Angle Estimation of Instrument for Mosaicplasty by using Knowledge of Force Distribution

Abstract

Mosaicplasty is one of the surgeries for knee cartilage damage. It transplants the bone autograft with the cartilage to the injured area. In this surgery, it is important to harvest the cartilage graft vertically and transplant it vertically by using a harvester for preventing area around transplant from discontinuous of the cartilage surface. This study set the goal to develop a system to estimate the pose of harvester against the articular surface in considering with a force distribution measured by a force sensor. The proposed method measures a force distribution on the cartilage surface by using eight force sensors which are attached to the front edge of the harvestor of the surfical instrument. It estimates the angle between the articular surface and harvester based on the force distribution. The experiment used a portable force tester for loading, and estimated the angle of the harvester. The result shows the maximum of the angle estimation error was 8 degrees. The experiment of angle estimation performed multiple times, it was confirmed reproducibility. As a future work, angle of estimation is displayed in real time.