Factors Influencing Contact Force in Robotic Magnetic Navigation Ablation

Area of Science:

• Medical Devices
• Electrophysiology
• Robotic Surgery

Background:

• Catheter-tissue contact stability is vital in robotic magnetic navigation (RMN) systems.
• Contact force (CF) is critical for effective radiofrequency (RF) ablation lesion formation.
• Current RMN systems lack quantitative intraoperative CF monitoring.

Purpose of the Study:

• To investigate the impact of magnetic field parameters on catheter-tissue contact force (CF) in RMN systems.
• To provide data for developing quantitative CF monitoring in RMN-guided procedures.

Main Methods:

• 1200 CF measurements were performed using an RMN system and an 8 Fr RF ablation catheter.
• Variables included four magnetic field vectors, two field strengths (0.08T and 0.1T), and three catheter extension positions.
• A precision jewelry scale was used for CF measurements.

Main Results:

• Significant variations in CF were observed across different magnetic field vectors, strengths, and catheter extensions.
• Cranial and caudal vectors showed the largest CF differences (up to ~20%) at Position 1.
• Higher magnetic field strength (0.1T) generally increased CF, particularly in the transverse vector at Position 3.

Conclusions:

• Magnetic field vectors, catheter extension, and field strength significantly affect RMN catheter CF.
• These parameters must be considered alongside power and duration for optimal RF ablation lesion creation.
• Findings contribute to addressing the need for intraoperative CF monitoring in RMN systems.