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Bergstrand S, Jonasson H, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Association between cardiovascular risk profile and impaired microvascular function in a Swedish middle-aged cohort (the SCAPIS study). Eur J Prev Cardiol 2024; 31:1152-1161. [PMID: 38333959 DOI: 10.1093/eurjpc/zwae052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 01/04/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
AIMS The aim was to investigate the relationship between microvascular function, cardiovascular risk profile, and subclinical atherosclerotic burden. METHODS AND RESULTS The study enrolled 3809 individuals, 50-65 years old, participating in the population-based observational cross-sectional Swedish CArdioPulmonary bioImage Study. Microvascular function was assessed in forearm skin using an arterial occlusion and release protocol determining peak blood oxygen saturation (OxyP). Cardiovascular risk was calculated using the updated Systematic Coronary Risk Evaluation [SCORE2; 10-year risk of fatal and non-fatal cardiovascular disease (CVD) events]. The OxyP was compared with coronary artery calcification score (CACS) and to plaques in the carotid arteries. Individuals with OxyP values in the lowest quartile (Q1; impaired microvascular function) had a mean SCORE2 of 5.8% compared with 3.8% in those with the highest values of OxyP (Q4), a relative risk increase of 53%. The risk of having a SCORE2 > 10% was five times higher for those in Q1 (odds ratio: 4.96, 95% confidence interval: 2.76-8.93) vs. Q4 when adjusting for body mass index and high-sensitivity C-reactive protein. The OxyP was lower in individuals with CACS > 0 and in those with both carotid plaques and CACS > 0, compared with individuals without subclinical atherosclerotic burdens (87.5 ± 5.6% and 86.9 ± 6.0%, vs. 88.6 ± 5.8%, P < 0.01). CONCLUSION In a population without CVD or diabetes mellitus, impaired microvascular function is associated with cardiovascular risk profiles such as higher SCORE2 risk and CACS. We suggest that OxyP may serve as a microcirculatory functional marker of subclinical atherosclerosis and CVD risk that is not detected by structural assessments.
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Affiliation(s)
- Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Building 511, Entrance 75, Room 13.1309 Campus US, 581 83 Linköping, Sweden
| | - Hanna Jonasson
- Department of Biomedical Engineering, 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, Building 511, Entrance 75, Room 13.1309 Campus US, 581 83 Linköping, Sweden
- Centre of Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Wang Q, Zhang X, Li B, Liu X, Li A, Li H, Shi X, Han J. Tumor-Derived Exosomes Promote Tumor Growth Through Modulating Microvascular Hemodynamics in a Human Ovarian Cancer Xenograft Model. Microcirculation 2024:e12876. [PMID: 39005221 DOI: 10.1111/micc.12876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 04/27/2024] [Accepted: 06/29/2024] [Indexed: 07/16/2024]
Abstract
OBJECTIVE Abnormal tumor vascular network contributes to aberrant blood perfusion and reduced oxygenation in tumors, which lead to poor efficacy of chemotherapy and radiotherapy. We aimed to explore the effects of the tumor-derived exosomes (TDEs) and C188-9 (a small molecule inhibitor of signal transducer and activator of transcription 3, STAT3) on tumor microvascular hemodynamics and determine which blood flow oscillations for various frequency intervals are responsible for these changes. METHODS Microvascular hemodynamics parameters were recorded using a PeriFlux 6000 EPOS system in tumor surface in a nude mouse subcutaneous xenograft model. Oscillations of laser Doppler flowmetry (LDF) signal were investigated by wavelet transform analysis. RESULTS TDEs facilitated tumor growth at least partially was associated with increasing blood flow in smaller vessels with lower speed and decreasing the blood flow at larger vessels with higher speed. Lower oxyhemoglobin saturation (SO2) on tumor surface was aggravated by TDEs, and C188-9 treatment significantly alleviated this decrease. Wavelet transform spectral analysis revealed that TDEs increased the amplitude of oscillations in four frequency intervals related to endothelial (NO-dependent and -independent), myogenic and neurogenic activities, and C188-9 had no effect on this increase. CONCLUSIONS TDEs facilitated tumor growth partially was associated with increasing blood flow in distributing vessels, reducing blood perfusion in larger vessels, and lowering SO2 on tumor surface. Enhanced vascular smooth muscle, endothelial and neurogenic activities occurred in tumor superficial zone.
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Affiliation(s)
- Qin Wang
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoyan Zhang
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Bingwei Li
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Xueting Liu
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Ailing Li
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Hongwei Li
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaohua Shi
- Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
| | - Jianqun Han
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- International Center of Microvascular Medicine, Chinese Academy of Medical Sciences, Beijing, China
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Elawa S, Fredriksson I, Steinvall I, Zötterman J, Farnebo S, Tesselaar E. Skin perfusion and oxygen saturation after mastectomy and radiation therapy in breast cancer patients. Breast 2024; 75:103704. [PMID: 38460441 PMCID: PMC10943105 DOI: 10.1016/j.breast.2024.103704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/11/2024] Open
Abstract
The pathophysiological mechanism behind complications associated with postmastectomy radiotherapy (PMRT) and subsequent implant-based breast reconstruction are not completely understood. The aim of this study was to examine if there is a relationship between PMRT and microvascular perfusion and saturation in the skin after mastectomy and assess if there is impaired responsiveness to a topically applied vasodilator (Methyl nicotinate - MN). Skin microvascular perfusion and oxygenation >2 years after PMRT were measured using white light diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) in the irradiated chest wall of 31 women with the contralateral breast as a control. In the non-irradiated breast, the perfusion after application of MN (median 0.84, 25th-75th centile 0.59-1.02 % RBC × mm/s) was higher compared to the irradiated chest wall (median 0.51, 25th-75th centile 0.21-0.68 % RBC × mm/s, p < 0.001). The same phenomenon was noted for saturation (median 91 %, 25th-75th centile 89-94 % compared to 89 % 25th-75th centile 77-93 %, p = 0.001). Eight of the women (26%) had a ≥10 % difference in skin oxygenation between the non-irradiated breast and the irradiated chest wall. These results indicate that late microvascular changes caused by radiotherapy of the chest wall significantly affect skin perfusion and oxygenation.
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Affiliation(s)
- Sherif Elawa
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden.
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Perimed AB, Järfälla, Stockholm, Sweden
| | - Ingrid Steinvall
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Johan Zötterman
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Medical Radiation Physics, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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Björkman S, Lilliecreutz C, Bladh M, Strömberg T, Östgren CJ, Mahmoud A, Kafashian A, Bergstrand S, Sederholm Lawesson S. Microvascular dysfunction in women with a history of hypertensive disorders of pregnancy: A population-based retrospective cohort study. BJOG 2024; 131:433-443. [PMID: 37732494 DOI: 10.1111/1471-0528.17665] [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: 04/24/2023] [Revised: 08/04/2023] [Accepted: 08/31/2023] [Indexed: 09/22/2023]
Abstract
OBJECTIVE To evaluate microvascular function in women with previous hypertensive disorders of pregnancy (HDP). DESIGN Retrospective population-based cohort study. SETTING Linköping, Sweden. POPULATION Women aged 50-65 years, participating in the Swedish CArdioPulmonary bioImage Study (SCAPIS) at one site (Linköping) 2016-18, who underwent microcirculatory assessment (N = 1222). METHODS Forearm skin comprehensive microcirculatory assessment was performed with a PeriFlux PF6000 EPOS (Enhanced Perfusion and Oxygen Saturation) system measuring oxygen saturation and total speed resolved perfusion. Obstetric records were reviewed to identify women with previous HDP. Data on cardiovascular risk factors, comorbidities, medication, lifestyle, anthropometric data, and biochemical analyses were obtained from SCAPIS. The microcirculatory data were compared between women with and without previous HDP. MAIN OUTCOME MEASURES Skin microcirculatory oxygen saturation and total speed resolved perfusion at baseline and post-ischaemic peak. RESULTS Women with previous pre-eclampsia displayed impaired post-ischaemic peak oxygen saturation compared with women with normotensive pregnancies (88%, interquartile range [IQR] 84-89% vs 91%, IQR 87-94%, p = 0.001) 6-30 years after pregnancy. The difference remained after multivariable adjustment (β -2.69, 95% CI -4.93 to -0.45). CONCLUSIONS The findings reveal microvascular dysfunction at long-term follow up in women with previous pre-eclampsia and strengthen the possible role of endothelial dysfunction as a link to the increased risk of cardiovascular disease in women with HDP.
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Affiliation(s)
- Stina Björkman
- Department of Obstetrics and Gynaecology in Norrköping, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Caroline Lilliecreutz
- Department of Obstetrics and Gynaecology in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Marie Bladh
- Department of Obstetrics and Gynaecology in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- Department of Health, Medicine and Caring Sciences, and CMIV Centre of Medical Image Science and Visualization, Linköping University, Linköping, Sweden
| | | | | | - Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Sofia Sederholm Lawesson
- Department of Cardiology, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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Jonasson H, Fredriksson I, Bergstrand S, Östgren CJ, Larsson M, Strömberg T. Absorption and reduced scattering coefficients in epidermis and dermis from a Swedish cohort study. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:115001. [PMID: 38078153 PMCID: PMC10704088 DOI: 10.1117/1.jbo.28.11.115001] [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: 07/10/2023] [Revised: 09/25/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023]
Abstract
Significance Knowledge of optical properties is important to accurately model light propagation in tissue, but in vivo reference data are sparse. Aim The aim of our study was to present in vivo skin optical properties from a large Swedish cohort including 3809 subjects using a three-layered skin model and spatially resolved diffuse reflectance spectroscopy (Periflux PF6000 EPOS). Approach Diffuse reflectance spectra (475 to 850 nm) at 0.4 and 1.2 mm source-detector separations were analyzed using an inverse Monte Carlo method. The model had one epidermis layer with variable thicknesses and melanin-related absorptions and two dermis layers with varying hemoglobin concentrations and equal oxygen saturations. The reduced scattering coefficient was equal across all layers. Results Median absorption coefficients (mm - 1 ) in the upper dermis ranged from 0.094 at 475 nm to 0.0048 at 850 nm and similarly in the lower dermis from 0.059 to 0.0035. The reduced scattering coefficient (mm - 1 ) ranged from 3.22 to 1.20, and the sampling depth (mm) ranged from 0.23 to 0.38 (0.4 mm separation) and from 0.49 to 0.68 (1.2 mm separation). There were differences in optical properties across sex, age groups, and BMI categories. Conclusions Reference material for skin optical properties is presented.
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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
| | - Sara Bergstrand
- Linköping University, Department of Health, Medicine, and Caring Sciences, Linköping, Sweden
| | - Carl Johan Östgren
- Linköping University, Department of Health, Medicine, and Caring Sciences, Linköping, Sweden
- Linköping University, Centre of Medical Image Science and Visualization Linköping, 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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Samils L, Henricson J, Strömberg T, Fredriksson I, Iredahl F. Workload and sex effects in comprehensive assessment of cutaneous microcirculation. Microvasc Res 2023; 148:104547. [PMID: 37192688 DOI: 10.1016/j.mvr.2023.104547] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/25/2023] [Accepted: 05/11/2023] [Indexed: 05/18/2023]
Abstract
INTRODUCTION Workload and sex-related differences have been proposed as factors of importance when evaluating the microcirculation. Simultaneous assessments with diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) enable a comprehensive evaluation of the microcirculation. The aim of the study was to compare the response between sexes in the microcirculatory parameters red blood cell (RBC) tissue fraction, RBC oxygen saturation, average vessel diameter, and speed-resolved perfusion during baseline, cycling, and recovery, respectively. METHODS In 24 healthy participants (aged 20 to 30 years, 12 females), cutaneous microcirculation was assessed by LDF and DRS at baseline, during a workload generated by cycling at 75 to 80 % of maximal age-predicted heart rate, and recovery, respectively. RESULTS Females had significantly lower RBC tissue fraction and total perfusion in forearm skin microcirculation at all phases (baseline, workload, and recovery). All microvascular parameters increased significantly during cycling, most evident in RBC oxygen saturation (34 % increase on average) and perfusion (9-fold increase in total perfusion). For perfusion, the highest speeds (>10 mm/s) increased by a factor of 31, whereas the lowest speeds (<1 mm/s) increased by a factor of 2. CONCLUSION Compared to a resting state, all studied microcirculation measures increased during cycling. For perfusion, this was mainly due to increased speed, and only to a minor extent due to increased RBC tissue fraction. Skin microcirculatory differences between sexes were seen in RBC concentration and total perfusion.
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Affiliation(s)
- Linda Samils
- Department of Health, Medicine and Caring Sciences, Division of Community Medicine, Linköping University, Linköping, Sweden
| | - Joakim Henricson
- Department of Emergency Medicine in Linköping, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Fredrik Iredahl
- Department of Health, Medicine and Caring Sciences, Division of Community Medicine, Linköping University, Linköping, Sweden.
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Taylor-Williams M, Spicer G, Bale G, Bohndiek SE. Noninvasive hemoglobin sensing and imaging: optical tools for disease diagnosis. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-220074VR. [PMID: 35922891 PMCID: PMC9346606 DOI: 10.1117/1.jbo.27.8.080901] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/27/2022] [Indexed: 05/08/2023]
Abstract
SIGNIFICANCE Measurement and imaging of hemoglobin oxygenation are used extensively in the detection and diagnosis of disease; however, the applied instruments vary widely in their depth of imaging, spatiotemporal resolution, sensitivity, accuracy, complexity, physical size, and cost. The wide variation in available instrumentation can make it challenging for end users to select the appropriate tools for their application and to understand the relative limitations of different methods. AIM We aim to provide a systematic overview of the field of hemoglobin imaging and sensing. APPROACH We reviewed the sensing and imaging methods used to analyze hemoglobin oxygenation, including pulse oximetry, spectral reflectance imaging, diffuse optical imaging, spectroscopic optical coherence tomography, photoacoustic imaging, and diffuse correlation spectroscopy. RESULTS We compared and contrasted the ability of different methods to determine hemoglobin biomarkers such as oxygenation while considering factors that influence their practical application. CONCLUSIONS We highlight key limitations in the current state-of-the-art and make suggestions for routes to advance the clinical use and interpretation of hemoglobin oxygenation information.
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Affiliation(s)
- Michaela Taylor-Williams
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
| | - Graham Spicer
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
| | - Gemma Bale
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Electrical Division, Department of Engineering, Cambridge, United Kingdom, United Kingdom
| | - Sarah E Bohndiek
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
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Svensson C, Bjarnegård N, Eriksson P, Jonasson H, Strömberg T, Sjöwall C, Zachrisson H. Affected Microcirculation and Vascular Hemodynamics in Takayasu Arteritis. Front Physiol 2022; 13:926940. [PMID: 35864897 PMCID: PMC9294362 DOI: 10.3389/fphys.2022.926940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: Takayasu arteritis (TAK) is a rare inflammatory disease affecting aorta and its major branches. Ultrasound (US) can detect inflammatory features in the arterial wall, but less is known regarding skin microcirculation and vascular hemodynamics. The aim was to study if assessment of these variables could add valuable information regarding vascular affection in TAK.Methods: 17 patients diagnosed with TAK and 17 age- and sex-matched healthy controls were included. Microcirculatory peak oxygen saturation (OxyP) in the skin after induced ischemia was evaluated with laser Doppler flowmetry/diffuse reflectance spectroscopy. Cerebrovascular reserve capacity (CVR) in the brain was assessed with transcranial Doppler (TCD). Pulse waves were recorded in the radial artery by the aid of applanation tonometry, for calculation of central augmentation index (AIx75). Intima-media thickness (IMT) and stenosis/occlusions were evaluated using US in carotid and central arteries.Results: Reduced OxyP (79 ± 8% vs. 87 ± 4%, p < 0.001) was seen in patients with TAK regardless of significant arterial stenosis/occlusion or not. Increased AIx75 (22.3 ± 13.6 vs. 9.2 ± 16.3, p = 0.01) was seen in TAK patients without significant stenosis/occlusions. No differences were found in CVR, regardless of proximal stenosis. However, signs of a more high-resistance flow profile were seen in arteria cerebri media.Conclusion: Regardless of arterial stenosis or not, impaired microcirculation of the skin and preserved CVR in the brain were found in subjects with TAK. Signs of increased arterial stiffness in the brain and central arteries were observed. The value of these findings for prediction of future cardiovascular events needs to be clarified in further studies.
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Ma KF, Kleiss SF, Schuurmann RCL, Nijboer TS, El Moumni M, Bokkers RPH, de Vries JPPM. Laser Doppler Flowmetry Combined with Spectroscopy to Determine Peripheral Tissue Perfusion and Oxygen Saturation: A Pilot Study in Healthy Volunteers and Patients with Peripheral Arterial Disease. J Pers Med 2022; 12:jpm12060853. [PMID: 35743638 PMCID: PMC9224808 DOI: 10.3390/jpm12060853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/20/2022] [Indexed: 12/27/2022] Open
Abstract
Background: In this study, we assessed the ability of the EPOS system (Perimed AB, Järfälla, Stockholm, Sweden) to detect differences in tissue perfusion between healthy volunteers and patients with peripheral arterial disease (PAD) with different severity of disease. Methods: This single-center prospective pilot study included 10 healthy volunteers and 20 patients with PAD scheduled for endovascular therapy (EVT). EPOS measurements were performed at rest at 32 °C and 44 °C, followed by transcutaneous oxygen pressure (TcPo2) measurements. The measurements were performed on the dorsal and medial side of the foot, as well as the lateral side of the calf. EPOS parameters included hemoglobin oxygen saturation (HbSo2) and speed-resolved red blood cell (RBC) perfusion. Results: HbSo2 at 44 °C was significantly different between the three groups for all measurement locations. The overall speed-resolved RBC perfusion at 44 °C was statistically significant between the groups on the dorsal and medial side of the foot but not on the calf. TcPo2 values were not significantly different between the three groups. Conclusions: This study demonstrates that the EPOS system can depict differences in tissue perfusion between healthy volunteers, patients with Fontaine class IIb PAD, and those with Fontaine class III or IV PAD but only after heating to 44 °C.
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Affiliation(s)
- Kirsten F. Ma
- Division of Vascular Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.F.K.); (R.C.L.S.); (T.S.N.); (J.-P.P.M.d.V.)
- Correspondence:
| | - Simone F. Kleiss
- Division of Vascular Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.F.K.); (R.C.L.S.); (T.S.N.); (J.-P.P.M.d.V.)
| | - Richte C. L. Schuurmann
- Division of Vascular Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.F.K.); (R.C.L.S.); (T.S.N.); (J.-P.P.M.d.V.)
| | - Thomas S. Nijboer
- Division of Vascular Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.F.K.); (R.C.L.S.); (T.S.N.); (J.-P.P.M.d.V.)
| | - Mostafa El Moumni
- Division of Trauma Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands;
| | - Reinoud P. H. Bokkers
- Department of Radiology, Medical Imaging Center, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands;
| | - Jean-Paul P. M. de Vries
- Division of Vascular Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.F.K.); (R.C.L.S.); (T.S.N.); (J.-P.P.M.d.V.)
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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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11
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Majedy M, Saager RB, Strömberg T, Larsson M, Salerud EG. Spectral characterization of liquid hemoglobin phantoms with varying oxygenation states. JOURNAL OF BIOMEDICAL OPTICS 2021; 27:JBO-210213SSR. [PMID: 34850613 PMCID: PMC8632618 DOI: 10.1117/1.jbo.27.7.074708] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/16/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE For optical methods to accurately assess hemoglobin oxygen saturation in vivo, an independently verifiable tissue-like standard is required for validation. For this purpose, we propose three hemoglobin preparations and evaluate methods to characterize them. AIM To spectrally characterize three different hemoglobin preparations using multiple spectroscopic methods and to compare their absorption spectra to commonly used reference spectra. APPROACH Absorption spectra of three hemoglobin preparations in solution were characterized using spectroscopic collimated transmission: whole blood, lysed blood, and ferrous-stabilized hemoglobin. Tissue-mimicking phantoms composed of Intralipid, and the hemoglobin solutions were characterized using spatial frequency-domain spectroscopy (SFDS) and enhanced perfusion and oxygen saturation (EPOS) techniques while using yeast to deplete oxygen. RESULTS All hemoglobin preparations exhibited similar absorption spectra when accounting for methemoglobin and scattering in their oxyhemoglobin and deoxyhemoglobin forms, respectively. However, systematic differences were observed in the fitting depending on the reference spectra used. For the tissue-mimicking phantoms, SFDS measurements at the surface of the phantom were affected by oxygen diffusion at the interface with air, associated with higher values than for the EPOS system. CONCLUSIONS We show the validity of different blood phantoms and what considerations need to be addressed in each case to utilize them equivalently.
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Affiliation(s)
- Motasam Majedy
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Rolf B. Saager
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - E. Göran Salerud
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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12
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Jonasson H, Bergstrand S, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Post-ischemic skin peak oxygen saturation is associated with cardiovascular risk factors: a Swedish cohort study. Microvasc Res 2021; 140:104284. [PMID: 34826433 DOI: 10.1016/j.mvr.2021.104284] [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] [Received: 05/10/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 02/08/2023]
Abstract
The objective of this study was to explore the associations between skin microcirculatory function and established cardiovascular risk factors in a large Swedish cohort. As part of the Swedish CArdioPulmonary bioImage Study (SCAPIS), microcirculatory data were acquired at Linköping University hospital, Linköping, Sweden during 2016-2017. The subjects, aged 50-64 years, were randomly selected from the national population register. Microcirculatory reactivity was assessed using a 5-min arterial occlusion-release protocol. Comprehensive skin microcirculatory data were continuously acquired by using a fiberoptic probe placed on the lower right arm. After exclusion of missing data (208), 1557 subjects were remaining. Among the parameters, skin microcirculatory peak oxygen saturation after occlusion release, had the strongest relationship to the cardiovascular risk factors. The linear associations between peak oxygen saturation and cardiovascular risk factors were analyzed adjusted for age and sex. We found a negative association with peak oxygen saturation (standardized regression coefficient) for blood pressure (systolic -0.05 (95% CI: -0.10;-0.003) and diastolic -0.05 (-0.10; -0.003)), BMI -0.18 (-0.23; -0.13), waist circumference (males -0.20 (-0.32; -0.16), females -0.18 (-0.25; -0.11)), prevalent diabetes -0.31 (-0.49; -0.12), hypertension -0.30 (-0.42; -0.18), dyslipidemia -0.24 (-0.40; -0.09), fasting glucose level -0.06 (-0.12; -0.01), HbA1c -0.07 (-0.12; -0.02), triglyceride level -0.09 (-0.14; -0.04), hsCRP -0.12 (-0.17; -0.07), and current smoker versus never smoked -0.50 (-0.67; -0.34). A positive association with peak oxygen saturation was found for cholesterol level 0.05 (0.005; 0.11) and HDL 0.11 (0.06; 0.17). This is the first study showing that post-ischemic skin microvascular peak oxygen saturation is associated with virtually all established cardiovascular risk factors in a population-based middle-aged cohort.
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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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13
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Svensson C, Eriksson P, Bjarnegård N, Jonasson H, Strömberg T, Sjöwall C, Zachrisson H. Impaired Microcirculation and Vascular Hemodynamics in Relation to Macrocirculation in Patients With Systemic Lupus Erythematosus. Front Med (Lausanne) 2021; 8:722758. [PMID: 34790671 PMCID: PMC8591084 DOI: 10.3389/fmed.2021.722758] [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: 06/09/2021] [Accepted: 10/04/2021] [Indexed: 12/23/2022] Open
Abstract
Introduction: Systemic lupus erythematosus (SLE) is associated with premature cardiovascular disease (CVD) and mortality, unexplained by traditional risk factors. Impairment of microcirculation and vascular hemodynamics may represent early signs of vascular affection. We hypothesized that studies of microcirculation and pulse waves may provide additional information, compared to ultrasound (US) alone, for the detection of early vascular disease in SLE. Methods: Sixty well-characterized SLE-patients (52 women, eight men; mean age 43.21 ± 1.3 years) characterized by lupus nephritis (LN; n = 20), antiphospholipid syndrome (APS; n = 20) or skin and joint involvement (n = 20) and 60 healthy controls were included. Microcirculatory peak oxygen saturation (OxyP) was evaluated using a novel combined laser Doppler flowmetry/diffuse reflectance spectroscopy method. Pulse waves were recorded in the radial artery by the aid of applanation tonometry in order to calculate central augmentation index (AIx75). Intima-media thickness (IMT) and plaque occurrence were evaluated using high frequency US, in carotid and central arteries. Results: Lower OxyP (84 ± 8 vs. 87 ± 5 %, p = 0.01) and higher AIx75 (17.3 ± 13.9 vs. 10.0 ± 14.2 %, p = 0.005) were seen in the SLE cohort. OxyP was inversely correlated with IMT in internal carotid artery (ICA), (R = -0.32, p = 0.01). AIx75 correlated with IMT in common carotid artery (CCA), (R = 0.36, p = 0.005), common femoral artery (CFA), (R = 0.43, p = 0.001), and ICA (R = 0.27, p = 0.04). AIx75 correlated negatively with OxyP (R = -0.29, p = 0.02). SLE-patients with plaque had lower OxyP values (80 ± 8 vs. 85 ± 7 %, p < 0.001) and higher AIx75 (23.0 ± 11.6 vs. 15.5 ± 14.2 %, p < 0.001) compared to those without plaque. Conclusion: Impaired microcirculation and vessel hemodynamics were observed in SLE. These methods correlated with IMT and plaque occurrence. The importance of early macro- and micro-circulatory vascular affection for increased risk of CVD in SLE will be followed-up in future studies.
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Affiliation(s)
- Christina Svensson
- Department of Clinical Physiology, University Hospital, Linköping, Sweden.,Division of Diagnostics and Specialist Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Per Eriksson
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Niclas Bjarnegård
- Division of Diagnostics and Specialist Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Christopher Sjöwall
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Helene Zachrisson
- Department of Clinical Physiology, University Hospital, Linköping, Sweden.,Division of Diagnostics and Specialist Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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14
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Fredriksson I, Larsson M, Strömberg T, Iredahl F. Vasomotion analysis of speed resolved perfusion, oxygen saturation, red blood cell tissue fraction, and vessel diameter: Novel microvascular perspectives. Skin Res Technol 2021; 28:142-152. [PMID: 34758168 PMCID: PMC9907591 DOI: 10.1111/srt.13106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/21/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Vasomotion is the spontaneous oscillation in vascular tone in the microcirculation and is believed to be a physiological mechanism facilitating the transport of blood gases and nutrients to and from tissues. So far, Laser Doppler flowmetry has constituted the gold standard for in vivo vasomotion analysis. MATERIALS AND METHODS We applied vasomotion analysis to speed-resolved perfusion, oxygen saturation, red blood cell tissue (RBC) tissue fraction, and average vessel diameter from five healthy individuals at rest measured by the newly developed Periflux 6000 EPOS system over 10 minutes. Magnitude scalogram and the time-averaged wavelet spectra were divided into frequency intervals reflecting endothelial, neurogenic, myogenic, respiratory, and cardiac function. RESULTS Recurrent high-intensity periods of the myogenic, neurogenic, and endothelial frequency intervals were found. The neurogenic activity was considerably more pronounced for the oxygen saturation, RBC tissue fraction, and vessel diameter signals, than for the perfusion signals. In a correlation analysis we found that changes in perfusion in the myogenic, neurogenic, and endothelial frequency intervals precede changes in the other signals. Furthermore, changes in average vessel diameter were in general negatively correlated to the other signals in the same frequency intervals, indicating the importance of capillary recruitment. CONCLUSION We conclude that vasomotion can be observed in signals reflecting speed resolved perfusion, oxygen saturation, RBC tissue fraction, and vessel diameter. The new parameters enable new aspects of the microcirculation to be observed.
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Affiliation(s)
- Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Fredrik Iredahl
- Department of Health, Medicine and Caring Sciences, Linköping University, Division of Community Medicine, Linköping, Sweden.,Department of Primary health care, Region Östergötland, Linköping, Sweden
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15
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Ewerlöf M, Salerud EG, Strömberg T, Larsson M. Estimation of skin microcirculatory hemoglobin oxygen saturation and red blood cell tissue fraction using a multispectral snapshot imaging system: a validation study. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200291RR. [PMID: 33583154 PMCID: PMC7881095 DOI: 10.1117/1.jbo.26.2.026002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/13/2021] [Indexed: 05/08/2023]
Abstract
SIGNIFICANCE Hemoglobin oxygen saturation and red blood cell (RBC) tissue fraction are important parameters when assessing microvascular status. Functional information can be attained using temporally resolved measurements performed during stimulus-response protocols. Pointwise assessments can currently be conducted with probe-based systems. However, snapshot multispectral imaging (MSI) can be used for spatial-temporal measurements. AIM To validate if hemoglobin oxygen saturation and RBC tissue fraction can be quantified using a snapshot MSI system and an inverse Monte Carlo algorithm. APPROACH Skin tissue measurements from the MSI system were compared to those from a validated probe-based system during arterial and venous occlusion provocation on 24 subjects in the wavelength interval 450 to 650 nm, to evaluate a wide range of hemoglobin oxygen saturation and RBC tissue fraction levels. RESULTS Arterial occlusion results show a mean linear regression R2 = 0.958 for hemoglobin oxygen saturation. Comparing relative RBC tissue fraction during venous occlusion results in R2 = 0.925. The MSI system shows larger dynamic changes than the reference system, which might be explained by a deeper sampling including more capacitance vessels. CONCLUSIONS The snapshot MSI system estimates hemoglobin oxygen saturation and RBC tissue fraction in skin microcirculation showing a high correlation (R2 > 0.9 in most subjects) with those measured by the reference method.
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Affiliation(s)
- Maria Ewerlöf
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - E. Göran Salerud
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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16
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Fredriksson I, Larsson M, Strömberg T. Machine learning for direct oxygen saturation and hemoglobin concentration assessment using diffuse reflectance spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200177SSR. [PMID: 33205635 PMCID: PMC7670094 DOI: 10.1117/1.jbo.25.11.112905] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/28/2020] [Indexed: 05/13/2023]
Abstract
SIGNIFICANCE Diffuse reflectance spectroscopy (DRS) is frequently used to assess oxygen saturation and hemoglobin concentration in living tissue. Methods solving the inverse problem may include time-consuming nonlinear optimization or artificial neural networks (ANN) determining the absorption coefficient one wavelength at a time. AIM To present an ANN-based method that directly outputs the oxygen saturation and the hemoglobin concentration using the shape of the measured spectra as input. APPROACH A probe-based DRS setup with dual source-detector separations in the visible wavelength range was used. ANNs were trained on spectra generated from a three-layer tissue model with oxygen saturation and hemoglobin concentration as target. RESULTS Modeled evaluation data with realistic measurement noise showed an absolute root-mean-square (RMS) deviation of 5.1% units for oxygen saturation estimation. The relative RMS deviation for hemoglobin concentration was 13%. This accuracy is at least twice as good as our previous nonlinear optimization method. On blood-intralipid phantoms, the RMS deviation from the oxygen saturation derived from partial oxygen pressure measurements was 5.3% and 1.6% in two separate measurement series. Results during brachial occlusion showed expected patterns. CONCLUSIONS The presented method, directly assessing oxygen saturation and hemoglobin concentration, is fast, accurate, and robust to noise.
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Affiliation(s)
- Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Stockholm, Sweden
- Address all correspondence to Ingemar Fredriksson,
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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17
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Hultman M, Larsson M, Strömberg T, Fredriksson I. Real-time video-rate perfusion imaging using multi-exposure laser speckle contrast imaging and machine learning. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200207R. [PMID: 33191685 PMCID: PMC7666876 DOI: 10.1117/1.jbo.25.11.116007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
SIGNIFICANCE Multi-exposure laser speckle contrast imaging (MELSCI) estimates microcirculatory blood perfusion more accurately than single-exposure LSCI. However, the technique has been hampered by technical limitations due to massive data throughput requirements and nonlinear inverse search algorithms, limiting it to an offline technique where data must be postprocessed. AIM To present an MELSCI system capable of continuous acquisition and processing of MELSCI data, enabling real-time video-rate perfusion imaging with high accuracy. APPROACH The MELSCI algorithm was implemented in programmable hardware (field programmable gate array) closely interfaced to a high-speed CMOS sensor for real-time calculation. Perfusion images were estimated in real-time from the MELSCI data using an artificial neural network trained on simulated data. The MELSCI perfusion was compared to two existing single-exposure metrics both quantitatively in a controlled phantom experiment and qualitatively in vivo. RESULTS The MELSCI perfusion shows higher signal dynamics compared to both single-exposure metrics, both spatially and temporally where heartbeat-related variations are resolved in much greater detail. The MELSCI perfusion is less susceptible to measurement noise and is more linear with respect to laser Doppler perfusion in the phantom experiment (R2 = 0.992). CONCLUSIONS The presented MELSCI system allows for real-time acquisition and calculation of high-quality perfusion at 15.6 frames per second.
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Affiliation(s)
- Martin Hultman
- Linköping University, Department of Biomedical Engineering, Linköping, 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, Järfälla, Stockholm, Sweden
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18
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Towards shifted position-diffuse reflectance imaging of anatomically correctly scaled human microvasculature. Sci Rep 2020; 10:17391. [PMID: 33060791 PMCID: PMC7567838 DOI: 10.1038/s41598-020-74447-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/30/2020] [Indexed: 11/10/2022] Open
Abstract
Due to significant advantages, the trend in the field of medical technology is moving towards minimally or even non-invasive examination methods. In this respect, optical methods offer inherent benefits, as does diffuse reflectance imaging (DRI). The present study attempts to prove the suitability of DRI—when implemented alongside a suitable setup and data evaluation algorithm—to derive information from anatomically correctly scaled human capillaries (diameter: \documentclass[12pt]{minimal}
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\begin{document}$$45\,\upmu \hbox {m}$$\end{document}45μm) by conducting extensive Monte–Carlo simulations and by verifying the findings through laboratory experiments. As a result, the method of shifted position-diffuse reflectance imaging (SP-DRI) is established by which average signal modulations of up to 5% could be generated with an illumination wavelength of \documentclass[12pt]{minimal}
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\begin{document}$$\lambda =424\,\hbox {nm}$$\end{document}λ=424nm and a core diameter of the illumination fiber of \documentclass[12pt]{minimal}
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\begin{document}$$50\,\upmu \hbox {m}$$\end{document}50μm. No reference image is needed for this technique. The present study reveals that the diffuse reflectance data in combination with the SP-DRI normalization are suitable to localize human capillaries within turbid media.
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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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20
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Bergkvist M, Henricson J, Bergstrand S, Strömberg T, Tesselaar E, Farnebo S. Assessment of oxygenation with polarized light spectroscopy enables new means for detecting vascular events in the skin. Microvasc Res 2020; 130:104000. [PMID: 32194082 DOI: 10.1016/j.mvr.2020.104000] [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: 09/01/2019] [Revised: 03/12/2020] [Accepted: 03/12/2020] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Impaired oxygenation in the skin may occur in disease states and after reconstructive surgery. We used tissue viability imaging (TiVi) to measure changes in oxygenation and deoxygenation of haemoglobin in an in vitro model and in the dermal microcirculation of healthy individuals. MATERIALS AND METHODS Oxygenation was measured in human whole blood with different levels of oxygenation. In healthy subjects, changes in red blood cell concentration (CRBC,TiVi), oxygenation (ΔCOH,TiVi) and deoxygenation (ΔCDOH,TiVi) of haemoglobin were measured during and after arterial and venous occlusion using TiVi and were compared with measurements from the enhanced perfusion and oxygen saturation system (EPOS). RESULTS During arterial occlusion, CRBC,TiVi remained unchanged while ΔCOH,TiVi decreased to -44.2 (10.4) AU (p = 0.04), as compared to baseline. After release, CRBC,TiVi increased to 39.2 (18.8) AU (p < 0.001), ΔCOH,TiVi increased to 38.5. During venous occlusion, CRBC,TiVi increased to 28.9 (11.2) AU (p < 0.001), ΔCOH,TiVi decreased to -52.2 (46.1) AU (p < 0.001) compared to baseline after 5 min of venous occlusion. There was a significant correlation between the TiVi Oxygen Mapper and EPOS, for arterial (r = 0.92, p < 0.001) and venous occlusion (r = 0.87, p < 0.001), respectively. CONCLUSION This study shows that TiVi can measure trends in oxygenation and deoxygenation of haemoglobin during arterial and venous stasis in healthy individuals.
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Affiliation(s)
- Max Bergkvist
- Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Joakim Henricson
- Department of Biomedical and Clinical Sciences, Linköping University, Sweden; Departement of Emergency Medicine, Local Health Care Services in Central Östergötland, Linköping, Östergötland, Sweden
| | - Sara Bergstrand
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Medical Radiation Physics, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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21
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Wang G, Jia S, Liu M, Song X, Li H, Chang X, Zhang W. Impact of local thermal stimulation on the correlation between oxygen saturation and speed-resolved blood perfusion. Sci Rep 2020; 10:183. [PMID: 31932611 PMCID: PMC6957488 DOI: 10.1038/s41598-019-57067-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/18/2019] [Indexed: 11/23/2022] Open
Abstract
The physiologically important relationship between oxygen saturation and blood flow is not entirely understood, particularly with regard to the multiple velocity components of flow and temperature. While our previous studies used classic laser Doppler flowmetry combined with an enhanced perfusion probe to assess local blood flow following thermal stimulation, oxygen saturation signals were not assessed. Thus, the current study used multiscale entropy (MSE) and multiscale fuzzy entropy (MFE) to measure the complexity of oxygen saturation signals following thermal stimulation in healthy subjects. The results indicate that thermal stimulation increases oxygen saturation and affects the measured signal complexity in a temperature-dependent fashion. Furthermore, stimulus temperature not only affects the correlation between speed-resolved blood perfusion and oxygen saturation, but also the correlation between the complexity area indices (CAI) of the two signals. These results reflect the complexity of local regulation and adaptation processes in response to stimuli at different temperatures.
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Affiliation(s)
- Guangjun Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Shuyong Jia
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Mi Liu
- Acupuncture and Tuina School, Hunan University of Chinese Medicine, Changsha, China
| | - Xiaojing Song
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hongyan Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaorong Chang
- Acupuncture and Tuina School, Hunan University of Chinese Medicine, Changsha, China.
| | - Weibo Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China.
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Johansson JD, Portaluppi D, Buttafava M, Villa F. A multipixel diffuse correlation spectroscopy system based on a single photon avalanche diode array. JOURNAL OF BIOPHOTONICS 2019; 12:e201900091. [PMID: 31339649 DOI: 10.1002/jbio.201900091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/19/2019] [Accepted: 07/21/2019] [Indexed: 05/21/2023]
Abstract
The autocorrelation of laser speckles from coherent near infrared light is used for noninvasive estimates of relative changes in blood perfusion in techniques such as laser Doppler flowmetry (LDF) and diffuse correlation spectroscopy (DCS). In this study, a 2D array of single photon avalanche diodes (SPADs) was used to combine the strengths of multiple detectors in LDF with high light sensitivity in DCS. The system was tested on milk phantoms with varying detector fiber diameter (200 and 600 μm), source-detector fiber separation (4.6-10.2 mm), fiber-SPAD distance (2.5-36.5 mm), contiguous measurement time per repetition for the autocorrelation (1-33 ms) and temperature (15.6-46.7°C). An in vivo blood occlusion test was also performed. The multipixel approach improved signal-to-noise ratio (SNR) and, in our setup, the use of a multimode detector fiber was beneficial for SNR. In conclusion, the multipixel system works, but improvements and further studies regarding, for example, the data acquisition and optimal settings are still needed.
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Affiliation(s)
| | - Davide Portaluppi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
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23
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Wang G, Jia S, Li H, Song X, Zhang W. Exploring the relationship between the speed-resolved perfusion of blood flux and HRV following different thermal stimulations using MSE and MFE analyses. PLoS One 2019; 14:e0217973. [PMID: 31167001 PMCID: PMC6550418 DOI: 10.1371/journal.pone.0217973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 05/23/2019] [Indexed: 12/22/2022] Open
Abstract
Our previous study employed the classic laser Doppler flux (LDF) to explore the complexity of local blood flow signals and their relationship with heart rate variability (HRV). However, microcirculation blood flow is composed of different velocity components. To investigate the complexity of local speed-resolved perfusion and HRV following stimulation with different temperatures in healthy subjects, multiscale entropy (MSE) and multiscale fuzzy entropy (MFE) were used to measure the complexity of local speed-resolved perfusion signals. MSE was also used to evaluate the complexity of HRV. The results indicated that thermal stimulation increased all components of local speed-resolved perfusion and that stimulation with different temperatures resulted in different changes in the complexity area index. However, the same stimulation had no effect on the MSE of HRV. Further research showed that 44°C thermal stimulation resulted in a weak correlation between the composite speed-resolved perfusion and the HRV complexity. The current study provides a new approach for studying the relationship between speed-resolved perfusion signals and cardiac function.
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Affiliation(s)
- Guangjun Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
- * E-mail: (GW); (WZ)
| | - Shuyong Jia
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hongyan Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaojing Song
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Weibo Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
- * E-mail: (GW); (WZ)
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24
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Jonasson H, Fredriksson I, Bergstrand S, Östgren CJ, Larsson M, Strömberg T. In vivo characterization of light scattering properties of human skin in the 475- to 850-nm wavelength range in a Swedish cohort. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-6. [PMID: 30267487 DOI: 10.1117/1.jbo.23.12.121608] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/31/2018] [Indexed: 05/04/2023]
Abstract
We have determined in vivo optical scattering properties of normal human skin in 1734 subjects, mostly with fair skin type, within the Swedish CArdioPulmonary bioImage Study. The measurements were performed with a noninvasive system, integrating spatially resolved diffuse reflectance spectroscopy and laser Doppler flowmetry. Data were analyzed with an inverse Monte Carlo algorithm, accounting for both scattering, geometrical, and absorbing properties of the tissue. The reduced scattering coefficient was found to decrease from 3.16 ± 0.72 to 1.13 ± 0.27 mm-1 (mean ± SD) in the 475- to 850-nm wavelength range. There was a negative correlation between the reduced scattering coefficient and age, and a significant difference between men and women in the reduced scattering coefficient as well as in the fraction of small scattering particles. This large study on tissue scattering with mean values and normal variation can serve as a reference when designing diagnostic techniques or when evaluating the effect of therapeutic optical systems.
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Affiliation(s)
- Hanna Jonasson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Linköping University, Department of Medical and Health Sciences, Linköping, Sweden
| | - Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Järfälla, Stockholm, Sweden
| | - Sara Bergstrand
- Linköping University, Department of Medical and Health Sciences, Linköping, Sweden
| | - Carl Johan Östgren
- Linköping University, Department of Medical and Health Sciences, Linköping, 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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25
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Saager RB, Baldado ML, Rowland RA, Kelly KM, Durkin AJ. Method using in vivo quantitative spectroscopy to guide design and optimization of low-cost, compact clinical imaging devices: emulation and evaluation of multispectral imaging systems. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-12. [PMID: 29633609 PMCID: PMC5890028 DOI: 10.1117/1.jbo.23.4.046002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 03/16/2018] [Indexed: 05/30/2023]
Abstract
With recent proliferation in compact and/or low-cost clinical multispectral imaging approaches and commercially available components, questions remain whether they adequately capture the requisite spectral content of their applications. We present a method to emulate the spectral range and resolution of a variety of multispectral imagers, based on in-vivo data acquired from spatial frequency domain spectroscopy (SFDS). This approach simulates spectral responses over 400 to 1100 nm. Comparing emulated data with full SFDS spectra of in-vivo tissue affords the opportunity to evaluate whether the sparse spectral content of these imagers can (1) account for all sources of optical contrast present (completeness) and (2) robustly separate and quantify sources of optical contrast (crosstalk). We validate the approach over a range of tissue-simulating phantoms, comparing the SFDS-based emulated spectra against measurements from an independently characterized multispectral imager. Emulated results match the imager across all phantoms (<3 % absorption, <1 % reduced scattering). In-vivo test cases (burn wounds and photoaging) illustrate how SFDS can be used to evaluate different multispectral imagers. This approach provides an in-vivo measurement method to evaluate the performance of multispectral imagers specific to their targeted clinical applications and can assist in the design and optimization of new spectral imaging devices.
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Affiliation(s)
- Rolf B. Saager
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Melissa L. Baldado
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Rebecca A. Rowland
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Kristen M. Kelly
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Dermatology, Irvine, California, United States
| | - Anthony J. Durkin
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
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26
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Fredriksson I, Saager RB, Durkin AJ, Strömberg T. Evaluation of a pointwise microcirculation assessment method using liquid and multilayered tissue simulating phantoms. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-9. [PMID: 29139245 PMCID: PMC5872620 DOI: 10.1117/1.jbo.22.11.115004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/26/2017] [Indexed: 05/03/2023]
Abstract
A fiber-optic probe-based instrument, designed for assessment of parameters related to microcirculation, red blood cell tissue fraction (fRBC), oxygen saturation (SO2), and speed resolved perfusion, has been evaluated using state-of-the-art tissue phantoms. The probe integrates diffuse reflectance spectroscopy (DRS) at two source-detector separations and laser Doppler flowmetry, using an inverse Monte Carlo method for identifying the parameters of a multilayered tissue model. Here, we characterize the accuracy of the DRS aspect of the instrument using (1) liquid blood phantoms containing yeast and (2) epidermis-dermis mimicking solid-layered phantoms fabricated from polydimethylsiloxane, titanium oxide, hemoglobin, and coffee. The root-mean-square (RMS) deviations for fRBC for the two liquid phantoms were 11% and 5.3%, respectively, and 11% for the solid phantoms with highest hemoglobin signatures. The RMS deviation for SO2 was 5.2% and 2.9%, respectively, for the liquid phantoms, and 2.9% for the solid phantoms. RMS deviation for the reduced scattering coefficient (μs'), for the solid phantoms was 15% (475 to 850 nm). For the liquid phantoms, the RMS deviation in average vessel diameter (D) was 1 μm. In conclusion, the skin microcirculation parameters fRBC and SO2, as well as, μs' and D are estimated with reasonable accuracy.
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Affiliation(s)
- Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Stockholm, Sweden
- Address all correspondence to: Ingemar Fredriksson, E-mail:
| | - Rolf B. Saager
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Anthony J. Durkin
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
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27
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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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28
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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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29
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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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