MEMS-Based Sensor for Simultaneous Measurement of Pulse Wave and Respiration Rate

Abstract

The continuous measurements of vital signs (body temperature, blood pressure, pulse wave, and respiration rate) are important in many applications across various fields, including healthcare and sports. To realize such measurements, wearable devices that cause minimal discomfort to the wearers are highly desired. Accordingly, a device that can measure multiple vital signs simultaneously using a single sensing element is important in order to reduce the number of devices attached to the wearer’s body, thereby reducing user discomfort. Thus, in this study, we propose a device with a microelectromechanical systems (MEMS)-based pressure sensor that can simultaneously measure the blood pulse wave and respiration rate using only one sensing element. In particular, in the proposed device, a thin silicone tube, whose inner pressure can be measured via a piezoresistive cantilever, is attached to the nose pad of a pair of eyeglasses. On wearing the eyeglasses, the tube of sensor device is in contact with the area above the angular artery and nasal cavity of the subject, and thus, both pulse wave and breath of the subject cause the tube’s inner pressure to change. We experimentally show that it is possible to extract information related to pulse wave and respiration as the low-frequency and high-frequency components of the sensor signal, respectively.

Sensing Systems for Respiration Monitoring: A Technical Systematic Review

“…Regarding the duration of the experiments, most of the studies carried out short experiments of a few minutes. In fact, 58% of the studies performed tests of less than 5 minutes [ 69 , 70 , 81 , 86 , 87 , 88 , 96 , 100 , 102 , 104 , 111 , 125 , 136 , 161 , 163 , 165 , 171 , 172 , 173 , 174 , 193 , 195 , 196 , 200 , 212 , 215 , 221 , 228 , 229 , 232 ]. Most of the works that conducted longer tests included sleep studies [ 7 , 17 , 53 , 60 , 115 , 146 , 148 , 164 , 165 , 169 , 173 , 192 , 198 , 205 , 211 , 220 , 223 ].…”

Mask-Type Sensor for Pulse Wave and Respiration Measurements and Eye Blink Detection

“…The sponge pad was used to prevent the air chamber from remaining collapsed due to the sticking of the film to the tape. Finally, the substrate on which the cantilever chip was mounted was attached to the back side of the tape with the To calibrate the cantilever, we applied differential pressure in the range of ±3 Pa to the cantilever and measured the fractional resistance change of the cantilever using a setup described in previous papers [13,14]. The calibration results in Figure 2c clearly show that the fractional resistance change of the cantilever ∆R/R is proportional to the applied differential pressure ∆P.…”

“…Thus, to realize simultaneous measurements of multiple physiological parameters, it is often necessary to use multiple sensors simultaneously. Recently, our group reported a sensor type of eyeglasses that could simultaneously measure pulse waves and respiration using a single sensing element [ 13 ]. In this device, a tube-shaped pressure sensor was attached to the nose pad of eyeglasses and the pulse wave and respiration of the subject were extracted as low frequency (<10 Hz) and high frequency (>100 Hz) components of the sensor signal, respectively.…”

Advances and current challenges in non‐invasive wearable sensors and wearable biosensors—A mini‐review

“…(d) The wearable micro‐recorder with a cloud web portal that allows objective measurement for sleep apnoea (credit: braebon (Braebon Medical Corporation, 2015)). (e) The smart eyeglasses with the sensor device (reproduced under the terms of the CC BY‐NC licence (Nguyen & Ichiki, 2019) Copyright 2019, the authors, sensors, MDPI, Basel, Switzerland). (f) WBS for ECG measurements (Lee, Ha, et al, 2018) (reproduced under the terms of the CC BY‐NC licence (Lee, Ha, et al, 2018) Copyright © 2018, Springer Nature).…”