Flexible instrument insertion using an adaptive insertion force threshold

Abstract

A robotic system is described for determining and using an insertion force threshold to avoid too much force being applied to a flexible instrument placed within a patient. The robotic system comprises a medical instrument comprising an elongate body, and further comprises a robotic arm coupled to the instrument as well as a controller configured to receive instrument data based in part on a current location of the elongate body, access patient data associated with the patient, determine an insertion force threshold, receive an insertion force detected by a force sensor coupled to the robotic arm, compare the insertion force with the insertion force threshold, and responsive to the insertion force exceeding the force threshold, generate a recommendation signal for the robotic system.

1 - 20 . (canceled) 
     
     
         21 . A robotic system, comprising:
 a medical instrument comprising an elongate body;   a first sensor comprising a shape sensor placed in or on a first portion of the elongate body; and   a controller configured to:
 direct a command to move the elongate body, 
 receive sensor data generated from the first sensor, the sensor data comprising information regarding a first measured status comprising a measured shape of the first portion of the elongate body, 
 compare the first measured status with a first expected status comprising an expected shape of the first portion of the elongate body expected to be caused by the command; and 
 responsive to the first measured status deviating from the first expected status by more than a first associated threshold, determine that the elongate body has buckled. 
   
     
     
         22 . The system of  claim 21 , wherein the elongate body comprises at least one of a catheter and an endoscope. 
     
     
         23 . The system of  claim 21 , wherein the elongate body comprises a leader and a sheath, the leader being telescopically disposed within the sheath. 
     
     
         24 . The system of  claim 23 , wherein the first portion of the elongate body comprises at least one of:
 a first region covering a volume near a tip of the leader;   a second region covering a portion of the leader in a range from a distal end of a sheath of the elongated body to an edge of the first region; and   a third region covering the distal end of the sheath where the leader extends from as well as a portion of the sheath proximal to its distal end.   
     
     
         25 . The system of  claim 23 , wherein the first portion of the elongate body comprises at least one of:
 a first region covering a volume near an end of the sheath;   a second region covering a first portion of the sheath in a range from a first location of the sheath to an edge of the first region; and   a third region covering a second portion of the sheath in a range from a second location of the sheath to an edge of the second region, wherein the second location is further from the first region than the second location.   
     
     
         26 . The system of  claim 21 , wherein the first sensor is coupled to at least one of:
 a portion of an outer surface of the elongate body;   a portion of a wall of the elongate body;   a portion of an inner surface of a lumen inside the elongate body;   a portion of an inner surface of a conduit inside the elongate body; and   a portion of a pull wire of the elongate body.   
     
     
         27 . The system of  claim 21 , wherein the first measured status and the first expected status represent a determination of bending by the elongate body, and wherein responsive to the first measured status deviating from the first expected status more than the first threshold, determining that the elongate body has buckled. 
     
     
         28 . The system of  claim 21 , wherein the shape sensor comprises an optical fiber shape sensing sensor. 
     
     
         29 . The system of  claim 21 , wherein the shape sensor comprises a plurality of position sensors, wherein the plurality of position sensors generates a plurality of discrete positions able to be fitted by a function to estimate a shape. 
     
     
         30 . The system of  claim 21 , wherein the command comprises command data configured to, when executed by a robotic manipulator coupled to the instrument, control the manipulator to cause the portion of the elongate body to move towards an expected position. 
     
     
         31 . The system of  claim 21 , further comprising:
 a second sensor placed in a second portion of the elongate body;   wherein the controller is further configured to:
 receive sensor data generated from the second sensor, the second sensor data comprising information regarding a second measured status of the second portion of the elongate body; 
 compare the second measured status with a second expected status expected to be caused by the command; and 
 responsive to the first measured status deviating from the first expected status by more than a first associated threshold and the second measured status deviating from the second expected status by more than a second associated threshold, determine that the elongate body has buckled. 
   
     
     
         32 . The system of  claim 31 , wherein the second sensor comprises a position sensor, and wherein the second measured status and the second expected status represent determinations of a change in position of the elongate body. 
     
     
         33 . The system of  claim 31 , wherein the second sensor comprises a force sensor, and wherein the second measured status and the second expected status represent determinations of force experienced by the force sensor. 
     
     
         34 . The system of  claim 31 , wherein the second sensor comprises an image sensor, and wherein the second measured status and the second expected status represent determinations of movement of the elongate body based on at least one image captured by the image sensor. 
     
     
         35 . The system of  claim 21 , wherein the controller is further configured to:
 generate feedback for a user indicating that the elongate body has buckled, wherein generating feedback for the user comprises at least one of:
 determining one or more modifications to a recommendation to move the elongate body, 
 generating a message indicating that the elongate body has buckled, and 
 generating a warning indicating that the elongate body has bucked; and 
   provide the feedback to the user.   
     
     
         36 . A method for determining buckling of an elongate body of a medical instrument, the method comprising:
 commanding a robotic manipulator to move the elongate body of the medical instrument, the elongate body comprising a first sensor comprising a shape sensor placed in or on a first portion of the elongate body;   receiving sensor data generated from the first sensor, the sensor data comprising information regarding a first measured status comprising a measured shape of the first portion of the elongate body,   comparing the first measured status with a first expected status comprising an expected shape of the first portion of the elongate body expected to be caused by the command; and   responsive to the first measured status deviating from the first expected status by more than a first associated threshold, determining that the elongate body has buckled.   
     
     
         37 . The method of  claim 36 , further comprising:
 generating feedback for a user indicating that the elongate body has buckled, wherein generating feedback for the user comprises at least one of:
 one or more modifications to a recommendation to move the elongate body, 
 a message indicating that the elongate body has buckled, and 
 a warning indicating that the elongate body has bucked; and provide the feedback to the user. 
   
     
     
         38 . The method of  claim 36 , wherein the shape sensor comprises an optical fiber shape sensing sensor. 
     
     
         39 . The method of  claim 36 , wherein the shape sensor comprises a plurality of position sensors, wherein the plurality of position sensors generates a plurality of discrete positions able to be fitted by a function to estimate a shape. 
     
     
         40 . The method of  claim 36 , wherein the first measured status and the first expected status represent a determination of bending by the elongate body, and wherein responsive to the first measured status deviating from the first expected status more than the first threshold, determining that the elongate body has buckled.