Five-Bar Spherical Linkage Robotic Arm for Endoscopic Camera Control
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Solution Overview
Problem
Traditional minimally invasive surgery requires high surgical skill due to the need for unnatural hand motions to control surgical tools at a distance, and robotic assistance is needed to enhance precision and ease of motion control.
Innovation Solution
A robotic arm with a parallel spherical five-bar linkage that supports laparoscopic cameras and instruments, allowing them to pivot about a remote center of spherical rotation, enabling precise motion control with reduced lateral movement at the incision site, using servo motors and control cables for precise positioning and movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional manual control of surgical instruments is used, then the surgeon has direct control over the instruments, but the surgeon must perform unnatural hand motions to control tools at a distance
Solution Approach 1:
A robotic arm with five-bar spherical linkage acts as an intermediary between the surgeon's natural hand motions and the surgical instruments. The linkage mechanism with five bars (ground link, two inboard links, two outboard links) and five pivot axes all passing through a common remote center of spherical rotation transforms simple rotational inputs into precise instrument positioning without requiring unnatural surgeon movements.
Solution Approach 2:
The patent replaces the direct mechanical control system (surgeon's hands directly manipulating instruments) with a robotic mechanical system. The five-bar spherical linkage mechanism substitutes for the surgeon's manual dexterity, providing precise control while allowing natural hand motions at the control interface.
2Measurement precision
If robotic assistance is introduced to improve precision and ease of motion control, then precision and ease of control are enhanced, but the device complexity increases
Solution Approach 1:
The robotic arm is segmented into distinct functional components: a ground link, two inboard links with first pivot axes, two outboard links with second pivot axes, and a common remote center of spherical rotation. This segmentation allows each component to be optimized independently while maintaining overall precision, breaking down the complex system into manageable modular units.
Solution Approach 2:
The patent employs a spherical linkage mechanism where all five pivot axes converge at a common remote center of spherical rotation. This spherical geometry enables precise three-dimensional positioning and orientation of surgical instruments while maintaining a compact structure, as the spherical arrangement naturally constrains motion to a controlled volume around the remote center.
Data Source
AI summary
A robotic arm including a parallel spherical five-bar linkage with a remote center of spherical rotation. The robotic arm movably supports an endoscopic camera. Two outboard links are pivotally coupled together. At least one of the two outboard links supports the endoscopic camera. Two inboard links are respectively pivotally coupled to the two outboard links such that the two inboard links are able to cross over one another. The two inboard links moveably support the two outboard links. A ground link is pivotally coupled to the two inboard links. The ground link moveably supports the two inboard links.