A variable stiffness wrist structure and surgical robotic arm of a surgical robot

Abstract

The invention discloses a variable-rigidity wrist structure of a surgical robot and a surgical mechanical arm. The technical solution is as follows: the structure includes an elastic framework, a flexible temperature control pipe is arranged on the outer side of the elastic framework, and a notch-type shape memory alloy pipe is arranged on the outer side of the flexible temperature control pipe; on the premise that the flexible temperature control pipe can ensure the contact area with the notch-type shape memory alloy pipe, a gap is left for matching a chuck mechanism fixed on the elastic framework with the notch-type shape memory alloy pipe; and the chuck mechanism is used to connect drive wires. According to the structure, a nickel-titanium alloy is used as a variable-rigidity material,hot water does not need to be continuously poured to maintain temperature when wrist shape changing is performed, so that the movement performance of the variable-rigidity wrist is improved; and the variable-rigidity wrist is driven by a driving unit through the wires, and the structure has a small volume, and is more flexible.

Description

technical field [0001] The invention relates to the field of medical instruments, in particular to a variable-stiffness wrist structure and a surgical robot arm of a surgical robot. Background technique [0002] In single-port laparoscopic surgery, minimally invasive robotics can greatly reduce the size of the incision in the body cavity wall, thereby reducing postoperative pain and shortening recovery time. At present, a variety of minimally invasive surgical robot system structures have been proposed and applied. For surgical robots, the mechanical arm needs to be flexible when adjusting the spatial position of the end effector, and the mechanical arm is required to be rigid and able to withstand a certain load when performing actions such as pulling. Therefore, it is required that the mechanical arm of minimally invasive robots should have the function of stiffness transformation. However, existing surgical robots cannot fully meet this demand. [0003] For stiffness t...

AI Technical Summary

Problems solved by technology

As far as the former is concerned, a mechanical locking method can be used to change the stiffness of the mechanical arm, but although this method can significantly change the stiffness, the structure is too complicated and the volume is large, and it is not suitable for use on surgical robot arms; It is also possible to change the driving force by changing the tension of the driving wire, but this requires too much wear resistance and strength of the driving wire

As far as the latter is concerned, many scholars have made a series of attempts, a method that uses the blocking method of solid particles to change the stiffness of the mechanical arm, but more solid particles are needed to achieve high stiffness, which will make the mechanism bloated and not compact enough; Using discrete joints and phase-change alloy skeletons to achieve variable stiffness, but many phase-change alloys such as gallium alloys are harmful to the human body, and some phase-change alloys have too long phase-change time, which will cause a large hysteresis in surgical robots

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