the cutaneous microcirculation in T2DM patients.
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Affiliation(s)
- Nadia Antonova
- Department of Biomechanics, Institute of Mechanics to the Bulgarian Academy of Sciences, Bulgaria
| | - Irena Velcheva
- Clinic of Neurology, Uni Hospital, Panagyurishte, Bulgaria
| | - Vasilka Paskova
- Department of Biomechanics, Institute of Mechanics to the Bulgarian Academy of Sciences, Bulgaria
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17
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Efficacy and Function of Feathers, Hair, and Glabrous Skin in the Thermoregulation Strategies of Domestic Animals. Animals (Basel) 2021; 11:ani11123472. [PMID: 34944249 PMCID: PMC8697956 DOI: 10.3390/ani11123472] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Animals adopt several strategies to regulate their body temperature by promoting heat loss or gain in hot and cold environments, respectively. This mechanism of heat loss or production is performed in thermal windows. A thermal window is a structure where many blood capillaries facilitate thermal exchange in this region. The presence of feathers, hair, or glabrous (hairless) skin and their structural characteristics greatly influence each species’ capacity to maintain thermal comfort. This factor needs to be considered when implementing new monitoring or measuring techniques such as infrared thermography since interpretations may vary due to the presence or absence of these structures. It is essential to recognize the effects of glabrous skin, hair, and feathers on thermoregulation to identify species-specific thermal windows that allow accurate evaluations of the thermal state of domestic animals. Abstract The objective of this review is to describe and analyze the effect of feathers, hair, and glabrous (hairless) skin on the thermoregulation of domestic and endotherm animals, especially concerning the uses and scope of infrared thermography (IRT), scientific findings on heat and cold stress, and differences among species of domestic animals. Clinical medicine considers thermoregulation a mechanism that allows animals to adapt to varying thermal environmental conditions, a process in which the presence of feathers, hair, or glabrous skin influences heat loss or heat retention, respectively, under hot and cold environmental conditions. Evaluating body temperature provides vital information on an individual’s physiological state and health status since variations in euthermia maintenance in vertebrates reflect a significant cellular metabolism deviation that needs to be assessed and quantified. IRT is a non-invasive tool for evaluating thermal responses under thermal stress conditions in animals, where the presence or absence of feathers, hair, and glabrous skin can affect readings and the differences detected. Therefore, anatomical regions, the characteristics of feathers, hair, glabrous skin such as structure, length, color, and extension, and strategies for dissipating or retaining heat together constitute a broad area of opportunity for future research into the phenomena of dermal thermoregulation in domestic species.
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18
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Awopetu AI, Gohel MS, Sadat U, Hayes PD. Clinical feasibility of diffuse speckle contrast analysis for real-time tissue perfusion monitoring. INT ANGIOL 2021; 41:82-89. [PMID: 34825799 DOI: 10.23736/s0392-9590.21.04740-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Adequate tissue perfusion is an important prognostic and diagnostic factor during the management of lower limb peripheral arterial disease. Convenient and real-time tissue perfusion monitoring remains an elusive challenge. METHODS Tissue perfusion on the dorsal and plantar surfaces of both feet of 20 participants was measured during and after cuff-induced ischemia using a novel 4-channel, laser-based perfusion monitoring device based on diffuse speckle contrast analysis technology (Pedra sensors). Participants were free of significant peripheral arterial disease. Transcutaneous partial pressure of oxygen (TcPO2) measurements were recorded concurrently for comparison. RESULTS Pedra sensors detected perfusion changes significantly more quickly than TcPO2 sensors. One minute after induced ischemia, the mean percent changes from baseline values (before ischemia) were -22.7±32.0% and -3.1±8.8% (P<.001) for Pedra and TcPO2 sensors, respectively. One minute into induced ischemia, Pedra sensors had reached 50.5% of the 5-minute ischemia reading whereas TcPO2 sensors had reached only 18.6% of the 5-minute reading (P=.046). Pedra sensors reported hyperemia immediately after cuff release with a mean percent change from baseline of 143.8±122.3%/173.4±121.8% on the dorsal/plantar surfaces while TcPO2 measurements were still recording negative changes at that time (-26.7±19.4%/-18.6±24.4% dorsal/plantar). Pedra sensors exhibited markedly lower interobserver and intraobserver variability than TcPO2 sensors. CONCLUSIONS A device based on diffuse speckle contrast analysis reported tissue perfusion in real time. Cuff-induced ischemia and hyperemia following cuff release were rapidly and consistently detected on both the dorsal and plantar surfaces of the foot. Diffuse speckle contrast analysis may have value for real-time perfusion monitoring during angiography procedures.
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Affiliation(s)
- Ayoola I Awopetu
- Department of Vascular Surgery, Cambridge University Hospitals, Cambridge, UK
| | - Manjit S Gohel
- Department of Vascular Surgery, Cambridge University Hospitals, Cambridge, UK
| | - Umar Sadat
- Department of Vascular Surgery, Cambridge University Hospitals, Cambridge, UK
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19
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Schaap MJ, Chizari A, Knop T, Groenewoud HMM, van Erp PEJ, de Jong EMGJ, Steenbergen W, Seyger MMB. Perfusion measured by laser speckle contrast imaging as a predictor for expansion of psoriasis lesions. Skin Res Technol 2021; 28:104-110. [PMID: 34619003 PMCID: PMC9293292 DOI: 10.1111/srt.13098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/31/2021] [Indexed: 11/27/2022]
Abstract
Background Skin microvasculature changes are crucial in psoriasis development and correlate with perfusion. The noninvasive Handheld Perfusion Imager (HAPI) examines microvascular skin perfusion in large body areas using laser speckle contrast imaging (LSCI). Objectives To (i) assess whether increased perilesional perfusion and perfusion inhomogeneity are predictors for expansion of psoriasis lesions and (ii) assess feasibility of the HAPI system in a mounted modality. Methods In this interventional pilot study in adults with unstable plaque psoriasis, HAPI measurements and color photographs were performed for lesions present on one body region at week 0, 2, 4, 6 and 8. The presence of increased perilesional perfusion and perfusion inhomogeneity was determined. Clinical outcome was categorized as increased, stable or decreased lesion surface between visits. Patient feedback was collected on a 10‐point scale. Results In total, 110 lesions with a median follow‐up of 6 (IQR 6.0) weeks were assessed in 6 patients with unstable plaque psoriasis. Perfusion data was matched to 281 clinical outcomes after two weeks. A mixed multinomial logistic regression model revealed a predictive value of perilesional increased perfusion (OR 9.90; p < 0.001) and perfusion inhomogeneity (OR 2.39; p = 0.027) on lesion expansion after two weeks compared to lesion stability. HAPI measurements were considered fast, patient‐friendly and important by patients. Conclusion Visualization of increased perilesional perfusion and perfusion inhomogeneity by noninvasive whole field LSCI holds potential for prediction of psoriatic lesion expansion. Furthermore, the HAPI is a feasible and patient‐friendly tool.
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Affiliation(s)
- Mirjam J Schaap
- Department of Dermatology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ata Chizari
- Biomedical Photonic Imaging, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Tom Knop
- Biomedical Photonic Imaging, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Hans M M Groenewoud
- Department for Health Evidence, Radboud University, Nijmegen, The Netherlands
| | - Piet E J van Erp
- Department of Dermatology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elke M G J de Jong
- Department of Dermatology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wiendelt Steenbergen
- Biomedical Photonic Imaging, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Marieke M B Seyger
- Department of Dermatology, Radboud University Medical Center, Nijmegen, The Netherlands
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20
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Oral Glucose Load and Human Cutaneous Microcirculation: An Insight into Flowmotion Assessed by Wavelet Transform. BIOLOGY 2021; 10:biology10100953. [PMID: 34681052 PMCID: PMC8533385 DOI: 10.3390/biology10100953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/31/2021] [Accepted: 09/10/2021] [Indexed: 01/10/2023]
Abstract
Simple Summary There is increasing evidence to suggest that microcirculation becomes dysfunctional earlier than large blood vessels or the heart in several diseases. In diabetes mellitus, a disease characterized by chronic hyperglycemia, microvascular impairment is well-established; on the contrary, the effect of acute hyperglycemia in microcirculation remains unclarified. Our aim was to investigate the microvascular effect of an oral glucose load (OGL) using laser Doppler flowmetry (LDF) as a perfusion quantification technique, coupled with wavelet transform (WT) to perform a spectral decomposition of the LDF signal. On two distinct occasions (pre-load and post-load), sixteen healthy subjects drank either a standard glucose solution or water. Perfusion was assessed by LDF and WT while resting and during post-occlusive reactive hyperemia (PORH), evoked by a transient three-min occlusion of the brachial artery, in the forearm and the finger pulp. The OGL affected microcirculation in both sites compared to water, significantly blunting the PORH response in the forearm. The WT revealed significant differences in the cardiac and sympathetic components after OGL between the pre-load and post-load periods. These results suggest that an OGL induces a short-term subtle microvascular impairment, probably involving a modulation of the sympathetic nervous system. Abstract Microcirculation in vivo has been assessed using non-invasive technologies such as laser Doppler flowmetry (LDF). In contrast to chronic hyperglycemia, known to induce microvascular dysfunction, the effects of short-term elevations in blood glucose on microcirculation are controversial. We aimed to assess the impact of an oral glucose load (OGL) on the cutaneous microcirculation of healthy subjects, quantified by LDF and coupled with wavelet transform (WT) as an interpretation tool. On two separate occasions, sixteen subjects drank either a glucose solution (75 g in 250 mL water) or water (equal volume). LDF signals were obtained in two anatomical sites (forearm and finger pulp) before and after each load (pre-load and post-load, respectively), in resting conditions and during post-occlusive reactive hyperemia (PORH). The WT allowed decomposition of the LDF signals into their spectral components (cardiac, respiratory, myogenic, sympathetic, endothelial NO-dependent). The OGL blunted the PORH response in the forearm, which was not observed with the water load. Significant differences were found for the cardiac and sympathetic components in the glucose and water groups between the pre-load and post-load periods. These results suggest that an OGL induces a short-term subtle microvascular impairment, probably involving a modulation of the sympathetic nervous system.
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21
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Troy AM, Cheng HM. Human microvascular reactivity: a review of vasomodulating stimuli and non-invasive imaging assessment. Physiol Meas 2021; 42. [PMID: 34325417 DOI: 10.1088/1361-6579/ac18fd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/29/2021] [Indexed: 11/11/2022]
Abstract
The microvasculature serves an imperative function in regulating perfusion and nutrient exchange throughout the body, adaptively altering blood flow to preserve hemodynamic and metabolic homeostasis. Its normal functioning is vital to tissue health, whereas its dysfunction is present in many chronic conditions, including diabetes, heart disease, and cognitive decline. As microvascular dysfunction often appears early in disease progression, its detection can offer early diagnostic information. To detect microvascular dysfunction, one uses imaging to probe the microvasculature's ability to react to a stimulus, also known as microvascular reactivity (MVR). An assessment of MVR requires an integrated understanding of vascular physiology, techniques for stimulating reactivity, and available imaging methods to capture the dynamic response. Practical considerations, including compatibility between the selected stimulus and imaging approach, likewise require attention. In this review, we provide a comprehensive foundation necessary for informed imaging of MVR, with a particular focus on the challenging endeavor of assessing microvascular function in deep tissues.
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Affiliation(s)
- Aaron M Troy
- Institute of Biomedical Engineering, University of Toronto, Toronto, CANADA
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22
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Zehra T, Cupples WA, Braam B. Tubuloglomerular Feedback Synchronization in Nephrovascular Networks. J Am Soc Nephrol 2021; 32:1293-1304. [PMID: 33833078 PMCID: PMC8259654 DOI: 10.1681/asn.2020040423] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To perform their functions, the kidneys maintain stable blood perfusion in the face of fluctuations in systemic BP. This is done through autoregulation of blood flow by the generic myogenic response and the kidney-specific tubuloglomerular feedback (TGF) mechanism. The central theme of this paper is that, to achieve autoregulation, nephrons do not work as single units to manage their individual blood flows, but rather communicate electrically over long distances to other nephrons via the vascular tree. Accordingly, we define the nephrovascular unit (NVU) to be a structure consisting of the nephron, glomerulus, afferent arteriole, and efferent arteriole. We discuss features that require and enable distributed autoregulation mediated by TGF across the kidney. These features include the highly variable topology of the renal vasculature which creates variability in circulation and the potential for mismatch between tubular oxygen demand and delivery; the self-sustained oscillations in each NVU arising from the autoregulatory mechanisms; and the presence of extensive gap junctions formed by connexins and their properties that enable long-distance transmission of TGF signals. The existence of TGF synchronization across the renal microvascular network enables an understanding of how NVUs optimize oxygenation-perfusion matching while preventing transmission of high systemic pressure to the glomeruli, which could lead to progressive glomerular and vascular injury.
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Affiliation(s)
- Tayyaba Zehra
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - William A. Cupples
- Department of Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Branko Braam
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada,Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
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23
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Guerraty M, Bhargava A, Senarathna J, Mendelson AA, Pathak AP. Advances in translational imaging of the microcirculation. Microcirculation 2021; 28:e12683. [PMID: 33524206 PMCID: PMC8647298 DOI: 10.1111/micc.12683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 12/21/2022]
Abstract
The past few decades have seen an explosion in the development and use of methods for imaging the human microcirculation during health and disease. The confluence of innovative imaging technologies, affordable computing power, and economies of scale have ushered in a new era of "translational" imaging that permit us to peer into blood vessels of various organs in the human body. These imaging techniques include near-infrared spectroscopy (NIRS), positron emission tomography (PET), and magnetic resonance imaging (MRI) that are sensitive to microvascular-derived signals, as well as computed tomography (CT), optical imaging, and ultrasound (US) imaging that are capable of directly acquiring images at, or close to microvascular spatial resolution. Collectively, these imaging modalities enable us to characterize the morphological and functional changes in a tissue's microcirculation that are known to accompany the initiation and progression of numerous pathologies. Although there have been significant advances for imaging the microcirculation in preclinical models, this review focuses on developments in the assessment of the microcirculation in patients with optical imaging, NIRS, PET, US, MRI, and CT, to name a few. The goal of this review is to serve as a springboard for exploring the burgeoning role of translational imaging technologies for interrogating the structural and functional status of the microcirculation in humans, and highlight the breadth of current clinical applications. Making the human microcirculation "visible" in vivo to clinicians and researchers alike will facilitate bench-to-bedside discoveries and enhance the diagnosis and management of disease.
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Affiliation(s)
- Marie Guerraty
- Division of Cardiovascular Medicine, Department of
Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA,
USA
| | - Akanksha Bhargava
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Janaka Senarathna
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Asher A. Mendelson
- Department of Medicine, Section of Critical Care, Rady
Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Arvind P. Pathak
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, The Johns Hopkins
University School of Medicine, Baltimore, MD, USA
- Department of Electrical Engineering, Johns Hopkins
University, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, The Johns
Hopkins University School of Medicine, Baltimore, MD, USA
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Allan D, Chockalingam N, Naemi R. Validation of a non-invasive imaging photoplethysmography device to assess plantar skin perfusion, a comparison with laser speckle contrast analysis. J Med Eng Technol 2021; 45:170-176. [PMID: 33750251 DOI: 10.1080/03091902.2021.1891309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Assessing skin perfusion is an established and reliable method to study impaired lower limb blood flow. Laser Speckle Contrast Analysis (LASCA) has been identified as the current gold standard to measure skin perfusion. Imaging photoplethysmography (iPPG) is a new low-cost imaging technique to assess perfusion. However, it is unclear how results obtained from this technique compare against that of LASCA at plantar skin. Therefore, the aim of this study was to investigate the association between the skin perfusion at the plantar surface of the foot using iPPG and LASCA. Perfusion at six plantar locations (Hallux, 1st 3rd 5th metatarsal heads, midfoot, heel) was simultaneously measured using LASCA and iPPG in 20 healthy participants. Skin thickness and skin temperature were also collected at the same plantar locations. Spearman's rank tests showed significant associations with medium strength between the perfusion values measured with LASCA and iPPG for most tested sites. No improvement in the relationship between iPPG and LASCA data was observed when controlling for either skin thickness or skin temperature. Skin perfusion values obtained using iPPG were found to be significantly associated with the corresponding values obtained using the gold standard LASCA device. Additionally, the measurement of perfusion using iPPG is shown to be robust.
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Affiliation(s)
- David Allan
- Centre for Biomechanics and Rehabilitation Technologies, Staffordshire University, Stoke-on-Trent, UK
| | - Nachiappan Chockalingam
- Centre for Biomechanics and Rehabilitation Technologies, Staffordshire University, Stoke-on-Trent, UK
| | - Roozbeh Naemi
- Centre for Biomechanics and Rehabilitation Technologies, Staffordshire University, Stoke-on-Trent, UK
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Berggren JV, Tenland K, Memarzadeh K, Sheikh R, Hult J, Lindstedt S, Malmsjö M. The Effect of Canthotomy on Blood Perfusion During the Repair of Lower Eyelid Defects. Ophthalmic Plast Reconstr Surg 2021; 36:135-138. [PMID: 31743283 DOI: 10.1097/iop.0000000000001489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Canthotomy is frequently used to mobilize extra tissue when repairing larger lower eyelid defects. The aim of this study was to explore the effect of canthotomy on blood perfusion and oxygen tension. METHODS Eight pigs underwent a wedge resection of the lower eyelid and canthotomy (with cantholysis involving the lateral palpebral artery). The wedge resection was performed 8, 6, and 4 mm from the canthotomy. Perfusion and oxygen tension were monitored in the eyelid between the wedge resection and canthotomy using laser Doppler velocimetry and a Clark electrode. Verapamil was administered, and measurements were also performed 12 hours after surgery, to investigate the possible effects of vasospasm RESULTS:: The wedge resection alone did not affect perfusion. Canthotomy led to a reduction in perfusion; being 60% when the length of remaining eyelid was 8 mm, 32% when it was 6 mm, and 24% when it was 4 mm. Similar results were observed for oxygen tension. Vasospasm did not affect the results. CONCLUSIONS Canthotomy in combination with a wedge resection of the lower eyelid affects blood perfusion. A smaller length of remaining eyelid tissue will have less perfusion. This may not have any implications in cases of direct closure, but may play a role when the eyelid is to provide oxygen and nutrients to avascular grafts.
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Affiliation(s)
| | | | | | - Rafi Sheikh
- Department of Clinical Sciences Lund, Ophthalmology
| | - Jenny Hult
- Department of Clinical Sciences Lund, Ophthalmology
| | - Sandra Lindstedt
- Department of Clinical Sciences Lund, Cardiothoracic Surgery, Lund University, Skåne University Hospital, Lund, Sweden
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Characterization of microvascular disease in pediatric sickle cell disease using nailfold capillaroscopy. Microvasc Res 2021; 136:104150. [PMID: 33647341 DOI: 10.1016/j.mvr.2021.104150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 11/22/2022]
Abstract
Sickle cell disease (SCD) is a disorder with repetitive vaso-occlusive crises resulting in microvascular obstruction and tissue ischemia that may lead to multi-organ ischemia and dysfunction. Nailfold videocapillaroscopy (NFC) is an imaging technique utilized in clinical rheumatology to visualize capillaries located near the fingertip. To characterize NFC abnormalities in the setting of pediatric SCD, we performed NFC using a video capillaroscope on 8 digits in 44 stable SCD patients and 65 age matched healthy controls. Mean capillary number was lower (6.4 ± 1.3 vs 7.5 ± 1.8, p = 0.001) in the SCD group compared to controls. The percentage of dilated capillaries was similar (7.1 ± 8.3 vs. 5.9 ± 8.2, p = 0.4). The large majority of capillaries visualized in the SCD and control groups were normal capillary types per the EULAR definition, with a similar percentage of normal, nonspecific capillary morphologies and abnormal types. Regarding normal capillary sub-types, the SCD group and controls exhibited similar percentages of stereotype hairpin shapes, and tortuous or once or twice crossing type capillaries. On multivariate analyses, mean capillary number was independently associated with SCD after adjusting for age, body mass index, systolic blood pressure and gender. In conclusion, pediatric SCD is associated with lower capillary number but similar percentage of dilated capillaries and morphology on NFC. In our SCD cohort, capillary number was unrelated to our available markers of disease severity, including history of sickle crises, previous hospitalization for crises or Hemoglobin F levels.
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Miziołek B, Lis-Święty A, Skrzypek-Salamon A, Brzezińska-Wcisło L. Correlation between the infrared thermogram and microvascular abnormalities of the nailfold in patients with systemic sclerosis. Postepy Dermatol Alergol 2021; 38:115-122. [PMID: 34408577 PMCID: PMC8362778 DOI: 10.5114/ada.2021.104286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/09/2019] [Indexed: 12/04/2022] Open
Abstract
INTRODUCTION Systemic sclerosis (SSc) is a multisystemic disease with an extensive microvasculopathy. The gold standard for its investigation is nailfold videocapillaroscopy (NVC). AIM To assess the value of thermography (IRT) for the assessment of microvasculopathy in patients with SSc. MATERIAL AND METHODS Nineteen patients with limited cutaneous SSc were enrolled in the study. They underwent IRT imaging and NVC. An average temperature (Tavg) at the nailfold and a gradient of temperatures (ΔTavg) between the central metacarpus of the hand and the nailfold was determined for all fingers. NVC pictures were classified to capillaroscopic patterns according to Cutolo et al. system and they were analysed quantitatively to measure the density of capillaries and to calculate capillaroscopic skin ulcers risk index (CSURI) for each finger separately. RESULTS There was only a moderate correlation (0.4 < r < 0.6) between thermographic parameters and density of capillaries in fingers II-V (r = 0.5; p < 0.001 for Tavg and r = -0.45; p < 0.001 for ΔTavg), but none in thumbs (r = 0.29; p = 0.089 for Tavg and r = -0.19; p = 0.275 for ΔTavg). Early pattern was associated with a significantly greater surface temperature (Tavg) of nailfolds and essentially milder ΔTavg in fingers II-V when compared to all other capillaroscopic patterns in fingers II-V. Surface temperature (Tavg) was significantly lower and ΔTavg was markedly more pronounced in fingers II-V with a greater risk of development of digital ulcers (DU) calculated by CSURI. CONCLUSIONS Although IRT measurements correlate only moderately with density of capillaries, this technique seems to be substantial to determine the capillaroscopic pattern and to identify patients at greater risk of DU development.
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Affiliation(s)
- Bartosz Miziołek
- Department of Dermatology, School of Medicine, Medical University of Silesia, Katowice, Poland
| | - Anna Lis-Święty
- Department of Dermatology, School of Medicine, Medical University of Silesia, Katowice, Poland
| | - Alina Skrzypek-Salamon
- Department of Dermatology, School of Medicine, Medical University of Silesia, Katowice, Poland
| | - Ligia Brzezińska-Wcisło
- Department of Dermatology, School of Medicine, Medical University of Silesia, Katowice, Poland
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Capaccione KM, Li G, Salvatore MM. Pulmonary embolism rate in patients infected with SARS-CoV-2. Blood Res 2020; 55:275-278. [PMID: 33139587 PMCID: PMC7784133 DOI: 10.5045/br.2020.2020168] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Kathleen M Capaccione
- Division of Cardiothoracic Imaging, Department of Radiology, Columbia University Irving Medical Center
| | - Gen Li
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Mary M Salvatore
- Division of Cardiothoracic Imaging, Department of Radiology, Columbia University Irving Medical Center
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Chen C, Zhang M, Yu N, Zhang W, Long X, Wang Y, Wang X. Heterogeneous Features of Keloids Assessed by Laser Speckle Contrast Imaging: A Cross-Sectional Study. Lasers Surg Med 2020; 53:865-871. [PMID: 33027537 DOI: 10.1002/lsm.23331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 09/01/2020] [Accepted: 09/20/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND OBJECTIVES Keloids are described as benign dermal fibroproliferative lesions, and vascularization may play a significant role in their pathogenesis. In this study, laser speckle contrast imaging (LSCI) was used to assess perfusion within keloids and surrounding skin, and perfusion of keloids at different stages was compared. STUDY DESIGN/MATERIALS AND METHODS A total of 59 patients with 110 untreated keloids on the anterior chest were enrolled in this study. Different keloid stages (progressive, stable, and regressive) were defined according to patients' descriptions of whether keloids became larger, stable, or smaller during the previous year. Vancouver Scar Scale (VSS) was assessed by a plastic surgeon, and patient reports on pain and itching were documented. LSCI was used to evaluate blood perfusion of keloids (K), skin adjacent to keloids (A), and nonadjacent skin (N). The mean perfusion of these regions was determined, and ratios (K/N, A/N) were calculated. RESULTS A heterogeneous perfusion map was observed among the keloid groups, as well as within each keloid. A positive correlation was found between keloid perfusion and VSS. There were 62 (56.4%) keloids in the progressive stage, 33 (30.0%) keloids in the stable stage, and 15 (13.6%) keloids in the regressive stage. The mean K/N ratios in the progressive, stable, and regressive stages were 2.3 ± 0.5, 1.8 ± 0.3, and 1.5 ± 0.5, respectively. The mean A/N ratios were 1.2 ± 0.4, 1.2 ± 0.2, and 1.0 ± 0.5, respectively. Within each keloid, significantly higher perfusion was noted in the keloid and adjacent skin compared with nonadjacent skin. CONCLUSION These results indicate that LSCI is a promising technique for evaluating keloid blood perfusion and distinguishing heterogeneous keloids. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.
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Affiliation(s)
- Cheng Chen
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China.,Department of Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Mingzi Zhang
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Nanze Yu
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Wenchao Zhang
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Xiao Long
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Youbin Wang
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Xiaojun Wang
- Department of Plastic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
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Herrick AL, Dinsdale G, Murray A. New perspectives in the imaging of Raynaud's phenomenon. Eur J Rheumatol 2020; 7:S212-S221. [PMID: 33164735 PMCID: PMC7647685 DOI: 10.5152/eurjrheum.2020.19124] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 03/05/2020] [Indexed: 12/15/2022] Open
Abstract
The last 10-20 years have seen huge strides in imaging science. The aim of this review article is to share with the reader the key recent advances in non-invasive imaging of the digital (finger) vasculature in patients with Raynaud's phenomenon (RP), including in systemic sclerosis (SSc)-related digital vasculopathy. For the rheumatologist, seeing a patient with RP is an opportunity for early diagnosis of an underlying SSc-spectrum disorder or (conversely) for reassuring the patient with primary (idiopathic) RP. Non-invasive imaging techniques can help to provide diagnostic certainty. In addition, they can provide new insights into pathophysiology and have the potential to facilitate the development of much needed effective treatments by providing primary and secondary endpoints for randomized controlled trials: validation studies are ongoing. This review article focuses on nailfold capillaroscopy, thermography, and laser Doppler methods but also discusses (briefly) other technologies, including optical coherence tomography, multispectral imaging, and photoacoustic imaging. Key recent advances are the increasing use/availability of nailfold capillaroscopy (and better understanding of the role of low-cost hand-held devices), increased accessibility of thermography (including mobile phone thermography), and increased application of laser Doppler methods to the study of RP/digital vasculopathy (in particular of laser Doppler imaging and laser speckle contrast imaging, both of which measure blood flow over an area rather than at a single site). In an era of precision medicine, non-invasive imaging techniques can help stratify risk of (a) SSc in the patient with RP and (b) digital vascular disease progression in the patient with an SSc-spectrum disorder.
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Affiliation(s)
- Ariane L. Herrick
- Division of Musculoskeletal and Dermatological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, UK
| | - Graham Dinsdale
- Division of Musculoskeletal and Dermatological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, UK
| | - Andrea Murray
- Division of Musculoskeletal and Dermatological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, UK
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Intraoperative Imaging of Cortical Blood Flow by Camera-Based Photoplethysmography at Green Light. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10186192] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Intraoperative evaluation of blood perfusion in the brain cortex is an important but hitherto unresolved problem. Our aim was to demonstrate the feasibility of cerebral microcirculation assessment during open brain surgery by using camera-based photoplethysmography (cbPPG) synchronized with an electrocardiograph. Cortical blood flow was monitored in five patients with different diagnoses. Two cases (tumor resection and extra-intracranial bypass grafting) are presented in detail. Blood-flow parameters were visualized after processing cortex images recorded under green-light illumination before and after surgical intervention. In all cases, blood flow was successfully visualized in >95% of open brain. Distributions of blood pulsation amplitude, a parameter related to cortical blood perfusion; pulse arrival time; and blood-pressure-pulse shape were calculated with high spatial resolution (in every pixel). Changes in cerebral blood supply caused by surgical intervention were clearly revealed. We have shown that the temporal spread of pulse arrival time and the spatiotemporal variability of pulse shape are very sensitive markers of brain circulatory disturbances. The green-light cbPPG system offers a new approach to objective assessment of blood-flow changes in the brain during surgical intervention. The proposed system allows for contactless monitoring of cortex blood flow in real time with high resolution, thus providing useful information for surgery optimization and minimization of brain tissue damage.
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Zhu Y, Kim M, Hoerig C, Insana MF. Experimental Validation of Perfusion Imaging With HOSVD Clutter Filters. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:1830-1838. [PMID: 32324548 PMCID: PMC7501588 DOI: 10.1109/tuffc.2020.2989109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Novel pulsed-Doppler methods for perfusion imaging are validated using dialysis cartridges as perfusion phantoms. Techniques that were demonstrated qualitatively at 24 MHz, in vivo, are here examined quantitatively at 5 and 12.5 MHz using phantoms with the blood-mimicking fluid flow within cellulose microfibers. One goal is to explore a variety of flow states to optimize measurement sensitivity and flow accuracy. The results show that 2-3-s echo acquisitions at roughly 10 frames/s yield the highest sensitivity to flows of 1-4 mL/min. A second goal is to examine methods for setting the parameters of higher order singular value decomposition (HOSVD) clutter filters. For stationary or moving clutter, the velocity of the blood-mimicking fluid in the microfibers is consistently estimated within measurement uncertainty (mean coefficient of variation = 0.26). Power Doppler signals were equivalent for stationary and moving clutter after clutter filtering, increasing approximately 3 dB/mL/min of blood-mimicking fluid flow for 0 ≤ q ≤ 4 mL/min. Comparisons between phantom and preclinical images show that peripheral perfusion imaging can be reliably achieved without contrast enhancement.
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Li Y, Guo M, Qian X, Lin W, Zheng Y, Yu K, Zeng B, Xu Z, Zheng C, Xu M. Single snapshot spatial frequency domain imaging for risk stratification of diabetes and diabetic foot. BIOMEDICAL OPTICS EXPRESS 2020; 11:4471-4483. [PMID: 32923057 PMCID: PMC7449725 DOI: 10.1364/boe.394929] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 05/29/2023]
Abstract
Diabetic foot is one of the major complications of diabetes. In this work, a real-time Single Snapshot Multiple-frequency Demodulation (SSMD) - Spatial Frequency Domain Imaging (SFDI) system was used to image the forefoot of healthy volunteers, diabetes, and diabetic foot patients. A layered skin model was used to obtain the 2D maps of optical and physiological parameters, including cutaneous hemoglobin concentration, oxygen saturation, scattering properties, melanin content, and epidermal thickness, from every single snapshot. We observed a strong correlation between the measured optical and physiological parameters and the degree of diabetes. The cutaneous hemoglobin concentration, oxygen saturation, and epidermal thickness decrease, whereas the melanin content increases with the progress of diabetes. The melanin content further increases, and the reduced scattering coefficient and scattering power are lower for diabetic foot patients than those of both healthy and diabetic subjects. High accuracies (AUC) of 97.2% (distinguishing the diabetic foot patients among all subjects), 95.2% (separating healthy subjects from the diabetes patients), and 87.8% (classifying mild vs severe diabetes), respectively, are achieved in binary classifications in sequence using the SSMD-SFDI system, demonstrating its applicability to risk stratification of diabetes and diabetic foot. The prognostic value of the SSMD-SFDI system in the prediction of the occurrence of the diabetic foot and other applications in monitoring tissue microcirculation and peripheral vascular disease are also addressed.
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Affiliation(s)
- Ying Li
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Mingrou Guo
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Xiafei Qian
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Weihao Lin
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Yang Zheng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Kangyuan Yu
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Bixin Zeng
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Zhang Xu
- The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
| | - Chao Zheng
- The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
| | - M. Xu
- Institute of Lasers and Biomedical Photonics, Biomedical Engineering College, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Dept. of Physics and Astronomy, Hunter College and the Graduate Center, The City University of New York, 695 Park Avenue, New York, NY 10065, USA
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35
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Lakatos S, Jancsó G, Horváth Á, Dobos I, Sántha P. Longitudinal Study of Functional Reinnervation of the Denervated Skin by Collateral Sprouting of Peptidergic Nociceptive Nerves Utilizing Laser Doppler Imaging. Front Physiol 2020; 11:439. [PMID: 32528300 PMCID: PMC7253695 DOI: 10.3389/fphys.2020.00439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/08/2020] [Indexed: 11/13/2022] Open
Abstract
Restitution of cutaneous sensory function is accomplished by neural regenerative processes of distinct mechanisms following peripheral nerve lesions. Although methods available for the study of functional cutaneous nerve regeneration are specific and accurate, they are unsuitable for the longitudinal follow-up of the temporal and spatial aspects of the reinnervation process. Therefore, the aim of this study was to develop a new, non-invasive approach for the longitudinal examination of cutaneous nerve regeneration utilizing the determination of changes in the sensory neurogenic vasodilatatory response, a salient feature of calcitonin gene-related peptide-containing nociceptive afferent nerves, with scanning laser Doppler flowmetry. Scanning laser Doppler imaging was applied to measure the intensity and spatial extent of sensory neurogenic vasodilatation elicited by the application of mustard oil onto the dorsal skin of the rat hindpaw. Mustard oil induced reproducible and uniform increases in skin perfusion reaching maximum values at 2-4 min after application whereafter the blood flow gradually returned to control level after about 8-10 min. Transection and ligation of the saphenous nerve largely eliminated the vasodilatatory response in the medial aspect of the dorsal skin of the hindpaw. In the 2 nd to 4 th weeks after injury, the mustard oil-induced vasodilatatory reaction gradually recovered. Since regeneration of the saphenous nerve was prevented, the recovery of the vasodilatatory response may be accounted for by the collateral sprouting of neighboring intact sciatic afferent nerve fibers. This was supported by the elimination of the vasodilatatory response in both the saphenous and sciatic innervation territories following local treatment of the sciatic nerve with capsaicin to defunctionalize nociceptive afferent fibers. The present findings demonstrate that this novel technique utilizing scanning laser Doppler flowmetry to quantitatively measure cutaneous sensory neurogenic vasodilatation, a vascular response mediated by peptidergic nociceptive nerves, is a reliable non-invasive approach for the longitudinal study of nerve regeneration in the skin.
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Affiliation(s)
- Szandra Lakatos
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Gábor Jancsó
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Ágnes Horváth
- 1st Department of Internal Medicine, University of Szeged, Szeged, Hungary
| | - Ildikó Dobos
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Péter Sántha
- Department of Physiology, University of Szeged, Szeged, Hungary
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Magnin M, Junot S, Cardinali M, Ayoub JY, Paquet C, Louzier V, Garin JMB, Allaouchiche B. Use of infrared thermography to detect early alterations of peripheral perfusion: evaluation in a porcine model. BIOMEDICAL OPTICS EXPRESS 2020; 11:2431-2446. [PMID: 32499935 PMCID: PMC7249846 DOI: 10.1364/boe.387481] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/10/2020] [Accepted: 03/18/2020] [Indexed: 05/08/2023]
Abstract
This study aimed to evaluate the variations of infrared thermography according to rapid hemodynamic changes, by measuring the peripheral skin temperature in a porcine model. Eight healthy piglets were anesthetized and exposed to different levels of arterial pressure. Thermography was performed on the left forelimb to measure carpus and elbow skin temperature and their associated gradient with the core temperature. Changes in skin temperature in response to variations of blood pressure were observed. A negative correlation between arterial pressure and temperature gradients between peripheral and core temperature and a negative correlation between cardiac index and these temperature gradients were observed. Thermography may serve as a tool to detect early changes in peripheral perfusion.
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Affiliation(s)
- Mathieu Magnin
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Vetagro Sup, Campus Vétérinaire de Lyon, Unité de Physiologie, Pharmacodynamie et Thérapeutique, F-69280 Marcy l’Etoile, France
| | - Stephane Junot
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, Anesthésiologie, F-69280 Marcy l’Etoile, France
| | - Martina Cardinali
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, Anesthésiologie, F-69280 Marcy l’Etoile, France
| | - Jean Yves Ayoub
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Vetagro Sup, Campus Vétérinaire de Lyon, Unité de Physiologie, Pharmacodynamie et Thérapeutique, F-69280 Marcy l’Etoile, France
| | - Christian Paquet
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Vetagro Sup, Campus Vétérinaire de Lyon, Unité de Physiologie, Pharmacodynamie et Thérapeutique, F-69280 Marcy l’Etoile, France
| | - Vanessa Louzier
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Vetagro Sup, Campus Vétérinaire de Lyon, Unité de Physiologie, Pharmacodynamie et Thérapeutique, F-69280 Marcy l’Etoile, France
| | - Jeanne Marie Bonnet Garin
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Vetagro Sup, Campus Vétérinaire de Lyon, Unité de Physiologie, Pharmacodynamie et Thérapeutique, F-69280 Marcy l’Etoile, France
| | - Bernard Allaouchiche
- Université de Lyon, APCSe Agressions Pulmonaires et Circulatoires dans le Sepsis, VetAgro Sup, F-69280 Marcy l’Etoile, France
- Université de Lyon, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Réanimation Médicale, Unité APCSE, Pierre-Bénite, France
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The preliminary validation of laser Doppler flowmetry in systemic sclerosis in accordance with the OMERACT filter: A systematic review. Semin Arthritis Rheum 2020; 50:321-328. [DOI: 10.1016/j.semarthrit.2019.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 07/09/2019] [Accepted: 08/21/2019] [Indexed: 11/20/2022]
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Koch S, Zelembaba A, Tran R, Laeremans M, Hives B, Carlsten C, De Boever P, Koehle MS. Vascular effects of physical activity are not modified by short-term inhaled diesel exhaust: Results of a controlled human exposure study. ENVIRONMENTAL RESEARCH 2020; 183:109270. [PMID: 32311911 DOI: 10.1016/j.envres.2020.109270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/23/2020] [Accepted: 02/17/2020] [Indexed: 05/22/2023]
Abstract
BACKGROUND The combined effects of physical activity and air pollution exposure on vascular function are insufficiently understood, particularly after the inhalation of a β2-agonist, a vasodilating agent. OBJECTIVE To assess the micro- and macrovascular response to physical activity after β2-agonist use while breathing diesel exhaust (DE) in individuals with exercise-induced bronchoconstriction. METHODS On four exposure visits, eighteen adults inhaled either 400 μg of the β2-agonist salbutamol or placebo before resting for 60 min, followed by a 30-min cycling bout. During rest and cycling, participants inhaled filtered air (FA) or DE (300 μg/m3 of PM2.5). Microvascular (central retinal arteriolar and venular equivalents, CRAE and CRVE, respectively) and macrovascular parameters (blood pressure (BP)) and heart rate (HR)) were assessed at baseline (T1), 10 min (T2) and 70 min (T3) after cycling. RESULTS The cycling bout increased CRAE (T2-T1 difference (95th % confidence interval): 4.88 μm (4.73, 5.00 μm), p < 0.001; T3-T1 difference: 2.10 μm (1.62, 2.58 μm), p = 0.031) and CRVE (T2-T1 difference: 3.78 μm (3.63, 3.92 μm), p < 0.001; T3-T1 difference: 3.73 μm (3.63, 3.92 μm), p < 0.001). The exposure to DE had no effect on CRAE (FA-DE difference at T2: 0.46 μm (-0.02, 0.92 μm); p = 0.790; FA-DE difference at T3: 1.76 μm (1.36, 2.16 μm), p = 0.213) and CRVE (FA-DE difference at T2: 0.26 μm (-0.35, 0.88 μm), p = 0.906; FA-DE difference at T3: 0.55 μm (0.05, 1.06 μm), p = 0.750). Compared to T1, systolic BP was decreased at T2 by 2.5 mmHg (2.8, 2.3 mmHg, p = 0.047), independent of inhaled exposure. Heart rate at T2 was significantly increased by 3 bpm (2, 3 bpm, p = 0.025) after the DE-exposure when compared to FA. DISCUSSION Acute physical activity induces a vasodilatory response in the micro- and macrovasculature in healthy adults by increasing CRAE and CRVE, and by reducing systolic BP post exercise, despite breathing DE. The DE-associated increase in HR might be indicative of an increased sympathetic response to physical activity while breathing DE.
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Affiliation(s)
- Sarah Koch
- School of Kinesiology, University of British Columbia, Vancouver, 6081 University Boulevard, Vancouver, British Columbia, V6T 1Z1, Canada.
| | - Ana Zelembaba
- School of Kinesiology, University of British Columbia, Vancouver, 6081 University Boulevard, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Raymond Tran
- School of Kinesiology, University of British Columbia, Vancouver, 6081 University Boulevard, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Michelle Laeremans
- Health Unit, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Antwerp, Belgium; Centre for Environmental Sciences, Agoralaan building D, 3590 Diepenbeek, Belgium
| | - Benjamin Hives
- School of Kinesiology, University of British Columbia, Vancouver, 6081 University Boulevard, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Christopher Carlsten
- Faculty of Medicine, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Patrick De Boever
- Health Unit, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Antwerp, Belgium; Centre for Environmental Sciences, Agoralaan building D, 3590 Diepenbeek, Belgium
| | - Michael Stephen Koehle
- School of Kinesiology, University of British Columbia, Vancouver, 6081 University Boulevard, Vancouver, British Columbia, V6T 1Z1, Canada; Faculty of Medicine, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
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Kumar M, Suliburk JW, Veeraraghavan A, Sabharwal A. PulseCam: a camera-based, motion-robust and highly sensitive blood perfusion imaging modality. Sci Rep 2020; 10:4825. [PMID: 32179806 PMCID: PMC7075982 DOI: 10.1038/s41598-020-61576-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 02/27/2020] [Indexed: 11/08/2022] Open
Abstract
Blood carries oxygen and nutrients to the trillions of cells in our body to sustain vital life processes. Lack of blood perfusion can cause irreversible cell damage. Therefore, blood perfusion measurement has widespread clinical applications. In this paper, we develop PulseCam - a new camera-based, motion-robust, and highly sensitive blood perfusion imaging modality with 1 mm spatial resolution and 1 frame-per-second temporal resolution. Existing camera-only blood perfusion imaging modality suffers from two core challenges: (i) motion artifact, and (ii) small signal recovery in the presence of large surface reflection and measurement noise. PulseCam addresses these challenges by robustly combining the video recording from the camera with a pulse waveform measured using a conventional pulse oximeter to obtain reliable blood perfusion maps in the presence of motion artifacts and outliers in the video recordings. For video stabilization, we adopt a novel brightness-invariant optical flow algorithm that helps us reduce error in blood perfusion estimate below 10% in different motion scenarios compared to 20-30% error when using current approaches. PulseCam can detect subtle changes in blood perfusion below the skin with at least two times better sensitivity, three times better response time, and is significantly cheaper compared to infrared thermography. PulseCam can also detect venous or partial blood flow occlusion that is difficult to identify using existing modalities such as the perfusion index measured using a pulse oximeter. With the help of a pilot clinical study, we also demonstrate that PulseCam is robust and reliable in an operationally challenging surgery room setting. We anticipate that PulseCam will be used both at the bedside as well as a point-of-care blood perfusion imaging device to visualize and analyze blood perfusion in an easy-to-use and cost-effective manner.
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Affiliation(s)
- Mayank Kumar
- Electrical and Computer Engineering, Rice University, 6100 Main St, Houston, TX, 77005, USA
| | - James W Suliburk
- Division of General Surgery, Baylor College of Medicine, 6620 Main St, Houston, TX, 77030, USA
| | - Ashok Veeraraghavan
- Electrical and Computer Engineering, Rice University, 6100 Main St, Houston, TX, 77005, USA
| | - Ashutosh Sabharwal
- Electrical and Computer Engineering, Rice University, 6100 Main St, Houston, TX, 77005, USA.
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Blood Perfusion in Rotational Full-Thickness Lower Eyelid Flaps Measured by Laser Speckle Contrast Imaging. Ophthalmic Plast Reconstr Surg 2020; 36:148-151. [DOI: 10.1097/iop.0000000000001496] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dynamic Volume Perfusion CT of the Foot in Critical Limb Ischemia: Response to Percutaneous Revascularization. AJR Am J Roentgenol 2020; 214:1398-1408. [PMID: 32097028 DOI: 10.2214/ajr.19.21520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE. The purpose of this study was to assess the reproducibility and validity of quantitative perfusion parameters derived from dynamic volume perfusion CT in patients with critical limb ischemia (CLI) and to evaluate perfusion parameter changes before and after endovascular revascularization. SUBJECTS AND METHODS. Patients with CLI referred for unilateral extremity endovascular arterial recanalization were enrolled in this study. CT examinations obtained 1-3 days before the procedure and then within 1 week after the treatment were evaluated at two reading sessions. Blood flow (BF), blood volume (BV), and time to peak (TTP) were measured on color-coded maps and compared statistically. Intraobserver agreement was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS. Endovascular treatment was technically successful for all 16 patients. The posttreatment BF and BV showed a statistically significant increase in both dermal and muscle areas (p < 0.05). The posttreatment TTP shortened at a statistically significant level (p < 0.05). In the 3-month clinical follow-up period, the limb salvage rate was 81% and the percentage change in BF and BV of patients with poor response to treatment had no statistically significant increase after treatment, consistent with the clinical assessment. The percentage change in BF and BV correlated well with the improvement of the clinical condition (r = 0.673-0.901). ICC values showed excellent agreement in the range of 0.95-0.98. CONCLUSION. As a reproducible method, dynamic volume perfusion CT of the foot may enable quantitative evaluation of the perfusion of soft tissues and also provide a novel approach to assessing response to endovascular recanalization in CLI.
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Thermography in systemic sclerosis patients and other rheumatic diseases: Diagnosis, disease activity assessment, and therapeutic monitoring. Autoimmun Rev 2019; 19:102449. [PMID: 31838167 DOI: 10.1016/j.autrev.2019.102449] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 09/01/2019] [Indexed: 12/11/2022]
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Characterization of microvascular disease in patients with sickle cell disease using nailfold capillaroscopy. Microvasc Res 2019; 125:103877. [DOI: 10.1016/j.mvr.2019.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 03/21/2019] [Accepted: 04/28/2019] [Indexed: 11/21/2022]
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Gyldenløve T, Jørgensen LP, Schroeder TV. Micro-Lightguide Spectrophotometry (O2C) for Lower Limb Perfusion: Effects of Exercise Walking in Claudicants. Int J Angiol 2019; 28:161-166. [PMID: 31452583 DOI: 10.1055/s-0039-1692661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Background Exercise walking has improved walking capacity in patients with intermittent claudication without affecting the macrocirculation reflected in ankle pressures. We wanted to investigate microcirculation in the skin related to exercise walking by using Micro-Lightguide Spectrophotometry (O2C). Materials and Methods Twenty-eight patients with intermittent claudication-bilateral in 17-were included in a 12 weeks of structured home-based exercise program. The pain-free and maximal walking distances were determined on a treadmill. Saturation and flow, monitored by O2C, were examined immediately before and after the treadmill test. O2C examination took place before as well as after completion of the exercise program. Ankle-brachial index was obtained before treadmill testing. Results As expected, walking performance improved significantly without affecting ankle pressures. Neither oxygen saturation nor flow, assessed at 2 mm depth, was affected following a 12 weeks of exercise program. We observed a significant decrease in oxygen saturation and flow upon treadmill testing in the both limbs in patients with bilateral peripheral arterial disease (PAD). In contrast, the treadmill test elicited no changes in the opposite and asymptomatic limb in patients with only unilateral PAD. Conclusion The findings suggest that O2C may be used to study microcirculatory changes. However, it is best suited for the study of phenomena resulting in major changes as it eliminates some inherent variability.
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Affiliation(s)
- Thomas Gyldenløve
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark.,University of Copenhagen, Copenhagen, Denmark
| | - Lise P Jørgensen
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark.,University of Copenhagen, Copenhagen, Denmark
| | - Torben V Schroeder
- University of Copenhagen, Copenhagen, Denmark.,Copenhagen Academy for Medical Education and Simulation at Rigshospitalet, Capital Region, Denmark
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Mennes OA, van Netten JJ, van Baal JG, Steenbergen W. Assessment of microcirculation in the diabetic foot with laser speckle contrast imaging. Physiol Meas 2019; 40:065002. [DOI: 10.1088/1361-6579/ab2058] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Abstract
INTRODUCTION Anastomotic insufficiency (AI) remains the most feared surgical complication in gastrointestinal surgery, which is closely associated with a prolonged inpatient hospital stay and significant postoperative mortality. Hyperspectral imaging (HSI) is a relatively new medical imaging procedure which has proven to be promising in tissue identification as well as in the analysis of tissue oxygenation and water content. Until now, no data exist on the in vivo HSI analysis of gastrointestinal anastomoses. METHODS Intraoperative images were obtained using the TIVITA™ tissue system HSI camera from Diaspective Vision GmbH (Pepelow, Germany). In 47 patients who underwent gastrointestinal surgery with esophageal, gastric, pancreatic, small bowel or colorectal anastomoses, 97 assessable recordings were generated. Parameters obtained at the sites of the anastomoses included tissue oxygenation (StO2), the tissue hemoglobin index (THI), near-infrared (NIR) perfusion index, and tissue water index (TWI). RESULTS Obtaining and analyzing the intraoperative images with this non-invasive imaging system proved practicable and delivered good results on a consistent basis. A NIR gradient along and across the anastomosis was observed and, furthermore, analysis of the tissue water and oxygenation content showed specific changes at the site of anastomosis. CONCLUSION The HSI method provides a non-contact, non-invasive, intraoperative imaging procedure without the use of a contrast medium, which enables a real-time analysis of physiological anastomotic parameters, which may contribute to determine the "ideal" anastomotic region. In light of this, the establishment of this methodology in the field of visceral surgery, enabling the generation of normal or cut off values for different gastrointestinal anastomotic types, is an obvious necessity.
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Dremin V, Kozlov I, Volkov M, Margaryants N, Potemkin A, Zherebtsov E, Dunaev A, Gurov I. Dynamic evaluation of blood flow microcirculation by combined use of the laser Doppler flowmetry and high-speed videocapillaroscopy methods. JOURNAL OF BIOPHOTONICS 2019; 12:e201800317. [PMID: 30636028 DOI: 10.1002/jbio.201800317] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 01/06/2018] [Accepted: 01/09/2019] [Indexed: 05/06/2023]
Abstract
The dynamic light scattering methods are widely used in biomedical diagnostics involving evaluation of blood flow. However, there exist some difficulties in quantitative interpretation of backscattered light signals from the viewpoint of diagnostic information. This study considers the application of the high-speed videocapillaroscopy (VCS) method that provides the direct measurement of the red blood cells (RBCs) velocity into a capillary. The VCS signal presents true oscillation nature of backscattered light caused by moving RBCs. Thus, the VCS signal can be assigned as a reference one with respect to more complicated signals like in laser Doppler flowmetry (LDF). An essential correlation between blood flow velocity oscillations in a separate human capillary and the integral perfusion estimate obtained by the LDF method has been found. The observation of blood flow by the VCS method during upper arm occlusion has shown emergence of the reverse blood flow effect in capillaries that corresponds to the biological zero signal in the LDF. The reverse blood flow effect has to be taken into account in interpretation of LDF signals.
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Affiliation(s)
- Viktor Dremin
- Research & Development Center of Biomedical Photonics, Orel State University named after I.S. Turgenev, Orel, Russia
- Optoelectronics and Measurement Techniques Unit, University of Oulu, Oulu, Finland
| | - Igor Kozlov
- Research & Development Center of Biomedical Photonics, Orel State University named after I.S. Turgenev, Orel, Russia
| | - Mikhail Volkov
- Faculty of Applied Optics, ITMO University, St. Petersburg, Russia
| | | | - Andrey Potemkin
- Faculty of Applied Optics, ITMO University, St. Petersburg, Russia
| | - Evgeny Zherebtsov
- Research & Development Center of Biomedical Photonics, Orel State University named after I.S. Turgenev, Orel, Russia
- Optoelectronics and Measurement Techniques Unit, University of Oulu, Oulu, Finland
| | - Andrey Dunaev
- Research & Development Center of Biomedical Photonics, Orel State University named after I.S. Turgenev, Orel, Russia
| | - Igor Gurov
- Faculty of Applied Optics, ITMO University, St. Petersburg, Russia
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Li W, Li P, Fang Y, Lei TC, Dong K, Zou J, Gong W, Xie S, Huang Z. Quantitative assessment of skin swelling using optical coherence tomography. Photodiagnosis Photodyn Ther 2019; 26:413-419. [DOI: 10.1016/j.pdpdt.2019.04.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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Moço A, Stuijk S, de Haan G. Posture effects on the calibratability of remote pulse oximetry in visible light. Physiol Meas 2019; 40:035005. [DOI: 10.1088/1361-6579/ab051a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Despite our understanding that the microvasculature plays a multifaceted role in the development and progression of various conditions, we know little about the extent of this involvement. A need exists for non-invasive, clinically meaningful imaging modalities capable of elucidating microvascular information to aid in our understanding of disease, and to aid in the diagnosis/monitoring of disease for more patient-specific care. In this review article, a number of imaging techniques are summarized that have been utilized to investigate the microvasculature of skin, along with their advantages, disadvantages and future perspectives in preclinical and clinical settings. These techniques include dermoscopy, capillaroscopy, Doppler sonography, laser Doppler flowmetry (LDF) and perfusion imaging, laser speckle contrast imaging (LSCI), optical coherence tomography (OCT), including its Doppler and dynamic variant and the more recently developed OCT angiography (OCTA), photoacoustic imaging, and spatial frequency domain imaging (SFDI). Attention is largely, but not exclusively, placed on optical imaging modalities that use intrinsic optical signals to contrast the microvasculature. We conclude that whilst each imaging modality has been successful in filling a particular niche, there is no one, all-encompassing modality without inherent flaws. Therefore, the future of cutaneous microvascular imaging may lie in utilizing a multi-modal approach that will counter the disadvantages of individual systems to synergistically augment our imaging capabilities.
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Affiliation(s)
- Anthony J Deegan
- Department of Bioengineering, University of Washington, 3720 15th Ave. NE., Seattle, WA 98195, United States of America
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