Patent ID: 6692487
Filing Date: 2004-02-17
Classification: A61B

Abstract:
A software module for a software controlled device for performing cryosurgical procedures on a treatment region with a cryosurgical probe, said software controlled device being responsive to user input settings, comprising:a temperature feedback control system which is adaptive to the external heat load of a treatment region and utilizes user input settings for determining an optimal rate of gas flow through a cryosurgical probe thereby enabling the user to precisely monitor and deliver a cryosurgical treatment, said temperature feedback control system being programmed to perform the following steps: a. reading a user input setting for a target temperature (Tuser); b. utilizing said Tuser for input into a temperature feedback loop, comprising the steps of: i. reading a temperature of a cryosurgical probe (Tprobe); ii. computing Tdiff=absolute difference between Tuser and Tprobe; iii. computing the rate of temperature change of the cryosurgical probe=Tdelta=Tprobe/dt; iv. computing the timing parameters of a pneumatic system that controls the gas flow to the cryosurgical probe based on Tdelta and Tdiff; and, v. controlling the pneumatic system based on the computed timing to produce an optimal rate of gas flow.