Electromagnetic Contact‐Force Sensing Electrophysiological Catheters: How Accurate Is the Technology?

Abstract

Catheter force measurements using the ST SF catheters show a high level of accuracy regarding differences to reference measurements and reproducibility. The reduced accuracy in measurements of 90° acting forces (parallel contact) might be clinically important when creating, for example, linear lesions.

Fiberoptic Contact‐Force Sensing Electrophysiological Catheters: How Precise Is the Technology?

“…This finding is in accordance with a previous study by Yokoyama et al, in which the correlation between the reference force and the force measured by TCQ was high (R 2 > 0.988) and not significantly different between the 3 tested angles . In contrast, in a previous study we showed that the accuracy of an electromagnetic CF sensing technology (SmartTouch SF) is indeed affected by the angle of the acting forces, being significantly lower with the catheter tip in a parallel orientation (6.6 g vs. ≤1.2 g; P < 0.01) . This difference might be explained by the difference in the CF sensing mechanism of the electromagnetic and fiber‐optic technologies (Fig.…”

“…Based on the known spring characteristics, the system can convert the tip deflection into CF (amount and orientation) . Therefore, CF measurements are based on changes of the relative position between the transmitter coil and the location sensors: very lateral forces can cause a deflection not only of the distal catheter tip, but also of more proximal parts of the tip (proximal to the spring), where the sensors are located, translating in underestimation of the CF force . On the other hand, in the fiberoptic CF sensing mechanism the acting forces are detected across the whole deformable body, located between electrodes 1 and 3.…”

“…CF sensing catheters provide real‐time estimation of tissue contact, resulting in effective lesion formation, better outcomes and a lower complication rate . We recently investigated the accuracy of electromagnetic CF sensors: it is high when sensing of non‐lateral forces, but reduced when sensing lateral forces . As detailed data on fiberoptic CF sensing technology are scarce, the goal of this study was to quantify its accuracy with in vitro experiments.…”

Determinants of Acute and Late Pulmonary Vein Reconnection in Contact Force–Guided Pulmonary Vein Isolation

“…Practically, it is impossible to reach 10 to 20 g at each RF site Moreover, calculation of CF (and FTI) might be inaccurate because of inadequate calibration, contact with neighboring electrodes, or the angle of incidence (underestimation when parallel contact). 21 Finally, FTI as a marker of lesion quality suffers from 2 major limitations: first, FTI (calculated as the product of force by application time) suggests a linear lesion formation during ablation, whereas it is known that lesion volume growth describes a monoexponential curve. 15 Second, FTI ignores the important and evident role of power delivery in lesion creation.…”

First clinical use of novel ablation catheter incorporating local impedance data

“…1 RF energy creates lesions through resistive heating of the subendocardium and heat is thermally conducted to the surrounding tissue. Mechanical and electrical coupling at the electrode-tissue interface are critical factors for lesion formation during RF ablation.…”