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Hu XX, Xing XM, Zhang ZM, Zhang C, Chen L, Huang JZ, Wang X, Ma X, Geng X. Wearable laser Doppler flowmetry for non-invasive assessment of diabetic foot microcirculation: methodological considerations and clinical implications. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:065001. [PMID: 38737791 PMCID: PMC11088439 DOI: 10.1117/1.jbo.29.6.065001] [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: 02/01/2024] [Revised: 04/15/2024] [Accepted: 04/18/2024] [Indexed: 05/14/2024]
Abstract
Significance Type 2 diabetes mellitus (T2DM) is a global health concern with significant implications for vascular health. The current evaluation methods cannot achieve effective, portable, and quantitative evaluation of foot microcirculation. Aim We aim to use a wearable device laser Doppler flowmetry (LDF) to evaluate the foot microcirculation of T2DM patients at rest. Approach Eleven T2DM patients and twelve healthy subjects participated in this study. The wearable LDF was used to measure the blood flows (BFs) for regions of the first metatarsal head (M1), fifth metatarsal head (M5), heel, and dorsal foot. Typical wavelet analysis was used to decompose the five individual control mechanisms: endothelial, neurogenic, myogenic, respiratory, and heart components. The mean BF and sample entropy (SE) were calculated, and the differences between diabetic patients and healthy adults and among the four regions were compared. Results Diabetic patients showed significantly reduced mean BF in the neurogenic (p = 0.044 ) and heart (p = 0.001 ) components at the M1 and M5 regions (p = 0.025 ) compared with healthy adults. Diabetic patients had significantly lower SE in the neurogenic (p = 0.049 ) and myogenic (p = 0.032 ) components at the M1 region, as well as in the endothelial (p < 0.001 ) component at the M5 region and in the myogenic component at the dorsal foot (p = 0.007 ), compared with healthy adults. The SE in the myogenic component at the dorsal foot was lower than at the M5 region (p = 0.050 ) and heel area (p = 0.041 ). Similarly, the SE in the heart component at the dorsal foot was lower than at the M5 region (p = 0.017 ) and heel area (p = 0.028 ) in diabetic patients. Conclusions This study indicated the potential of using the novel wearable LDF device for tracking vascular complications and implementing targeted interventions in T2DM patients.
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Affiliation(s)
- Xing-Xi Hu
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
- The Affiliated Hospital of Yunnan University (The Second People’s Hospital of Yunnan Province, The Eye Hospital of Yunnan Province), Department of Orthopedics and Trauma, Kunming, China
| | - Xiao-Man Xing
- University of Science and Technology of China, School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, Suzhou, China
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Suzhou, China
| | - Zhen-Ming Zhang
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
| | - Chao Zhang
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
| | - Li Chen
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
| | - Jia-Zhang Huang
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
| | - Xu Wang
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
| | - Xin Ma
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
- National Center for Orthopaedics, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiang Geng
- Huashan Hospital, Fudan University, Department of Orthopedic Surgery, Shanghai, China
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Ratter-Rieck JM, Roden M, Herder C. Diabetes and climate change: current evidence and implications for people with diabetes, clinicians and policy stakeholders. Diabetologia 2023; 66:1003-1015. [PMID: 36964771 PMCID: PMC10039694 DOI: 10.1007/s00125-023-05901-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/15/2023] [Indexed: 03/26/2023]
Abstract
Climate change will be a major challenge for the world's health systems in the coming decades. Elevated temperatures and increasing frequencies of heat waves, wildfires, heavy precipitation and other weather extremes can affect health in many ways, especially if chronic diseases are already present. Impaired responses to heat stress, including compromised vasodilation and sweating, diabetes-related comorbidities, insulin resistance and chronic low-grade inflammation make people with diabetes particularly vulnerable to environmental risk factors, such as extreme weather events and air pollution. Additionally, multiple pathogens show an increased rate of transmission under conditions of climate change and people with diabetes have an altered immune system, which increases the risk for a worse course of infectious diseases. In this review, we summarise recent studies on the impact of climate-change-associated risk for people with diabetes and discuss which individuals may be specifically prone to these risk conditions due to their clinical features. Knowledge of such high-risk groups will help to develop and implement tailored prevention and management strategies to mitigate the detrimental effect of climate change on the health of people with diabetes.
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Affiliation(s)
- Jacqueline M Ratter-Rieck
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
- German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany.
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany
- Department of Endocrinology and Diabetology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany
- Department of Endocrinology and Diabetology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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Hultman M, Larsson M, Strömberg T, Fredriksson I. Speed-resolved perfusion imaging using multi-exposure laser speckle contrast imaging and machine learning. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:036007. [PMID: 36950019 PMCID: PMC10027009 DOI: 10.1117/1.jbo.28.3.036007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/27/2023] [Indexed: 05/19/2023]
Abstract
SIGNIFICANCE Laser speckle contrast imaging (LSCI) gives a relative measure of microcirculatory perfusion. However, due to the limited information in single-exposure LSCI, models are inaccurate for skin tissue due to complex effects from e.g. static and dynamic scatterers, multiple Doppler shifts, and the speed-distribution of blood. It has been demonstrated how to account for these effects in laser Doppler flowmetry (LDF) using inverse Monte Carlo (MC) algorithms. This allows for a speed-resolved perfusion measure in absolute units %RBC × mm/s, improving the physiological interpretation of the data. Until now, this has been limited to a single-point LDF technique but recent advances in multi-exposure LSCI (MELSCI) enable the analysis in an imaging modality. AIM To present a method for speed-resolved perfusion imaging in absolute units %RBC × mm/s, computed from multi-exposure speckle contrast images. APPROACH An artificial neural network (ANN) was trained on a large simulated dataset of multi-exposure contrast values and corresponding speed-resolved perfusion. The dataset was generated using MC simulations of photon transport in randomized skin models covering a wide range of physiologically relevant geometrical and optical tissue properties. The ANN was evaluated on in vivo data sets captured during an occlusion provocation. RESULTS Speed-resolved perfusion was estimated in the three speed intervals 0 to 1 mm / s , 1 to 10 mm / s , and > 10 mm / s , with relative errors 9.8%, 12%, and 19%, respectively. The perfusion had a linear response to changes in both blood tissue fraction and blood flow speed and was less affected by tissue properties compared with single-exposure LSCI. The image quality was subjectively higher compared with LSCI, revealing previously unseen macro- and microvascular structures. CONCLUSIONS The ANN, trained on modeled data, calculates speed-resolved perfusion in absolute units from multi-exposure speckle contrast. This method facilitates the physiological interpretation of measurements using MELSCI and may increase the clinical impact of the technique.
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Affiliation(s)
- Martin Hultman
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Stockholm, Sweden
- Address all correspondence to Martin Hultman,
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Stockholm, Sweden
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4
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Guigui A, Loader J, Bellier A, Roustit M. Commentary: Multiple laser doppler flowmetry probes increase the reproducibility of skin blood flow measurements. Front Physiol 2022; 13:1025905. [PMID: 36324305 PMCID: PMC9619133 DOI: 10.3389/fphys.2022.1025905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/06/2022] [Indexed: 12/03/2022] Open
Affiliation(s)
- Alicia Guigui
- University Grenoble Alpes, Inserm U1300, Grenoble, France
- Grenoble University Hospital, Inserm CIC1406, University Grenoble Alpes, Grenoble, France
- *Correspondence: Alicia Guigui,
| | - Jordan Loader
- University Grenoble Alpes, Inserm U1300, Grenoble, France
- Grenoble University Hospital, Inserm CIC1406, University Grenoble Alpes, Grenoble, France
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Alexandre Bellier
- Grenoble University Hospital, Inserm CIC1406, University Grenoble Alpes, Grenoble, France
- Computational and Mathematical Biology Team, TIMC-IMAG UMR 5525, CNRS, University Grenoble Alpes, Grenoble, France
| | - Matthieu Roustit
- University Grenoble Alpes, Inserm U1300, Grenoble, France
- Grenoble University Hospital, Inserm CIC1406, University Grenoble Alpes, Grenoble, France
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Wang Q, Liu X, Li B, Yang X, Lu W, Li A, Li H, Zhang X, Han J. Sodium pentobarbital suppresses breast cancer cells growth partly via normalizing microcirculatory hemodynamics and oxygenation in tumors. J Pharmacol Exp Ther 2022; 382:11-20. [PMID: 35512800 DOI: 10.1124/jpet.121.001058] [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: 12/17/2021] [Accepted: 04/26/2022] [Indexed: 11/22/2022] Open
Abstract
Breast cancer remains the leading cause of cancer-related death among women worldwidely. Sodium pentobarbital was found to play an inhibitory role in glioma growth in rats. In this study, we aim to evaluate the effects of sodium pentobarbital on breast cancer growth both in vitro and in vivo, and its impacts on the microcirculatory changes both on skin and tumor surface in mice bearing subcutaneous xenograft. Cell counting assay was used to assess the anti-proliferative effect of sodium pentobarbital on MDA-MB-231 breast cancer cells. Subcutaneous xenograft model was established to study the role of sodium pentobarbital on in vivo tumor growth. Speed-resolved blood perfusion, hemoglobin oxygen saturation (SO2, %), total hemoglobin tissue concentration (THb, µM), and red blood cell (RBC) tissue fraction (%) were examined simultaneously by using EPOS system, to investigate the effects of sodium pentobarbital on microcirculatory hemodynamics and oxygenation. Sodium pentobarbital suppressed breast tumor growth both in vitro and in vivo Cutaneous blood flux in nutritive capillaries with low-speed flow was significantly increased in tumor-bearing mice, and high dose sodium pentobarbital treatment cause a reduction in this low-speed blood flux, whereas sodium pentobarbital therapy caused an elevated blood flux in larger microvessels with mid- and high-speed in a dose-dependent manner. Different doses of sodium pentobarbital exerted different actions on in SO2, ctTHb and RBC tissue fraction. Collectively, the inhibitory effect of sodium pentobarbital on breast tumor growth was at least partly associated with its ability to normalize microcirculatory hemodynamics and oxygenation in tumors. Significance Statement This study is the first to demonstrate the inhibiting effect of sodium pentobarbital on breast cancer growth both in vitro and in vivo, and such an inhibition was at least partly associated with its ability to normalize microcirculatory hemodynamics and oxygenation in tumors.
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Affiliation(s)
- Qin Wang
- Institute of Microcirculation, China
| | | | | | | | - Wenbao Lu
- Institute of Microcirculation, China
| | - Ailing Li
- Institute of Microcirculation, China
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O'Brien TD. Impaired dermal microvascular reactivity and implications for diabetic wound formation and healing: an evidence review. J Wound Care 2021; 29:S21-S28. [PMID: 32924808 DOI: 10.12968/jowc.2020.29.sup9.s21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Diabetic foot ulcers (DFUs) are among the most consequential and costly complications faced by patients with diabetes and the global healthcare system. Acknowledged risk factors for DFUs include diabetic peripheral neuropathy (DPN), peripheral arterial disease (PAD), microtrauma and foot deformities. Research on additional risk factors for DFUs has recently focused on dysregulated, autonomic vasomotor control in the skin of patients with DPN. In particular, impaired dermal microvascular reactivity (IDMR) with its attendant reduction in nutritive capillary blood flow has been identified as an emerging risk factor. This especially relates to refractory wounds noted in patients without overt PAD signs. In this paper, evidence will be reviewed supporting the evolving understanding of IDMR and its impact on DFU formation and healing. Advances in diagnostic instrumentation driving this research along with the most promising potential therapies aimed at improving microvascular function in the diabetic foot will be discussed in brief.
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Affiliation(s)
- Todd D O'Brien
- Penobscot Community Health Care, Bangor, ME, US.,University of Maine, Orono, ME, US
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7
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Cordova-Fraga T, García D, Murillo-Ortiz B, García M, Gomez C, Amador-Medina F, Guzman-Cabrera R. Digital processing of ultrasound images on dilated blood vessels from diabetic patients. JOURNAL OF INTELLIGENT & FUZZY SYSTEMS 2020. [DOI: 10.3233/jifs-179914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction Peripheral arterial disease (PAD) is a fairly common degenerative vascular condition in diabetic patients that leads to inadequate blood flow (BF), this disease is mainly due to atherosclerosis that causes chronic narrowing of arteries, which can precipitate acute thrombotic events. In patients with diabetes, atherosclerosis is the main reason for reducing life expectancy, as long as diabetic nephropathy and retinopathy are the largest contributors to end-stage renal disease and blindness, respectively. Objective This was an assessment of dilatation of the blood vessels on diabetic patients vs. healthy volunteers by using digital processing of imaging’s. Materials and Methods The study subject was ultrasound imaging processing of blood vessels dilation on low extremities of diabetic patients, the results were compared with ultrasound images of healthy subjects. Results The digital images processing suggests that there is a significant difference among images experimental of the diabetic group and healthy volunteers’ images, the control group. Discussion The digital imaging processing performed in the Matlab platform is an adequate procedure for blood vessels dilation analysis of the ultrasound images taken from the lower extremities in diabetic patients.
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Affiliation(s)
| | - Daniel García
- Department of Physical Engineering - DCI, University of Guanajuato León campus
| | | | - Marysol García
- Department of Physical Engineering - DCI, University of Guanajuato León campus
| | - Christian Gomez
- Department of Physical Engineering - DCI, University of Guanajuato León campus
| | | | - Rafael Guzman-Cabrera
- Department of Electrical Engineering - DICIS, University of Guanajuato campus, Irapuato Salamanca
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8
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Jonasson H, Bergstrand S, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Normative data and the influence of age and sex on microcirculatory function in a middle-aged cohort: results from the SCAPIS study. Am J Physiol Heart Circ Physiol 2020; 318:H908-H915. [PMID: 32142355 DOI: 10.1152/ajpheart.00668.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to assess normative values for comprehensive forearm skin microcirculatory function: oxygen saturation, tissue fraction of red blood cells (RBCs), and speed-resolved perfusion. Furthermore, to examine the influence of age and sex on microcirculatory function. Measurements were performed using a noninvasive probe-based system, including diffuse reflectance spectroscopy and laser-Doppler flowmetry, yielding output data in absolute units. The study was conducted within the Swedish CArdioPulmonary BioImage Study (SCAPIS) and included 1,765 men and women aged 50-65 yr from the Linköping general population. Normative values are given at baseline, at the end of a 5-min occlusion of the brachial artery and during hyperemia after occlusion release. We found a consistent age distribution, in which the oldest individuals had the lowest peak oxygen saturation (P < 0.001) and the highest baseline low-speed perfusion (P < 0.001). Women had higher peak oxygen saturation (P < 0.001), lower RBC tissue fraction, in general (P < 0.001), lower baseline perfusion in all speed regions (P = 0.01), and lower peak high-speed perfusion at hyperemia (P < 0.001). The normative data can be used as reference values in future studies of disease-specific populations. The results show that age and sex are important aspects to consider in studies of microvascular function. Women and younger age were factors associated with higher peak oxygen saturation after ischemia. This is a novel parameter that reflects overall microcirculatory function associated with vascular dilation capacity.NEW & NOTEWORTHY This study expands experimental microcirculatory research to clinical use by providing normative values on microcirculatory function in a large population-based cohort. Women and younger age were factors associated with higher peak oxygen saturation after ischemia, which implies that age and sex are important aspects to consider in studies of microvascular function. This study is the first step toward using microcirculatory assessment as a tool to improve diagnosis, prognosis, and treatment in disease-specific populations.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.,Perimed AB, Järfälla, Stockholm, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Jonasson H, Fredriksson I, Larsson M, Strömberg T. Validation of speed-resolved laser Doppler perfusion in a multimodal optical system using a blood-flow phantom. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-8. [PMID: 31512441 PMCID: PMC6997578 DOI: 10.1117/1.jbo.24.9.095002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/14/2019] [Indexed: 05/24/2023]
Abstract
The PeriFlux 6000 EPOS system combines diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) for the assessment of oxygen saturation (expressed in percentage), red blood cell (RBC) tissue fraction (expressed as volume fraction, %RBC), and perfusion (%RBC × mm / s) in the microcirculation. It also allows the possibility of separating the perfusion into three speed regions (0 to 1, 1 to 10, and >10 mm / s). We evaluate the speed-resolved perfusion components, i.e., the relative amount of perfusion within each speed region, using a blood-flow phantom. Human blood was pumped through microtubes with an inner diameter of 0.15 mm. Measured DRS and LDF spectra were compared to Monte Carlo-simulated spectra in an optimization routine, giving the best-fit parameters describing the measured spectra. The root-mean-square error for each of the three speed components (0 to 1, 1 to 10, and >10 mm / s, respectively) when describing the blood-flow speed in the microtubes was 2.9%, 8.1%, and 7.7%. The presented results show that the system can accurately discriminate blood perfusion originating from different blood-flow speeds, which may enable improved measurement of healthy and dysfunctional microcirculatory flow.
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Affiliation(s)
- Hanna Jonasson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Järfälla, Stockholm, Sweden
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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10
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Jan YK, Liao F, Cheing GL, Pu F, Ren W, Choi HM. Differences in skin blood flow oscillations between the plantar and dorsal foot in people with diabetes mellitus and peripheral neuropathy. Microvasc Res 2019; 122:45-51. [DOI: 10.1016/j.mvr.2018.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/07/2018] [Accepted: 11/07/2018] [Indexed: 12/11/2022]
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Henni S, Hersant J, Loufrani L, Duval G, Humeau-Heurtier A, Riou J, Abraham P. Painless local pressure application to test microvascular reactivity to ischemia. Microvasc Res 2018; 122:13-21. [PMID: 30399363 DOI: 10.1016/j.mvr.2018.10.013] [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: 06/29/2018] [Revised: 10/26/2018] [Accepted: 10/29/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Forearm cutaneous blood flux (CBF) measurement with post-occlusive reactive hyperemia (PORH) is uncomfortable and may not be devoid of risks. We aimed to investigate post-compression reactive hyperemia (PCRH) with a custom-made indenter that was designed to be easily used routinely by inexperienced observers. METHODS Medical students evaluated PCRH with 1- to 4-min pressure applications of 16 to 34 kPa and PORH with 3-min forearm cuff occlusion using laser speckle contrast imaging in 15 healthy volunteers. Participants were asked to quantify their discomfort with a visual analogue scale (VAS) of 10 cm. Total ischemia (ISCH) was quantified by the product of CBF during ischemia and ischemia duration (min). We subtracted the CBF changes in the skin from a reference ipsilateral (PCRH) or contralateral (PORH) non-stimulated area. RESULTS The average VAS was 1.0 for PCRH vs. 6.0 for PORH (p < 0.001). A strong linear relationship between ISCH and peak PCRH (r2 = 0.915, p < 0.001) was noted. Peak PORH values (63.9 laser perfusion units (LPU)) were significantly lower than all values of the 3-min PCRH (72.6 LPU), including the one obtained with 16 kPa. CONCLUSION Inexperienced observers could test microvascular reactivity with PCRH without inducing the discomfort that is typically experienced with PORH. Further, PCRH elicits a higher peak response to ischemia compared with PORH. This extremely simple method could influence a broad spectrum of routine cutaneous microcirculation investigations, especially when a painful approach is particularly inadequate or if the patient is fragile. CLINICAL TRIAL REGISTRATION NCT02861924.
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Affiliation(s)
- Samir Henni
- Vascular Medicine, University Hospital of Angers, France; MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Jeanne Hersant
- Vascular Medicine, University Hospital of Angers, France; MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Laurent Loufrani
- MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Guillaume Duval
- Department of Gerontology, University Hospital of Angers, France
| | - Anne Humeau-Heurtier
- Université Angers, LARIS - Laboratoire Angevin de Recherche en Ingénierie des Systèmes, Angers, France
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- Vascular Medicine, University Hospital of Angers, France
| | - Jeremie Riou
- UMR Inserm 1066 - CNRS 6021, Faculté de Médecine, Angers, France
| | - Pierre Abraham
- MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France; Sports Medicine, University Hospital of Angers, France.
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Berezhnoi A, Schwarz M, Buehler A, Ovsepian SV, Aguirre J, Ntziachristos V. Assessing hyperthermia-induced vasodilation in human skin in vivo using optoacoustic mesoscopy. JOURNAL OF BIOPHOTONICS 2018; 11:e201700359. [PMID: 29573174 DOI: 10.1002/jbio.201700359] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/14/2018] [Accepted: 03/18/2018] [Indexed: 06/08/2023]
Abstract
The aim of this study was to explore the unique imaging abilities of optoacoustic mesoscopy to visualize skin structures and microvasculature with the view of establishing a robust approach for monitoring heat-induced hyperemia in human skin in vivo. Using raster-scan optoacoustic mesoscopy (RSOM), we investigated whether optoacoustic (photoacoustic) mesoscopy can identify changes in skin response to local heating at microvasculature resolution in a cross-sectional fashion through skin in the human forearm. We visualized the heat-induced hyperemia for the first time with single-vessel resolution throughout the whole skin depth. We quantified changes in total blood volume in the skin and their correlation with local heating. In response to local heating, total blood volume increased 1.83- and 1.76-fold, respectively, in the volar and dorsal aspects of forearm skin. We demonstrate RSOM imaging of the dilation of individual vessels in the skin microvasculature, consistent with hyperemic response to heating at the skin surface. Our results demonstrate great potential of RSOM for elucidating the morphology, functional state and reactivity of dermal microvasculature, with implications for diagnostics and disease monitoring. Image: Cross-sectional view of skin microvasculature dilated in response to hyperthermia.
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Affiliation(s)
- Andrei Berezhnoi
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Mathias Schwarz
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- iThera Medical GmbH, Munich, Germany
| | - Andreas Buehler
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Saak V Ovsepian
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Juan Aguirre
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
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Kulikov D, Glazkov A, Dreval A, Kovaleva Y, Rogatkin D, Kulikov A, Molochkov A. Approaches to improve the predictive value of laser Doppler flowmetry in detection of microcirculation disorders in diabetes mellitus. Clin Hemorheol Microcirc 2018; 70:173-179. [DOI: 10.3233/ch-170294] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Dmitry Kulikov
- Moscow Regional Research and Clinical Institute, Moscow, Russia
| | - Alexey Glazkov
- Moscow Regional Research and Clinical Institute, Moscow, Russia
| | | | - Yulia Kovaleva
- Moscow Regional Research and Clinical Institute, Moscow, Russia
| | - Dmitry Rogatkin
- Moscow Regional Research and Clinical Institute, Moscow, Russia
| | - Alexander Kulikov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Anton Molochkov
- Moscow Regional Research and Clinical Institute, Moscow, Russia
- Peoples’ Friendship University of Russia, Moscow, Russia
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14
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Kulikov DA, Glazkov AA, Kovaleva YA, Balashova NV, Kulikov AV. Prospects of Laser Doppler flowmetry application in assessment of skin microcirculation in diabetes. DIABETES MELLITUS 2017. [DOI: 10.14341/dm8014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This review includes results of scientific and clinical use of laser Doppler flowmetry (LDF) in patients with diabetes mellitus. LDF is a non-invasive method for the quantitative evaluation of microcirculation, which can assess microcirculatory rhythms and conduct functional tests with various impacts, allowing the exploration of regulatory mechanisms of microcirculation.
LDF reveals specific diabetes changes in the regulatory function of microcirculation. Microcirculation disturbances, which are traditionally associated with the pathogenesis of complications, also occur in patients with early disorders of carbohydrate metabolism and may precede the manifestation of diabetes. However, this method is still not applied in clinical practice. In this review, we analysed factors limiting the implementation of LDF in practical medicine and suggest ways to improve its clinical significance.
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15
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Bergstrand S, Morales MA, Coppini G, Larsson M, Strömberg T. The relationship between forearm skin speed-resolved perfusion and oxygen saturation, and finger arterial pulsation amplitudes, as indirect measures of endothelial function. Microcirculation 2017; 25. [PMID: 29044805 DOI: 10.1111/micc.12422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 10/11/2017] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Endothelial function is important for regulating peripheral blood flow to meet varying metabolic demands and can be measured indirectly during vascular provocations. In this study, we compared the PAT finger response (EndoPAT) after a 5-minutes arterial occlusion to that from forearm skin comprehensive microcirculation analysis (EPOS). METHODS Measurements in 16 subjects with varying cardiovascular risk factors were carried out concurrently with both methods during arterial occlusion, while forearm skin was also evaluated during local heating. RESULTS Peak values for EPOS skin Perfconv and speed-resolved total perfusion after the release of the occlusion were significantly correlated to the EndoPAT RHI (ρ = .68, P = .007 and ρ = .60, P = .025, respectively), mainly due to high-speed blood flow. During local heating, EPOS skin oxygen saturation, SO2, was significantly correlated to RHI (ρ = .62, P = .043). This indicates that SO2 may have diagnostic value regarding endothelial function. CONCLUSIONS We have demonstrated for the first time a significant relationship between forearm skin microcirculatory perfusion and oxygen saturation and finger PAT. Both local heating and reactive hyperemia are useful skin provocations. Further studies are needed to understand the precise regulation mechanisms of blood flow and oxygenation during these tests.
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Affiliation(s)
- Sara Bergstrand
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | | | | | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Dremin VV, Zherebtsov EA, Sidorov VV, Krupatkin AI, Makovik IN, Zherebtsova AI, Zharkikh EV, Potapova EV, Dunaev AV, Doronin AA, Bykov AV, Rafailov IE, Litvinova KS, Sokolovski SG, Rafailov EU. Multimodal optical measurement for study of lower limb tissue viability in patients with diabetes mellitus. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 28825287 DOI: 10.1117/1.jbo.22.8.085003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/21/2017] [Indexed: 05/22/2023]
Abstract
According to the International Diabetes Federation, the challenge of early stage diagnosis and treatment effectiveness monitoring in diabetes is currently one of the highest priorities in modern healthcare. The potential of combined measurements of skin fluorescence and blood perfusion by the laser Doppler flowmetry method in diagnostics of low limb diabetes complications was evaluated. Using Monte Carlo probabilistic modeling, the diagnostic volume and depth of the diagnosis were evaluated. The experimental study involved 76 patients with type 2 diabetes mellitus. These patients were divided into two groups depending on the degree of complications. The control group consisted of 48 healthy volunteers. The local thermal stimulation was selected as a stimulus on the blood microcirculation system. The experimental studies have shown that diabetic patients have elevated values of normalized fluorescence amplitudes, as well as a lower perfusion response to local heating. In the group of people with diabetes with trophic ulcers, these parameters also significantly differ from the control and diabetes only groups. Thus, the intensity of skin fluorescence and level of tissue blood perfusion can act as markers for various degrees of complications from the beginning of diabetes to the formation of trophic ulcers.
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Affiliation(s)
- Viktor V Dremin
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Evgeny A Zherebtsov
- Aston University, Aston Institute of Photonic Technologies, Optoelectronics and Biomedical Photonics, United Kingdom
| | | | | | - Irina N Makovik
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Angelina I Zherebtsova
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Elena V Zharkikh
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Elena V Potapova
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Andrey V Dunaev
- Orel State University named after I.S. Turgenev, Biomedical Photonics Laboratory of University Clini, Russia
| | - Alexander A Doronin
- Yale University, Department of Computer Science, Computer Graphics Group, New Haven, Connecticut, United States
| | - Alexander V Bykov
- University of Oulu, Optoelectronics and Measurement Techniques Laboratory, Faculty of Information Te, Finland
| | - Ilya E Rafailov
- Aston University, School of Engineering and Applied Sciences, Aston Institute of Photonic Technologi, United Kingdom
| | | | - Sergei G Sokolovski
- Aston University, Aston Institute of Photonic Technologies, Optoelectronics and Biomedical Photonics, United Kingdom
| | - Edik U Rafailov
- Aston University, Aston Institute of Photonic Technologies, Optoelectronics and Biomedical Photonics, United Kingdom
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17
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Jonasson H, Bergstrand S, Nystrom FH, Länne T, Östgren CJ, Bjarnegård N, Fredriksson I, Larsson M, Strömberg T. Skin microvascular endothelial dysfunction is associated with type 2 diabetes independently of microalbuminuria and arterial stiffness. Diab Vasc Dis Res 2017; 14:363-371. [PMID: 28482676 DOI: 10.1177/1479164117707706] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Skin and kidney microvascular functions may be affected independently in diabetes mellitus. We investigated skin microcirculatory function in 79 subjects with diabetes type 2, where 41 had microalbuminuria and 38 not, and in 41 age-matched controls. The oxygen saturation, fraction of red blood cells and speed-resolved microcirculatory perfusion (% red blood cells × mm/s) divided into three speed regions: 0-1, 1-10 and above 10 mm/s, were assessed during baseline and after local heating of the foot with a new device integrating diffuse reflectance spectroscopy and laser Doppler flowmetry. Arterial stiffness was assessed as carotid-femoral pulse wave velocity. Subjects with diabetes and microalbuminuria had significantly higher carotid-femoral pulse wave velocity compared to subjects without microalbuminuria and to controls. The perfusion for speeds 0-1 mm/s and red blood cell tissue fraction were reduced in subjects with diabetes at baseline and after heating, independent of microalbuminuria. These parameters were correlated to HbA1c. In conclusion, the reduced nutritive perfusion and red blood cell tissue fraction in type 2 diabetes were related to long-term glucose control but independent of microvascular changes in the kidneys and large-vessel stiffness. This may be due to different pathogenic pathways in the development of nephropathy, large-vessel stiffness and cutaneous microvascular impairment.
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Affiliation(s)
- Hanna Jonasson
- 1 Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- 1 Department of Biomedical Engineering, Linköping University, Linköping, Sweden
- 2 Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Fredrik H Nystrom
- 2 Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Toste Länne
- 2 Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- 2 Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Niclas Bjarnegård
- 2 Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- 1 Department of Biomedical Engineering, Linköping University, Linköping, Sweden
- 3 Perimed AB, Stockholm, Sweden
| | - Marcus Larsson
- 1 Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- 1 Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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18
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Mizeva IA. Phase coherence of 0.1 Hz microvascular tone oscillations during the local heating. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1757-899x/208/1/012027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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19
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Strömberg T, Sjöberg F, Bergstrand S. Temporal and spatiotemporal variability in comprehensive forearm skin microcirculation assessment during occlusion protocols. Microvasc Res 2017; 113:50-55. [PMID: 28455225 DOI: 10.1016/j.mvr.2017.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
Forearm skin hyperemia during release after brachial occlusion has been proposed for evaluating peripheral arterial disease and endothelial dysfunction. We used a novel fiberoptic system integrating Laser Doppler Flowmetry and Diffuse Reflectance Spectroscopy for a comprehensive pointwise model based microcirculation characterization. The aim was to evaluate and compare the temporal and the spatiotemporal variabilities in forearm skin microcirculation parameters (speed resolved perfusion; low speed <1mm/s, PerfSR, <1; mid-speed 1-10mm/s, high speed >10mm/s, and total perfusion (PerfSR, tot); the concentration and oxygenation of red blood cells, CRBC and SO2). Ten healthy subjects underwent arterial and venous forearm occlusions (AO, VO), repeated within one week. The repeatability was calculated as the coefficient of variation (CV) and the agreement as the intra-class correlation coefficient (ICC). The temporal CVs for conventional perfusion, Perfconv, PerfSR, tot, CRBC and SO2 were 14%, 12%, 9% and 9%, respectively, while the ICC were >0.75 (excellent). The perfusion measures generally had a higher spatiotemporal than temporal variability, which was not the case for SO2 and CRBC. The corresponding spatiotemporal CVs were 33%, 32%, 18% and 15%, respectively. During VO, CRBC had a CV<35% and ICC>0.40 (fair-good), and after release this was the case for CRBC (AO and VO), SO2 (VO) and PerfSR, <1 (VO). In conclusion, the skin microcirculation parameters showed excellent temporal repeatability, while the spatiotemporal repeatability especially for perfusion was poorer. The parameters with acceptable repeatability and fair-good agreement were: CRBC during and after release of VO, the PerfSR, <1 after release of VO, the SO2 and the CRBC after release of AO. However, the value of these parameters in discriminating endothelial function remains to be studied.
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Affiliation(s)
- Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
| | - Folke Sjöberg
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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20
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Jonasson H, Fredriksson I, Pettersson A, Larsson M, Strömberg T. Oxygen saturation, red blood cell tissue fraction and speed resolved perfusion - A new optical method for microcirculatory assessment. Microvasc Res 2015; 102:70-7. [PMID: 26279347 DOI: 10.1016/j.mvr.2015.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 07/31/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022]
Abstract
We have developed a new fiber-optic system that combines diffuse reflectance spectroscopy (DRS) and laser Doppler Flowmetry (LDF) for a multi-modal assessment of the microcirculation. Quantitative data is achieved with an inverse Monte Carlo algorithm based on an individually adaptive skin model. The output parameters are calculated from the model and given in absolute units: hemoglobin oxygen saturation (%), red blood cell (RBC) tissue fraction (%), and the speed resolved RBC perfusion separated into three speed regions; 0-1mm/s, 1-10mm/s and above 10mm/s (% mm/s). The aim was to explore microcirculatory parameters using the new optical method, integrating DRS and LDF in a joint skin model, during local heating of the dorsal foot and venous and arterial occlusion of the forearm in 23 healthy subjects (age 20-28years). There were differences in the three speed regions in regard to blood flow changes due to local heating, where perfusion for high speeds increased the most. There was also a high correlation between changes in oxygenation and changes in perfusion for higher speeds. Oxygen saturation at baseline was 44% on foot, increasing to 83% at plateau after heating. The larger increase in perfusion for higher speeds than for lower speeds together with the oxygenation increase during thermal provocation, shows a local thermoregulatory blood flow in presumably arteriolar dermal vessels. In conclusion, there are improved possibilities to assess microcirculation using integrated DRS and LDF in a joint skin model by enabling both oxygenation and speed resolved blood flow assessment simultaneously and in the same skin site. Output parameters in absolute units may also yield new insights about the microcirculatory system.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden.
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden; Perimed AB, Datavägen 9A, 175 43 Järfälla, Stockholm, Sweden
| | | | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden
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21
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Johnson JM, Minson CT, Kellogg DL. Cutaneous vasodilator and vasoconstrictor mechanisms in temperature regulation. Compr Physiol 2014; 4:33-89. [PMID: 24692134 DOI: 10.1002/cphy.c130015] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this review, we focus on significant developments in our understanding of the mechanisms that control the cutaneous vasculature in humans, with emphasis on the literature of the last half-century. To provide a background for subsequent sections, we review methods of measurement and techniques of importance in elucidating control mechanisms for studying skin blood flow. In addition, the anatomy of the skin relevant to its thermoregulatory function is outlined. The mechanisms by which sympathetic nerves mediate cutaneous active vasodilation during whole body heating and cutaneous vasoconstriction during whole body cooling are reviewed, including discussions of mechanisms involving cotransmission, NO, and other effectors. Current concepts for the mechanisms that effect local cutaneous vascular responses to local skin warming and cooling are examined, including the roles of temperature sensitive afferent neurons as well as NO and other mediators. Factors that can modulate control mechanisms of the cutaneous vasculature, such as gender, aging, and clinical conditions, are discussed, as are nonthermoregulatory reflex modifiers of thermoregulatory cutaneous vascular responses.
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Affiliation(s)
- John M Johnson
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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22
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Strömberg T, Karlsson H, Fredriksson I, Nyström FH, Larsson M. Microcirculation assessment using an individualized model for diffuse reflectance spectroscopy and conventional laser Doppler flowmetry. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:057002. [PMID: 24788373 DOI: 10.1117/1.jbo.19.5.057002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/07/2014] [Indexed: 06/03/2023]
Abstract
Microvascular assessment would benefit from co-registration of blood flow and hemoglobin oxygenation dynamics during stimulus response tests. We used a fiber-optic probe for simultaneous recording of white light diffuse reflectance (DRS; 475-850 nm) and laser Doppler flowmetry (LDF; 780 nm) spectra at two source-detector distances (0.4 and 1.2 mm). An inverse Monte Carlo algorithm, based on a multiparameter three-layer adaptive skin model, was used for analyzing DRS data. LDF spectra were conventionally processed for perfusion. The system was evaluated on volar forearm recordings of 33 healthy subjects during a 5-min systolic occlusion protocol. The calibration scheme and the optimal adaptive skin model fitted DRS spectra at both distances within 10%. During occlusion, perfusion decreased within 5 s while oxygenation decreased slowly (mean time constant 61 s; dissociation of oxygen from hemoglobin). After occlusion release, perfusion and oxygenation increased within 3 s (inflow of oxygenized blood). The increased perfusion was due to increased blood tissue fraction and speed. The supranormal hemoglobin oxygenation indicates a blood flow in excess of metabolic demands. In conclusion, by integrating DRS and LDF in a fiber-optic probe, a powerful tool for assessment of blood flow and oxygenation in the same microvascular bed has been presented.
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Affiliation(s)
- Tomas Strömberg
- Linköping University, University Hospital, Department of Biomedical Engineering, Linköping 581 85, Sweden
| | - Hanna Karlsson
- Linköping University, University Hospital, Department of Biomedical Engineering, Linköping 581 85, Sweden
| | - Ingemar Fredriksson
- Linköping University, University Hospital, Department of Biomedical Engineering, Linköping 581 85, SwedenbPerimed AB, Datavägen 9A, Järfälla 175 43, Sweden
| | - Fredrik H Nyström
- Linköping University, University Hospital, Department of Medical and Health Sciences, Linköping 581 85, Sweden
| | - Marcus Larsson
- Linköping University, University Hospital, Department of Biomedical Engineering, Linköping 581 85, Sweden
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Abstract
In this review of thermoregulatory function in health and disease, we review the basic mechanisms controlling skin blood flow of the hairy and glabrous skin and illustrate the major differences in blood flow to glabrous skin, which is, in essence, sympathetically mediated, while hairy skin is dependent upon neuropeptidergic signals, nitric oxide, and prostaglandin, among others. Laser Doppler methods of quantification of blood flow--in response to iontophoresis of acetylcholine or heat--and nociceptor-mediated blood flow have relatively uniformly demonstrated an impaired capacity to increase blood flow to the skin in diabetes and in its forerunners, prediabetes and the metabolic syndrome. This reduced capacity is likely to be a significant contributor to the development of foot ulcerations and amputations in diabetes, and means of increasing blood flow are clearly needed. Understanding the pathogenic mechanisms is likely to provide a means of identifying a valuable therapeutic target. Thermoregulatory control of sweating is intimately linked to the autonomic nervous system via sympathetic C fibers, and sweat glands are richly endowed with a neuropeptidergic innervation. Sweating disturbances are prevalent in diabetes and its precursors, and quantification of sweating may be useful as an index of diagnosis of somatic and, probably, autonomic dysfunction. Moreover, quantifying this disturbance in sweating by various methods may be useful in identifying the risk of progression from prediabetes to diabetes, as well as responses to therapeutic intervention. We now have the technological power to take advantage of this physiological arrangement to better understand, monitor, and treat disorders of small nerve fibers and the somatic and autonomic nervous system (ANS). Newer methods of sudomotor function testing are rapid, noninvasive, not technically demanding, and accessible to the outpatient clinic. Whether the potential applications are screening for diabetes, following poorly controlled diabetes subjects during alteration of their treatment regimen, or simply monitoring somatic and autonomic function throughout the course of treatment, sudorimetry can be an invaluable tool for today's clinicians.
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Affiliation(s)
- Aaron I Vinik
- Strelitz Diabetes Center for Endocrine and Metabolic Disorders, Eastern Virginia Medical School, Norfolk, VA 23510, USA.
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Yardley JE, Stapleton JM, Sigal RJ, Kenny GP. Do heat events pose a greater health risk for individuals with type 2 diabetes? Diabetes Technol Ther 2013; 15:520-9. [PMID: 23530578 DOI: 10.1089/dia.2012.0324] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Chronic medical conditions such as type 2 diabetes may alter the body's normal response to heat. Evidence suggests that the local heat loss response of skin blood flow (SkBF) is affected by diabetes-related impairments in both endothelium-dependent and non-endothelium-dependent mechanisms, resulting in lower elevations in SkBF in response to a heat or pharmacological stimulus. Thermoregulatory sweating may also be diminished by type 2 diabetes, impairing the body's ability to transfer heat from its core to the environment. Diabetes-associated co-morbidities and the medications (particularly those affecting fluid balance) required to treat these conditions may exacerbate the risk of heat-related illness by decreasing SkBF and sweating further. Unfortunately, the majority of studies measure local heat loss responses in the hands and feet and lack measures of core temperature. Therefore, the impact of these impairments on whole-body heat loss remains unknown. This review addresses heat-related vulnerability in individuals with type 2 diabetes by examining the literature related to heat loss responses in this population. Type 2 diabetes, its associated co-morbidities, and the medications required in their treatment may cause dehydration, lower SkBF, and reduced sweating, which could consequently impair thermoregulation. This effect is most evident in individuals with poor blood glucose control. Although type 2 diabetes can be associated with impairments in SkBF and sweating, more physically active individuals requiring fewer medications and having good blood glucose control may be able to tolerate heat as well as those of similar age and body composition.
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Affiliation(s)
- Jane E Yardley
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
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25
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Spångéus A, Wijkman M, Lindström T, Engvall JE, Östgren CJ, Nystrom FH, Länne T. Toe brachial index in middle aged patients with diabetes mellitus type 2: not just a peripheral issue. Diabetes Res Clin Pract 2013; 100:195-202. [PMID: 23522916 DOI: 10.1016/j.diabres.2013.03.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/19/2013] [Accepted: 03/01/2013] [Indexed: 11/18/2022]
Abstract
AIM To explore risk factors for peripheral arterial disease (PAD) as well as the association between toe blood pressure and subclinical and clinical central vascular disease in patients with type 2 diabetes. METHOD Toe brachial index (TBI) was cross-sectionally analyzed in 742 middle-aged (54-66 years) patients with type 2 diabetes as well as non-diabetic controls and related to other vascular measures (e.g. carotid intima media thickness (IMT), presence of carotid plaque, central arterial stiffness and left ventricular mass index) and previous cardiovascular events. RESULTS A TBI ≤ 0.7 was seen in 22% of the patients but only one patient had severe TBI reduction (TBI ≤ 0.3). The corresponding figures in the controls were 13% and 0%, respectively. Mean TBI was significantly lower in patients with type 2 diabetes than in controls (0.81 ± 0.14 vs. 0.87 ± 0.15, p<0.001). In patients with diabetes, a lower TBI was associated with increased central arterial stiffness (p<0.001), IMT (p<0.001) and carotid plaque (p<0.001) as well as with decreasing glomerular filtration rate (p<0.001). Lower TBI was found in patients with previous macrovascular ischemic events. Furthermore, TBI was negatively correlated with age (p<0.001), diabetes duration (p<0.001) and HbA1c (p=0.01). CONCLUSION PAD, assessed with TBI, is common in a Swedish middle-aged diabetes type 2 cohort, affecting about one-fifth. As ankle pressure may be confounded by falsely high values in patients with diabetes due to media calcification we conclude that information about TBI may improve the risk evaluation regarding arteriosclerotic disease in both small and large vessels in type 2 diabetes.
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Affiliation(s)
- Anna Spångéus
- Department of Endocrinology, County council of Östergötland, Linköping, Sweden.
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26
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The influence of autonomic dysfunction associated with aging and type 2 diabetes on daily life activities. EXPERIMENTAL DIABETES RESEARCH 2012; 2012:657103. [PMID: 22566994 PMCID: PMC3332074 DOI: 10.1155/2012/657103] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 01/28/2012] [Accepted: 01/30/2012] [Indexed: 11/17/2022]
Abstract
Type 2 diabetes (T2D) and ageing have well documented effects on every organ in the body. In T2D the autonomic nervous system is impaired due to damage to neurons, sensory receptors, synapses and the blood vessels. This paper will concentrate on how autonomic impairment alters normal daily activities. Impairments include the response of the blood vessels to heat, sweating, heat transfer, whole body heating, orthostatic intolerance, balance, and gait. Because diabetes is more prevalent in older individuals, the effects of ageing will be examined. Beginning with endothelial dysfunction, blood vessels have impairment in their ability to vasodilate. With this and synaptic damage, the autonomic nervous system cannot compensate for effectors such as pressure on and heating of the skin. This and reduced ability of the heart to respond to stress, reduces autonomic orthostatic compensation. Diminished sweating causes the skin and core temperature to be high during whole body heating. Impaired orthostatic tolerance, impaired vision and vestibular sensing, causes poor balance and impaired gait. Overall, people with T2D must be made aware and counseled relative to the potential consequence of these impairments.
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Franck N, Länne T, Astrand O, Engvall J, Lindström T, Ostgren CJ, Nystrom FH. Cardiovascular risk factors related to the PPARγ Pro12Ala polymorphism in patients with type 2 diabetes are gender dependent. Blood Press 2011; 21:122-7. [PMID: 22017455 DOI: 10.3109/08037051.2011.623349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The interaction of the PPARγ Pro12Ala polymorphism with diabetes and cardiovascular risk is controversial. We studied 173 women and 309 men in the observational CARDIPP trial in which determination of left ventricular mass, carotid intima-media thickness (IMT) and pulse wave velocity (PWV) were performed. Blood pressures were measured with 24-h ambulatory technique (ABP). Heterozygotes and homozygotes of Ala were defined as Ala in the analyses. Men with Ala-isoform displayed higher waist circumference (Ala: 107 ± 14 cm, Pro: 104 ± 11 cm, p = 0.045) and body weight (Ala: 95.7 ± 18 kg, Pro: 91.6 ± 14 kg, p = 0.042) than Pro-homozygotes. Men with ALA-isoform also showed higher systolic ABP levels (Ala: 134 ± 15 mmHg, Pro: 130 ± 14 mmHg, p = 0.004), whereas left ventricular mass index, IMT and PWV were unrelated to isoforms. In contrast, carotid-radial PWV was lower in women with the Ala-isoform (Ala: 7.9 ± 1.0 m/s, Pro: 8.5 ± 1.3 m/s, p = 0.01) and levels of apolipoprotein A1 were higher (Ala: 1.43 ± 0.27 g/l, Pro: 1.35 ± 0.17 g/l, p = 0.03). In conclusion, we found that men with type 2 diabetes having the Ala-isoform of PPARγ Pro12Ala had an unfavorable cardiovascular risk profile, whereas women with this isoform had lower carotid-radial PWV and higher apolipoprotein A1 levels suggesting a beneficial prognosis. These differences according to gender of the ALA isoform in type 2 diabetes deserve further attention.
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Affiliation(s)
- Niclas Franck
- Department of Medical and Health Sciences, Division of Cardiovascular Medicine, Linköping University, Linköping, Sweden
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Mani R, Yarde S, Edmonds M. Prevalence of Deep Venous Incompetence and Microvascular Abnormalities in Patients With Diabetes Mellitus. INT J LOW EXTR WOUND 2011; 10:75-9. [DOI: 10.1177/1534734611409372] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The involvement of venous disease in the diabetic neuropathic foot is widely accepted. This article reports the result of prevalence of venous incompetence, impaired calf vein hemodynamics, and loss of microvascular control in the skin over the dorsum of the foot in an effort to document whether increased retrograde pressure caused by venous incompetence or loss of sympathetic regulation of the microcirculation is present in the diabetic patient who is at risk of foot disease. It was found that 64% and 70.7% of diabetic patients had deep venous incompetence in their right and left legs, respectively, which was statistically significantly greater than what was found in a previous report on the general population ( P < .05); 42.7% and 49.3% of patients had a reduced venous refilling time in the right and left legs, respectively, and 30.7% and 33.3% of patients had loss of the arteriovenous response in the right and left legs. Some previous reports have suggested evidence of hemodynamic and morphological changes in patients with diabetic foot disease. The outstanding contribution of this report is the finding of venous incompetence in patients with diabetes but not foot disease. Because some 15% of the population with diabetes develop foot complications, the reported observations offer hope of alleviating symptoms if not preventing ulcers.
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Affiliation(s)
- Raj Mani
- Southampton University Hospital NHS Trust, Southampton, UK,
| | - Starla Yarde
- The University of Southampton School of Medicine, Southampton, UK
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Coelho SCDS, Guimarães MM, Fernandes TJ. Endotelium in Turner syndrome with capillaroscopy. J Vasc Bras 2011. [DOI: 10.1590/s1677-54492011000200005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE: The aim of this study was to assess the endothelium function in patients with Turner syndrome using videocapillaroscopy and to compare the results with healthy control. METHODS: Subjects and controls were studied in a temperature-controlled room, 20 days after no nailfold manipulations. The capillaries were visualized by a microscope connected to a television and a computer. The test of post-occlusive reactive hyperemia was performed using a sphygmomanometer attached to the fourth left finger, 20mmHg above maximum arterial pressure during 1 minute, and the following patterns were studied: area of transverse segment, maximal post-ischemia area and time to reach maximal post-ischemia area. RESULTS: The value of measure of transverse segment projected area , the maximal postischemia area of hand nailfold capillary loops using computerized videophotometry and the time to reach maximal post ischemia area were studied in 40 patients with Turner syndrome and 26 healthy women controls of comparable age (20±7.5 versus 18±8.1 years old; p=0.57). There were differences between transverse segment area (706.8±139.1 versus 548.8±117.2; p=0.001). Maximal post-ischemia area (891.3±226.1 versus 643.5±134.3; p=0.001) and the time to reach it (10.8±4.3 versus 5.5±2.5; p=0.001) were different between patients and controls. CONCLUSIONS: Changes of capillary response to ischemia could be observed in patients with Turner syndrome using videocapillaroscopy when they were compared to a healthy control group.
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Keymel S, Heinen Y, Balzer J, Rassaf T, Kelm M, Lauer T, Heiss C. Characterization of macro-and microvascular function and structure in patients with type 2 diabetes mellitus. AMERICAN JOURNAL OF CARDIOVASCULAR DISEASE 2011; 1:68-75. [PMID: 22254187 PMCID: PMC3253507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Accepted: 05/13/2011] [Indexed: 05/31/2023]
Abstract
OBJECTIVE Diabetes mellitus (DM) leads to accelerated progression of arteriosclerosis with an increased risk of coronary events in comparison to non-diabetic patients with coronary artery disease (CAD). The precise and early detection of DM-induced vascular alterations is crucial to identify patients with high risk for cardiovascular complications. Thus, we aimed at simultaneously characterizing functional, physicomechanical, and structural vascular alterations in diabetic patients using a non-invasive approach. RESEARCH DESIGN AND METHODS In CAD patients with and without type 2 diabetes mellitus (n=50), we non-invasively measured flow-mediated dilation (FMD) of the brachial artery as a marker for endothelial function, fractional diameter changes (FDC) as a marker for physicomechanical properties, intima-media thickness (IMT) as a marker for structural properties, and forearm blood flow (FBF) as a marker for microvascular function. RESULTS DM was associated with reduced FMD (2.5±0.2 vs 4.8±0.4%; p≤0.001) indicating impaired macrovascular endothelial function. In parallel, reduced FDC (0.024±0.002 vs 0.034±0.004; p≤0.05) and increased IMT (0.38±0.01 vs 0.31±0.01mm; p≤0.001) indicated increased stiffness and enhanced structural alterations. Furthermore, reduced forearm blood flow during reactive hyperemia (10.7±1.0 vs. 15.3±1.4mL/min*100mL; p≤0.05) was found indicating microvascular dysfunction. Plasma glucose and HbA(1c) correlated with FMD (glucose: r=-0.32; HbA(1c): r=-0.45), IMT (glucose: r=0.54; HbA(1c): r=0.48) and FBF (glucose: r=-0.30) suggesting diabetes-specific effects on vascular properties. CONCLUSION In patients with CAD, DM leads to functional and structural vascular alterations of the peripheral vasculature which are determined by the control of the disease underlining the relevance of a strict control of the DM to prevent accelerated atherosclerosis.
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Affiliation(s)
- Stefanie Keymel
- University Duesseldorf, Medical Faculty, Department of Cardiology, Pulmonology, and Vascular Diseases, University Hospital Duesseldorf Germany
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Humeau A, Buard B, Mahé G, Rousseau D, Chapeau-Blondeau F, Abraham P. Multiscale entropy of laser Doppler flowmetry signals in healthy human subjects. Med Phys 2011; 37:6142-6. [PMID: 21302770 DOI: 10.1118/1.3512796] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The cardiovascular system (CVS) regulation can be studied from a central viewpoint, through heart rate variability (HRV) data, and from a peripheral viewpoint, through laser Doppler flowmetry (LDF) signals. Both the central and peripheral CVSs are regulated by several interacting mechanisms, each having its own temporal scale. The central CVS has been the subject of many multiscale studies. By contrast, these studies at the level of the peripheral CVS are very recent. Among the multiscale studies performed on the central CVS data, multiscale entropy has been proven to give interesting physiological information for diagnostic purposes. However, no multiscale entropy analysis has been performed on LDF signals. The authors' goal is therefore to propose a first multiscale entropy study of LDF data recorded in healthy subjects. METHODS The LDF signals recorded in the forearm of seven healthy subjects are processed. Their period sampling is T=50 ms, and coarse-graining scales from T to 23T are studied. Also, for validation, the algorithm is first tested on synthetic signals of known theoretical multiscale entropy. RESULTS The results reveal nonmonotonic evolution of the multiscale entropy of LDF signals, with a maximum at small scales around 7T and a minimum at longer scales around 18T, singling out in this way two distinctive scales where the LDF signals undergo specific changes from high to low complexity. This also marks a strong contrast with the HRV signals that usually display a monotonic increase in the evolution of the multiscale entropy. CONCLUSIONS Multiscale entropy of LDF signals in healthy subjects shows variation with scales. Moreover, as the variation pattern observed appears similar for all the tested signals, multiscale entropy could potentially be a useful stationary signature for LDF signals, which otherwise are probe-position and subject dependent. Further work could now be conducted to evaluate possible diagnostic purposes of the multiscale entropy of LDF signals.
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Affiliation(s)
- Anne Humeau
- Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, 62 Avenue Notre Dame du Lac, 49000 Angers, France.
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Mahé G, Rousseau P, Durand S, Bricq S, Leftheriotis G, Abraham P. Laser speckle contrast imaging accurately measures blood flow over moving skin surfaces. Microvasc Res 2010; 81:183-8. [PMID: 21156183 DOI: 10.1016/j.mvr.2010.11.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 11/29/2010] [Accepted: 11/30/2010] [Indexed: 12/01/2022]
Abstract
Cutaneous blood flow (CBF) can be assessed non-invasively with lasers. Unfortunately, movement artefacts in the laser skin signal (LS(sk)) might sometimes compromise the interpretation of the data. To date, no method is available to remove movement artefacts point-by-point. Using a laser speckle contrast imager, we simultaneously recorded LS(sk) and the signal backscattered from an adjacent opaque surface (LS(os)). The completion of a first protocol allowed a definition of a simple equation to calculate the CBF from movement artefact-affected traces of LS(sk) and LS(os). We then recorded LS(sk) and LS(os) before, during and for 5 min after the tourniquet ischemia, both when subjects (n=8) were immobile or submitted to external passive movements of random intensity throughout the test. The typical post-occlusive reactive hyperemia trace was not identifiable within the LS(sk) recordings, with LS(sk) being 2 to 3 times higher during movements than in the immobile situation. After the calculation of CBF, traces in the immobile versus movement conditions were comparable, with the "r" cross-correlation coefficient being 0.930+/-0.010. Our method might facilitate future investigations in microvascular physiology and pathophysiology, specifically in subjects who have frequent or continuous involuntary movements.
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Affiliation(s)
- Guillaume Mahé
- Laboratory of Vascular Investigations, University Hospital of Angers, France
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Fredriksson I, Larsson M, Strömberg T. Model-based quantitative laser Doppler flowmetry in skin. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:057002. [PMID: 21054118 DOI: 10.1117/1.3484746] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Laser Doppler flowmetry (LDF) can be used for assessing the microcirculatory perfusion. However, conventional LDF (cLDF) gives only a relative perfusion estimate for an unknown measurement volume, with no information about the blood flow speed distribution. To overcome these limitations, a model-based analysis method for quantitative LDF (qLDF) is proposed. The method uses inverse Monte Carlo technique with an adaptive three-layer skin model. By analyzing the optimal model where measured and simulated LDF spectra detected at two different source-detector separations match, the absolute microcirculatory perfusion for a specified speed region in a predefined volume is determined. qLDF displayed errors<12% when evaluated using simulations of physiologically relevant variations in the layer structure, in the optical properties of static tissue, and in blood absorption. Inhomogeneous models containing small blood vessels, hair, and sweat glands displayed errors<5%. Evaluation models containing single larger blood vessels displayed significant errors but could be dismissed by residual analysis. In vivo measurements using local heat provocation displayed a higher perfusion increase with qLDF than cLDF, due to nonlinear effects in the latter. The qLDF showed that the perfusion increase occurred due to an increased amount of red blood cells with a speed>1 mm∕s.
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Affiliation(s)
- Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, University Hospital, 581 85 Linköping, Sweden.
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