Catheter Lumen Flow Control for Uniform Distal Seal Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transcatheter delivery apparatuses face challenges in maintaining a consistent flow of flush fluid through various lumens, leading to potential thrombus formation due to varying resistances and changes in resistance during implantation procedures for transcatheter heart valves.
Innovation Solution
A delivery apparatus with an outer shaft, inner shaft, and sleeve shaft configuration that includes apertures and paddle gears to maintain a consistent fluid flow, reducing blood stagnation and thrombus formation by ensuring uniform fluid distribution through lumens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a catheter delivery system is designed to be minimally invasive with a small profile, then it can be delivered through smaller vessels and cause less trauma, but it becomes difficult to maintain adequate fluid pressure for effective firing of the distal seal
Solution Approach 1:
The fluid delivery system is segmented into multiple independent lumens within the catheter shaft. Each lumen can independently deliver fluid to different segments of the distal seal, allowing pressure to be maintained at the firing site while keeping the overall catheter profile small. The segmentation enables distributed fluid delivery rather than relying on a single high-pressure source.
Solution Approach 2:
A fluid reservoir positioned proximal to the distal seal acts as an intermediary, storing fluid under pressure and delivering it through multiple pathways to the seal. This intermediary allows the system to maintain adequate firing pressure without requiring the entire catheter to be large or rigid, as the reservoir can be compact and the fluid distribution through multiple lumens efficiently transmits pressure to the distal endpoint.
2Device complexity
If fluid is delivered through a single central lumen to the distal seal, then the catheter structure is simplified, but fluid distribution across the entire circumference of the seal is inadequate leading to poor sealing
Solution Approach 1:
The single central lumen is replaced with multiple lumens arranged circumferentially around the catheter axis. Each lumen delivers fluid to a specific sector of the distal seal, ensuring complete circumferential coverage. This segmentation of fluid delivery pathways allows reliable seal formation across the entire balloon circumference while maintaining a relatively simple catheter construction using standard multi-lumen tubing.
Solution Approach 2:
The fluid delivery system transitions from a single-dimensional central pathway to a multi-dimensional circumferential arrangement. Multiple lumens are positioned at different angular positions around the catheter, delivering fluid simultaneously to different circumferential locations of the distal seal. This spatial distribution in the angular dimension ensures complete seal formation without requiring complex mechanical structures.
3Adaptability or versatility
If the catheter is designed for over-the-wire delivery, then delivery flexibility is improved, but the ability to maintain fluid pressure for seal firing is compromised due to wire interference
Solution Approach 1:
The guidewire is nested within the catheter structure, specifically positioned within a dedicated lumen or channel that is separate from the fluid delivery lumens. This nesting arrangement allows the wire to provide delivery flexibility and support while the fluid lumens maintain independent pathways for pressure delivery to the distal seal. The wire and fluid system are spatially separated yet integrated within the same catheter assembly.
Solution Approach 2:
The catheter internal structure is segmented into distinct functional zones: a guidewire lumen for mechanical support and flexibility, and separate fluid delivery lumens for pressure transmission to the seal. This segmentation prevents the guidewire from interfering with fluid pressure delivery, as each component has its own dedicated pathway. The multi-lumen design accommodates both the wire and fluid systems without compromise.
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 apparatus ensures a consistent flow of fluid through the lumens, reducing blood stagnation and thrombus formation, thereby enhancing the secure implantation of prosthetic valves at native heart valves.
Implementation Method 1
a first fluid deliverable through a first lumen of the catheter to the tissue to promote the ingrowth of tissue into the distal seal
Implementation Method 2
a second fluid dissolvable in the first fluid, wherein the second fluid comprises a fibrinolytic agent capable of dissolving a fibrin clot
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Methods and systems for providing a consistent flow of fluid through lumens of a delivery apparatus are disclosed. As one example, a delivery apparatus can include an outer shaft configured to retain a prosthetic implant in a delivery configuration, an inner shaft disposed within the outer shaft and configured to interface with an end of the prosthetic implant and move axially relative to the outer shaft, and a sleeve shaft disposed within the outer shaft and configured to cover the prosthetic implant in the delivery configuration. In some examples, the inner shaft can include one or more openings defined therein that extend between an inner surface and an outer surface of the inner shaft and that are configured to fluidly couple an inner lumen of the inner shaft with a lumen disposed between the outer surface of the inner shaft and an inner surface of the sleeve shaft.