Rotatable Atherectomy Tip Dynamics for Plaque Removal
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Solution Overview
Problem
Current minimally invasive vascular surgical methods for removing plaque, such as balloon angioplasty and atherectomy, face challenges like difficulty in navigating through occluded passageways, risk of restenosis, and limitations in effectively removing small particles, leading to suboptimal blood flow restoration.
Innovation Solution
An atherectomy device with a rotatable shaft and tip designed for high-speed rotation, featuring a unique tip geometry with scalloped sections and an optional auger mechanism for enhanced plaque removal, allowing for efficient aspiration of particles through a fixed gap between the shaft and outer member, facilitating larger plaque removal areas with reduced introducer sheath size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a larger atherectomy tip is used to remove more plaque, then the plaque removal area is improved, but the device complexity and introducer sheath size increase
Solution Approach 1:
The atherectomy tip is made rotatable to dynamically engage with plaque throughout the vessel circumference, enabling a larger effective removal area without requiring a proportionally larger static tip diameter, thus avoiding increased introducer sheath size
Solution Approach 2:
The tip transitions from a static two-dimensional cross-section to a three-dimensional rotatable structure that engages plaque along the entire vascular circumference, effectively increasing the removal area without increasing the tip's baseline dimensions or sheath requirements
2Productivity
If high rotation speed is used to improve plaque removal efficiency, then the productivity is improved, but the device complexity increases
Solution Approach 1:
The complex mechanical rotation mechanism is replaced with a simpler design where the atherectomy tip rotates passively or through minimal actuation, reducing device complexity while maintaining high rotation speeds for efficient plaque removal
Solution Approach 2:
The rotation speed parameter is optimized to achieve effective plaque removal at high velocities without requiring overly complex control systems, balancing productivity improvement with manageable device complexity
3Reliability
If aspiration capability is enhanced to remove small particles, then the plaque removal completeness is improved, but the device complexity increases
Solution Approach 1:
The aspiration function is merged with the existing catheter structure, integrating particle removal capability into the delivery system without adding separate complex aspiration mechanisms, thus improving plaque removal completeness while minimizing device complexity increase
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 effectively breaks up and removes plaque, widening the blood passageway with reduced trauma and increased efficiency, enabling better blood flow restoration while minimizing the need for larger introducer sheaths and potentially reducing complications like restenosis.
Implementation Method 1
Atherectomy procedures typically involve inserting a cutting or ablating device through the access artery, e.g., the femoral artery or the radial artery, and advancing it over a guidewire through the vascular system to the occluded region, and rotating the device at high speed to cut through or ablate the plaque
Implementation Method 2
an auger positioned on the rotatable shaft, the auger positioned proximally of the rotatable tip and extending along the outer shaft, wherein rotation of the shaft rotates the auger to move particles abraded by the tip proximally into the outer member
Implementation Method 3
The particles can be aspirated through the outer member in the space between the rotatable shaft and an inner wall of the outer member
Data Source
AI summary
An atherectomy device for removing deposits such as plaque from an interior of a vessel including an outer member and a rotatable shaft positioned for rotational movement within the outer member. The outer member is fixed axially. A rotatable tip is mounted to the distal region of the rotatable shaft for rotation about its longitudinal axis upon rotation of the shaft. The rotatable shaft includes a guidewire lumen for receiving a guidewire to enable over the wire insertion of the device.