Surgical Instrument Articulation Assembly for Limited Robotic Inputs
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Solution Overview
Problem
The design of surgical instruments for robotic surgical systems is constrained by the limited number and configuration of inputs provided by the robotic arm, making it challenging to achieve desired functionalities.
Innovation Solution
An articulation assembly comprising a lead screw sub-assembly and multiple gear sub-assemblies with diagonally-opposite lead screws and gears, which utilize a system of articulation cables and housings to enable precise articulation and input rotation, allowing for the tensioning and untensioning of cables to achieve pitch and yaw movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a robotic arm with limited inputs is used to operate surgical instruments, then the system structure is simplified and ease of operation is improved, but the functionality and versatility of the surgical instrument are constrained
Solution Approach 1:
The surgical instrument is divided into multiple independent functional modules including articulation mechanism, cutting mechanism, coagulation mechanism, and irrigation/suction mechanism. Each module can be independently controlled through the limited robotic arm inputs using mechanical transmission mechanisms such as lead screws and gears, enabling complex functions to be achieved through coordinated operation of segmented components
Solution Approach 2:
The surgical instrument is designed with multi-functional capabilities where a single instrument can perform cutting, coagulation, irrigation, and suction functions. The robotic arm inputs are mechanically transmitted through universal mechanisms like lead screws and gear systems to control multiple functional modules, allowing one instrument to replace multiple specialized tools
2Measurement precision
If multiple lead screws and gear sub-assemblies are used to achieve precise articulation, then articulation precision and functionality are improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The articulation mechanism employs a nested structure where multiple gear sub-assemblies are housed within compact housings. The first, second, and third gear sub-assemblies are arranged in a nested configuration with each sub-assembly containing multiple gears that work together. This nesting approach reduces the overall spatial footprint while maintaining the precision of multiple lead screw actuators
Solution Approach 2:
Multiple functional components are merged into integrated sub-assemblies. For example, the first gear sub-assembly combines multiple gears and a lead screw into a single functional unit that controls articulation. The housings are designed to contain and integrate multiple components, reducing the number of separate parts while maintaining articulation precision through coordinated mechanical transmission
3Adaptability or versatility
If diagonally-opposite lead screws with opposite pitch are used to tension and untension articulation cables, then articulation control and functionality are improved, but the manufacturing precision and assembly difficulty increase
Solution Approach 1:
Diagonally-opposite lead screws are designed with opposite thread pitches (one right-handed, one left-handed) to enable differential control of articulation cables. This asymmetric design allows one lead screw to tension its cable while the other untensions its cable, creating precise articulation control. The asymmetric pitch configuration is integrated into the symmetric diagonal arrangement of the lead screws
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 enables the surgical instrument to achieve precise articulation and movement, effectively utilizing the robotic arm's inputs to enhance the functionality and versatility of the surgical instrument, improving its compatibility and effectiveness with robotic surgical systems.
Implementation Method 1
The lead screw sub-assembly includes first, second, third, and fourth lead screws. Rotation of one of the first, second, third, or fourth lead screws translates the corresponding collar to tension or un-tension the corresponding articulation cable.
Implementation Method 2
The first gear sub-assembly includes a first housing at least partially capturing first and second gears therein. The first and second gears are coupled to the first and third lead screws.
Data Source
AI summary
A surgical instrument articulation assembly includes a lead screw sub-assembly including four lead screws. A first gear sub-assembly includes first and second gears coupled to the first and third lead screws. A second gear sub-assembly includes third and fourth gears coupled to the second and fourth lead screws, respectively, a first compound gear including a distal gear coupling the first and second gears with one another, and a proximal gear coupled with a first coupling gear disposed about a first input. The third gear sub-assembly includes a second compound gear including a distal gear coupling the third and fourth gears with one another, and a proximal gear coupled with a second coupling gear disposed about a second input. A rotational input provided to the first or second input respectively rotates the first and third lead screws and or the second and fourth lead screws.