Steerable Catheter with Sliding Subassembly for Valve Alignment
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Solution Overview
Problem
Conventional steerable catheters face challenges in precisely aligning implantable devices, such as rings or cinching cords, with cardiac valve annuli due to the significant distance between the catheter's bending section and the implant, making precise alignment difficult, especially when the implant is positioned far from the catheter's actuatable bending section.
Innovation Solution
The implementation of a steerable catheter with a secondary actuatable bending section in a subassembly slidably disposed with respect to the support structure, allowing for adjustable spacing and improved maneuverability, combined with a primary actuatable bending section within the catheter, enables precise alignment of the implant with the cardiac valve annulus by providing both coarse and fine adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional steerable catheter with a single bending section is used to deliver an implant, then the device can be delivered through the vasculature, but precise alignment of the implant with the cardiac valve annulus becomes difficult when the implant is positioned far from the catheter's actuatable bending section
Solution Approach 1:
The catheter system is divided into two functional segments: a first actuatable bending section in the distal portion of the catheter for coarse alignment, and a second actuatable bending section in the subassembly for fine alignment. This segmentation allows each section to address different aspects of positioning, resolving the alignment precision problem despite the long distance between the catheter operator and the implant.
Solution Approach 2:
The subassembly acts as an intermediary between the catheter and the implant. It includes a second actuatable bending section that provides additional maneuverability closer to the implant, serving as a mediator that translates operator inputs into precise implant positioning despite the long catheter length.
2Measurement precision
If the subassembly is positioned close to the support structure, then alignment precision is improved, but the device cannot be properly delivered through the sheath
Solution Approach 1:
The subassembly is designed to be slidable with respect to the support structure, allowing it to dynamically change its position. During delivery, it is retracted to minimize the device profile for sheath passage. During alignment, it is advanced to provide precise positioning close to the implant. This dynamic positioning resolves the contradiction between delivery constraints and alignment precision.
Solution Approach 2:
The subassembly is initially nested within or adjacent to the support structure in a compact configuration that fits through the delivery sheath. Once deployed, it can be extended or advanced to its working position for precise alignment, embodying the nested doll principle where a smaller configuration contains or leads to a larger functional configuration.
3Volume of moving object
If the support arms are confined within the sheath, then the device maintains a compact delivery profile, but the support arms cannot spring apart to support the implant
Solution Approach 1:
The support arms are pre-configured in a compressed state within the sheath for delivery. Once the sheath is removed, the constraint is eliminated and the support arms automatically spring apart to their expanded support configuration. This preliminary compression followed by automatic expansion resolves the contradiction between compact delivery and effective implant support.
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 configuration enhances the precision and ease of aligning the implant with the cardiac valve annulus, improving the alignment process by allowing for both coarse and fine adjustments, thereby facilitating more accurate implantation.
Implementation Method 1
The balloon is configured so that when the subassembly is at the second position, inflation of the balloon causes the balloon to press outward against at least some of the support arms
Implementation Method 2
The proximal segment of the subassembly has at least one second mating feature that is shaped and dimensioned to form a keyed connection with the at least one first mating feature
Data Source
AI summary
An implant may be affixed to a cardiac valve annulus by an apparatus that includes a catheter with a first actuatable bending section and a support structure affixed to the distal end of the catheter. Support arms extend distally beyond the support structure. In some embodiments, a shaft with a second actuatable bending section is permanently positioned between the support arms, and an inflatable balloon surrounds at least a portion of the shaft. In other embodiments, a subassembly that includes a shaft with a second actuatable bending section and an inflatable balloon is slidably mounted so that it can move from an initial position that is spaced apart from the support structure to a second position where the balloon is between the at least four support arms. In either case, actuating the second bending section when the balloon is inflated will move the support arms that support the implant.