Work / Medical Device R&D

Catheter Spline Deformation Investigation

Experimental investigation into factors contributing to catheter deformation and basket behavior in a pulsed field ablation catheter system.

Domain: Medical Device R&D Status: Completed Tools: SolidWorks, 3D Printing, DOE, Mechanical Testing
Catheter Testing Design Verification DOE Fixture Design Medical Devices
Domain:Medical Device R&D
Status:Completed
Tools:SolidWorks, 3D Printing, DOE, Mechanical Testing

Mission

Investigate physician-reported catheter deformation in the catheter system under simulated clinical use conditions.

Problem

Spline deformation was observed during catheter deployment and manipulation. The investigation needed to determine which use-condition and device-interface factors contributed most strongly to deformation risk.

What is Spline Deformation?

Spline deformation occurs when portions of the catheter basket deform or fold inward during deployment. Changes in basket geometry can affect device behavior and were therefore investigated as part of this study.

Why It Matters

  • Basket geometry affects catheter performance.
  • Deformation can influence deployment consistency.
  • Understanding contributors helps improve future designs.

Approach

Designed and fabricated test fixtures to simulate sheath curves, guidewire stiffness, deployment paths, and clinical handling conditions. Used structured testing to compare how different inputs affected spline deformation behavior.

Key Findings

Stiffer guidewires increased deformation risk. Smaller or more aggressive sheath curves increased spline loading. Deployment path and device-interface conditions influenced catheter deformation behavior, while fixture-based testing helped isolate mechanical contributors under repeatable conditions.

Outcome

Identified the strongest contributors to spline deformation and generated test evidence to support future design decisions, risk assessment, and verification planning.

Tags
Catheter Testing Design Verification DOE Fixture Design Medical Devices

Catheter / Spline Interface Overview

Observed catheter deformation

Close-up view of the catheter basket structure used to explain how guidewire and sheath conditions can influence spline loading, deformation, and catheter deformation behavior during deployment.

Test Setup

To investigate catheter deformation, a modular benchtop setup was developed to simulate different guidewire and sheath conditions under controlled, repeatable test conditions.

Fixture setup for catheter simulated use testing

Purpose & Variables Tested

The setup was built to rapidly test primary, secondary, and contributing factors influencing catheter deformation using one adjustable fixture. It allowed the team to reproduce earlier guidewire-related findings and further investigate sheath-related variables.

Variables Tested

  • Guidewire stiffness
  • Sheath angle
  • Curve size
  • Curve straight section
  • Tip inner diameter
  • Tip material

Numbered Fixture Components

Numbers correspond to the callouts in the setup image.

  1. 0° Axis
  2. 40° Axis
  3. Sheath Angle Arm
  4. Guidewire Angle Arm
  5. Guidewire — Amplatz Super Stiff 0.035"
  6. Guidewire Clamp
  7. Sheath Clamp A
  8. Sheath Clamp B
  9. Fixed Tube
  10. 3D Printed Tip Clamps
  11. Catheter
  12. Sliding Piece to Change Sheath Angle
  13. Track for Sliding Piece
  14. Sheath Clamp C
  15. Pivot Point
  16. Setup Dial
  17. 3D Printed Tips
  18. 3D Printed Curved Tracks

Test Workflow

The investigation translated a clinical observation into controlled benchtop testing and design recommendations.

Clinical Observation Hypothesis Fixture Development Controlled Testing Analysis Design Recommendations