Abstract: Apparatus for positioning a surgical instrument during a surgical orthopaedic procedure relative to the coordinate system of the apparatus, comprises a surgical instrument and a robotic control system for moving the surgical instrument within the apparatus coordinate system according to program instructions. An instrument sensor is fixed relative to the instrument to indicate the true position of the instrument within the apparatus coordinate system, and a reference sensor is then fixed to a patient's bone to indicate the position of the patient's bone within the apparatus coordinate system.

Abstract: The invention relates to a device for positioning and guiding a surgical instrument during orthopaedic interventions, comprising an industrial robot which has a program-controlled robot arm (1) with several articulated joints and a mounting plate (2) at the end of said arm, an instrument (3) for the orthopaedic intervention attached to the mounting plate (2) and a program control with computer. Sensors for detecting the position of the joints in an instrument-coordinating system defined in the program control are situated in the joints of the robot arm (1). According to the invention, a manually guided sensor device, for example in the form of a sensor arm (4) with multiple joints, is used for the three-dimensional measurement of an object by the instrument-coordinating system of the industrial robot. Using the sensor device (4), and with a previously adopted basic position of the robot arm (1) specified by the program control, reference points can be detected on the bone of the patient.