Active compliance in robotic surgery—the use of force control as a dynamic constraint

Abstract

Robotic surgery can be carried out automatically by using a robot to move the cutting tool under position control. However, although the surgeon can observe the procedure on a visual display and has the ability to stop the operation in an emergency, he has little direct contact with the task. An alternative approach is to involve the surgeon more directly, by his moving a robot using active force control. The robot is then used to allow motion in preprogrammed regions, by the surgeon back-driving the robot motors, while preventing motion in prohibited areas. This active constraint robot (or ACROBOT) is described in this paper applied to knee surgery, in which the knee bones are accurately machined to allow the fitting of prosthetic knee implants. The ACROBOT is, however, ideally suited to a range of surgical procedure, because it allows the surgeon to feel the forces exerted during cutting and take appropriate action. This ability to be in direct control, while being constrained to cut within a permitted region, enhances safety and makes the system more acceptable to the medical community. The system of programmable constraint also allows the ACROBOT to provide the traditional benefits of robot surgery, namely the ability to machine complex geometrical surfaces very accurately and to make repetitive motions tirelessly. The system also has a potential for minimally invasive procedures. In knee surgery, for example, the robot could operate through a small incision in the skin and excise a volume into which a small, specially designed, unicompartmental prosthesis could fit.

Blood loss in computer-assisted mobile bearing total knee arthroplasty. A comparison of computer-assisted surgery with a conventional technique

“…Computer-assisted surgery (CAS) in TKA has been a very successful modality in the treatment of knee arthritis and has become increasingly common during recent years [3,18,19].…”

Implicit active constraints for a compliant surgical manipulator

“…II-A, both interpolated contours are projected onto the plane defined in (16) using (5). To transform the projected points into 2D, the two vectors spanning the plane determined in (16) are required.…”

Spatial Motion Constraints for Robot Assisted Suturing Using Virtual Fixtures

“…Different techniques [5,6,7,8] have been proposed to provide interaction modes in which the surgeon shares the control of the robot with the computer process.…”