Limitations
Despite an extensive set of measurements, some limitations remain: First, with n=3 catheters for each model, the variability within one catheter model cannot be assessed reliably and it cannot be excluded that another catheter performs better or worse than described here. Second, we measured static contact force, while in-vivo contact force is dynamic. Given that the sensor technology involved is the same and that contact force sampling rates are significantly higher than the heart rate, this should not have a major impact on the clinical implications of our findings.

Conclusion

The catheter-to-tissue contact force measured by force-sensing ablation catheters is accurate with an absolute mean error of <3g in a clinical range of 10g to 40g for all four currently available force-sensing ablation catheters. Some combinations of model and angle may be prone to significant errors at higher forces with >10g of overestimation and >15g of underestimation of true contact force, which may be clinically relevant.