Posture Determination of Wheelchair Caregivers Using Acceleration and Gyro Sensors

Abstract

Japan’s aging population is one of the highest in the world, and the need for nursing care is expected to increase more and more. Back pain accounts for more than 60% of all work-related illnesses, and by industry, the insurance and sanitation industry accounts for about 24% of the total. As the correlation between back pain and the physical load of moving and transfer care has been reported in the health insurance industry, measures to prevent back pain among caregivers are an urgent issue. In this research, we will develop a posture determination system for wheelchair caregivers. The system consists of an Arduino Uno and a 9-axis sensor module, and acquires data from acceleration sensors and angular rate sensors. The system is attached to the subject’s body and evaluates the burden during the work operation based on the values of the accelerometer and angular rate sensor. In the experiment with different postures, the frequency of the sensor value exceeding the threshold value under the condition of forward leaning posture is 0.62, which means that the forward leaning posture is a slightly more burdensome posture. On the other hand, in the experiment with different inclinations, the frequency with which the sensor value exceeded the threshold value in the condition with an inclination was 0.78, indicating that the condition is quite burdensome. Furthermore, in the walking experiment with different walking speeds, the frequency with which the sensor value exceeds the threshold under the condition of fast walking speed is 0.40, indicating that the walking speed does not affect the physical burden during the work.