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EP-4321120-B1 - REAR-END TRANSMISSION DEVICE, MEDICAL INSTRUMENT, AND SURGICAL ROBOT

EP4321120B1EP 4321120 B1EP4321120 B1EP 4321120B1EP-4321120-B1

Inventors

  • YIP, Hoiwut

Dates

Publication Date
20260506
Application Date
20220303

Claims (10)

  1. A rear-end transmission device (150), comprising: a first rotating member (151); a second rotating member (152); a third rotating member (153); a first transmission assembly connected to a first cable (141) and a second cable (142) and further connected to the first rotating member (151) and the third rotating member (153); and a second transmission assembly connected to a third cable (143) and a fourth cable (144) and further connected to the second rotating member (152) and the third rotating member (153); wherein the first rotating member (151) is rotatable to pull in one of the first cable (141) and the second cable (142) and to release another of the first cable (141) and the second cable (142) concurrently via the first transmission assembly; the second rotating member (152) is rotatable to pull in one of the third cable (143) and the fourth cable (144) and to release another of the third cable (143) and the fourth cable (144) concurrently via the second transmission assembly; and the third rotating member (153) is rotatable to perform via the first transmission assembly and the second transmission assembly: pulling in the first cable (141) and the second cable (142) while releasing the third cable (143) and the fourth cable (144); or pulling in the third cable (143) and the fourth cable (144) while releasing the first cable (141) and the second cable (142); characterized in that , the first transmission assembly comprises: a first movable pulley (156) connected to the first cable (141); a first transmission cable (158) riding on the first movable pulley (156), wherein the first transmission cable (158) has one end connected to the first rotating member (151) and has another end connected to the third rotating member (153); a second movable pulley (157) connected to the second cable (142); and a second transmission cable (159) riding on the second movable pulley (157), wherein the second transmission cable (159) has one end connected to the first rotating member (151) and has another end connected to the third rotating member (153); wherein the first transmission cable (158) wraps around the first rotating member (151) in a direction opposite to a direction in which the second transmission cable (159) wraps around the first rotating member (151), and the first transmission cable (158) wraps around the third rotating member (153) in a direction same as a direction in which the second transmission cable (159) wraps around the third rotating member (153); and in rotation of the first rotating member (151) or the third rotating member (153), the first movable pulley (156) is driven to move by the first transmission cable (158) and the second movable pulley (157) is driven to move by the second transmission cable (159); the second transmission assembly comprises: a third movable pulley (164) connected to the third cable (143); a third transmission cable (166) riding on the third movable pulley (164), wherein the third transmission cable (166) has one end connected to the second rotating member (152) and has another end connected to the third rotating member (153); a fourth movable pulley (165) connected to the fourth cable (144); and a fourth transmission cable (167) riding on the fourth movable pulley (165), wherein the fourth transmission cable (167) has one end connected to the second rotating member (152) and has another end connected to the third rotating member (153); wherein the third transmission cable (166) wraps around the second rotating member (152) in a direction opposite to a direction in which the fourth transmission cable (167) wraps around the second rotating member (152), and each of the third transmission cable (166) and the fourth transmission cable (167) wraps around the third rotating member (153) in a direction opposite to a direction in which each of the first transmission cable (158) and the second transmission cable (159) wraps around the third rotating member (153); and in rotation of the second rotating member (152) or the third rotating member (153), the third movable pulley (164) is driven to move by the third transmission cable (166) and the fourth movable pulley (165) is driven to move by the fourth transmission cable (167).
  2. The rear-end transmission device (150) of claim 1, wherein the first rotating member (151) is rotatable around a first central axis (A1) of the first rotating member (151), the second rotating member (152) is rotatable around a second central axis (A2) of the second rotating member (152), and the third rotating member (153) is rotatable around a third central axis (A3) of the third rotating member (153); and wherein the first central axis (A1) is parallel to the second central axis (A2) and parallel to the third central axis (A3).
  3. The rear-end transmission device (150) of claim 1, wherein the first transmission assembly further comprises a first guide pulley (163), and wherein a portion of the first transmission cable (158) located between the first rotating member (151) and the first movable pulley (156) rides on the first guide pulley (163), such that a portion of the first transmission cable (158) located between the first guide pulley (163) and the first movable pulley (156) is parallel to a portion of the first transmission cable (158) located between the first movable pulley (156) and the third rotating member (153).
  4. The rear-end transmission device (150) of claim 3, wherein a portion of the second transmission cable (159) located between the first rotating member (151) and the second movable pulley (157) is parallel to a portion of the second transmission cable (159) located between the second movable pulley (157) and the third rotating member (153) and parallel to the portion of the first transmission cable (158) located between the first movable pulley (156) and the third rotating member (153).
  5. The rear-end transmission device (150) of claim 1, wherein the first movable pulley (156) is pivotably connected to a first pulley seat (181) via a first shaft (161), and the first pulley seat (181) is connected to the first cable (141), and wherein the second movable pulley (157) is pivotably connected to a second pulley seat (182) via a second shaft (162), and the second pulley seat (182) is connected to the second cable (142), wherein the first shaft (161) is parallel to the second shaft (162) and parallel to the first central axis (A1).
  6. The rear-end transmission device (150) of claim 5, wherein the third movable pulley (164) is pivotably connected to a third pulley seat (183) via a third shaft (168), and the third pulley seat (183) is connected to the third cable (143), and wherein the fourth movable pulley (165) is pivotably connected to a fourth pulley seat (184) via a fourth shaft (169), and the fourth pulley seat (184) is connected to the fourth cable (144), wherein the third shaft (168) is parallel to the fourth shaft (169) and parallel to the first central axis (A1).
  7. The rear-end transmission device (150) of any of claims 5 to 6, wherein the second transmission assembly further includes a second guide pulley (171), and wherein a portion of the fourth transmission cable (167) located between the second rotating member (152) and the fourth movable pulley (165) rides on the second guide pulley (171), such that a portion of the fourth transmission cable (167) located between the second guide pulley (171) and the fourth movable pulley (165) is parallel to a portion of the fourth transmission cable (167) located between the fourth movable pulley (165) and the third rotating member (153).
  8. The rear-end transmission device (150) of claim 7, wherein a portion of the third transmission cable (166) located between the second rotating member (152) and the third movable pulley (164) is parallel to a portion of the third transmission cable (166) located between the third movable pulley (164) and the third rotating member (153), and parallel to the portion of the fourth transmission cable (167) located between the fourth movable pulley (165) and the third rotating member (153).
  9. A medical device (120), comprising the rear-end transmission device (150) of any of claims 1 to 8.
  10. A surgical robot (100), comprising the medical device (120) of claim 9.

Description

TECHNICAL FIELD The various embodiments described in this document relate in general to the technical field of medical devices, and more specifically to a rear-end transmission device, a medical device, and a surgical robot. BACKGROUND In robot-assisted minimally invasive surgery, surgical instruments connected at the end of the robot enter the human body through wounds on the surface of the human body or natural canals of the human body, to be operated on tissues in the human body. The surgical instrument mainly includes an effector or tool (such as a pair of surgical forceps, a cutting tool, or a cauterizing tool) mounted to a wrist mechanism at a front end of the instrument, the wrist mechanism providing multiple degrees of freedom for movement of the front end, a main shaft extending from a rear end of the instrument to the front end, and a power and transmission device at the rear end of the instrument. The effector at the front end and the wrist mechanism are generally driven by multiple cables fixed thereto, and the cables run through the main shaft of the surgical instrument and are driven by the power and transmission device at the rear end. For surgical forceps and other holding or cutting tools, the wrist mechanism is generally required to realize three degrees of freedom: pitch, yaw, and grip. Cooperated with extra degrees of freedom of the rear end of the robot, the wrist mechanism can realize the movement required to perform surgical operations. According to specific implementation of the wrist mechanism, the number of driving cables required for the wrist mechanism varies, for example, there are generally 4 or 6 cables configured for the wrist mechanism. In addition, in order to realize a large-scale movement (for example, rotation of -90° to 90°) of each joint of the wrist mechanism, it is necessary to arrange extra pulleys on the wrist mechanism to guide cables. However, addition of the extra pulleys may hinder the miniaturization of the front end of the surgical instrument, and the use of more cables may also increase the size and cost of the instrument. The existing rear-end transmission device for driving the 4-cable wrist mechanism realizes release of two cables and pulling in of other two cables through swing of a connecting rod or a rocker arm, thereby realizing the pitch of the wrist mechanism. In this way, with the change of a pitch angle, a length of a pulled-in cable is not equal to a length of a released cable, which may lead to a change in tension of the cables, and then lead to problems such as reduced accuracy due to transmission error caused by loosened cables, or accelerated wear due to excessive frictional resistance caused by over-tensioned cables. To avoid such problems, one method is to limit a range of a rotation angle of a pitch joint, but this method may affect the function of the instrument. In addition, when using this mechanism, a rotation angle of an output terminal of the motor at the rear end has a nonlinear relationship with the pitch angle of the wrist mechanism, which requires extra calibration to achieve accurate position control and thus increases extra workload. WO2010009224A1 relates to a transmission or backend mechanism for a medical instrument connects four cables to three motorized degrees of freedom. The transmission employs a first drive mechanism attached to first and second cables and a second drive mechanism attached to third and fourth cables, where each mechanism can include a capstan or a lever system that pulls in one cable while simultaneously feeding out another cables. A third drive mechanism has a first pivot about which a portion of the first drive mechanism rotates, a second pivot about which a portion of the second drive mechanism rotates, and a third pivot about which the third drive mechanism rotates. Rotation of the third drive mechanism about the third pivot pulls in at least one of the first and second cables and feeds out at least one of the third and fourth cables. WO2020252184A1 relates to an actuation assembly for a medical instrument connects four bands to three motorized degrees of freedom. The actuation assembly includes a first actuator, a second actuator and a third actuator. The first actuator is coupled to a first band and a second band, the first actuator being operable to pull in one of the first and second bands and feed out the other of the first and second bands. The third actuator is coupled to a third band and a fourth band, the third actuator being operable to pull in one of the third and fourth bands and feed out the other of the third and fourth bands. Each of the first, second, third, and fourth bands pass through a second actuator, and the second actuator is operable to increase the travel path of both the first and second bands or both the third and fourth bands. WO2014151952A1 relates to a surgical tool includes a tool shaft, and end effector and a wrist that couples the end effector to the tool shaft. The