Head Posture Distribution in the Job, Measured by a Remote Accelerometer

In order to measure head posture of the working dentists, we have developed a remote measuring device. The purpose of this study is to examine the performance of the device and the availability for the actual daily works. One 2-axes accelerometer was used for the sensor of head movement. The output of the sensor was transported wirelessly with the Bluetooth protocol. The sensor was put on the left ear of a subject by a headphone type attachment. The receiver was connected to a computer and the data was stored directly. The data of the accelerometer was converted to the angle of the head rotation in the computer. The range of the sensor was ±90°with resolution of 0.18°. The axes of the sensor was set as that can measure the front-back bending and side bending movement of the head with sampling rate of 100 Hz. The subject instructed to make a desk work and a dental treatment. The device could be ready for measure within five minutes. The measurable period by one battery was more than two hours. The confirmed effective distance of the transmitter was a range of six meters. By this device we could measure enough period of the dental works and cover the movement range and detect the characteristic head movement of the jobs. With the easiness of preparation and the accuracy, we concluded that this device is available for our purpose.