Robotic systems for computer-assisted surgery involve both tools and techniques that are new to the surgical arena. Registration and immobilization in particular are key problems. Registration is the spatial alignment of the coordinate frames of the robot, an anatomic object (e.g., a bone), and the preoperative plan (a computer model). Immobilization is necessary to maintain that alignment. We discuss various approaches to registration and immobilization and solutions appropriate for an orthopedic surgical system. J h u g e &id Surg 1: 80-87 (1995). 01995 Wiey-Liss, Inc.

Robotic systems for computer assisted surgery involve both tools and techniques which are new to the surgical arena. Registration and immobilization in particular are key problems. Registration is the spatial alignment of the coordinate frames of the robot, an anatomic object (e.g., a bone), and the preoperative plan (a computer model). Immobilization is necessary to maintain that alignment. We discuss various approaches to registration and immobilization, and solutions appropriate for an orthopedic surgical system.