Medical system and control method

Patent metadata

Field	Value
Publication number	US-9161682-B2
Application number	US-201113154878-A
Country	US
Kind code	B2
Filing date	Jun 7, 2011
Priority date	Mar 2, 2010
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

A medical system includes a movable portion configured to allow an angle to be changed within a predetermined angular range, an actuator configured to drive the movable portion so as to change the angle of the movable portion when a wire is pulled, a control unit configured to perform drive control of the actuator, a slack detection unit configured to detect a driving condition as to whether or not the wire is slack, a slack adjustment unit configured to adjust slack of the wire based on a detection result produced by the slack detection unit; and a slack adjustment command input unit used to input a command to adjust the slack of the wire, wherein the slack adjustment unit adjusts the slack of the wire to a predetermined state of adjustment in response to the command to adjust the slack of the wire.

First claim

What is claimed is:

1. A medical system comprising:
a movable portion installed in a medical instrument, made up of a plurality of pivotally coupled movable members, and configured to allow an angle to be changed within a predetermined angular range in at least one plane;
an actuator installed in the medical instrument and including a drive shaft configured to drive the movable portion so as to change the angle of the movable portion when a wire coupled to the movable portion is pulled;
a rotation angle detection unit configured to detect a rotation angle actually rotated with the drive shaft by the actuator;
a control unit configured to perform drive control of the actuator;
a slack detection unit configured to detect a driving condition as to whether or not the wire is slack;
a slack adjustment command input unit configured to input a command to adjust the slack of the wire; and
a slack adjustment unit configured to, when the command to adjust the slack is inputted, cause the drive shaft to rotate so as to reciprocate in each of a first rotation direction and a second rotation direction opposite to the first rotation direction within the predetermined angular range of the movable portion, to thereby pull the wire, and configured to cause the drive shaft to drive such that the drive shaft is at a specific rotation angle in a range between a first rotation angle and a second rotation angle, to thereby adjust a position at which a slack of the wire is produced, based on the first rotation angle which is the rotation angle detected by the rotation angle detection unit in a case where the slack detection unit detects that the wire is not slack in one of two directions including the first rotation direction and the second rotation direction and the second rotation angle which is the rotation angle detected by the rotation angle detection unit in a case where the slack detection unit detects that the wire is not slack in the other of the two directions;
a characteristics storage unit configured to store characteristics of respective rotation angles by which the drive shaft is rotated in the first rotation direction and the second rotation direction so as to cover the predetermined angular range of the movable portion and characteristics of an angle of the movable portion to change in accordance with the respective rotation angles associating the characteristics as characteristics of a reference rotation angle representing the respective rotation angles and a reference angle representing the angle corresponding to the reference rotation angle, in advance with each other;
an angle detection unit configured to detect an angle by which the movable portion actually rotated;
a storage unit configured to store the rotation angle detected by the rotation angle detection unit and the angle detected by the angle detection unit by associating with each other the rotation angle and the angle in time sequence as passage of time, the storage unit including the characteristics storage unit; and
a correction unit configured to, when the rotation angle detected by the rotation angle detection unit and the angle detected by the angle detection unit are stored in the storage unit by being associated with each other in time sequence and if the slack detection unit detects that the slack exists, rotate the drive shaft until the stack does not exist, and to correct, in time sequence, the rotation angle detected by the rotation angle detection unit in a state where the slack does not exist and the angle detected by the angle detection unit corresponding to the rotation angle so as to replace a previous reference rotation angle and a previous reference angle stored in the characteristics storage unit with a current reference rotation angle and a current reference angle corresponding to the current reference rotation angle as information associating the current reference rotation angle and the current reference angle.

2. The medical system according to claim 1 , wherein the specific rotation angle is equal to the first rotation angle or the second rotation angle.

3. The medical system according to claim 1 , wherein the specific rotation angle is a rotation angle intermediate between the first rotation angle and the second rotation angle.

4. The medical system according to claim 1 , wherein the slack detection unit detects the slack of the wire by detecting a load applied to the actuator or a load applied to the wire when the movable portion is driven to bend to change the angle of the movable portion.

5. The medical system according to claim 1 , wherein the slack detection unit detects the slack of the wire by detecting a load applied to the actuator by detecting an amount of driving force of the actuator or detecting a value of current, or detecting a load applied to the wire by detecting tension acting on the wire, when the movable portion is driven to bend to change the angle of the movable portion.

6. The medical system according to claim 1 , wherein the actuator includes a motor configured to pull the wire by rotating.

7. The medical system according to claim 6 , wherein the slack adjustment unit causes the drive shaft to drive such that the drive shaft of the motor has the specific rotation angle, to thereby adjust a position at which the slack is produced, based on detection results detected by the slack detection unit at two rotation angles with the slack of the wire removed in the first rotation direction and the second rotation direction as the two mutually opposite directions when the movable portion is rotated by the motor in the first rotation direction and the second rotation direction.

8. The medical system according to claim 7 , wherein the slack adjustment unit calculates the specific rotation angle from average values of the two rotation angles over a plurality of times detected respectively when the movable portion is rotated in the first rotation direction and the second rotation direction, reciprocating the plurality of times and causes the drive shaft to drive such that the drive shaft has the specific rotation angle, to thereby adjust a position at which the slack is produced.

9. The medical system according to claim 6 , wherein the storage unit stores in advance information about torque of the motor, a rotation angle detected by the rotation angle detection unit, and an angle of the movable portion detected by the angle detection unit in time sequence together with information about time under a driving condition in which the movable portion is driven by the motor.

10. The medical system according to claim 9 , wherein even when a command to adjust the slack is not inputted from the slack adjustment command input unit, the slack adjustment unit adjusts the slack of the wire based on the detection result produced by the slack detection unit and updates the information in the storage unit based on a slack adjustment result.

11. The medical system according to claim 6 , wherein
a characteristics storage unit stores in advance characteristics of a rotation angle of the drive shaft of the motor and the angle of the movable portion corresponding to a rotation angle as characteristics of the reference rotation angle and the reference angle corresponding to the reference rotation angle; and
a correction unit corrects and replaces the previous reference rotation angle stored in the characteristics storage unit with the previous reference angle corresponding to the previous reference rotation angle with a current rotation angle of the drive shaft of the motor and a current angle of the movable portion corresponding to the current rotation angle stored in the storage unit stored in the characteristics storage unit, based

Assignees

• Umemoto Yoshitaka
• Takahashi Kazuhiko
• Olympus Corp

Inventors

• Umemoto Yoshitaka
• Takahashi Kazuhiko

Classifications

• G02B23/2476

  Non-optical details, e.g. housings, mountings, supports · CPC title

• A61B1/0052

  Constructional details of control elements, e.g. handles · CPC title

• A61B1/0057

  Constructional details of force transmission elements, e.g. control wires · CPC title

• A61B1/008 Primary

  Articulations · CPC title

• A61B1/0016

  using motor drive units · CPC title