Sealed Switch Bezel and Cable Circuitry for Arthroscopic Handpiece
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Solution Overview
Problem
Conventional surgical handpiece switch designs fail to reliably seal and actuate due to inadequate sealing strength, and they are difficult to assemble and protect against external factors like water and sterilization liquids, with microprocessor and circuitry typically located within the housing and exposed to contaminants.
Innovation Solution
Embedding microprocessor circuitry in the cable and potting it to prevent external interference, and using a sealed switch design with a bezel and button system that forms a sealed enclosure around the switch, employing elastomeric materials and seals like x-rings or o-rings to ensure reliable actuation and protection from external elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large elastomer membrane is used to seal the switch cavity with bezel pressure, then the switch can be sealed from external elements, but the seal fails and the switch does not reliably actuate
Solution Approach 1:
The sealing system is divided into separate components: a bezel that attaches to the housing, a button that seals within the bezel opening, and distinct switch cavity sealing. This segmentation allows each component to be optimized independently - the bezel provides structural support while the button provides the actual seal, preventing the seal failure issues seen in conventional single-membrane designs.
Solution Approach 2:
The patent employs an elastomeric button material that forms a flexible seal within the bezel opening. This flexible elastomeric component creates a reliable seal against external elements while maintaining the ability to transmit actuation force to the switch, resolving the contradiction between sealing effectiveness and switch actuation reliability.
2Device complexity
If microprocessor and circuitry are located within the housing, then the handpiece structure is simplified, but the circuitry is exposed to water, contaminants, and sterilization liquids
Solution Approach 1:
The microprocessor and associated circuitry are extracted from the handpiece housing and relocated to the cable assembly. This extraction removes the sensitive electronics from the contaminated environment within the handpiece, protecting them from water, contaminants, and sterilization liquids while maintaining system functionality through the cable connection.
3Ease of manufacture
If conventional switch designs are used with bezel pressure sealing, then assembly is straightforward, but the design does not provide adequate protection against external factors
Solution Approach 1:
The button is nested within the bezel structure, with the button sealing against the inner surface of the bezel opening. This nested arrangement provides robust protection against external factors while maintaining ease of assembly - the button simply inserts into and seals within the pre-formed bezel opening, combining structural protection with manufacturing simplicity.
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 solution provides a reliable sealing mechanism that prevents water, contaminants, and sterilization liquids from reaching the switch and circuitry, ensuring consistent function during surgical use and post-use processes, while also simplifying assembly and enhancing the handpiece's resistance to external factors.
Implementation Method 1
The button may be formed of an elastomeric material and have a bulge that seals the button to the bezel
Implementation Method 2
The button may be sealed to the bezel using an x-ring or o-ring seal
Implementation Method 3
the microprocessor circuitry of the handpiece is embedded in the cable and potted, so that no external or internal factors (such as liquid, for example) may impede the function of the circuitry
Data Source
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AI summary
A button for actuating a switch in a surgical handpiece. The button is sealed to a bezel, and the bezel is sealed to the handpiece. The button, bezel, and handpiece create a sealed enclosure surrounding the switch to prevent external substances from contacting the switch. Further, a control board for controlling the handpiece is embedded in a cable endcap instead of being housed within the handpiece.