Endoscope system, control device, and control method

Abstract

An endoscope system includes: an endoscope including an insertion portion having a joint and first and second wires fixed on both sides of the joint; a drive device that is connected to the endoscope and bends the joint by driving the first and second wires; and a processor that controls the drive device. The processor can perform position control that controls traction amount or delivery amount of one of the first and second wires based on target position for bending the joint, and tension control that controls traction amount or delivery amount so that tension of the other of the first and second wires matches a specified set value, and execute a drive mode in which one of the first and second wires is controlled by the position control and the other of the first and second wires is controlled by the tension control.

What is claimed is: 
     
         1 . An endoscope system comprising:
 an endoscope comprising an insertion portion comprising a joint, a first wire fixed to the joint, and a second wire fixed on the opposite side of a longitudinal central axis of the joint with respect to the first wire;   a drive device that is connected to the endoscope and bends the joint by driving the first wire and second wires; and   a processor that controls the drive device,   wherein the processor is capable of performing
 position control that controls traction amount or delivery amount of one of the first and second wires based on target position for bending the joint, and 
 tension control that controls traction amount or delivery amount so that tension of the other of the first and second wires matches a specified set value, 
   the processor is capable of executing a drive mode in which one of the first and second wires is controlled by the position control and the other of the first and second wires is controlled by the tension control, and   the processor switches the drive mode based on a bending angle of the joint.   
     
     
         2 . The endoscope system according to  claim 1 , wherein,
 when bending the joint so as to increase the bending angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control, and   when bending the joint so as to reduce the bending angle and the bending angle is larger than a predetermined bending angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the tension control and a wire to be sent out of the first and second wires is controlled by the position control.   
     
     
         3 . The endoscope system according to  claim 2 , wherein,
 when bending the joint so as to reduce the bending angle and the joint has a second shape in which the bending angle is smaller than a predetermined angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control.   
     
     
         4 . The endoscope system according to  claim 3 , wherein the processor switches the drive mode at an angle at which a magnitude relationship between a restoring force for returning the joint to a linear state and a frictional force for maintaining a shape of the joint against the restoring force as the predetermined angle. 
     
     
         5 . The endoscope system according to  claim 3 , wherein the processor sets a target tension in the tension control lower than the traction tension generated during the position control. 
     
     
         6 . A processor that controls a drive device of an endoscope system, the endoscope system including an endoscope having an insertion portion with a joint, and first and second wires fixed to both sides of the joint with a central axis in the longitudinal direction of the joint interposed therebetween, and the drive device which is connected to the endoscope and bends the joint by driving the first and second wires,
 wherein the processor is capable of performing
 position control that controls traction amount or delivery amount of one of the first and second wires based on target position for bending the joint, and 
 tension control that controls traction amount or delivery amount so that tension of the other of the first and second wires matches a specified set value, 
   the processor is capable of executing a drive mode in which one of the first and second wires is controlled by the position control and the other of the first and second wires is controlled by the tension control, and   the processor switches the drive mode based on a bending angle of the joint.   
     
     
         7 . The processor according to  claim 6 , wherein,
 when bending the joint so as to increase the bending angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control, and   when bending the joint so as to reduce the bending angle and the bending angle is larger than a predetermined bending angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the tension control and a wire to be sent out of the first and second wires is controlled by the position control.   
     
     
         8 . The processor according to  claim 7 , wherein,
 when bending the joint so as to reduce the bending angle and the joint has a second shape in which the bending angle is smaller than a predetermined angle, the processor switches the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control.   
     
     
         9 . The processor according to  claim 8 , wherein the processor switches the drive mode at an angle at which a magnitude relationship between a restoring force for returning the joint to a linear state and a frictional force for maintaining a shape of the joint against the restoring force as the predetermined angle. 
     
     
         10 . The processor according to  claim 9 , wherein the processor sets a target tension in the tension control lower than the traction tension generated during the position control. 
     
     
         11 . A control method of controlling an endoscope system, the endoscope system including an endoscope having an insertion portion with a joint, and first and second wires fixed to both sides of the joint with a central axis in the longitudinal direction of the joint interposed therebetween, and a drive device which is connected to the endoscope and bends the joint by driving the first and second wires, the control method comprising:
 performing position control that controls traction amount or delivery amount of one of the first and second wires based on target position for bending the joint;   performing tension control that controls traction amount or delivery amount so that tension of the other of the first and second wires matches a specified set value;   executing a drive mode in which one of the first and second wires is controlled by the position control and the other of the first and second wires is controlled by the tension control; and   switching the drive mode based on a bending angle of the joint.   
     
     
         12 . The control method according to  claim 11 , further comprising:
 when bending the joint so as to increase the bending angle, switching the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control; and   when bending the joint so as to reduce the bending angle and the bending angle is larger than a predetermined bending angle, switching the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the tension control and a wire to be sent out of the first and second wires is controlled by the position control.   
     
     
         13 . The control method according to  claim 12 , further comprising:
 when bending the joint so as to reduce the bending angle and the joint has a second shape in which the bending angle is smaller than a predetermined angle, switching the drive mode to a mode in which a wire to be towed of the first and second wires is controlled by the position control and a wire to be sent out of the first and second wires is controlled by the tension control.   
     
     
         14 . The control method according to  claim 13 , further comprising:
 switching the drive mode at an angle at which a magnitude relationship between a restoring force for returning the joint to a linear state and a frictional force for maintaining a shape of the joint against the restoring force as the predetermined angle.   
     
     
         15 . The control method according to  claim 14 , further comprising:
 setting a target tension in the tension control lower than the traction tension generated during the position control.