https://www.researchgate.net/profile/Thorsten-Lewalter/publi...

Combined High Density Mapping and Ablation of Atrial Fibrillation.

The geometry of the electrodes is two opposing 18 electrode interwoven helices with thermocouples placed at the edge of each of four quadrants of the circumference to provide temperature sensing during ablation. Figure 1 shows a schematic representation of the HD Mesh Ablator catheter construction, showing the relative position of the four temperature sensors (TC).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4956011/

The geometry of the electrodes is two opposing 18-electrode interwoven helices with thermocouples placed at the edge of each of four quadrants of the circumference to provide temperature sensing during ablation. [Figure 12] shows a schematic representation of the HD Mesh Ablator catheter construction, showing the relative position of the four temperature sensors (TC). The HD Mesh Ablator catheter delivers pulsed RF energy via Pulsed RF Controller, a device that accepts the output of a compatible RF generator and distributes the RF energy to the electrodes of the BARD HD Mesh Ablator in a pulsed-energy manner.

Pulmonary vein (PV) isolation is a successful treatment strategy in patients with drug-resistant, symptomatic, paroxysmal atrial fibrillation (AF).
https://academic.oup.com/europace/article/12/10/1428/419819

The high-density mesh ablation system
In summary, the high-density mesh ablation system consists of an 8-F catheter with an expandable electrode array of 30 or 35 mm, a radiofrequency (RF) generator and a TemPulse pulsed RF controller. The expandable electrode array utilizes 36 wires woven into a braid. Retraction of a central wire leads to deployment of the mesh whereas advancing the wire restores a low profile conformation for advancement through the vasculature. The HDMA catheter wires contain an annular ring of exposed wires at its perimeter that serves as the electrodes for high-resolution recording as well as for delivery of RF current. Four thermocouples divide the circumference of the catheter into four quadrants allowing RF delivery in a temperature controlled mode. Pulsed RF energy from a 100 W RF generator is transferred to the TemPulse, where the energy is multiplexed into 5 ms pulses and delivered through half of the electrodes (every other wire), and then alternated to the other half in a unipolar mode. RF energy is delivered at all electrodes or in a selected quadrant of the HDMA catheter. Once the target temperature (58°C) is reached in any thermocouple, the duty cycle is automatically varied to maintain the programmed temperature. RF energy is delivered at a maximum power of 70–100 W for 180–300 s. A single discrete fluoroscopically visible marker is located at the 12-o'clock position and two other markers at the 3-o'clock position from a proximal view in order to provide visual orientation of the four quadrants of the HDMA catheter.
https://academic.oup.com/europace/article/12/10/1428/419819