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Lee Y, Byun S, Yi C, Jung J, Lee SA. Rolling shutter speckle plethysmography for quantitative cardiovascular monitoring. BIOMEDICAL OPTICS EXPRESS 2024; 15:1540-1552. [PMID: 38495693 PMCID: PMC10942690 DOI: 10.1364/boe.511755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/15/2024] [Accepted: 02/05/2024] [Indexed: 03/19/2024]
Abstract
We propose a new speckle-based plethysmography technique, termed rolling shutter speckle plethysmography (RSSPG), which can quantitatively measure the velocity and volume fluctuations of blood flow during the cardiac cycle. Our technique is based on the rolling shutter speckle imaging, where the short row-by-row time differences in the rolling shutter image sensors are used to measure the temporal decorrelation behavior of vertically elongated speckles from a single image capture. Temporal analysis of the speckle field provides rich information regarding the dynamics of the scattering media, such as both the dynamic scattering fraction and the speckle decorrelation time. Using a sequence of images, RSSPG can monitor fluctuations in the blood flow dynamics while separating velocity and volume changes in blood vessels and obtaining high-quality plethysmography waveforms compared to regular photoplethysmography. We demonstrate the quantitative RSSPG based on accurate fitting of the speckle dynamics model, as well as the qualitative RSSPG based on simple row-by-row correlation (RIC) calculation for fast and robust analysis. Based on exploratory in vivo experiment, we show that RSSPG can reliably measure pulsatile waveforms and heart rate variations in various conditions, potentially providing physiologically relevant information for cardiovascular monitoring.
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Affiliation(s)
| | | | - Changyoon Yi
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jaewoo Jung
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Seung Ah Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
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2
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Crouzet C, Dunn CE, Choi B. Quantifying tissue properties and absolute hemodynamics using coherent spatial imaging. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:127001. [PMID: 38116026 PMCID: PMC10730023 DOI: 10.1117/1.jbo.28.12.127001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/12/2023] [Accepted: 10/30/2023] [Indexed: 12/21/2023]
Abstract
Significance Measuring hemodynamic function is crucial for health assessment. Optical signals provide relative hemoglobin concentration changes, but absolute measurements require costly, bulky technology. Speckleplethysmography (SPG) uses coherent light to detect speckle fluctuations. Combining SPG with multispectral measurements may provide important physiological information on blood flow and absolute hemoglobin concentration. Aim To develop an affordable optical technology to measure tissue absorption, scattering, hemoglobin concentrations, tissue oxygen saturation (StO 2 ), and blood flow. Approach We integrated reflectance spectroscopy and laser speckle imaging to create coherent spatial imaging (CSI). CSI was validated against spatial frequency domain imaging (SFDI) using phantom-based measurements. In vivo arterial and venous occlusion experiments compared CSI with diffuse optical spectroscopy/diffuse correlation spectroscopy (DOS/DCS) measurements. Results CSI and SFDI agreed on tissue absorption and scattering in phantom tests. CSI and DOS/DCS showed similar trends and agreement in arterial occlusion results. During venous occlusion, both uncorrected and corrected blood flow decreased with increasing pressure, with an ∼ 200 % difference in overall blood flow decrease between the methods. CSI and DOS/DCS data showed expected hemoglobin concentrations, StO 2 , and blood flow trends. Conclusions CSI provides affordable and comprehensive hemodynamic information. It can potentially detect dysfunction and improve measurements, such as blood pressure, S p O 2 , and metabolism.
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Affiliation(s)
- Christian Crouzet
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Cody E. Dunn
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
| | - Bernard Choi
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, Department of Surgery, Irvine, California, United States
- University of California, Irvine, Edwards Lifesciences Foundation Cardiovascular Innovation Research Center, California, United States
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3
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Phan T, Crouzet C, Kennedy GT, Durkin AJ, Choi B. Quantitative hemodynamic imaging: a method to correct the effects of optical properties on laser speckle imaging. NEUROPHOTONICS 2023; 10:045001. [PMID: 37795105 PMCID: PMC10546199 DOI: 10.1117/1.nph.10.4.045001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/22/2023] [Accepted: 09/12/2023] [Indexed: 10/06/2023]
Abstract
Significance Studying cerebral hemodynamics may provide diagnostic information on neurological conditions. Wide-field imaging techniques, such as laser speckle imaging (LSI) and optical intrinsic signal imaging, are commonly used to study cerebral hemodynamics. However, they often do not account appropriately for the optical properties of the brain that can vary among subjects and even during a single measurement. Here, we describe the combination of LSI and spatial-frequency domain imaging (SFDI) into a wide-field quantitative hemodynamic imaging (QHI) system that can correct the effects of optical properties on LSI measurements to achieve a quantitative measurement of cerebral blood flow (CBF). Aim We describe the design, fabrication, and testing of QHI. Approach The QHI hardware combines LSI and SFDI with spatial and temporal synchronization. We characterized system sensitivity, accuracy, and precision with tissue-mimicking phantoms. With SFDI optical property measurements, we describe a method derived from dynamic light scattering to obtain absolute CBF values from LSI and SFDI measurements. We illustrate the potential benefits of absolute CBF measurements in resting-state and dynamic experiments. Results QHI achieved a 50-Hz raw acquisition frame rate with a 10 × 10 mm field of view and flow sensitivity up to ∼ 4 mm / s . The extracted SFDI optical properties agreed well with a commercial system (R 2 ≥ 0.98 ). The system showed high stability with low coefficients of variations over multiple sessions within the same day (< 1 % ) and over multiple days (< 4 % ). When optical properties were considered, the in-vivo hypercapnia gas challenge showed a slight difference in CBF (- 1.5 % to 0.5% difference). The in-vivo resting-state experiment showed a change in CBF ranking for nine out of 13 animals when the correction method was applied to LSI CBF measurements. Conclusions We developed a wide-field QHI system to account for the confounding effects of optical properties on CBF LSI measurements using the information obtained from SFDI.
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Affiliation(s)
- Thinh Phan
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
| | - Christian Crouzet
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Gordon T. Kennedy
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
| | - Bernard Choi
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, Department of Surgery, Irvine, California, United States
- University of California, Irvine, Edwards Lifesciences Cardiovascular Innovation Research Center, Irvine, California, United States
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4
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Herranz Olazabal J, Lorato I, Kling J, Verhoeven M, Wieringa F, Van Hoof C, Verkruijsse W, Hermeling E. Comparison between Speckle Plethysmography and Photoplethysmography during Cold Pressor Test Referenced to Finger Arterial Pressure. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115016. [PMID: 37299743 DOI: 10.3390/s23115016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/15/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Speckle Plethysmography (SPG) and Photoplethysmography (PPG) are different biophotonics technologies that allow for measurement of haemodynamics. As the difference between SPG and PPG under low perfusion conditions is not fully understood, a Cold Pressor Test (CPT-60 s full hand immersion in ice water), was used to modulate blood pressure and peripheral circulation. A custom-built setup simultaneously derived SPG and PPG from the same video streams at two wavelengths (639 nm and 850 nm). SPG and PPG were measured at the right index finger location before and during the CPT using finger Arterial Pressure (fiAP) as a reference. The effect of the CPT on the Alternating Component amplitude (AC) and Signal-to-Noise Ratio (SNR) of dual-wavelength SPG and PPG signals was analysed across participants. Furthermore, waveform differences between SPG, PPG, and fiAP based on frequency harmonic ratios were analysed for each subject (n = 10). Both PPG and SPG at 850 nm show a significant reduction during the CPT in both AC and SNR. However, SPG showed significantly higher and more stable SNR than PPG in both study phases. Harmonic ratios were found substantially higher in SPG than PPG. Therefore, in low perfusion conditions, SPG seems to offer a more robust pulse wave monitoring with higher harmonic ratios than PPG.
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Affiliation(s)
- Jorge Herranz Olazabal
- IMEC NL, 5656 AE Eindhoven, The Netherlands
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
| | | | | | | | - Fokko Wieringa
- IMEC NL, 5656 AE Eindhoven, The Netherlands
- Division of Internal Medicine, Department of Nephrology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Chris Van Hoof
- IMEC NL, 5656 AE Eindhoven, The Netherlands
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
- IMEC, 3000 Leuven, Belgium
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Garrett A, Kim B, Sie EJ, Gurel NZ, Marsili F, Boas DA, Roblyer D. Simultaneous photoplethysmography and blood flow measurements towards the estimation of blood pressure using speckle contrast optical spectroscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:1594-1607. [PMID: 37078049 PMCID: PMC10110303 DOI: 10.1364/boe.482740] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 05/03/2023]
Abstract
Non-invasive continuous blood pressure monitoring remains elusive. There has been extensive research using the photoplethysmographic (PPG) waveform for blood pressure estimation, but improvements in accuracy are still needed before clinical use. Here we explored the use of an emerging technique, speckle contrast optical spectroscopy (SCOS), for blood pressure estimation. SCOS provides measurements of both blood volume changes (PPG) and blood flow index (BFi) changes during the cardiac cycle, and thus provides a richer set of parameters compared to traditional PPG. SCOS measurements were taken on the finger and wrists of 13 subjects. We investigated the correlations between features extracted from both the PPG and BFi waveforms with blood pressure. Features from the BFi waveforms were more significantly correlated with blood pressure than PPG features ( R = - 0.55, p = 1.1 × 10-4 for the top BFi feature versus R = - 0.53, p = 8.4 × 10-4 for the top PPG feature). Importantly, we also found that features combining BFi and PPG data were highly correlated with changes in blood pressure ( R = - 0.59, p = 1.7 × 10-4 ). These results suggest that the incorporation of BFi measurements should be further explored as a means to improve blood pressure estimation using non-invasive optical techniques.
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Affiliation(s)
- Ariane Garrett
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Byungchan Kim
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Edbert J. Sie
- Reality Labs, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - Nil Z. Gurel
- Reality Labs, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | | | - David A. Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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Guo Y, Weng Y, Zhang Y, Tong S, Liu Y, Lu Z, Miao P. Random matrix-based laser speckle contrast imaging enables quasi-3D blood flow imaging in laparoscopic surgery. BIOMEDICAL OPTICS EXPRESS 2023; 14:1480-1493. [PMID: 37078051 PMCID: PMC10110314 DOI: 10.1364/boe.483655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 05/03/2023]
Abstract
Laser speckle contrast imaging (LSCI) provides full-field and label-free imaging of blood flow and tissue perfusion. It has emerged in the clinical environment, including the surgical microscope and endoscope. Although traditional LSCI has been improved in resolution and SNR, there are still challenges in clinical translations. In this study, we applied a random matrix description for the statistical separation of single and multiple scattering components in LSCI using a dual-sensor laparoscopy. Both in-vitro tissue phantom and in-vivo rat experiments were performed to test the new laparoscopy in the laboratory environment. This random matrix-based LSCI (rmLSCI) provides the blood flow and tissue perfusion in superficial and deeper tissue respectively, which is particularly useful in intraoperative laparoscopic surgery. The new laparoscopy provides the rmLSCI contrast images and white light video monitoring simultaneously. Pre-clinical swine experiment was also performed to demonstrate the quasi-3D reconstruction of the rmLSCI method. The quasi-3D ability of the rmLSCI method shows more potential in other clinical diagnostics and therapies using gastroscopy, colonoscopy, surgical microscope, etc.
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Affiliation(s)
- Yong Guo
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuanchi Weng
- Department of General Surgury, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yifan Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shanbao Tong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan Liu
- Department of Gastroenterology, The First Medical Center of PLA General Hospital, Beijing, 100171, China
| | - Zheng Lu
- Senior Department of Hepatology, The Fifth Medical Center of PLA General Hospital, Beijing, 100039, China
| | - Peng Miao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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Herranz Olazabal J, Wieringa F, Hermeling E, Van Hoof C. Comparing Remote Speckle Plethysmography and Finger-Clip Photoplethysmography with Non-Invasive Finger Arterial Pressure Pulse Waves, Regarding Morphology and Arrival Time. BIOENGINEERING (BASEL, SWITZERLAND) 2023; 10:bioengineering10010101. [PMID: 36671673 PMCID: PMC9854800 DOI: 10.3390/bioengineering10010101] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/04/2023] [Accepted: 01/08/2023] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The goal was to compare Speckle plethysmography (SPG) and Photoplethysmography (PPG) with non-invasive finger Arterial Pressure (fiAP) regarding Pulse Wave Morphology (PWM) and Pulse Arrival Time (PAT). METHODS Healthy volunteers (n = 8) were connected to a Non-Invasive Blood Pressure (NIBP) monitor providing fiAP pulse wave and PPG from a clinical transmission-mode SpO2 finger clip. Biopac recorded 3-lead ECG. A camera placed at a 25 cm distance recorded a video stream (100 fps) of a finger illuminated by a laser diode at 639 nm. A chest belt (Polar) monitored respiration. All signals were recorded simultaneously during episodes of spontaneous breathing and paced breathing. ANALYSIS Post-processing was performed in Matlab to obtain SPG and analyze the SPG, PPG and fiAP mean absolute deviations (MADs) on PWM, plus PAT modulation. RESULTS Across 2599 beats, the average fiAP MAD with PPG was 0.17 (0-1) and with SPG 0.09 (0-1). PAT derived from ECG-fiAP correlated as follows: 0.65 for ECG-SPG and 0.67 for ECG-PPG. CONCLUSION Compared to the clinical NIBP monitor fiAP reference, PWM from an experimental camera-derived non-contact reflective-mode SPG setup resembled fiAP significantly better than PPG from a simultaneously recorded clinical transmission-mode finger clip. For PAT values, no significant difference was found between ECG-SPG and ECG-PPG compared to ECG-fiAP.
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Affiliation(s)
- Jorge Herranz Olazabal
- IMEC, 3000 Leuven, Belgium
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
- IMEC NL, 5656 AE Eindhoven, The Netherlands
| | - Fokko Wieringa
- IMEC NL, 5656 AE Eindhoven, The Netherlands
- Division of Internal Medicine, Department of Nephrology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | | | - Chris Van Hoof
- IMEC, 3000 Leuven, Belgium
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
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8
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Feng X, Geng M, Meng X, Zou D, Jin Z, Liu G, Zhou C, Ren Q, Lu Y. SGLSA: Sphygmus gated laser speckle angiography for microcirculation hemodynamics imaging. Comput Med Imaging Graph 2023; 103:102164. [PMID: 36563513 DOI: 10.1016/j.compmedimag.2022.102164] [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: 06/23/2022] [Revised: 11/16/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
Hemodynamics imaging of the retinal microcirculation has been demonstrated to be potential access to evaluating ophthalmic diseases, cardio-cerebrovascular diseases, and metabolic diseases. However, existing structural and functional imaging techniques are insufficient in spatial or temporal resolution. The sphygmus gated laser speckle angiography (SGLSA) is proposed for structural and functional imaging with high spatiotemporal resolution. Compared with classic LSCI algorithms, SGLSA presents a much clearer perfusion image and higher signal-to-noise ratio pulsatility. The SGLSA algorithm also shows better performance on patients than traditional LSCI methods. The high spatiotemporal resolution provided by the SGLSA algorithm greatly enhances the ability of retinal microcirculation analysis, which makes up for the deficiency of the LSCI technology, and attaches great significance to retinal hemodynamic imaging, biomarker research, and clinical diagnosis.
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Affiliation(s)
- Ximeng Feng
- Institute of Medical Technology, Peking University Health Science Center, Peking University, Beijing, China; Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China; National Biomedical Imaging Center, Peking University, Beijing, China; Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Mufeng Geng
- Institute of Medical Technology, Peking University Health Science Center, Peking University, Beijing, China; Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China; National Biomedical Imaging Center, Peking University, Beijing, China; Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xiangxi Meng
- Key Laboratory of Carcinogenesis and Translational Research, Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China
| | - Da Zou
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Zi Jin
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Gangjun Liu
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Chuanqing Zhou
- College of Medical Instrument, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Qiushi Ren
- Institute of Medical Technology, Peking University Health Science Center, Peking University, Beijing, China; Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China; National Biomedical Imaging Center, Peking University, Beijing, China; Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yanye Lu
- Institute of Medical Technology, Peking University Health Science Center, Peking University, Beijing, China; National Biomedical Imaging Center, Peking University, Beijing, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China.
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9
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Herranz Olazábal J, Wieringa F, Hermeling E, Van Hoof C. Camera-Derived Photoplethysmography (rPPG) and Speckle Plethysmography (rSPG): Comparing Reflective and Transmissive Mode at Various Integration Times Using LEDs and Lasers. SENSORS (BASEL, SWITZERLAND) 2022; 22:6059. [PMID: 36015822 PMCID: PMC9412985 DOI: 10.3390/s22166059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Background: Although both speckle plethysmography (SPG) and photoplethysmography (PPG) examine pulsatile changes in the vasculature using opto-electronics, PPG has a long history, whereas SPG is relatively new and less explored. The aim of this study was to compare the effects of integration time and light-source coherence on signal quality and waveform morphology for reflective and transmissive rSPG and rPPG. Methods: (A) Using time-domain multiplexing, we illuminated 10 human index fingers with pulsed lasers versus LEDs (both at 639 and 850 nm), in transmissive versus reflective mode. A synchronized camera (Basler acA2000-340 km, 25 cm distance, 200 fps) captured and demultiplexed four video channels (50 fps/channel) in four stages defined by illumination mode. From all video channels, we derived rPPG and rSPG, and applied a signal quality index (SQI, scale: Good > 0.95; Medium 0.95−0.85; Low 0.85−0.8; Negligible < 0.8); (B) For transmission videos only, we additionally calculated the intensity threshold area (ITA), as the area of the imaging exceeding a certain intensity value and used linear regression analysis to understand unexpected similarities between rPPG and rSPG. Results: All mean SQI-values. Reflective mode: Laser-rSPG > 0.965, LED-rSPG < 0.78, rPPG < 0.845. Transmissive mode: 0.853−0.989 for rSPG and rPPG at all illumination settings. Coherent mode: Reflective rSPG > 0.951, reflective rPPG < 0.740, transmissive rSPG and rPPG 0.990−0.898. Incoherent mode: Reflective all <0.798 and transmissive all 0.92−0.987. Linear regressions revealed similar R2 values of rPPG with rSPG (R2 = 0.99) and ITA (R2 = 0.98); Discussion: Laser-rSPG and LED-rPPG produced different waveforms in reflection, but not in transmission. We created the concept of ITA to investigate this behavior. Conclusions: Reflective Laser-SPG truly originated from coherence. Transmissive Laser-rSPG showed a loss of speckles, accompanied by waveform changes towards rPPG. Diffuse spatial intensity modulation polluted spatial-mode SPG.
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Affiliation(s)
- Jorge Herranz Olazábal
- IMEC, 3000 Leuven, Belgium
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
| | - Fokko Wieringa
- IMEC NL, 5656 AE Eindhoven, The Netherlands
- Division of Internal Medicine, Department of Nephrology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | | | - Chris Van Hoof
- IMEC, 3000 Leuven, Belgium
- Faculty of Engineering Science, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
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10
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Hayakawa CK, Malenfant L, Ranasinghesagara J, Cuccia DJ, Spanier J, Venugopalan V. MCCL: an open-source software application for Monte Carlo simulations of radiative transport. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210348SSTR. [PMID: 35415991 PMCID: PMC9005200 DOI: 10.1117/1.jbo.27.8.083005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
The Monte Carlo Command Line application (MCCL) is an open-source software package that provides Monte Carlo simulations of radiative transport through heterogeneous turbid media. MCCL is available on GitHub through our virtualphotonics.org website, is actively supported, and carries extensive documentation. Here, we describe the main technical capabilities, the overall software architecture, and the operational details of MCCL.
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Affiliation(s)
- Carole K. Hayakawa
- University of California at Irvine, Department of Chemical and Biomolecular Engineering, Irvine, California, United States
- University of California at Irvine, Beckman Laser Institute, Irvine, California, United States
| | - Lisa Malenfant
- University of California at Irvine, Beckman Laser Institute, Irvine, California, United States
| | - Janaka Ranasinghesagara
- University of California at Irvine, Department of Chemical and Biomolecular Engineering, Irvine, California, United States
- University of California at Irvine, Beckman Laser Institute, Irvine, California, United States
| | | | - Jerome Spanier
- University of California at Irvine, Beckman Laser Institute, Irvine, California, United States
| | - Vasan Venugopalan
- University of California at Irvine, Department of Chemical and Biomolecular Engineering, Irvine, California, United States
- University of California at Irvine, Beckman Laser Institute, Irvine, California, United States
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11
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Feng X, Yu Y, Zou D, Jin Z, Zhou C, Liu G, Fujimoto JG, Li C, Lu Y, Ren Q. Functional imaging of human retina using integrated multispectral and laser speckle contrast imaging. JOURNAL OF BIOPHOTONICS 2022; 15:e202100285. [PMID: 34726828 DOI: 10.1002/jbio.202100285] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/25/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
A novel integration of retinal multispectral imaging (MSI), retinal oximetry and laser speckle contrast imaging (LSCI) is presented for functional imaging of retinal blood vessels that could potentially allow early detection or monitoring of functional changes. We designed and built a cost-effective, scalable, retinal imaging instrument that integrates structural and functional retinal imaging techniques, including MSI, retinal oximetry and LSCI. Color fundus imaging was performed with 470 nm, 550 nm and 600 nm wavelength light emitting diode (LED) illumination. Retinal oximetry was performed using 550 nm and 600 nm LED illumination. LSCI of blood flow was performed using 850 nm laser diode illumination at 82 frames per second. LSCI can visualize retinal and choroidal vasculature without requiring exogenous contrast agents and can provide time-resolved information on blood flow, generating a cardiac pulse waveform from retinal vasculature. The technology can rapidly acquire structural MSI images, retinal oximetry and LSCI blood flow information in a simplified clinical workflow without requiring patients to move between instruments. Results from multiple modalities can be combined and registered to provide structural as well as functional information on the retina. These advances can reduce barriers for clinical adoption, accelerating research using MSI, retinal oximetry and LSCI of blood flow for diagnosis, monitoring and elucidating disease pathogenesis.
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Affiliation(s)
- Ximeng Feng
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
- Institute of Medical Technology, Peking University, Beijing, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- National Biomedical Imaging Center, Beijing, China
| | - Yue Yu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
- Institute of Medical Technology, Peking University, Beijing, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- National Biomedical Imaging Center, Beijing, China
| | - Da Zou
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
- Institute of Medical Technology, Peking University, Beijing, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- National Biomedical Imaging Center, Beijing, China
| | - Zi Jin
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Chuanqing Zhou
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Gangjun Liu
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Changhui Li
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
- National Biomedical Imaging Center, Beijing, China
| | - Yanye Lu
- Institute of Medical Technology, Peking University, Beijing, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiushi Ren
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
- Institute of Medical Technology, Peking University, Beijing, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- National Biomedical Imaging Center, Beijing, China
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12
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Li H, Wang Z, Cao Y, Ma Y, Feng X. Optical difference in the frequency domain to suppress disturbance for wearable electronics. BIOMEDICAL OPTICS EXPRESS 2020; 11:6920-6932. [PMID: 33408970 PMCID: PMC7747917 DOI: 10.1364/boe.403033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/07/2020] [Accepted: 10/11/2020] [Indexed: 06/12/2023]
Abstract
Measurements based on optics offer a wide range of unprecedented opportunities in the biological application due to the noninvasive or non-destructive detection. Wearable skin-like optoelectronic devices, capable of deforming with the human skin, play significant roles in future biomedical engineering such as clinical diagnostics or daily healthcare. However, the detected signals based on light intensity are very sensitive to the light path. The performance degradation of the wearable devices occurs due to device deformation or motion artifact. In this work, we propose the optical difference in the frequency domain of signals for suppressing the disturbance generated by wearable device deformation or motion artifact during the photoplethysmogram (PPG) monitoring. The signal processing is simulated with different input waveforms for analyzing the performance of this method. Then we design and fabricate a wearable optoelectronic device to monitor the PPG signal in the condition of motion artifact and use the optical difference in the frequency domain of signals to suppress irregular disturbance. The proposed method reduced the average error in heart rate estimation from 13.04 beats per minute (bpm) to 3.41 bpm in motion and deformation situations. These consequences open up a new prospect for improving the performance of the wearable optoelectronic devices and precise medical monitoring in the future.
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Affiliation(s)
- Haicheng Li
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
| | - Zhouheng Wang
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
| | - Yu Cao
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
| | - Yinji Ma
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
| | - Xue Feng
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
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13
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Aydemir T, Sahin M, Aydemir O. Determination of hypertension disease using chirp z-transform and statistical features of optimal band-pass filtered short-time photoplethysmography signals. Biomed Phys Eng Express 2020; 6. [PMID: 34035194 DOI: 10.1088/2057-1976/abc634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/30/2020] [Indexed: 11/11/2022]
Abstract
Hypertension is the condition where the normal blood pressure is high. This situation is manifested by the high pressure of the blood in the vein towards the vessel wall. Hypertension mostly affects the brain, kidneys, eyes, arteries and heart. Therefore, the diagnosis of this common disease is important. It may take days, weeks or even months for diagnosis. Often a device, called a blood pressure holter, is connected to the person for 24 or 48 h and the person's blood pressure is recorded at certain intervals. Diagnosis can be made by the specialist physician considering these results. In recent years, various physiological measurement techniques have been used to accelerate this time-consuming diagnostic phase and intelligent models have been proposed. One of these techniques is photopletesmography (PPG). In this study, a model for the detection of hypertension disease in individuals was proposed using chirp z-transform and statistical features (total band power, autoregressive model parameters, standard deviation of signal's derivative and zero crossing rate) of optimal band-pass filtered short-time PPG signals. The proposed method was successfully applied to 657 PPG trials, which each of them had only 2.1 s signal length and achieved a classification accuracy rate of 77.52% on the test data. The results showed that the diagnosis of hypertension can be performed effectively by chirp z-transform and statistical features and support vector machine classifier using optimal frequency range of 1.4-6 Hz.
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Affiliation(s)
- Tugba Aydemir
- Department of Physics, Recep Tayyip Erdogan University, Rize, Turkey
| | - Mehmet Sahin
- Department of Physics, Recep Tayyip Erdogan University, Rize, Turkey
| | - Onder Aydemir
- Department of Electrical and Electronics Engineering, Karadeniz Technical University, Trabzon, Turkey
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14
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Rice TB, Yang B, White S. Effect of skin optical absorption on speckleplethysmographic (SPG) signals. BIOMEDICAL OPTICS EXPRESS 2020; 11:5352-5361. [PMID: 33014619 PMCID: PMC7510879 DOI: 10.1364/boe.403501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 05/02/2023]
Abstract
Recent advances in optical technology have emerged for measuring blood flow in the extremities using speckleplethysmography (SPG), which may address needs in vascular medicine and other fields. SPG has demonstrated a highly linear response with flow rate, but the susceptibility to differences in skin tone is unclear. Two validation studies using skin-simulating phantoms and a simple clinical protocol were conducted to determine the impact of absorbing skin layers on SPG measurements. Benchtop results demonstrated that the coefficient of determination between known flow rate and SPG was highly linear (R2 = 0.990) and was unaffected by the addition of skin-phantom layers with variable absorption (R2 = 0.996-0.999). Additionally, no significant trend was found between the fit residuals of SPG and flow rate with increasing skin-phantom absorption (R2=0.025, p = 0.29). In clinical testing, no significant difference was found using both a 4-way ANOVA between demographic classifications (F = 0.89, p = 0.45), and a 2-way ANOVA test between lower- and higher-melanin subclassifications (F = 0.4, p = 0.52).
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15
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Bi R, Du Y, Singh G, Ho CJH, Zhang S, Attia ABE, Li X, Olivo M. Fast pulsatile blood flow measurement in deep tissue through a multimode detection fiber. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-10. [PMID: 32406214 PMCID: PMC7219964 DOI: 10.1117/1.jbo.25.5.055003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/27/2020] [Indexed: 05/05/2023]
Abstract
SIGNIFICANCE Noninvasive in vivo fast pulsatile blood flow measurement in deep tissue is important because the blood flow waveform is correlated with physiological parameters, such as blood pressure and elasticity of blood vessels. Compromised blood flow may cause diseases, such as stroke, foot ulcer, and myocardial ischemia. There is great clinical demand for a portable and cost-effective device for noninvasive pulsatile blood flow measurement. AIM A diffuse-optics-based method, diffuse speckle pulsatile flowmetry (DSPF), was developed for fast measurement (∼300 Hz) of deep tissue blood flow noninvasively. To validate its performance, both a phantom experiment and in vivo demonstration were conducted. APPROACH Over the past two decades, single-mode fibers have been used as detection fibers in most diffuse-optics-based deep tissue blood flow measurement modalities. We used a multimode (MM) detection fiber with a core size of 200 μm for diffused speckle pattern detection. A background intensity correction algorithm was implemented for speckle contrast calculation. The MM detection fiber helped to achieve a level of deep tissue blood flow measurement similar to that of conventional modalities, such as diffuse correlation spectroscopy and diffuse speckle contrast analysis, but it increases the measurement rate of blood flow to 300 Hz. RESULTS The design and implementation of the DSPF system were introduced. The theory of the background intensity correction for the diffused speckle pattern detected by the MM fiber was explained. A flow phantom was built for validation of the performance of the DSPF system. An in vivo cuff-induced occlusion experiment was performed to demonstrate the capability of the proposed DSPF system. CONCLUSIONS An MM detection fiber can help to achieve fast (∼300 Hz) pulsatile blood flow measurement in the proposed DSPF method. The cost-effective device and the fiber-based flexible probe increase the usability of the DSPF system significantly.
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Affiliation(s)
- Renzhe Bi
- Singapore Bioimaging Consortium, Singapore
| | - Yao Du
- Singapore Bioimaging Consortium, Singapore
| | | | | | | | | | - Xiuting Li
- Singapore Bioimaging Consortium, Singapore
| | - Malini Olivo
- Singapore Bioimaging Consortium, Singapore
- Address all correspondence to Malini Olivo, E-mail:
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16
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Wang C, Chen X, Hong J, Meng L, Cheng W, Zhu X, Lu J, Li P. Extendable, large-field multi-modal optical imaging system for measuring tissue hemodynamics. BIOMEDICAL OPTICS EXPRESS 2020; 11:2339-2351. [PMID: 32499927 PMCID: PMC7249820 DOI: 10.1364/boe.386197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 05/08/2023]
Abstract
Simultaneous imaging of multiple hemodynamic parameters helps to evaluate the physiological and pathological status of biological tissue. To achieve multimodal hemodynamics imaging with a large field of view, an infinite conjugate relay lens system compatible with the standard C-Mount camera lens is designed to adapt one camera lens with multiple CCD/CMOS cameras for simultaneously multi-wavelength imaging. Using this relay lens system, dual wavelength reflectance imaging and laser speckle contrast imaging were combined to simultaneously detect the changes in blood flow, oxygenation, and hemoglobin concentrations. To improve the accuracy of hemoglobin concentration measurement with an LED illumination source, an integral algorithm is proposed that accounts for the dependence of differential pathlength factors (DPF) on hemoglobin concentrations and the integral effect of both the emission spectrum of the light source and the spectrum response of the detector. The imaging system is validated by both phantom and in vivo experiments, including the arterial occlusion, and the detection of blood volume pulse (BVP) and blood flow pulse (BFP) signal in human subjects. The system helps in the exploration of macroscopic tissue hemodynamics.
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Affiliation(s)
- Chen Wang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xiao Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jiachi Hong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Liangwei Meng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Weimin Cheng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xuan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jinling Lu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Pengcheng Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- HUST-Suzhou Institute for Brainsmatics, Suzhou 215125, China
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17
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Crouzet C, Wilson RH, Lee D, Bazrafkan A, Tromberg BJ, Akbari Y, Choi B. Dissociation of Cerebral Blood Flow and Femoral Artery Blood Pressure Pulsatility After Cardiac Arrest and Resuscitation in a Rodent Model: Implications for Neurological Recovery. J Am Heart Assoc 2020; 9:e012691. [PMID: 31902319 PMCID: PMC6988151 DOI: 10.1161/jaha.119.012691] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Impaired neurological function affects 85% to 90% of cardiac arrest (CA) survivors. Pulsatile blood flow may play an important role in neurological recovery after CA. Cerebral blood flow (CBF) pulsatility immediately, during, and after CA and resuscitation has not been investigated. We characterized the effects of asphyxial CA on short‐term (<2 hours after CA) CBF and femoral arterial blood pressure (ABP) pulsatility and studied their relationship to cerebrovascular resistance (CVR) and short‐term neuroelectrical recovery. Methods and Results Male rats underwent asphyxial CA followed by cardiopulmonary resuscitation. A multimodal platform combining laser speckle imaging, ABP, and electroencephalography to monitor CBF, peripheral blood pressure, and brain electrophysiology, respectively, was used. CBF and ABP pulsatility and CVR were assessed during baseline, CA, and multiple time points after resuscitation. Neuroelectrical recovery, a surrogate for neurological outcome, was assessed using quantitative electroencephalography 90 minutes after resuscitation. We found that CBF pulsatility differs significantly from baseline at all experimental time points with sustained deficits during the 2 hours of postresuscitation monitoring, whereas ABP pulsatility was relatively unaffected. Alterations in CBF pulsatility were inversely correlated with changes in CVR, but ABP pulsatility had no association to CVR. Interestingly, despite small changes in ABP pulsatility, higher ABP pulsatility was associated with worse neuroelectrical recovery, whereas CBF pulsatility had no association. Conclusions Our results reveal, for the first time, that CBF pulsatility and CVR are significantly altered in the short‐term postresuscitation period after CA. Nevertheless, higher ABP pulsatility appears to be inversely associated with neuroelectrical recovery, possibly caused by impaired cerebral autoregulation and/or more severe global cerebral ischemia.
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Affiliation(s)
- Christian Crouzet
- Beckman Laser Institute and Medical Clinic Irvine CA.,Department of Biomedical Engineering University of California Irvine CA.,University of California, Irvine Irvine CA
| | - Robert H Wilson
- Beckman Laser Institute and Medical Clinic Irvine CA.,University of California, Irvine Irvine CA
| | - Donald Lee
- Department of Neurology University of California Irvine CA.,University of California, Irvine Irvine CA
| | - Afsheen Bazrafkan
- Department of Neurology University of California Irvine CA.,University of California, Irvine Irvine CA
| | - Bruce J Tromberg
- Beckman Laser Institute and Medical Clinic Irvine CA.,Department of Biomedical Engineering University of California Irvine CA.,Department of Surgery University of California Irvine CA.,University of California, Irvine Irvine CA
| | - Yama Akbari
- Beckman Laser Institute and Medical Clinic Irvine CA.,Department of Neurology University of California Irvine CA.,University of California, Irvine Irvine CA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic Irvine CA.,Department of Biomedical Engineering University of California Irvine CA.,Department of Surgery University of California Irvine CA.,Edwards Lifesciences Center for Advanced Cardiovascular Technology Irvine CA.,University of California, Irvine Irvine CA
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18
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Dremin V, Zherebtsov E, Bykov A, Popov A, Doronin A, Meglinski I. Influence of blood pulsation on diagnostic volume in pulse oximetry and photoplethysmography measurements. APPLIED OPTICS 2019; 58:9398-9405. [PMID: 31873531 DOI: 10.1364/ao.58.009398] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/25/2019] [Indexed: 05/27/2023]
Abstract
Recent advances in the development of ultra-compact semiconductor lasers and technology of printed flexible hybrid electronics have opened broad perspectives for the design of new pulse oximetry and photoplethysmography devices. Conceptual design of optical diagnostic devices requires careful selection of various technical parameters, including spectral range; polarization and intensity of incident light; actual size, geometry, and sensitivity of the detector; and mutual position of the source and detector on the surface of skin. In the current study utilizing a unified Monte Carlo computational tool, we explore the variations in diagnostic volume due to arterial blood pulsation for typical transmitted and back-scattered probing configurations in a human finger. The results of computational studies show that the variations in diagnostic volumes due to arterial pulse wave are notably (up to 45%) different in visible and near-infrared spectral ranges in both transmitted and back-scattered probing geometries. While these variations are acceptable for relative measurements in pulse oximetry and/or photoplethysmography, for absolute measurements, an alignment normalization of diagnostic volume is required and can be done by a computational approach utilized in the framework of the current study.
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19
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Dunn CE, Monroe DC, Crouzet C, Hicks JW, Choi B. Speckleplethysmographic (SPG) Estimation of Heart Rate Variability During an Orthostatic Challenge. Sci Rep 2019; 9:14079. [PMID: 31575905 PMCID: PMC6773734 DOI: 10.1038/s41598-019-50526-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/04/2019] [Indexed: 01/16/2023] Open
Abstract
Heart rate variability (HRV) provides insight into cardiovascular health and autonomic function. Electrocardiography (ECG) provides gold standard HRV measurements but is inconvenient for continuous acquisition when monitored from the extremities. Optical techniques such as photoplethysmography (PPG), often found in health and wellness trackers for heart rate measurements, have been used to estimate HRV peripherally but decline in accuracy during increased physical stress. Speckleplethysmography (SPG) is a recently introduced optical technique that provides benefits over PPG, such as increased signal amplitude and reduced susceptibility to temperature-induced vasoconstriction. In this research, we compare SPG and PPG to ECG for estimation of HRV during an orthostatic challenge performed by 17 subjects. We find that SPG estimations of HRV are highly correlated to ECG HRV for both time and frequency domain parameters and provide increased accuracy over PPG estimations of HRV. The results suggest SPG measurements are a viable alternative for HRV estimation when ECG measurements are impractical.
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Affiliation(s)
- Cody E Dunn
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612, USA.,Department of Biomedical Engineering, University of California, Irvine, California, 92697, USA.,Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, California, 92697, USA
| | - Derek C Monroe
- Department of Neurology, University of California, Irvine, California, 92697, USA
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612, USA.,Department of Biomedical Engineering, University of California, Irvine, California, 92697, USA
| | - James W Hicks
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, 92697, USA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612, USA. .,Department of Biomedical Engineering, University of California, Irvine, California, 92697, USA. .,Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, California, 92697, USA. .,Department of Surgery, University of California, Irvine, California, 92697, USA.
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20
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Lertsakdadet B, Dunn C, Bahani A, Crouzet C, Choi B. Handheld motion stabilized laser speckle imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:5149-5158. [PMID: 31646037 PMCID: PMC6788584 DOI: 10.1364/boe.10.005149] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/31/2019] [Accepted: 09/03/2019] [Indexed: 05/19/2023]
Abstract
Laser speckle imaging (LSI) is a wide-field, noninvasive optical technique that allows researchers and clinicians to quantify blood flow in a variety of applications. However, traditional LSI devices are cart or tripod based mounted systems that are bulky and potentially difficult to maneuver in a clinical setting. We previously showed that the use of a handheld LSI device with the use of a fiducial marker (FM) to account for motion artifact is a viable alternative to mounted systems. Here we incorporated a handheld gimbal stabilizer (HGS) to produce a motion stabilized LSI (msLSI) device to further improve the quality of data acquired in handheld configurations. We evaluated the msLSI device in vitro using flow phantom experiments and in vivo using a dorsal window chamber model. For in vitro experiments, we quantified the speckle contrast of the FM (KFM) using the mounted data set and tested 80% and 85% of KFM as thresholds for useable images (KFM,Mounted,80% and KFM,Mounted,85%). Handheld data sets using the msLSI device (stabilized handheld) and handheld data sets without the HGS (handheld) were collected. Using KFM,Mounted,80% and KFM,Mounted,85% as the threshold, the number of images above the threshold for stabilized handheld (38 ± 7 and 10 ± 2) was significantly greater (p = 0.031) than for handheld operation (16 ± 2 and 4 ± 1). We quantified a region of interest within the flow region (KFLOW), which led to a percent difference of 8.5% ± 2.9% and 7.8% ± 3.1% between stabilized handheld and handheld configurations at each threshold. For in vivo experiments, we quantified the speckle contrast of the window chamber (KWC) using the mounted data set and tested 80% of KWC (KWC,Mounted,80%). Stabilized handheld operation provided 53 ± 24 images above KWC,Mounted,80%, while handheld operation provided only 23 ± 13 images. We quantified the speckle flow index (SFI) of the vessels and the background to calculate a signal-to-background ratio (SBR) of the window chamber. Stabilized handheld operation provided a greater SBR (2.32 ± 0.29) compared to handheld operation (1.83 ± 0.21). Both the number of images above threshold and SBR were statistically significantly greater in the stabilized handheld data sets (p = 0.0312). These results display the improved usability of handheld data acquired with an msLSI device.
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Affiliation(s)
- Ben Lertsakdadet
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Cody Dunn
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
- Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, 2400 Engineering Hall, Irvine, CA 92697, USA
| | - Adrian Bahani
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
- Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, 2400 Engineering Hall, Irvine, CA 92697, USA
- Department of Surgery, University of California, Irvine, 333 City Boulevard West, Suite 1600, Orange, CA 92868, USA
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21
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Zaytsev VV, Miridonov SV, Mamontov OV, Kamshilin AA. Contactless monitoring of the blood-flow changes in upper limbs. BIOMEDICAL OPTICS EXPRESS 2018; 9:5387-5399. [PMID: 30460135 PMCID: PMC6238901 DOI: 10.1364/boe.9.005387] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/21/2018] [Accepted: 10/05/2018] [Indexed: 05/05/2023]
Abstract
Vasomotor reactivity, which is important to estimate neurogenic regulation of blood vessels in patients with different pathologies, is still assessed by occlusion plethysmography using sensors contacting the limbs. Recently we proposed a contactless approach for measuring blood flow changes during venous occlusion using imaging photoplethysmography [Kamshilin et al., Sci. Rep.7, 4642017]. In this work, the response of the vascular system on the occlusion was studied simultaneously by contact air-plethysmography system and remote optical system under illumination by incoherent polarized green light. A high correlation (r > 0.93) between the waveforms measured by both system was observed. Moreover, we found that the response of the optical system on the venous occlusion is uniform at the whole area of the forearm. The new optical technique is more convenient for assessment of the blood flow dynamics because it can be used for measurements in any part of the body. Method of imaging photoplethysmography is very promising for use in equipment intended for evaluation of neurogenic mechanisms of regulation of vascular blood flow.
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Affiliation(s)
- Valeriy V. Zaytsev
- Department of Computer Photonics and Videomatics, ITMO University, 49 Kronverksky Pr., 197101 St. Petersburg, Russia
| | - Serguei V. Miridonov
- Optics Department, Centro de Investigación Cientfica y de Educación Superior de Ensenada, 3918 Carretera Tijuana-Ensenada, 22860 Ensenada, Baja California, Mexico
| | - Oleg V. Mamontov
- Department of Computer Photonics and Videomatics, ITMO University, 49 Kronverksky Pr., 197101 St. Petersburg, Russia
- Department of Circulation Physiology, Almazov National Medical Research Center, 2 Akkuratova St., 197341 St. Petersburg, Russia
| | - Alexei A. Kamshilin
- Department of Computer Photonics and Videomatics, ITMO University, 49 Kronverksky Pr., 197101 St. Petersburg, Russia
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