Friction compensation in a minimally invasive surgical apparatus
First Claim
1. A method of performing a surgical procedure by means of a surgical apparatus having at least one master control operatively associated with at least one surgical instrument by means of a control system, the master control and its associated surgical instrument including a plurality of components at least some of which are selectively moveable in arbitrary positive component directions and arbitrary negative component directions, and at least one of which has an actuator operatively associated therewith, the method includingmoving the master control;
- causing the surgical instrument to move in response to master control movement by means of the control system thereby to cause the surgical instrument to perform at least part of a surgical procedure;
generating a friction compensation signal; and
loading the actuator with a load defined by the friction compensation signal so as to provide friction compensation to the component associated with the actuator.
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Accused Products
Abstract
The present invention provides improved devices, systems, and methods for compensating for friction within powered automatic systems, particularly for telesurgery and other telepresence applications. The invention allows uninhibited manipulation of complex linkages, enhancing the precision and dexterity with which jointed structures can be moved. This enhanced precision is particularly advantageous when applied to the robotic surgical systems now being developed. The friction compensation systems of the present invention address static friction (typically by applying a continuous load in the direction of movement of a joint) and the often more problematic static friction (generally by applying alternating loads in positive and negative joint actuation directions). The invention can accommodate imprecise velocity measurements by applying an oscillating load whenever the joint velocity reading falls within a low velocity range. Preferably, the oscillating load is insufficient to move the joint without additional input, and significantly reduces the break away input required to initiate movement. In the exemplary embodiment, a duty cycle of the oscillating load varies, favoring the apparent direction of movement of a velocity reading. The amplitude of the duty cycle may also vary, typically increasing as the velocity reading approaches zero.
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Citations
21 Claims
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1. A method of performing a surgical procedure by means of a surgical apparatus having at least one master control operatively associated with at least one surgical instrument by means of a control system, the master control and its associated surgical instrument including a plurality of components at least some of which are selectively moveable in arbitrary positive component directions and arbitrary negative component directions, and at least one of which has an actuator operatively associated therewith, the method including
moving the master control; -
causing the surgical instrument to move in response to master control movement by means of the control system thereby to cause the surgical instrument to perform at least part of a surgical procedure;
generating a friction compensation signal; and
loading the actuator with a load defined by the friction compensation signal so as to provide friction compensation to the component associated with the actuator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification