호흡 감지를 위한 복부 부착형 전도성 고무소자의 계측특성

Abstract

Conductive rubber material was molded in a belt shape to measure respiration. Its resistivity was approximately 0.03Ωm0.006 kΩ/oC negligible when practicaly applied on the abdomen. The conductive rubber belt was applied on a normalmale's abdomen with the dimensional change measured during resting breathing. The abdominal signal wasdiferentiated (Fm) and compared with the acurate standard air flow rate signal (Fs) obtained by pneumotachometry. Fmand Fs difered in waveform, but the start and end timings of each breaths were clearly synchronized, demonstrating thatthe respiratory frequency could be accurately estimated before further processing of Fm. Fm-Fshysteresis within each breath period, thus 6 piecewise linear approximation was performed, leading to a mean relativeeror of 14 %. This eror level was relatively large for clinical application, though customized calibration semed feasiblefor monitoring general variation of ventilation. The present technique would be of convenient and practical applicationas a new wearable respiratory transducer.