Relationship between Pulse Wave Velocity and Vascular Change in the Human Finger Measured with Near-Infrared Light during Upper Arm Compression

Flow-mediated slowing (FMS), defined as the minimum pulse wave velocity (PWVmin) during reactive hyperemia, is potentially a simple, user-objective test for examining endothelial function. The purpose of the current study was to determine the effects of a known endothelial dysfunction protocol on arm PWV and PWVmin. Complete data were successfully collected in 22 out of 23 healthy adults (23.8 years [SD 4.1], 16 F, 22.8 kg/m2 [SD 2.8]). Local endothelial dysfunction was induced by increasing retrograde shear stress in the upper arm, through inflation of a distal (forearm) tourniquet to 75 mmHg, for 30 min. Pre- and post-endothelial dysfunction, PWV was measured followed by simultaneous assessment of PWVmin and flow-mediated dilation (FMD). PWV was measured between the upper arm and wrist using an oscillometric device, and brachial FMD using ultrasound. FMD (%) and PWVmin (m/s) were calculated as the maximum increase in diameter and minimum PWV during reactive hyperemia, respectively. Endothelial dysfunction resulted in a large effect size (ES) decrease in FMD (∆ = −3.10%; 95% CI: –4.15, –2.05; ES = −1.3), and a moderate increase in PWV (∆ = 0.38 m/s; 95% CI: 0.07, 0.69; ES = 0.5) and PWVmin (∆ = 0.16 m/s; 95% CI: 0.05, 0.28; ES = 0.6). There was a large intra-individual (pre- vs post-endothelial dysfunction) association between FMD and PWVmin ( r = −0.61; 95% CI: –0.82, –0.24). In conclusion, acute change in PWV and PWVmin are at least partially driven by changes in endothelial function.

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Measurement of flow-mediated dilatation using near-infrared transmission images of finger blood vessels (Comparison with brachial-ankle pulse wave velocity)

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.17-00063 ◽

2017 ◽

Vol 83 (856) ◽

pp. 17-00063-17-00063

Author(s):

Satoshi SHIMAWAKI ◽

Kazuki YOSHIDA ◽

Masataka NAKABAYASHI

Keyword(s):

Pulse Wave Velocity ◽

Blood Vessels ◽

Wave Velocity ◽

Near Infrared ◽

Pulse Wave ◽

Infrared Transmission ◽

Flow Mediated Dilatation

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Non-Contact Heart Rate Detection Based on Hand Vein Transillumination Imaging

Applied Sciences ◽

10.3390/app11188470 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8470

Author(s):

Shuqiang Yang ◽

Deqiang Cheng ◽

Jun Wang ◽

Huafeng Qin ◽

Yike Liu

Keyword(s):

Heart Rate ◽

Near Infrared ◽

Pulse Wave ◽

Region Of Interest ◽

Personal Identification ◽

Infrared Light ◽

Near Infrared Light ◽

Baseline Drift ◽

Living Body ◽

Hand Vein

Vein recognition technology identifies human vein characteristics under near-infrared light and compares it with stored vein information for personal identification. Although this has high anti-counterfeiting performance, it is possible to fabricate artificial hands that simulate vein characteristics to deceive the identity authentication system. In view of this potential deficiency, we introduced heart rate information to vein authentication, a means of living body detection, which can further improve the anti-counterfeiting effect of vein authentication. A hand vein transillumination imaging experiment was designed to prove its effectiveness. In the proposed method, a near-infrared light source is used to transilluminate the hand, and the transillumination images are collected by a common camera. Then, the region of interest is selected for gray-scale image processing, the feature value of each frame is extracted by superimposing and averaging the images, and then the one-dimensional pulse wave is drawn. Furthermore, the baseline drift phenomenon is filtered by morphological methods, and the maximum percentage frequency is determined by Fast Fourier Transform, that is, the pulse wave frequency. The heart rate value is then calculated, and finally, the stability of the heart rate detection result is evaluated. The experiment shows that the method produces accurate and stable results, demonstrating that it can provide living information (heart rate value) for vein authentication, which has great application prospects and development opportunities in security systems.

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EFFECT OF MEASUREMENT POSITION ON CARDIO-ANKLE VASCULAR INDEX (CAVI)

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237216500058 ◽

2016 ◽

Vol 28 (01) ◽

pp. 1650005

Author(s):

Satoshi Shimawaki ◽

Kazuma Yusa

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Supine Position ◽

Pulse Wave ◽

Wave Pattern ◽

Time Difference ◽

Upper Arm ◽

Pulse Arrival Time ◽

Second Heart Sound ◽

Pulse Arrival

There is a need for new methods to measure the level of arterial stiffness easily at home. A previous report investigating the effect of measurement position on brachial–ankle pulse wave velocity (baPWV) showed that baPWV was higher in the sitting position than in the supine position. This was probably because the increased ankle PWV was associated with increased hydrostatic pressure in the arteries of lower extremities. Therefore, we investigated the effect of measurement position on the cardio-ankle vascular index (CAVI), which is hardly affected by blood pressure. CAVI was measured in 50 healthy males (20–74 years) in five positions: supine, sitting, sitting with the knees flexed at 0[Formula: see text], reclining 50[Formula: see text], and standing. Compared to other positions, CAVI in the supine position was the lowest ([Formula: see text]); [Formula: see text] (the time difference between the second heart sound and the notch of the pulse wave in the upper arm) in the supine position was the highest ([Formula: see text]); and [Formula: see text] (the time difference between the minimum upper arm and ankle pulse wave pattern values) in the supine position was the highest ([Formula: see text]). Thus, our results indicated that changes in measurement position reduced pulse arrival time (increasing pulse wave velocity). We also observed a good correlation between CAVI in the supine position and that in other positions. The present study showed that the measurement position affected CAVI as much as it affected baPWV. Accordingly, correcting for the measurement position would be required when the position differs from supine.

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