Capacitive Slip Ring Channels for Fluid-Exposed Surgical Shafts
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Solution Overview
Problem
Existing surgical instruments face challenges in effectively measuring and controlling the position and velocity of cutting members to adjust for tissue thickness, particularly in motorized surgical stapling and cutting instruments, and there is a need for improved electrical communication in slip ring assemblies that are exposed to water and body fluids during surgery.
Innovation Solution
The implementation of a shaft assembly with a slip ring assembly that forms capacitive channels using dielectric layers to maintain electrical communication between rotating and fixed portions, while providing a waterproof barrier to prevent signal noise and power loss, and includes sensors to detect transitions between articulation states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electrical cables are used in slip ring assemblies exposed to water and body fluids, then electrical communication can be maintained, but signal noise and power loss occur due to fluid exposure
Solution Approach 1:
The patent introduces a dielectric layer as an intermediary between the first and second conductors. This dielectric barrier prevents direct contact between electrical conductors and harmful fluids while allowing capacitive coupling for signal transmission, thus eliminating signal noise and power loss from fluid exposure while maintaining reliable electrical communication.
Solution Approach 2:
The patent replaces traditional direct electrical contact (mechanical connection) with capacitive coupling through a dielectric layer. This substitution eliminates the need for direct conductor-to-conductor contact that is vulnerable to fluid interference, achieving fluid-resistant electrical communication without mechanical exposure to harmful environments.
2Measurement precision
If a rotatable distal shaft portion is implemented for articulation control, then positioning precision is improved, but electrical connection stability deteriorates due to rotation and movement
Solution Approach 1:
The dielectric layer serves as a stable intermediary that maintains consistent capacitive coupling between rotating and fixed portions. This intermediary ensures that electrical connection stability is maintained even as the distal shaft portion rotates and moves for precise articulation control, as capacitive coupling is less sensitive to mechanical displacement than direct contact.
Solution Approach 2:
The slip ring assembly with capacitive coupling serves multiple functions simultaneously: it enables precise positioning control through rotatable shaft movement while maintaining stable electrical connection through the fluid-resistant dielectric barrier. This multi-functionality resolves the contradiction between movement precision and connection stability.
3Reliability
If dielectric layers are added to form capacitive channels, then waterproofing and signal integrity are improved, but device complexity increases
Solution Approach 1:
The patent merges the insulation function and the electrical transmission function into a single integrated structure. The dielectric layer simultaneously provides waterproofing, electrical insulation, and capacitive coupling for signal transmission, eliminating the need for separate components and thus reducing overall device complexity while improving reliability.
Solution Approach 2:
The dielectric layer performs multiple functions: it acts as a waterproof barrier, provides electrical insulation, and enables capacitive coupling for signal transmission. This multi-functionality achieves superior waterproofing and signal integrity without proportionally increasing device complexity, as one component accomplishes what would traditionally require multiple separate elements.
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 precise control of cutting member position and velocity based on tissue thickness, while ensuring reliable electrical communication and preventing signal interference and power loss due to exposure to surgical fluids.
Implementation Method 1
the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting an electrical signal between the end effector and the control circuit
Implementation Method 2
a dielectric layer between the first conductor and the second conductor
Data Source
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AI summary
A surgical shaft assembly includes a slip ring assembly. The slip ring assembly has a first connector, a first conductor mounted on the first connector, and a first water-proof insulative layer on the first conductor. The slip ring assembly has a second connector rotatable relative to the first connector, a second conductor mounted on the second connector, and a second water-proof insulative layer on the second conductor. The slip ring assembly also has a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer. The first conductor and the second conductor are configured to form a capacitive channel therebetween.