Steerable Septal Punch Guide for Stable Left Atrial Access
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Solution Overview
Problem
Existing catheter-based procedures for accessing the left side of the heart are challenging due to difficulty in accurately locating the fossa ovalis, instability during cardiac activity, and increased risk of inadvertent punctures, particularly in patients with abnormal anatomy or repeat procedures.
Innovation Solution
A septum puncture device with a steerable and stable platform between the inferior and superior vena cavae, featuring a guide stabilizer/actuator and side catheter guide, allows for precise and safe access to the left atrium by laterally deflecting and stabilizing the catheter guide to penetrate the septum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a flexible catheter assembly is used to access the left side of the heart, then the procedure can be performed percutaneously with minimal invasion, but the catheter becomes unstable during normal dynamic cardiac activity and is easily maneuvered out of ideal position
Solution Approach 1:
The catheter assembly incorporates a shape memory alloy wire (Nitinol) that can dynamically change its mechanical properties. The wire transitions from a flexible state during delivery to a rigid state when deployed in the left atrium, allowing the catheter to adapt its stability characteristics to different procedural phases while maintaining percutaneous access
2Stability of the object's composition
If a stiff-wire needle with bend is used for septal puncture, then the needle can maintain its shape during advancement, but it is difficult to accurately locate the fossa ovalis and prone to premature or misaligned puncturing
Solution Approach 1:
The needle assembly uses a shape memory alloy wire that transitions from flexible during delivery to rigid upon deployment. This dynamic rigidity change allows the needle to be easily maneuvered and precisely positioned against the fossa ovalis during delivery, then maintains its position and orientation stability during puncture, resolving the contradiction between positioning accuracy and shape stability
Solution Approach 2:
The catheter assembly includes imaging markers and visual feedback mechanisms that allow the operator to accurately locate the fossa ovalis before puncture. The shape memory wire's transition provides tactile and visual feedback confirming proper positioning, enabling precise alignment before the puncture action is taken
3Ease of operation
If the needle is not fixed to the catheter, then the catheter can be flexible and easy to maneuver, but accidental needle exposure and inadvertent cardiac puncture can occur
Solution Approach 1:
The needle is connected to the catheter via a shape memory alloy wire that is flexible during delivery, allowing easy maneuverability. Upon deployment in the left atrium, the wire rigidifies and mechanically locks the needle in place, providing secure retention and preventing accidental exposure or inadvertent puncture while maintaining operational ease during the procedure
4Measurement precision
If the catheter assembly is withdrawn from the SVC too far, then the procedure can be performed with proper positioning, but time-intensive procedural steps must be repeated because the device cannot be moved cephalad
Solution Approach 1:
The shape memory alloy wire enables the catheter assembly to be delivered in a compact, flexible state through the venous system to the correct position. Once deployed, the wire rigidifies to lock the catheter in the optimal position, preventing accidental withdrawal and eliminating the need to repeat time-intensive positioning steps. The dynamic rigidity change ensures both accurate initial positioning and maintenance of that position throughout the procedure
Data Source
AI summary
An apparatus includes a shaft, and a guide coupled and angularly deflectable relative to the shaft via a guide coupler. The guide is configured to be transitioned between a delivery configuration and a deployed configuration in which a distal end of the guide points away from a centerline of the shaft. The apparatus further includes an elongate member slidably disposable within a guide lumen and extendable distally relative to the distal end of the guide. The elongate member defines a lumen. A puncture member is slidably disposable elongate member lumen and configured to extend distally relative to a distal end of the elongate member. The puncture member defines a lumen configured to receive a guide wire, and has a first internal diameter at a distal end portion thereof and a second internal diameter, greater than the first internal diameter, in a portion proximal to the distal end portion.