Surgical Resection Guide Helical Dial Adjustment
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Solution Overview
Problem
Current surgical resection guides for knee replacement procedures face challenges in accurately adjusting the spacing between components due to small markings on gauges and the need for large motor groups to control fine movements, leading to potential overshooting of the required resection level.
Innovation Solution
A surgical resection guide featuring a linear adjustment mechanism with a shaft and a dial incorporating a helical groove, allowing for precise control through rotation of the dial, which reduces the need for large motor groups and enables larger numbering on the gauge, enabling more accurate adjustments without raising or lowering components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a linear adjustment mechanism with a dial and helical groove is used, then control precision and ease of operation are improved, but device complexity increases
Solution Approach 1:
The patent replaces the traditional mechanical sliding adjustment system with a dial-based rotary mechanism featuring a helical groove. This substitution transforms linear motion control into rotational motion control, providing finer adjustment precision through the dial's incremental rotations while maintaining a relatively simple mechanical structure.
Solution Approach 2:
The invention changes the control parameter from linear displacement to rotational angle. By using a dial that rotates around a helical groove, the adjustment precision is enhanced through angular increments, allowing for more precise control of the spacing between cutting guide and bone surface compared to direct linear adjustment.
2Force
If large motor groups are used to control fine movements, then control force is improved, but ease of operation deteriorates due to overshooting risk
Solution Approach 1:
The patent introduces a dynamic adjustment mechanism where the dial can be rotated to progressively adjust the spacing. This allows the surgeon to make small, controlled increments rather than attempting large movements, eliminating the overshooting risk associated with using large motor groups for fine adjustments.
Solution Approach 2:
Instead of applying full control force in a single action, the dial mechanism allows for partial adjustments through incremental rotations. The surgeon can rotate the dial in small steps to achieve the precise spacing required, avoiding the need to apply excessive force that could lead to overshooting the target position.
3Device complexity
If small markings are used on the gauge, then device complexity is reduced, but measurement precision deteriorates due to reading difficulty
Solution Approach 1:
The patent transitions from a linear gauge with small markings to a rotary dial with markings distributed around its circumference. This dimensional change from linear to circular arrangement allows for larger, more easily readable markings while maintaining compact device dimensions, improving reading accuracy without significantly increasing overall device complexity.
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
This solution enhances the accuracy and usability of the surgical resection guide by allowing fine control with minimal motor effort, improving the precision of resection plane adjustments and reducing the risk of overshooting, while enabling larger markings for easier reading.
Implementation Method 1
a dial rotatably coupled to the housing and incorporating a helical dial groove or rib defining a longitudinal axis offset from the longitudinal axis of the shaft; wherein the shaft tooth or groove engages the dial groove or rib such that rotating the dial relative to the housing causes the shaft tooth or groove to slide along the dial groove or rib causing the shaft to slide within the bore along its longitudinal axis
Data Source
AI summary
A surgical resection guide comprising: a housing (36); a stylus arm (38) extending through the housing (36) arranged such that when the housing (36) is coupled to the side of a bone, a tip of the stylus arm (38) is arranged to contact an end of a bone; and a linear adjustment mechanism. The linear adjustment mechanism comprises: a shaft (30) at least partially received within a bore extending through the housing (36) such that the shaft (30) can slide along its longitudinal axis relative to the housing (36), the shaft (30) incorporating a shaft tooth or groove (50); and a dial (44) rotatably coupled to the housing (36) and incorporating a helical dial groove or rib (48) defining a longitudinal axis offset from the longitudinal axis of the shaft (30). The shaft tooth or groove (50) engages the dial groove or rib (48) such that rotating the dial (44) relative to the housing (36) causes the shaft tooth or groove (50) to slide along the dial groove or rib (48) causing the shaft (30) to slide within the bore along its longitudinal axis. The housing (36) and the stylus arm (38) can rotate about the shaft (30) without causing the shaft (30) to slide within its bore along its longitudinal axis. A method of adjusting the surgical resection guide is also disclosed.