Ablation catheter and local impedance measurements
An open-irrigated MiFi ablation catheter with a 4.5 mm distal tip and an
open-irrigated STABLEPOINT ablation catheter with a 4.0 mm distal tip
were used for the experiment. The MiFi has 3 microelectrodes
incorporated within the distal tip electrode, and there are 3 equally
spaced 0.8 mm diameter microelectrodes located 2 mm from the tip of the
catheter. First, LI was measured between each microelectrode and the
4th ring electrode of the ablation catheter by a
driven nonstimulatory alternating current (5.0 𝜇A, 14.5 kHz) between the
distal tip electrode and the 4th ring electrode to
create a local potential field. After that, only the maximum LI was
selected for the actual LI. Since the CF cannot be measured in the MiFi
catheter, it was measured using the pressure-current transducer (load
cell), as described in the next section. On the other hand, the
STABLEPOINT does not have microelectrodes, and the LI was measured
between the whole distal tip (4 mm length) and 2ndring electrodes by being driven by a nonstimulatory alternating current
(5.0 𝜇A, 14.5 kHz) between the distal tip electrode and the
4th ring electrode to create a local potential field.