Brent D. Mittelstadt

An image-directed robotic system for precise orthopaedic surgery

The authors have developed an image-directed robotic system to augment the performance of human surgeons in precise bone machining procedures in orthopaedic surgery, initially targeted at cementless total hip replacement surgery. The total system consists of an interactive CT-based presurgical planning component and a surgical system consisting of a robot, redundant motion monitoring, and man-machine interface components. In vitro experiments conducted with this system have demonstrated an order-of-magnitude improvement in implant fit and placement accuracy, compared to standard manual preparation techniques. The first generation system described in this paper was used in a successful veterinary clinical trial on 26 dogs needing hip replacement surgery. It was the basis for subsequent development of a second-generation system that is now in human clinical trials. >

Force sensing and control for a surgical robot

The authors describe the use of force feedback in a surgical robot system (ROBODOC). The application initially being addressed is total hip replacement (THR) surgery, where the robot must prepare a cavity in the femur for an artificial implant. In this system, force feedback is used to provide safety, tactile search capabilities, and an improved man-machine interface. Output of the force sensor is monitored by a safety processor, which initiates corrective action if any of several application-defined thresholds are exceeded. The robot is able to locate objects using guarded moves and force control (ball-in-cone strategy). In addition, the force control algorithm provides an intuitive man-machine interface which allows the surgeon to guide the robot by leading its tool to the desired location. An application of force control currently under development is described, where the force feedback is used to modify the cutter feed rate (force controlled velocity).<<ETX>>

An integrated system for cementless hip replacement

Describes robotics and medical imaging technology in the enhancement of precision surgery. The authors consider: cementless total hip replacement application; system overview; ORTHODOC preoperative planning workstation; ROBODOC surgical assistant; safety features; surgical protocol. >

Development of a surgical robot for cementless total hip replacement

The combination of robotics and medical imaging may soon provide orthopaedic surgeons with a tool that significantly increases the precision of cementless total hip replacement operations and directly links preoperative planning with surgical execution. Twenty-six successful robot-assisted operations have been performed on dogs and the first clinical trials on human patients have recently taken place.

Architecture of a surgical robot

The ROBODOC Surgical Assistant System has been developed to increase the accuracy and efficacy of surgical procedures. The first application is total hip replacement surgery, where the function of the robot is to machine a cavity in the patients femure for a prosthetic implant. The authors describe the hardware and software architecture of the operating room component of the system. The design satisfies the unique requirements of the surgical environment and the general requirements of a complex robotic system.<<ETX>>

Robotic total hip replacement surgery in dogs

Approximately half of over 120000 total hip replacement operations performed annually in the United States use cementless implants. The standard method for preparing the femoral cavity for such implants improves the use of mallet-driven handheld broach whose shape matches that of the desired implant. In vitro experiments have supported the possibility that more accurate (and efficacious) results can be achieved by using a robot to machine the cavity. The authors are developing a second-generation system suitable for use in an operating room, targeted at clinical trials on dogs needing hip implants. A description is given of the background, objectives, architecture, and surgical procedure for this system. Also provided are brief descriptions of key results from earlier experiments and planned future work.<<ETX>>