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 instruments at a distance from the surgeon's hands, making it challenging to perform precise movements with precision and ease.
Innovation Solution
A robotic arm with a parallel spherical five-bar linkage that supports and moves a laparoscopic camera, allowing the tool shaft and cannula to pivot about a remote center of spherical rotation, enabling precise and intuitive control of surgical instruments by constraining motion to rotation about a center in space along the cannula, reducing lateral motion at the incision and allowing two-dimensional motion of the end effector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional laparoscopic instruments are used with long tool shafts, then minimally invasive surgery can be performed through small incisions, but the surgeon experiences unnatural hand motions and difficulty controlling instruments at a distance
Solution Approach 1:
The patent replaces the traditional long mechanical tool shaft with a robotic arm system that uses a parallel spherical five-bar linkage mechanism. This mechanical substitution allows the surgeon to control the end effector through a robotic interface rather than directly manipulating a long instrument, eliminating unnatural hand motions while maintaining minimally invasive access through small incisions.
Solution Approach 2:
The robotic arm acts as an intermediary between the surgeon's hands and the surgical instrument at the distal end. The five-bar linkage mechanism serves as a mechanical mediator that translates surgeon inputs into precise movements at the remote center of spherical rotation, providing intuitive control while keeping the incision site minimal in size.
2Ease of operation
If a robotic arm with five-bar spherical linkage is used, then precise and intuitive control is achieved with motion constrained to rotation about a center in space, but the device complexity increases
Solution Approach 1:
The robotic arm is segmented into distinct components: the five-bar spherical linkage mechanism, the tool shaft, the end effector, and the control system. This segmentation allows each component to perform its specific function independently, making the complex system manageable and maintainable while achieving precise control through the coordinated operation of segmented parts.
Solution Approach 2:
The patent employs a spherical five-bar linkage mechanism where all motion is constrained to rotation about a remote center of spherical rotation. This spherical geometry provides intuitive control characteristics that match natural surgical manipulation, allowing the end effector to move precisely along a spherical path centered at the incision site, thereby simplifying the control interface despite the mechanical complexity.
3Length of moving object
If the tool shaft is made longer to reach deeper surgical sites, then access to internal surgical sites is improved, but lateral motion at the incision increases causing instability
Solution Approach 1:
The patent replaces the traditional long tool shaft with a robotic arm system that achieves deep surgical site access through a different mechanical architecture. The five-bar spherical linkage allows the end effector to reach the remote center of spherical rotation at the incision site while maintaining stability, eliminating the need for a long rigid tool shaft that would otherwise cause lateral motion and instability.
Solution Approach 2:
The patent transitions from linear motion along a long tool shaft to spherical motion about a remote center. By constraining movement to rotation about a fixed center point in three-dimensional space, the system achieves deep access to surgical sites while maintaining stability at the incision site, effectively solving the trade-off between reach and stability through dimensional transformation of the motion space.
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.