Atherectomy Catheter With Isolated OCT Imaging Shaft
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Solution Overview
Problem
Current atherectomy devices face challenges such as high cost, complexity, limited applicability, and inefficiency in treating complex lesions due to large crossing profiles, unpredictable tissue collection, and lack of real-time image guidance, leading to increased vessel trauma and restenosis rates.
Innovation Solution
The development of atherectomy catheters with on-board imaging, featuring a mechanically isolated drive shaft and imaging shaft, an inflatable element to urge the cutter against the vessel wall, and an optical coherence tomography (OCT) imaging element, allowing for precise cutting and tissue collection without disrupting the imaging process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If atherectomy devices use large distal collection elements to store tissue, then tissue collection capability is improved, but the device crossing profile increases and capability to access small lesions is limited
Solution Approach 1:
The drive shaft with cutter is nested within the imaging shaft, allowing both functions (cutting and imaging) to be integrated in a compact configuration. This nesting enables tissue collection without requiring large external collection elements, maintaining a small crossing profile for accessing small lesions while still providing effective tissue removal capability
Solution Approach 2:
The invention transitions from storing tissue in the distal tip (one-dimensional storage) to aspirating tissue proximally through the catheter body (utilizing the length dimension). This dimensional change allows tissue collection without increasing distal profile, enabling access to small lesions while maintaining tissue removal capability
2Quantity of substance
If atherectomy devices apply negative pressure to aspirate tissue, then tissue collection is improved, but the artery collapses around the cutting element causing vessel wall injury
Solution Approach 1:
The imaging shaft is designed to be movable relative to the drive shaft, allowing dynamic adjustment of the imaging element position. This enables the imaging shaft to be retracted or positioned to avoid collapse during aspiration, maintaining vessel patency while still allowing tissue collection through controlled negative pressure application
Solution Approach 2:
The imaging shaft acts as an intermediary structure between the cutting element and the external environment. By providing this intermediate chamber and controlled aspiration pathway, tissue can be removed without direct collapse of the artery onto the cutter, reducing vessel wall injury while maintaining effective tissue collection
3Manufacturing precision
If atherectomy devices use directional cutting with cup-shaped cutters, then plaque removal precision is improved, but the device complexity and size increase
Solution Approach 1:
The device is segmented into functionally independent modules: an imaging shaft containing the OCT imaging element and a separate drive shaft containing the cutter. This segmentation allows each component to be optimized for its specific function (imaging or cutting) without requiring complex integration, maintaining directional cutting precision while reducing overall device complexity
Solution Approach 2:
The rotatable cutter is designed to perform multiple functions: directional plaque cutting when rotated, and potential imaging window exposure when positioned appropriately. This multi-functionality reduces the need for separate specialized components, simplifying device design while maintaining precise plaque removal capability
4Device complexity
If atherectomy devices lack real-time image guidance, then device complexity is reduced, but treatment precision increases vessel trauma
Solution Approach 1:
The OCT imaging element and cutter are merged into a single integrated catheter assembly with concentric shafts. This combination allows real-time imaging guidance during cutting procedures without requiring separate imaging devices, reducing vessel trauma through precise targeting while maintaining relatively simple device architecture through the integrated design
Solution Approach 2:
The invention replaces complex mechanical imaging systems (such as rotating mirrors or multiple lenses) with optical coherence tomography technology that uses light interference patterns. This substitution provides real-time cross-sectional imaging with micrometer resolution through a compact fiber-optic-based system, enabling precise treatment guidance without significantly increasing mechanical device complexity
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
This solution enhances the precision and safety of atherectomy procedures by reducing vessel trauma, improving lumen size gains, and lowering restenosis rates through real-time imaging and efficient tissue collection, while simplifying the device design and operation.
Implementation Method 1
an optical coherence tomography (OCT) imaging element
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
An atherectomy catheter includes an elongate flexible catheter body, a cutter near the distal end of the catheter body, a drive shaft connected to the cutter and extending within the catheter body, an imaging element near the distal end of the catheter body and an imaging sha connected to the imaging element and extending within the catheter body. The cutter and the imaging element are mechanically isolated, and the drive shaft is configured to be axially translated relative to the imaging shaft and the catheter body.