Lazaro Marc, Lazaro Antonio, Villarino Ramon, Girbau David
Department of Electronics, Electrics and Automatic Control Engineering, Rovira i Virgili University, 43007 Tarragona, Spain.
Sensors (Basel). 2021 Nov 10;21(22):7472. doi: 10.3390/s21227472.
The COVID-19 pandemic has highlighted a large amount of challenges to address. To combat the spread of the virus, several safety measures, such as wearing face masks, have been taken. Temperature controls at the entrance of public places to prevent the entry of virus carriers have been shown to be inefficient and inaccurate. This paper presents a smart mask that allows to monitor body temperature and breathing rate. Body temperature is measured by a non-invasive dual-heat-flux system, consisting of four sensors separated from each other with an insulating material. Breathing rate is obtained from the temperature changes within the mask, measured with a thermistor located near the nose. The system communicates by means of long-range (LoRa) backscattering, leading to a reduction in average power consumption. It is designed to establish the relative location of the smart mask from the signal received at two LoRa receivers installed inside and outside an access door. Low-cost LoRa transceivers with WiFi capabilities are used in the prototype to collect information and upload it to a server. Accuracy in body temperature measurements is consistent with measurements made with a thermistor located in the armpit. The system allows checking the correct placement of the mask based on the recorded temperatures and the breathing rate measurements. Besides, episodes of cough can be detected by sudden changes in thermistor temperature.
新冠疫情凸显了大量需要应对的挑战。为了抗击病毒传播，人们采取了一些安全措施，比如佩戴口罩。事实证明，在公共场所入口处进行体温检测以防止病毒携带者进入的做法效率低下且不准确。本文介绍了一种智能口罩，它能够监测体温和呼吸频率。体温由一个非侵入式双热流系统测量，该系统由四个用绝缘材料彼此隔开的传感器组成。呼吸频率通过口罩内的温度变化获取，温度变化由位于鼻子附近的热敏电阻测量。该系统通过远距离（LoRa）反向散射进行通信，从而降低了平均功耗。它旨在根据安装在通道门内外的两个LoRa接收器接收到的信号来确定智能口罩的相对位置。原型中使用了具有WiFi功能的低成本LoRa收发器来收集信息并上传至服务器。体温测量的准确性与使用腋下热敏电阻进行的测量结果一致。该系统能够根据记录的温度和呼吸频率测量结果检查口罩的正确佩戴位置。此外，通过热敏电阻温度的突然变化可以检测到咳嗽发作。
