Conductive rubber belt to monitor respiratory changes

Conductive rubber material was molded in a belt shape to incorporate with patient's pants for continuous monitoring of breathing activity. Dimension changes of the abdomen resulted in corresponding resistance changes, which successfully monitored respiration. When the standard air flow rate was simultaneously measured by a pneumotachometer, mean relative error was approximately 15%, presumably due to lack of chest signal. Wireless Zigbee transmission also provided a great convenience for monitoring. The present device would be of advantages for wearable applications for its simplicity, low cost, and being washable.