Stent Delivery Handle Assembly for One-Handed Precise Deployment
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Solution Overview
Problem
Existing stent delivery systems, particularly those using push-pull catheter handles, require two hands for deployment and lack precise control, making it difficult to accurately deploy self-expanding stents without moving relative to the patient.
Innovation Solution
A stent delivery handle system with a thumbwheel and selector tab mechanism that allows one-handed deployment, enabling controlled sheath retraction and stent distal pushing, while maintaining a stationary position relative to the patient, and featuring a stabilizer for maintaining alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a push-pull catheter handle is used for stent deployment, then the stent can be deployed, but two hands are required and precise control is difficult
Solution Approach 1:
The patent combines the functions of sheath retraction and stent pushing into a single thumbwheel mechanism. Rotating the thumbwheel simultaneously controls the sheath spool (for sheath retraction) and the pusher spool (for stent pushing), enabling one-handed operation while maintaining precise control over stent deployment position.
Solution Approach 2:
The ratchet members provide mechanical feedback through tactile engagement and disengagement. When the selector member engages the ratchet members, it creates distinct tactile sensations that give the operator feedback on the deployment process, enhancing control precision during one-handed operation.
2Measurement precision
If the handle moves relative to the patient during deployment, then deployment can occur, but accurate placement is difficult to achieve
Solution Approach 1:
The stabilizer is pre-positioned within the catheter shaft before deployment. This preliminary positioning ensures that the handle remains stable and stationary relative to the patient during the entire deployment process, eliminating the need for complex active stabilization mechanisms while maintaining placement accuracy.
3Ease of operation
If a simple push-pull mechanism is used, then the device is simple, but controlled retraction of the sheath while pushing the stent is not achieved
Solution Approach 1:
The thumbwheel mechanism transforms rotational motion into coordinated linear motion of both the sheath and stent. The differential gear system allows the sheath and pusher to move at different rates and directions, providing dynamic control over the deployment process that a simple push-pull mechanism cannot achieve.
Solution Approach 2:
The ratchet members act as intermediaries between the selector member and the spools. They translate the rotational motion of the thumbwheel into controlled linear motion while providing mechanical advantage and ensuring unidirectional movement, enabling precise control without excessive complexity.
4Productivity
If two hands are required for deployment, then control may be achieved, but productivity and efficiency are reduced
Solution Approach 1:
The patent merges multiple control functions (sheath retraction, stent pushing, and deployment sequencing) into a single thumbwheel operation. This consolidation allows one-handed operation while maintaining the coordinated control necessary for efficient and safe stent deployment, thereby improving productivity without sacrificing ease of operation.
Data Source
AI summary
A stent delivery catheter assembly for delivering and implanting a self-expanding stent in a body lumen includes a handle assembly for one handed use. The handle assembly has a mode selection for advancing, reversing and locking the stent delivery components. Rotation of a thumbwheel allows the physician to deploy and implant the self-expanding stent in the body lumen with control and precision by simultaneously pulling a sheath proximally and pushing a pusher member distally.