An ultra-sensitive wearable accelerometer for continuous heart and lung sound monitoring.
This paper presents a chest-worn accelerometer with high sensitivity for continuous cardio-respiratory sound monitoring. The accelerometer is based on an asymmetrical gapped cantilever which is composed of a bottom mechanical layer and a top piezoelectric layer separated by a gap. This novel structure helps to increase the sensitivity by orders of magnitude compared with conventional cantilever based accelerometers. The prototype with a resonant frequency of 1100Hz and a total weight of 5 gram is designed, constructed and characterized. The size of the prototype sensor is 35mm×18mm×7.8mm (l×w×t). A built-in charge amplifier is used to amplify the output voltage of the sensor. A sensitivity of 86V/g and a noise floor of 40ng/√Hz are obtained. Preliminary tests for recording both cardiac and respiratory signals are carried out on human body and the new sensor exhibits better performance compared with a high-end electronic stethoscope.
Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI 48202, USA. eb2256@wayne.edu
Yating
Y
Hu
Yong
Y
Xu
D061725:Accelerometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D001314:Auscultation / Q000295:instrumentation* / Q000706:statistics & numerical data; D004867:Equipment Design; D006326:Heart Auscultation / Q000295:instrumentation* / Q000706:statistics & numerical data; D006347:Heart Sounds / Q000502:physiology*; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000706:statistics & numerical data; D012135:Respiratory Sounds / Q000502:physiology*; D019023:Stethoscopes