Force Feedback Device and Its Application (CN113081275A / WO2022204869A1)

A force feedback device and its application (Chinese invention patent CN113081275A / PCT published WO2022204869A1)

The patent focuses on the issue of force feedback at the main hand end of the puncture robot and proposes a joystick feedback device based on two sets of mutually perpendicular coils and permanent magnets. It achieves force and posture feedback by synthesizing bidirectional torque, combining transmission ropes and hysteresis brakes, and reduces structural complexity and system costs while meeting the requirements for freedom of puncture action.

Patent information

china open	CN113081275A
international public	WO2022204869A1
Application number	202110333369.4
Application date	2021.03.29
China announcement day	2021.07.09
Invention name	A force feedback device and its application
applicant	Shenzhen National Research Institute of High Performance Medical Devices Co., Ltd.
inventor	Zheng Hairong, Zhou Shoujun, Wen Tiexiang, Lin Xiaofeng
Classification number	A61B 34/30; A61B 17/34; G06F 3/01

Core structure and design points

• Two sets of coils arranged perpendicularly to each other are used to apply a controllable magnetic field to the permanent magnet inside the joystick in the central area, thereby synthesizing torque feedback in two directions.
• The permanent magnet is linked to the joystick through the universal joint assembly, allowing the operator to obtain more direct angle and force feedback when adjusting the puncture posture.
• A guide column, a transmission rope and a puncture connection pipe are installed inside the joystick to form a long-stroke operating structure that takes into account both puncture action and feedback loading.
• The bottom force loading component consists of a coil spring, a coupling, a hysteresis brake, a reel and an encoder, and is used to adjust tension and record motion status.
• The patented system positioning is not simply a main handle, but uses the force feedback device as part of the main hand of the puncture robot to achieve more complete intraoperative interaction.

Technical background

This patent focuses on human-machine interaction issues in puncture robots. Although traditional force feedback equipment can reproduce part of the tactile and force information, when facing the requirements for posture, stroke and main hand-end freedom during puncture surgery, it is often difficult to implement due to complex structure, redundant degrees of freedom or high cost.

The entry point of this plan is relatively clear: it does not pursue a universal large and full feedback platform, but focuses on the puncture task itself, integrating magnetic field torque feedback, joystick mechanism, line drive loading and encoding measurement into the same main hand-end structure.

Device composition and working methods

1. Two sets of coils create a uniform magnetic field in the central area and apply torque to the permanent magnets inside the joystick.
2. The gimbal and encoder are responsible for recording changes in joystick posture, allowing the system to sense the operator’s angular input.
3. The guide column and transmission rope transmit the action in the puncture direction to the bottom loading assembly, forming an interactive feedback link along the axial direction.
4. The hysteresis brake achieves damping/feedback changes by adjusting the tension, while the reel and coil spring are responsible for the cable retraction and return functions.
5. The entire device can communicate with the robot and serve as part of the main hand terminal of the puncture robot to provide a feedback experience that is closer to the surgical scene.

patent value

Judging from the patent text, the value of this device lies in compressing the degree of freedom, stroke and feedback methods really needed for the puncture task into a more manufacturable and integrated structure. It not only takes into account the operator’s operating habits, but also takes into account the system cost and the possibility of subsequent implementation.

For a research portfolio, this patent also provides a good demonstration of the connection between “actuator design” and “main hand-end interaction design” in medical robots: not only focusing on how the robot moves, but also on how the operator can control it more naturally.

Picture information