Medical robotic system with dynamically adjustable slave manipulator characteristics

Patent metadata

Field	Value
Publication number	US-2020237456-A1
Application number	US-202016847267-A
Country	US
Kind code	A1
Filing date	Apr 13, 2020
Priority date	Aug 29, 2007
Publication date	Jul 30, 2020
Grant date	—

Abstract

A slave manipulator manipulates a medical device in response to operator manipulation of an input device through joint control systems. The stiffness and strength of the slave manipulator are adjustable according to criteria such as the mode of operation of the slave manipulator, the functional type of the medical device currently being held by the slave manipulator, and the current phase of a medical procedure being performed using the slave manipulator by changing corresponding parameters of the control system. For safety purposes, such changes are not made until it is determined that it can be done in a smooth manner without causing jerking of the medical device. Further, an excessive force warning may be provided to surgery staff when excessive forces are being commanded on the slave manipulator for more than a specified period of time.

First claim

1 - 25 . (canceled)

26 . A method for dynamically adjusting a characteristic of a slave manipulator adapted to manipulate a medical device according to operator manipulation of an input device as controlled by a control system during a medical procedure performed on a patient, comprising:
determining whether a change in a parameter of the control system that results in adjusting the characteristic would also result in an actuator command generated within the control system to drive an actuator of the slave manipulator that exceeds a threshold value immediately following the change in the parameter; and changing the parameter so as to adjust the characteristic if it is determined that the characteristic is to be adjusted and the actuator command would not exceed the threshold value immediately following the change in the parameter.

27 . The method according to claim 26 ,
wherein the slave manipulator includes a joint that is coupled to the actuator; and wherein the control system includes a joint controller for driving the actuator in response to the actuator command.

28 . The method according to claim 27 , wherein the parameter of the control system is a position error gain in the joint controller.

29 . The method according to claim 28 , wherein the determination of whether the change in the parameter of the control system would result in the actuator command exceeding the threshold value immediately following the change in the parameter comprises:
determining the current actuator command generated within the control system using a current position error gain in the control system; determining a prospective actuator command to be generated within the control system immediately following the change in the parameter using a new position error gain in the control system; and determining whether an absolute value of a difference between the current and the prospective actuator command is greater than the threshold value.

30 . (canceled)

31 . The method according to claim 27 , wherein the parameter of the control system is a limit on a path within the joint controller.

32 . The method according to claim 31 , wherein the determination of whether the change in the parameter of the control system would result in the actuator command generated within the control system exceeding the threshold value immediately following the change in the parameter comprises:
determining whether an output of the path is being limited by using a current limit on the path; determining whether a prospective output of the path would be limited by using a new limit on the path; and if either the output or the prospective output is limited, then determining that the actuator command generated within the control system would exceed the threshold value immediately following the change in the parameter value.

33 . The method according to claim 31 , further comprising:
if the actuator command exceeds a second threshold value for a programmed period of time after changing the parameter of the control system, then issuing a sensory warning of excessive force.

34 . The method according to claim 33 , wherein the sensory warning includes a visual warning displayed on one of: a display screen and the slave manipulator.

35 . (canceled)

36 . (canceled)

37 . The method according to claim 33 ,
wherein the sensory warning includes an auditory warning; and wherein the auditory warning is provided through a right speaker if the input device is being manipulated by a right hand of an operator, and through a left speaker if the input device is being manipulated by a left hand of the operator.

38 . (canceled)

39 . The method according to claim 33 ,
wherein the sensory warning includes a tactile vibration; and wherein the tactile vibration is provided on the input device.

40 . A medical system comprising:
a medical device; a slave manipulator adapted to manipulate the medical device, the slave manipulator having a characteristic; an input device; a control system operatively coupling the input device to the slave manipulator; and a processor programmed to dynamically adjust the characteristic of the slave manipulator by:
determining whether a change in a parameter of the control system that results in adjusting the characteristic would also result in an actuator command generated within the control system to drive an actuator of the slave manipulator that exceeds a threshold value immediately following the change in the parameter; and
changing the parameter so as to adjust the characteristic if it is determined that the characteristic is to be adjusted and the actuator command would not exceed the threshold value immediately following the change in the parameter.

41 . The medical system according to claim 40 ,
wherein the slave manipulator includes a joint that is coupled to the actuator; and wherein the control system includes a joint controller for driving the actuator in response to the actuator command.

42 . The medical system according to claim 41 , wherein the parameter of the control system is a position error gain in the joint controller.

43 . The medical system according to claim 42 ,
wherein the processor is programmed to determining whether the change in the parameter of the control system would result in the actuator command exceeding the threshold value immediately following the change in the parameter by:
determining the current actuator command generated within the control system using a current position error gain in the control system;
determining a prospective actuator command to be generated within the control system immediately following the change in the parameter using a new position error gain in the control system; and
determining whether an absolute value of a difference between the current and the prospective actuator command is greater than the threshold value.

44 . The medical system according to claim 41 , wherein the parameter of the control system is a limit on a path within the joint controller.

45 . The medical system according to claim 44 ,
wherein the processor is programmed to determining whether the change in the parameter of the control system would result in the actuator command generated within the control system exceeding the threshold value immediately following the change in the parameter by:
determining whether an output of the path is being limited by using a current limit on the path;
determining whether a prospective output of the path would be limited by using a new limit on the path; and
if either the output or the prospective output is limited, then determining that the actuator command generated within the control system would exceed the threshold value immediately following the change in the parameter value.

46 . The medical system according to claim 44 ,
wherein the processor is further programmed to dynamically adjust the characteristic of the slave manipulator by:
conditioned upon the actuator command exceeding a second threshold value for a programmed period of time after changing the parameter of the control system, issuing a sensory warning of excessive force.

47 . The medical system according to claim 46 , further comprising:
a display; wherein the sensory warning includes a visual warning displayed on one of: the display and the slave manipulator.

48 . The medical system according to claim 46 , further comprising:
a right speaker and a left

Assignees

• Intuitive Surgical Operations

Inventors

• Prisco Giuseppe Maria
• Stein Hubert
• Millman Paul
• Bailey David W
• Nowlin William C
• Toth Gregory K
• Nixon Thomas R

Classifications

• G05B2219/49144

  Limit movement on an axis by setting limits · CPC title

• G05B2219/40405

  Leader-follower position control · CPC title

• G05B2219/40146

  Telepresence, teletaction, sensor feedback from follower to operator · CPC title

• B25J9/1676

  Avoiding collision or forbidden zones · CPC title

• A61B34/37

  Leader-follower robots (A61B34/35 takes precedence) · CPC title