실시간 정합을 이용한 인공 슬관절 치환 수술 로봇의 개발

Abstract

Total knee arthroplasty (TKA) is a surgical operation for replacing a degenerated or damaged knee joint that can no longer perform simple function, such as knee bending or walking, with an artificial knee implant. The artificial knee implant alignment with the mechanical axis of the leg is a one of most important factors in TKA. Thus, precise bone cutting result is essential to guarantee accurate insertion of the artificial knee implant. To obtain precise TKA outcomes, a registration process is performed to locate the pre-operatively planned bone cutting area in the operation room by calculating the position and posture of the femur and tibia. In this paper, we propose the patient-specific registration guide which can simplify registration process in terms of required time and effort without a loss of accuracy. Furthermore, the patient-specific registration guide allows implementing a real-time registration. Therefore, continuous surgical information can be provided without any invasive tracking devices. And, using real-time registration result, the tool paths were modified and updated to compensate bone movement due to be changed invasive fixation method as a non-invasive way. The precision and accuracy of the proposed registration guide were confirmed through animal tests with a digitizer, stereo camera and linear motion generator. And new bone cutting method was validated with 6-axis robot by comparing cutting result, ideal surgical planned cutting plane, cutting plane with invasive fixation and cutting plane with non-invasive fixation as following tool path compensation. The error of our registration method, including measurement and guide attachment errors, reached a maximum of 0.3 mm for one pair of cow legs. And the total surgical error of our system was below 0.5mm for artificial human leg.