Image Number 8 for United States Patent #5672945.
A surgical system, adapted to operate with at least one surgical device, has a handpiece containing a motor which is adapted to receive the surgical device. The surgical device is driven through a continuum of positions by the motor output shaft. A controller microprocessor controls the operation of the system. The motor has sensors for generating electrical position signals and the controller is responsive to input signals for defining both a stop position and a reversal position for the surgical device. As a result, the controller initiates operation of the surgical device at the so called stop position and stops operation of the surgical device so that it comes to rest substantially at the stop position. In an oscillatory mode of operation, the controller also forces reversals to occur at a reversal position dictated by the system, under the control of the user, unless a stall condition is sensed, in which case the reversal takes place as soon as possible. In connection with an arthroscopic cutting device, the control enables the surgeon to control, for example, the opening of the aperture through which tissue and fluids are removed from the surgical site during the reversal and start/stop conditions.