A method of forming a lesion at a predetermined heart location is provided. Some embodiments receive a request to perform a memory access, wherein the request includes a virtual address. The sample memory is operable to store sample pulses of the frequency domain sample pulse train to produce a stored sample pulse train. The change in the water’s conductivity over that period is determined. At a final depth, the power supply is finally turned on for actual use of the wireless device, and the casing is hermetically closed by the operating member.