Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review

Abstract

Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW) radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends.

Simultaneous Life Detection and Localization Using a Wideband Chaotic Signal with an Embedded Tone

“…Single-tone continuous wave is also called Doppler radar or interferometry radar, and it has high receiving sensitivity, high measurement accuracy, simple structure, low cost and relatively easy post-processing [15]. However, it is difficult to detect range information, which is important for assisted-living, trapped victim searching, and through wall hostage rescue.…”

“…Multiple Doppler radars based on angle of arrival algorithms [17] can estimate the position of moving targets, but they can only determine an enclosed region instead of giving a precise location of the target. The FMCW, SFCW, and IR-UWB radar can localize and separate multiple targets, even in through-wall scenarios, but suffer from higher cost, more complex architecture, and more complicated advanced signal processing algorithms [15,18,19,20,21]. Besides that, to achieve high range resolution a large bandwidth is needed, which will reduce the receiving sensitivity and thus harm the robust detection of the weak vital signal.…”

Non-contact physiological signal monitoring system based on Doppler radar

“…The systems overcome the shortcomings of traditional physiological monitoring system, with advantages of non-contact, remote monitoring and simple [1]. Therefore, it has been more and more attention in the fields of clinical medicine, health care and many other applications [2]. The aim of this paper is to design an analog and digital filters for a Doppler radar signal acquisition system to separate physiological signals.…”

Ultra-Wide Patch Antenna Array Design at 60 GHz Band for Remote Vital Sign Monitoring with Doppler Radar Principle

“…vital sign monitoring devices, such as electrocardiogram (ECG), pulse oximetry and capnography, because the conventional devices need direct sensors plantation on the subject body as well as they consume comparatively much longer implementation time to start the measurements [1][2][3][4][5][6][7][8]. However, the results accuracy and reliability of RVSM system need to be dealt appropriately for its real-life applications [2].…”

“…However, the results accuracy and reliability of RVSM system need to be dealt appropriately for its real-life applications [2]. RVSM finds a vast number of applications in regular and special health care, emergency services, security and defence sectors [1][2][3][4][5][6][7][8][9][10][11][12].…”