Systems and methods for flexible computer-assisted instrument control

Abstract

A medical system includes a flexible elongate instrument and a control system. The flexible elongate instrument includes a plurality of wires useable to control articulation of the flexible elongate instrument. The control system is configured to monitor movement of the flexible elongate instrument, determine an extent of motion of the flexible elongate instrument based on the monitoring, and determine a mode of operation for the flexible elongate instrument from a plurality of modes of operation based on the monitoring. The plurality of modes of operation includes a retraction mode, an insertion mode, and a parking mode. The control system is further configured to, in response to a change in the mode of operation, alter a rigidity of the flexible elongate instrument with a rate of rigidity change that is based on the extent of motion using one or more of the plurality of wires.

1 - 48 . (canceled) 
     
     
         49 . A medical system, comprising:
 a flexible elongate instrument comprising a plurality of wires useable to control articulation of the flexible elongate instrument; and   a control system configured to:
 monitor movement of the flexible elongate instrument; 
 determine an extent of motion of the flexible elongate instrument based on the monitoring; 
 determine a mode of operation for the flexible elongate instrument from a plurality of modes of operation based on the monitoring, the plurality of modes of operation including a retraction mode, an insertion mode, and a parking mode; and 
 in response to a change in the mode of operation, alter a rigidity of the flexible elongate instrument with a rate of rigidity change that is based on the extent of motion using one or more of the plurality of wires. 
   
     
     
         50 . The medical system of  claim 49 , wherein:
 the rate of rigidity change is non-linear with respect to the extent of motion; and   the extent of motion is at least one of a velocity of the movement, an elapsed time of the movement, or a distance traveled of the movement.   
     
     
         51 . The medical system of  claim 49 , wherein the control system is configured to determine the change in the mode of operation to one of the retraction mode or the insertion mode based on a velocity of the movement satisfying a threshold value. 
     
     
         52 . The medical system of  claim 51 , wherein the extent of motion includes an elapsed time of the movement. 
     
     
         53 . The medical system of  claim 51 , wherein the extent of motion includes a distance traveled of the movement. 
     
     
         54 . The medical system of  claim 49 , wherein the control system is configured to determine the change in the mode of operation to one of the retraction mode or the insertion mode based on a distance traveled of the movement exceeding a threshold value. 
     
     
         55 . The medical system of  claim 54 , wherein the extent of motion includes an elapsed time of the movement. 
     
     
         56 . The medical system of  claim 54 , wherein the extent of motion includes the distance traveled of the movement. 
     
     
         57 . The medical system of  claim 49 , wherein the control system is configured to decrease the rigidity of the flexible elongate instrument in response to the mode of operation changing to the retraction mode. 
     
     
         58 . The medical system of  claim 49 , wherein the control system is configured to increase the rigidity of the flexible elongate instrument in response to the mode of operation changing to one of the insertion mode or the parking mode. 
     
     
         59 . The medical system of  claim 49 , wherein the control system is configured to determine the change in the mode of operation from the parking mode based on a velocity of the movement exceeding a threshold value. 
     
     
         60 . The medical system of  claim 49 , wherein the control system is configured to determine the change in the mode of operation to the parking mode based on a velocity of the movement failing to exceed a threshold value. 
     
     
         61 . The medical system of  claim 49 , wherein the control system is configured to alter the rigidity of the flexible elongate instrument with a higher rate of rigidity change in the parking mode than in the insertion mode or the retraction mode. 
     
     
         62 . The medical system of  claim 49 , wherein the control system is configured to:
 determine whether a velocity of the movement in a retraction direction exceeds a first threshold value;   in response to the velocity exceeding the first threshold value, decrease the rigidity of the flexible elongate instrument based on an elapsed time of the movement; and   in response to the velocity failing to exceed the first threshold value and a distance traveled of the movement exceeding a second threshold value, decrease the rigidity of the flexible elongate instrument based on the elapsed time of the movement.   
     
     
         63 . A method of controlling a medical system with a control system, comprising:
 monitoring movement of a flexible elongate instrument comprising a plurality of wires useable to control articulation of the flexible elongate instrument;   determining an extent of motion of the flexible elongate instrument based on the monitoring;   determining a mode of operation for the flexible elongate instrument from a plurality of modes of operation based on the monitoring, the plurality of modes of operation including a retraction mode, an insertion mode, and a parking mode; and   in response to a change in the mode of operation, altering a rigidity of the flexible elongate instrument with a rate of rigidity change that is based on the extent of motion using one or more of the plurality of wires.   
     
     
         64 . The method of  claim 63 , wherein:
 the rate of rigidity change is non-linear with respect to the extent of motion; and   the extent of motion is at least one of a velocity of the movement, an elapsed time of the movement, or a distance traveled of the movement.   
     
     
         65 . The method of  claim 63 , wherein determining the change in the mode of operation to one of the retraction mode or the insertion mode is based on a velocity of the movement satisfying a threshold value. 
     
     
         66 . The method of  claim 63 , wherein determining the change in the mode of operation to one of the retraction mode or the insertion mode is based on a distance traveled of the movement exceeding a threshold value. 
     
     
         67 . The method of  claim 63 , further comprising:
 determining whether a velocity of the movement in a retraction direction exceeds a first threshold value;   in response to the velocity exceeding the first threshold value, decreasing the rigidity of the flexible elongate instrument based on an elapsed time of the movement; and   in response to the velocity failing to exceed the first threshold value and a distance traveled of the movement exceeding a second threshold value, decreasing the rigidity of the flexible elongate instrument based on the elapsed time of the movement.   
     
     
         68 . A non-transitory machine-readable medium comprising machine-readable instructions which, when executed by one or more processors of a control system, cause the one or more processors to perform:
 monitoring movement of a flexible elongate instrument comprising a plurality of wires useable to control articulation of the flexible elongate instrument;   determining an extent of motion of the flexible elongate instrument based on the monitoring;   determining a mode of operation for the flexible elongate instrument from a plurality of modes of operation based on the monitoring, the plurality of modes of operation including a retraction mode, an insertion mode, and a parking mode; and   in response to a change in the mode of operation, altering a rigidity of the flexible elongate instrument with a rate of rigidity change that is based on the extent of motion using one or more of the plurality of wires.