Abstract
We developed a system that estimates finger angle with a wearable device like a wrist watch. The device measures wrist contour shape changing with finger motion. Wrist contour sensing is realized by tiny photo-reflectors on the band of the device. The photo-reflectors measure distance between the band and the wrist surface. For switching the photo-reflectors, shift-register circuit is also implemented. Finger angle estimation consists of 4 steps; 1) aggregating wrist contour data of various finger motion in advance, 2) measuring wrist contour by the device, 3) selecting some similar wrist contour from the pre-measured data, 4) averaging finger angle of selected data. Moreover, contour data is corrected using particular finger motion for reduction of bad effect caused by difference of device attachment. In experiment, this system successfully estimated finger angle of finger flexion with wrist pronation.
