A wearable data acquisition system employing one tri-axis accelerometer - biomed 2009

We have developed a heart rate, respiration rate, posture, behavior and activity data acquisition system for monitoring certain health and activity features during daily life. The recording system consists of one tri-axis accelerometer, six low-power active filters, a low-power 8-bit microcontroller (MC) and a 128MB compact flash memory (CFM). The system is attached to the subject's chest and can simultaneously measure dynamic and static acceleration forces. The microcontroller continuously monitors X, Y and Z axis large dynamic acceleration forces that reveal patient movement. If the patient is moving, the MC detects whether the patient is changing body position, walking or running. If the patient is at rest, the MC detects heart rate and respiration rates from the X axis small dynamic acceleration force. The patient's posture is detected from the X and Y axis static acceleration forces. These detected signals are stored into the CFM, and then the data are downloaded to the laptop computer and used for monitoring the certain of the patient's health conditions.