Fluid-Actuated Catheter Sheath Displacement
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Solution Overview
Problem
Current catheter-based minimally invasive surgical technologies face challenges in accurately controlling and positioning flexible guidewires and catheters within tortuously branched body lumens, leading to difficulties in aligning tools with target tissues and maintaining precise alignment during deployment of therapeutic devices like stents or prosthetic valves, due to complex articulation systems and the need for significant force transmission.
Innovation Solution
A catheter-based system utilizing fluid-driven actuators, such as balloons, to axially displace a sheath over a therapeutic tool, allowing for radial expansion of self-expanding devices within the body without requiring large deployment forces to be transmitted along the catheter shaft, enhancing control and precision through a modular manifold architecture with plate-mounted valves and microfluidic control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional catheter-based systems transmit large deployment forces along the catheter shaft, then therapeutic tools can be deployed, but control precision and positioning accuracy deteriorate due to complex articulation systems and force transmission through tortuous body lumens
Solution Approach 1:
The patent replaces traditional mechanical force transmission through catheter shafts with fluid-driven actuation. Fluid pressure is transmitted through catheter lumens to expandable balloons or compliant structures at the distal end, which then deploy the therapeutic tool. This substitution eliminates the need for mechanical force transmission along the entire catheter length, thereby improving positioning accuracy while maintaining deployment capability.
Solution Approach 2:
The patent utilizes fluid pressure (pneumatics/hydraulics) to actuate the deployment mechanism. Fluid is delivered through catheter lumens to inflate balloons or expand compliant structures at the distal end, generating the necessary force for tool deployment. This approach allows precise control of deployment force through fluid pressure regulation, independent of the catheter's mechanical articulation state.
2Adaptability or versatility
If complex articulation systems are used to navigate tortuous body lumens, then access to target tissues is improved, but the ability to maintain precise alignment during deployment deteriorates
Solution Approach 1:
The patent segments the catheter into multiple lumens with distinct functions: some lumens carry fluid for actuation, while others provide structural support or serve as guides. The articulation system is segmented into independent control zones, allowing navigation through tortuous paths while maintaining stable alignment at the deployment site through localized fluid pressure control.
Solution Approach 2:
The patent introduces fluid pressure as an intermediary between the operator and the deployment mechanism. Instead of directly mechanically coupling the operator's input to the tool deployment through complex articulation, fluid pressure mediates the transmission of force, allowing the catheter to navigate tortuous paths while maintaining precise alignment through independent fluid pressure regulation at the distal end.
3Force
If large forces are transmitted along the catheter shaft for tool deployment, then therapeutic devices can be deployed, but collateral tissue trauma increases
Solution Approach 1:
The patent replaces mechanical force transmission through the catheter shaft with localized fluid pressure actuation. Fluid pressure is delivered directly to expandable balloons or compliant structures at the distal end, generating deployment force locally without transmitting large mechanical forces along the entire catheter length. This reduces friction and mechanical stress on surrounding tissues, minimizing collateral trauma.
Solution Approach 2:
The patent enables the therapeutic tool to deploy itself through localized fluid pressure actuation at the distal end. The expandable balloons or compliant structures generate the necessary deployment force from the fluid pressure applied through catheter lumens, without requiring external mechanical force transmission. This self-service deployment mechanism reduces the need for large forces to be transmitted along the catheter shaft, thereby reducing tissue trauma.
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 approach enables precise and controlled deployment of therapeutic tools within the body, reducing the need for large force transmission and improving the accuracy and ease of use in navigating complex vascular structures, while minimizing collateral tissue trauma.
Implementation Method 1
A first fluid-driven actuator, such as a balloon, is expanded radially in response to fluid pressure driving a sheath axially from over a therapeutic tool
Data Source
AI summary
Catheter-supported therapeutic and diagnostic tools can be introduced into a patient body with a sheath slidably disposed over the tool. Once the tool is aligned with a target tissue, a first fluid-driven actuator can move the sheath axially from over the tool, for example, to allow a stent, stent-graft, prosthetic valve, or other self-expanding tool, to expand radially within the cardiovascular system, without having to transmit large deployment forces along the catheter shaft and sheath from outside the patient. A second fluid-driven actuator can be arranged in opposition to the first actuator to control release of the expanding tool or to recapture the tool within the sheath. The first and/or second actuators may comprise a balloon having a diameter larger than the sheath to provide the desired deployment and recapture forces with moderate fluid pressure.