Simultaneous measurements of tissue blood flow and oxygenation using a wearable fiber-free optical sensor

Liu, Xuhui; Gu, Yutong; Huang, Chong; Zhao, Mingjun; Cheng, Yanda; Jawdeh, Elie G. Abu; Bada, Henrietta S.; Chen, Lei; Yu, Guoqiang

doi:10.1117/1.jbo.26.1.012705

Cited by 14 publications

(17 citation statements)

References 63 publications

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“…1c), maximizing penetration depth at ~ 3 mm [32,41]. Our previous publications have verified the sufficiency of laser diode coherence for 6 mm S-D separation and the NanEye camera feasibility [37,39]. The S-D selection also promoted sensitivity primarily from the mouse brain region and is within the optimal instrument range (< 10 mm) [42][43][44].…”

Section: Wearable Fiber-free Head-stage/probe Optimized For Continuou...mentioning

confidence: 77%

“…Instead, rigid and fragile optical fibers couple the sources and detectors to the tissue surface, significantly constraining subject movement. Our group recently invented an innovative wearable diffuse speckle contrast flow oximetry (DSCFO) technique (US Patent #10842422, 2017) [36] , which provides a simple, low-cost, fiber-free, portable, and compact alternative for continuous and simultaneous monitoring of blood flow and oxygenation variations in tissues up to ~10 mm depth [37][38][39]. Herein, we focus only on blood flow aspects and refer to this simply as DSCF (diffuse speckle contrast flowmetry).…”

Section: Introductionmentioning

confidence: 99%

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A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Cerebral Blood Flow in Freely Behaving Mice

Liu

Irwin

Huang

et al. 2023

IEEE Trans. Biomed. Eng.

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Wearable technologies for functional brain monitoring in freely behaving subjects would advance our understanding of cognitive processing and adaptive behavior. Existing technologies are lacking in this capability or need procedures which are invasive and/or otherwise impede brain assessments during social behavioral conditions, exercise, and sleep. In response we developed a complete system combining cerebral blood flow (CBF) measurement, O 2 and CO 2 supplies, and behavior recording for use on conscious, freely behaving mice. An innovative diffuse speckle contrast flowmetry (DSCF) device and associated hardware were miniaturized and optimized for small subject applications. The installation and use of this wearable, fiber-free, near-infrared DSCF head-stage/probe required no craniotomy, invasive probe implantation, or restraints of awake animals. Significant correlations were found between measurements with the new DSCF design and an optical standard. The system successfully and repeatedly detected CBF responses to CO 2induced hypercapnia in both anesthetized and moving mice. Collecting CBF and activity information together during natural behaviors provides realistic physiological results and opens the path to exploring their correlations with pathophysiological conditions.

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Section: Wearable Fiber-free Head-stage/probe Optimized For Continuou...mentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Cerebral Blood Flow in Freely Behaving Mice

Liu

Irwin

Huang

et al. 2023

IEEE Trans. Biomed. Eng.

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“…In order to evaluate the performance of our prototype in terms of measuring oxygenation levels in the blood, we use the Vascular Occlusion Test [8] [9], which uses a manually pressurized cuff on the upper arm to reduce the blood flow to the lower arm and fingers. In these experiments we monitor the transmission of the laser light through the volunteer's index finger.…”

Section: Vascular Occlusion Test Protocolmentioning

confidence: 99%

“…In this prototype, the TDC is based on a Field Programmable Gate Array (FPGA) which enables greater flexibility and integration during the prototyping phase. To evaluate our result, we use the Vascular Occlusion Test (VOT) which induces a measurable change to the tissue oxygenation and total hemoglobin [9]. During the occlusion stage, the oxygenation levels fall slowly, and de-oxygenation levels rise.…”

Section: Introductionmentioning

confidence: 99%

A pulse oximeter based on time-of-flight histograms

Hua

Bantounos

Jalajakumari

et al. 2021

Photonic Instrumentation Engineering VIII

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A pulse oximeter is an optical device that monitors tissue oxygenation levels. Traditionally, these devices estimate the oxygenation level by measuring the intensity of the transmitted light through the tissue and are embedded into everyday devices such as smartphones and smartwatches. However, these sensors require prior information and are susceptible to unwanted changes in the intensity, including ambient light, skin tone, and motion artefacts. Previous experiments have shown the potential of Time-of-Flight (ToF) techniques in measurements of tissue hemodynamics. Our proposed technology uses histograms of photon flight paths within the tissue to obtain tissue oxygenation, regardless of the changes in the intensity of the source. Our device is based on a 45ps time-to-digital converter (TDC) which is implemented in a Xilinx Zynq UltraScale+ field programmable gate array (FPGA), a CMOS Single Photon Avalanche Diode (SPAD) detector, and a low-cost compact laser source. All these components including the SPAD detector are manufactured using the latest commercially available technology, which leads to increased linearity, accuracy, and stability for ToF measurements. This proof-of-concept system is approximately 10cm×8cm×5cm in size, with a high potential for shrinkage through further system development and component integration. We demonstrate preliminary results of ToF pulse measurements and report the engineering details, trade-offs, and challenges of this design. We discuss the potential for mass adoption of ToF based pulse oximeters in everyday devices such as smartphones and wearables.

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“…Therefore, it can be easily monitored using optical biosensors. An optical biosensor consists of a bio-receptor to capture the target analyte and a transducer whose optical properties, such as absorption, reflectance, emission, and interferometeric pattern, is altered in the presence of analyte [7,8]. There are various popular methods for monitoring the change in optical properties, and some of these methods are surface plasmon resonance (SPR) [9], microring resonators [10,11], reflectometric interference spectroscopy (RifS) [12], photonic interferometric biosensors [13], and planar waveguide interferometers [9,14].…”

Section: Introductionmentioning

confidence: 99%

Sensitivity Estimation of a Planar Optical Waveguide Using Broadband Difference Interferometeric Principle for Detection of Hemoglobin Concentration in Blood

Upadhyay¹,

Yadav²,

Yadav³

et al. 2022

PIER C

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Broadband differences interferometeric analysis of a three-layer planar polymer optical waveguide is proposed and optimized to detect the concentration of hemoglobin in blood. The dispersion characteristic and cutoff film thickness of proposed waveguide are obtained by matching the field at various boundaries. The obtained cutoff film thickness for TE 0 and TM 0 modes is 0.09 µm, 0.1 µm at operating wavelength 400 nm, and 0.19 µm and 0.23 µm at operating wavelength 800 nm, respectively. The effective refractive indices of TE 0 and TM 0 modes are obtained at two considered wavelengths, i.e., 400 nm and 800 nm, and hence the difference of their propagation constant is calculated. It is observed that the propagation constant of these modes decreases with the increase of wavelength. Also, the difference of propagation constant attains its maximum value at certain wavelength and decreases either side of this wavelength. The interference maxima signals at output are considered as sensing signal. The maxima of interference signals, close to the maximum value of propagation constant, are shifted sufficiently with the change in cover refractive index. The maximum sensitivity 3.8 nm/RIU is obtained in the proposed broadband differences interferometeric analysis of waveguide at film thickness 300 nm. Hence, at this film thickness the sensing signal changes by 0.68 nm/g/L of hemoglobin concentration in blood.

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Simultaneous measurements of tissue blood flow and oxygenation using a wearable fiber-free optical sensor

Cited by 14 publications

References 63 publications

A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Cerebral Blood Flow in Freely Behaving Mice

A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Cerebral Blood Flow in Freely Behaving Mice

A pulse oximeter based on time-of-flight histograms

Sensitivity Estimation of a Planar Optical Waveguide Using Broadband Difference Interferometeric Principle for Detection of Hemoglobin Concentration in Blood

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