Dan Stoianovici

CT-directed robotic biopsy testbed: motivation and concept

As a demonstration platform, we are developing a robotic biopsy testbed incorporating a mobile CT scanner, a small needle driver robot, and an optical localizer. This testbed will be used to compare robotically assisted biopsy to the current manual technique, and allow us to investigate software architectures for integrating multiple medical devices. This is a collaboration between engineers and physicians from three universities and a commercial vendor. In this paper we describe the CT-directed biopsy technique, review some other biopsy systems including passive and semi- autonomous devices, describe our testbed components, and present our software architecture. This testbed is a first step in developing the image-guided, robotically assisted, physician directed, biopsy systems of the future.

Ultrasound-, CT- and MR-Guided Robot-Assisted Interventions

The economic advantages and increased precision persistently demonstrated by industrial robots have stimulated the application of robots in the medical arena (Fichtinger et al. 2001; Cleary and Nguyen 2001; Nathoo et al. 2005). The main advantages of medical robotic systems include accurate needle guidance and stable access, leading to increased precision, accuracy and reproducible sampling of different parts of a lesion. Robotic-assisted procedures also involve the insertion of tubular therapy devices (ablation probes, catheters, bone drills, screws, tissue ablating devices, etc.) into the body, with the guidance of intra-operative imaging devices, such as CT, MRI, ultrasound or fluoroscopy (Cleary and Nguyen 2001; Cleary et al. 2006; Davies 2000; Fichtinger et al. 2001; Howe and Matsuoka 1999; Pott et al. 2005). The potential advantages are well known in the technical community (Fichtinger et al. 2001) and a variety of medical robots have been developed in recent years, including robotics for rehabilitation, or miniature robots that might be placed inside the body (Fichtinger et al. 2001; Kassim et al. 2005; Masamune et al. 2001; Nathoo et al. 2001; Satava 2003; Yanof et al. 2001).

Robotic percutaneous interventions

A robot is a mechanical device controlled by a computer. The first industrial robot was created by J. Engelberger and G. Deroe in 1961 and consisted of an articulated arm used in the automobile industry. The first robotic systems in the field of medicine began in the 1980s and were derived from industrial robots. However, the medical requirements for safety, sterility, and demanding constraints of the applications led to the development of specialized robots. In urology, robotics was introduced in 1989 by B. Davies at the Imperial College in London for transurethral resection of the prostate (TURP). 1

Software architecture for robotically assisted and image-guided minimally invasive interventions

Although more sophisticated software and hardware components are becoming available, technology for the operating room and interventional suite can be slow to change. The integration of vendor specific software and hardware components remains difficult, and the resulting systems are limited in reuse, flexibility, interoperability, and maintainability. One potential solution to this problem is to develop open software architectures as a platform for rapidly integrating new technologies into the operating room. In an ongoing effort to develop modular software architectures for systems designed to assist in minimally invasive interventions, two systems are outlined here: a “needle driver” robot and an image-guided surgery system based of magnetic tracking of internal organ motion. To date, the robot system has been used to complete a cadaver study of nerve and facet block placement under joystick control of the interventionalist. The image-guided surgery system has been used in phantom studies of liver needle placement. Potential future developments include fluoroscopy servoing in which the robot will automatically align the needle along the C-arm trajectory and the integration of the robot and tracking systems.