Cross-Axis Flexural Pivot Joints for Compact Surgical Articulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical instruments face challenges with joint mechanisms that lack flexibility, stability, and a large operating footprint, leading to increased friction, wear, and limited range of motion, particularly in minimally invasive surgery where instruments need to be compact and efficient.
Innovation Solution
The development of a cross-axis flexural pivot mechanism that includes a first and second joint member with a flexure configured to deform elastically, allowing for two or more degrees of freedom, reducing friction, and enabling a larger range of motion while maintaining stability and minimizing the size of the joint assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pin-in-slot joint is used to allow rotation between shaft portions, then mobility is achieved, but friction and wear increase leading to performance decline
Solution Approach 1:
The patent replaces the traditional pin-in-slot mechanical joint with a magnetic coupling system. Magnets embedded in the first and second shaft portions create magnetic attraction forces that enable rotational movement without physical contact between the shaft portions, thereby eliminating friction and wear while maintaining mobility.
2Length of moving object
If the instrument diameter is reduced to below 3 mm for minimally invasive surgery, then incision size is reduced, but flexibility and range of motion are compromised
Solution Approach 1:
The patent divides the instrument shaft into multiple segments (first shaft portion and second shaft portion) that can rotate relative to each other. This segmentation allows the instrument to maintain a compact diameter while achieving flexibility through the articulation of multiple segments, enabling the tool to navigate complex anatomical pathways.
Solution Approach 2:
The patent introduces rotational degrees of freedom between shaft segments, adding angular movement capability to the linear instrument structure. This dimensional addition allows the instrument to achieve flexibility and adaptability without increasing its primary diameter, enabling it to follow natural lumens and access hard-to-reach surgical sites.
3Adaptability or versatility
If wrist articulation is added to provide both wrist articulation and gripping function, then versatility is improved, but the throw distance from shaft axis to end effector tip increases requiring more volume
Solution Approach 1:
The patent nests the magnetic coupling mechanism within the shaft structure itself, with magnets embedded directly in the shaft portions. This nesting approach allows the wrist articulation mechanism to be integrated within the instrument's existing volume rather than adding external components, maintaining a compact operating footprint while providing articulation capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The cross-axis flexural pivot mechanism enhances the flexibility and stability of surgical instruments, allowing for a larger range of motion (up to 85 degrees) and reducing the overall size, while minimizing friction and the number of parts, making them suitable for minimally invasive procedures.
Implementation Method 1
a flexure configured to deform elastically when the first joint member and the second joint member move from a first configuration to a second configuration
Data Source
AI summary
The embodiments described herein can be used in a variety of grasping, cutting, and manipulating operations. In some embodiments, an apparatus includes a first joint member, a second joint member, and a flexure. The first joint member includes a first connection portion and a contact surface. The second joint member including a second connection portion. A first end portion of the flexure is coupled to the first connection portion, and a second end portion of the flexure is coupled to the second connection portion. The flexure is configured to deform elastically when the first joint member and the second joint member move from a first configuration to a second configuration. When in the first configuration, the central portion of the flexure is spaced apart from the contact portion. When in the second configuration, the central portion of the flexure contacting the contact portion.