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

Thanh-Vinh Nguyen,Masaaki Ichiki

doi:10.3390/s21144895

Abstract

This paper reports on a mask-type sensor for simultaneous pulse wave and respiration measurements and eye blink detection that uses only one sensing element. In the proposed sensor, a flexible air bag-shaped chamber whose inner pressure change can be measured by a microelectromechanical system-based piezoresistive cantilever was used as the sensing element. The air bag-shaped chamber is fabricated by wrapping a sponge pad with plastic film and polyimide tape. The polyimide tape has a hole to which the substrate with the piezoresistive cantilever adheres. By attaching the sensor device to a mask where it contacts the nose of the subject, the sensor can detect the pulses and eye blinks of the subject by detecting the vibration and displacement of the nose skin caused by these physiological parameters. Moreover, the respiration of the subject causes pressure changes in the space between the mask and the face of the subject as well as slight vibrations of the mask. Therefore, information about the respiration of the subject can be extracted from the sensor signal using either the low-frequency component (<1 Hz) or the high-frequency component (>100 Hz). This paper describes the sensor fabrication and provides demonstrations of the pulse wave and respiration measurements as well as eye blink detection using the fabricated sensor.

Highlights

Wearable devices that can measure physiological parameters such as pulse waves, respiration, and eye blinks are important in various applications, including medical diagnosis, sports, physical training, and health monitoring of workers, drivers, etc
Pulse waves can be used as an indicator to diagnose cardiovascular diseases and diabetes [1,2,3], whereas information on respiration is useful for monitoring chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease [4]
Changes in physiological parameters such as heart and respiration rates can be used for the early detection of COVID-19, which is extremely important in preventing the spread of this disease [9,10,11]

Summary

Introduction

Wearable devices that can measure physiological parameters such as pulse waves, respiration, and eye blinks are important in various applications, including medical diagnosis, sports, physical training, and health monitoring of workers, drivers, etc. 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 (100 Hz) components of the sensor signal, respectively. This paper reports the design, fabrication, and evaluation of the sensor device and demonstrates the feasibility of simultaneous pulse wave and respiration measurements and eye blink detection using the fabricated sensor

Sensor Fabrication

Discussion