MICROWAVE THERMOMETRY FOR MICROWAVE ABLATION SYSTEMS
A microwave ablation system incorporates a microwave thermometer that couples to a microwave transmission network connecting a microwave generator to a microwave applicator to measure noise temperature. The noise temperature is processed to separate out components of the noise temperature including the noise temperature of the tissue being treated and the noise temperature of the microwave transmission network. The noise temperature may be measured by a radiometer while the microwave generator is generating the microwave signal or during a period when the microwave signal is turned off. The microwave ablation system may be configured as a modular system having one or more thermometry network modules that are connectable between a microwave applicator and a microwave generator. Alternatively, the modular system includes a microwave generator, a microwave applicator, and a microwave cable that incorporate a microwave thermometry network module.
1 - 16 . (canceled)
17 . A cable comprising:
a microwave transmission line;
a first cable connector assembly coupled to a first end of the microwave transmission line and a second cable connector assembly coupled to a second end of the microwave transmission line; and
a thermometry network module disposed within the first cable connector assembly and coupled to the first end of the microwave transmission line, the thermometry network module including a radiometer and a microwave coupling network configured to couple a portion of a microwave signal propagating through the microwave transmission line to the radiometer, the radiometer being configured to process the portion of the microwave signal to determine a noise temperature signal.
18 . The cable according to claim 17 , further comprising a data bus coupled between the first and second cable connector assemblies,
wherein the thermometry network module further includes a controller coupled to the data bus and configured to determine a temperature value based on the noise temperature signal and transmit the temperature value to at least one component of a microwave ablation system connected to the first or second cable assembly.
19 . The cable according to claim 18 , further comprising a display driver and a display coupled to the display driver,
wherein the controller determines a temperature value based on the noise temperature signal and controls the display driver to display the temperature value.
20 . The cable according to claim 18 , further comprising a temperature selector for selecting a temperature at which the microwave signal is to be shut off,
wherein the controller determines a temperature value based on the noise temperature signal and transmits a shut off message to a microwave generator coupled to the cable via the data bus if the temperature value is greater than the selected temperature.
21 . The cable according to claim 18 , wherein the temperature value represents a temperature of tissue being treated or a temperature of a portion of a microwave ablation system component.
22 . The cable according to claim 17 , further comprising a power supply line coupled between the first and second cable connector assemblies and configured to carry a power signal between the first and second cable connector assemblies.
23 . A microwave ablation system comprising:
a microwave generator configured to generate microwave energy;
a microwave applicator coupled to the microwave generator and configured to deliver the microwave energy to ablate tissue;
a microwave cable having a first cable connector assembly and a second cable connector assembly, wherein the first connector assembly is configured to connect to the microwave generator and the second connector assembly is configured to connect to the microwave applicator; and
a microwave thermometry module integrated into the microwave cable, the microwave thermometry module including a radiometer configured to measure a noise temperature signal propagating from the microwave applicator to the microwave generator.
24 . The microwave ablation system according to claim 23 , wherein the microwave cable is a reusable cable.
25 . The microwave ablation system according to claim 23 , wherein the microwave cable includes a circuit for storing device identification data and thermometry data.
26 . The microwave ablation system according to claim 23 , wherein the microwave thermometry module includes a control interface circuit having a controller, a display driver coupled to the controller, and a display coupled to the display driver,
wherein the controller is in communication with the radiometer.
27 . The microwave ablation system according to claim 23 , further comprising a control interface module comprising a controller configured to communicate with the microwave thermometry module, a display driver coupled to the controller, and a display coupled to the display driver,
wherein the microwave generator includes a data connector, and wherein the control interface module includes a corresponding data connector configured to connect to the data connector of the microwave generator.
28 . The microwave ablation system according to claim 23 , further comprising a control interface module comprising a controller configured to communicate with the microwave thermometry module, a display driver coupled to the controller, and a display coupled to the display driver, the control interface module being integrated into the microwave generator.
29 . A cable comprising:
a microwave transmission line;
a cable connector assembly coupled to an end portion of the microwave transmission line; and
a thermometry network module disposed within the cable connector assembly, the thermometry network module including a radiometer and a microwave coupling network configured to couple a portion of a microwave signal propagating through the microwave transmission line to the radiometer, the radiometer being configured to obtain a noise temperature signal from the portion of the microwave signal.
30 . The cable according to claim 29 , wherein the thermometry network module further includes a filter coupled between the radiometer and the microwave coupling network.
31 . The cable according to claim 30 , wherein the filter isolates high frequency noise temperature signals from low frequency high power microwave signals.
32 . The cable according to claim 30 , wherein the filter filters the noise temperature signal to obtain a first noise temperature signal from tissue and a second noise temperature signal from components of a microwave ablation system.
33 . The cable according to claim 29 , further comprising a power supply line coupled between a first cable connector assembly and a second cable connector assembly, and configured to carry a power signal between the first cable connector assembly and the second cable connector assembly.
34 . The cable according to claim 29 , wherein the radiometer includes a low-noise amplifier, a local oscillator, a frequency mixer coupled to the low-noise amplifier and the local oscillator, a band pass filter coupled to the frequency mixer, an intermediate frequency (IF) amplifier coupled to the band pass filter, a detector coupled to the IF amplifier, and an integrator coupled to the detector.
35 . The cable according to claim 29 , wherein the radiometer includes a temperature sensor, a switch coupled to the temperature sensor and configured to switch between an input of the radiometer and the temperature sensor, a first amplifier coupled to the switch, a detector coupled to the first amplifier, a second amplifier coupled to the detector, a phase detector coupled to the second amplifier, an integrator coupled to the second amplifier, and a reference generator coupled between the phase detector and the switch.
36 . The cable according to claim 30 , wherein the filter includes a first filter that separates the noise temperature signal from a high power microwave signal and a second filter that extracts the noise temperature of tissue and the noise temperature of a transmission network from the noise temperature output from the first filter.