Modeling and estimation of tip contact force for steerable ablation catheters

Area of Science:

• Medical Devices
• Biomedical Engineering
• Interventional Cardiology

Background:

• Cardiac ablation efficacy is limited by the lack of real-time contact force data.
• Conventional ablation catheters lack integrated force-sensing capabilities.
• Accurate force measurement is crucial for optimizing ablation outcomes and patient safety.

Purpose of the Study:

• To develop a non-invasive technique for estimating catheter-tip-to-tissue contact forces.
• To leverage the mechanical properties of the deflectable catheter shaft for force sensing.
• To enhance the safety and effectiveness of catheter-based cardiac ablation procedures.

Main Methods:

• A kinematic model of the deflectable catheter shaft in free space was developed.
• Shaft curvature changes during tissue contact were analyzed to derive a force-indicating index.
• Experiments were conducted using steerable ablation catheters to validate the model.

Main Results:

• The proposed index accurately estimated contact force ranges in over 80% of experimental cases.
• A framework was established to obtain contact force information from shaft curvature measurements.
• The technique demonstrated the feasibility of inferring forces from catheter shaft deformation.

Conclusions:

• The developed kinematic model and force estimation technique enable real-time monitoring of catheter-tissue interaction.
• Contact detection and force range determination are achievable using shaft curvature analysis.
• Catheter shaft flexibility offers a viable pathway for non-invasive force estimation in ablation procedures.