Measurement of wheelchair size for analyzing transfer motion for SCI patients

We have proposed a system that measures the 3-D floor reaction forces of the left hands, both legs, and buttocks and the side and front view images using two charge-coupled-device (CCD) cameras during the side-transfer motion in order to clarify the side-transfer ability of spinal cord injury (SCI) patients. The purpose of this paper is to detect the body position on the wheelchair before the transfer motion by the side and front view images in order to analyze the motion such as the body, both upper limb, and the lower limb during the side-transfer motion. First, the wheelchair position and the wheelchair degree are detected from the center position of the right back wheel and the edge position of the both back wheels on the side and front view images. Next, the wheelchair size is measured by detecting the eleven points on the right side of the wheelchair and the measurement the wheelchair width such as the wheelchair seat and the distance between the hand rim and the back wheel. And then we can draw the wheelchair frame and the both back wheel on the side and front view transfer motion images using the calculated absolute coordinate values of the eleven points of the wheelchair.