A drive device includes a casing including a drive signal generator configured to generate a drive signal, a switching element configured to repeatedly turn on and off at a drive frequency of the drive signal or higher, and a heat sink including an outer surface provided with the switching element and an inner surface provided with at least one radiation fin. The drive device also includes first and second fans arranged such that airflows along the outer surface and inner surface of the heatsink are simultaneously formed from the first fan toward the second fan.

Embodiments herein relate to cryoablation systems. In an embodiment, a cryosurgery system includes a closed-loop working fluid circuit configured to contain a working fluid. The system can include a compressor configured to increase the pressure of the working fluid. The system can include a heat exchanger configured to lower the temperature of the working fluid. The system can include a cryoablation probe having a shaft having a supply tube and a return tube surrounding the supply tube. The system is configured so that, after exiting the first heat exchanger, the working fluid will enter the cryoablation probe, travel to the expansion chamber, expand in the expansion chamber at a Joule-Thomson orifice, travel to the cryoablation probe interface via the return tube, exit the cryoablation probe via the working fluid outlet, enter the compressor, and enter the first heat exchanger.

A cryoablation catheter assembly is described. The assembly comprises (a) an inlet for receiving an input flow of refrigerant fluid, (b) a cryo-applicator, (c) a flow splitter configured to split the input flow into a therapeutic flow portion and a precooling flow portion, and (d) a precooling arrangement configured to precool the therapeutic flow portion and guide the precooled therapeutic flow portion towards the cryo-applicator, wherein the precooling arrangement comprises a heat exchanger configured to apply an adjustable precooling power from the precooling flow portion to the therapeutic flow portion. Furthermore, a cryoablation system and a method are described.