Respiration monitoring during 6-min walk using wearable sensor measuring capacitance built across skin

A wearable respiratory sensor is developed based on capacitance sensing. The conductive cloth electrodes are sewn inside the belly band to give a natural feeling during wear. Respiration is unconsciously monitored using the capacitance built at the skin of the abdomen. Its expansion or contraction generates the capacitance change. Body motion other than respiration can cause noise. The coaxial electrode layout can be insensitive to the twisting body, which is included in the walking motion. Respiration is well monitored during a 6 min walk, which is the standard test in medical diagnoses. With the load of the exercise, metabolism requiring more oxygen is monitored.