System and method for monitoring a microwave tissue ablation process
AssigneeGyrus Medical Limited
InventorsDavid Nicholas Williams, Tudor Thomas
Life of this patent
Estimating the term…
Abstract
A method and system for monitoring a microwave tissue ablation process, particularly the determination of an ablation size estimate during microwave ablation of such tissue. The method includes applying a correction value to the determined temperature value, so as to provide a corrected temperature value.
Claims15
A method of monitoring a microwave tissue ablation process, the method comprising:
- providing a power source operable to provide a controlled microwave energy output;
- providing a microwave probe having a body and an antenna extending through the body and operable to deliver the microwave energy from the power source out of the microwave probe;
- providing a thermocouple on an outer surface of the body of the microwave probe, the thermocouple being separated from the body by a layer of thermally insulating material, the thermocouple being operable to generate an output voltage in dependence upon a temperature experienced by the thermocouple;
- supplying the controlled microwave energy output from the power source to the antenna, thereby causing the microwave energy to radiate from the antenna to form an ablation zone;
- detecting an output voltage generated by the thermocouple in response to a temperature experienced by the thermocouple;
- determining a temperature value relating to the detected output voltage;
- applying a predetermined correction value to the determined temperature value, so as to provide a corrected temperature value, the predetermined correction value relating to a total amount of the microwave energy supplied to the antenna from the start of the ablation process to the determination of the temperature value;
- and
- wherein the predetermined correction value also relates to a temperature of a coolant fluid used inside the body of the microwave probe.
The method as claimed in claiml, wherein the corrected temperature value is a predetermined multiple of the determined temperature value.
A microwave ablation apparatus comprising:
- a power source operable to provide a controlled microwave energy output;
- a microwave probe having a body and an antenna extending through the body and operable to deliver the microwave energy from the power source out of the microwave probe;
- a thermocouple on an outer surface of the body of the microwave probe, the thermocouple being separated from the body by a layer of thermally insulating material, the thermocouple being operable to generate an output voltage in dependence upon a temperature experienced by the thermocouple;
- a detector operable to detect an output voltage generated by the thermocouple in response to the temperature experienced by the thermocouple;
- a calculation unit operable to determine a temperature value relating to the detected output voltage;
- a correction unit operable to apply a predetermined correction value to the determined temperature value, and to provide a corrected temperature value, the predetermined correction value relating to a total amount of energy supplied to the antenna from a start of such ablation to the determination of the temperature value;
- a controller operable to control the microwave energy supplied to the antenna from the power source such that the corrected temperature value reaches a predetermined target value;
- and
- wherein the predetermined correction value also relates to a temperature of a coolant fluid used inside the body of the microwave probe.
The apparatus as claimed in claimed 9, wherein the predetermined correction value is chosen from a range of predetermined correction values in dependence upon power level and application time of the microwave energy.
Dependencies are inferred from the claim text.