Research on the non-contact respiratory detection sensor
The most prevalent method for respiration detection is by means of contact sensors. However,when worn for extended periods,these sensors may lead to skin irritation or discomfort. In contrast,non-contact respiration detection sensors utilize the Doppler effect to detect breathing,presenting a non-invasive alternative that effectively resolves these issues. The system encompasses modules such as a single-chip millimeter-wave radar and an STM32 microprocessor,all assembled through microfabrication technology. After the FMCW signal transmitted by the radar is mixed with the received signal,the signal noise is filtered via median filtering. Subsequently,zero-mean normalization is carried out before undergoing FFT transformation and spectrum analysis to calculate the respiratory rate. Test results indicate that when the distance is between 1.0 and 2.0 meters,the accuracy rate of detecting the respiratory rate for 30 to 60 seconds can reach 98.9％,with an error value within±1 time per minute. When installed obliquely,with a person lying flat for testing and a vertical distance of 1.0 to 1.5 meters,the accuracy rate of detecting within 10 to 30 seconds can reach 98.2％,and the accuracy rate of detecting for 60 seconds can reach 99.1％,also with an error value within±1 time per minute. The accuracy rate of supine respiratory detection at the same time and distance is higher than that of horizontal detection.
万方数据
维普
