Eccentric Abrading Head Segmentation for Rotational Atherectomy
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Solution Overview
Problem
Current rotational atherectomy devices are limited in their ability to effectively remove both hard and soft atherosclerotic plaques, often requiring multiple burrs and struggling with stent restenosis due to inflexible designs, hydraulic wedges, and inefficient abrasive surfaces, which restricts the diameter of arteries that can be opened and predictability of the procedure.
Innovation Solution
A high-speed rotational atherectomy device with a flexible, elongated drive shaft featuring an eccentric abrading head comprising multiple cylindrical segments with varying abrasive grit sizes and customizable eccentricity, allowing for increased flexibility and abrasive surface area, which breaks hydraulic wedges and effectively removes calcified and non-calcified plaque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a solid burr with abrasive material is used for rotational atherectomy, then the device can remove stenotic tissue, but the burr blocks blood flow and requires multiple burrs to open the artery to the desired diameter
Solution Approach 1:
The abrading head is divided into multiple discrete abrasive segments arranged in a circle, each capable of removing tissue. This segmentation allows the abrading head to function as a single integrated unit that can open the artery to the desired diameter without requiring multiple separate burrs, while maintaining effective tissue removal capability.
Solution Approach 2:
The abrading head combines multiple functions in a single component: it removes stenotic tissue, opens the artery to the desired diameter, and can be used with different burr sizes. The circular arrangement of abrasive segments provides universal applicability across different lesion types and artery sizes.
2Productivity
If an enlarged eccentric section of drive shaft is used, then the device can open the artery to a larger diameter, but the enlarged section may flex during placement and operation, providing less control over the abraded diameter
Solution Approach 1:
The eccentric abrading head is segmented into discrete abrasive segments rather than being a solid continuous structure. This segmentation allows the head to maintain its eccentric configuration for larger diameter opening while reducing excessive flexion and providing better control over the abraded diameter through the distributed nature of the abrasive segments.
Solution Approach 2:
The abrasive segments are strategically positioned and sized to provide localized abrasion capability. This local quality approach allows different portions of the abrading head to have different abrasive characteristics, improving control over the abraded diameter while maintaining the ability to open to larger diameters.
3Ease of manufacture
If a smooth abrasive surface is used on the burr, then the device is easier to manufacture, but the hydraulic wedge forms between the burr and arterial wall, reducing contact and abrading efficiency
Solution Approach 1:
The abrasive segments have surfaces that are optimized for contact with the arterial wall and plaque. The segments are positioned and shaped to break hydraulic wedges and maintain effective contact during rotation, improving abrading efficiency while remaining manufacturable.
Solution Approach 2:
The abrasive segments are designed with curved surfaces that conform to the arterial wall geometry. This curvature allows the segments to effectively break hydraulic wedges and maintain continuous contact during rotation, significantly improving abrading efficiency compared to flat smooth surfaces.
4Ease of operation
If the abrading head is made flexible to navigate tortuous vasculature, then the device can be placed through complex pathways, but the flexibility reduces control over the abraded diameter
Solution Approach 1:
The flexible drive shaft is segmented into discrete sections that can bend and flex independently, allowing navigation through tortuous vasculature. The eccentric abrading head is attached to this segmented shaft, providing flexibility for placement while maintaining control over the abraded diameter through the eccentric configuration and segmented abrasive structure.
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 device can open arteries to a diameter larger than the abrading head's nominal diameter, enhances tissue removal efficiency, reduces procedure time, and improves predictability by customizing the abrading head's mass and eccentricity, facilitating effective removal of both hard and soft stenotic tissues.
Implementation Method 1
Each individual abrading segment, comprises a first tissue removing surface, typically an abrasive coating on the outer surface, that is designed to abrade calcified, hard tissue
Implementation Method 2
Each abrading segment, as well as the abrading head comprising the collective segments, has a center of mass spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to open the stenotic lesion to a diameter larger than the outer diameter of the enlarged abrading head when operated at high speeds
Data Source
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AI summary
The invention provides a rotational atherectomy system, device and method having, in various embodiments, a flexible, elongated, rotatable drive shaft comprising an eccentric abrading head comprising at least one eccentric abrading cylindrical segments attached to the drive shaft and in spaced proximity with proximal and a distal conical segments. Each individual abrading segment, comprises a first tissue removing surface, typically an abrasive coating on the outer surface, that is designed to abrade calcified, hard tissue and abrasive coating on the leading and trailing surfaces designed to abrade non-calcified, soft tissue. Each abrading segment, as well as the abrading head comprising the collective segments, has a center of mass spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to open the stenotic lesion to a diameter larger than the outer diameter of the enlarged abrading head when operated at high speeds.