Rotary Atherectomy Device with Variable Support Alignment
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Solution Overview
Problem
Existing medical devices for treating stenosed sites within blood vessels, such as those using balloon catheters or stents, often fail to provide a sustained therapeutic effect and can cause new stenosis, especially in calcified or branched lesions, due to inadequate alignment and application of cutting force during atherectomy procedures.
Innovation Solution
A medical device with a rotatable elongated member and a rotary body equipped with a cutting edge, featuring a support portion that allows variable distance adjustment to align the cutting edge with the stenosed site, ensuring precise application of cutting force while preventing contact with biological tissue other than the target.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a rotary body with a cutting edge is used to cut the stenosed site, then the cutting force can be applied to remove plaque and calcified lesions, but the cutting edge may contact biological tissue other than the target stenosed site
Solution Approach 1:
A support portion acts as an intermediary structure between the rotary body and the biological lumen. This support portion includes a contact section that contacts the lumen wall to position and align the cutting edge with the stenosed site, thereby mediating the interaction between the cutting edge and biological tissue to prevent unnecessary contact while enabling effective cutting
2Force
If the cutting edge is positioned close to the stenosed site to apply sufficient cutting force, then the therapeutic effect is improved, but the risk of contacting non-target biological tissue increases
Solution Approach 1:
The support portion serves as a mediator that provides a stable base for positioning the cutting edge at the optimal distance from the stenosed site. This allows sufficient cutting force to be applied while maintaining precise control over the cutting edge's position relative to the target tissue
Solution Approach 2:
The contact section of the support portion is designed to preliminarily contact and align with the stenosed site before the cutting edge engages. This preliminary alignment action ensures that when cutting begins, the cutting edge is already properly positioned to apply force only to the target tissue
3Productivity
If the rotary body is rotated at high speed to efficiently cut calcified lesions, then the treatment time is reduced, but the control over cutting depth and precision is compromised
Solution Approach 1:
The support portion acts as a stable intermediary platform that remains relatively stationary while the rotary body rotates. This stable base provides reference points and geometric constraints that maintain cutting precision even at high rotation speeds, as the support portion's structure defines the cutting path and depth
Data Source
AI summary
A medical device has a rotatable drive shaft, a rotary body whose distal end includes a cutting edge for applying a cutting force to a stenosed site, and that is disposed on a distal side of the drive shaft so as to be rotated in conjunction with rotation of the drive shaft, and a distal member disposed in the rotary body. The distal member has a support portion extending to a distal side beyond a distal end of the rotary body, and configured to be capable of supporting the rotary body with respect to a blood vessel. The support portion is configured so that a distance from the rotary body is variable in a first direction (height direction) in which the rotary body is moved close to the stenosed site.