In vitro contact force evaluation of robotic magnetic navigation catheters; Head to head comparison of different catheters and different settings

The Stereotaxis Robotic Magnetic Navigation (RMN) system uses an external magnetic field to navigate catheters inside the heart during arrhythmia ablation. This study compared in vitro maximal contact force (CF) achieved with different irrigated RMN ablation catheters under various conditions.

An in vitro model was created to measure CF using a high-precision goldsmith scale mounted in a dedicated frame between the permanent magnets of the Stereotaxis RMN system. Four irrigated RMN catheters (Navistar RMT, Celsius RMT, Magnoflush, MAGiC™) were evaluated at three magnetic field intensities (0.10 T, 0.08 T, 0.05 T) and under multiple settings.

The MAGiC™ catheter consistently achieved significantly higher CF across all magnetic field intensities and orientations. At 0.10 T, longitudinal median CF ranged from 13.80 g (±0.10) to 19.80 g (±0.50), approximately 36% higher than the other catheters, which ranged from 7.00 g (±0.50) to 14.50 g (±0.38). In the perpendicular orientation, MAGiC™ ranged from 5.09 g (±0.65) to 10.83 g (±0.89), about 156% higher than the others, which ranged from 1.75 g (±0.18) to 4.22 g (±0.36). Across all catheters, CF increased with higher magnetic field intensity, with greater sheath support and with longitudinal orientation.

The MAGiC™ catheter achieved significantly higher CF than other RMN catheters in both longitudinal and perpendicular orientations. The remaining catheters demonstrated comparable CF performance across all magnetic field intensities. Contact force increased with greater magnetic field strength and enhanced sheath support, and was consistently higher in the longitudinal compared with the perpendicular orientation.