Microwave thermometry for microwave ablation systems
First Claim
1. A microwave ablation system comprising:
- a microwave applicator including an antenna configured to deliver microwave energy to ablate tissue;
a microwave generator coupled to the microwave applicator via a transmission network and configured to generate a microwave signal and transmit the microwave signal to the antenna;
a radiometer configured to measure a noise temperature from a signal propagating through the transmission network;
a controller configured to turn off the microwave signal generated by the microwave generator for a predetermined period and to control the radiometer to measure the noise temperature during the predetermined period; and
at a first thermocouple configured to measure a first temperature of a cooling fluid and a second thermocouple configured to measure a second temperature of the cooling fluid, the radiometer configured to measure the noise temperature when the first temperature is substantially the same as the second temperature.
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Accused Products
Abstract
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 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.
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Citations
11 Claims
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1. A microwave ablation system comprising:
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a microwave applicator including an antenna configured to deliver microwave energy to ablate tissue; a microwave generator coupled to the microwave applicator via a transmission network and configured to generate a microwave signal and transmit the microwave signal to the antenna; a radiometer configured to measure a noise temperature from a signal propagating through the transmission network; a controller configured to turn off the microwave signal generated by the microwave generator for a predetermined period and to control the radiometer to measure the noise temperature during the predetermined period; and at a first thermocouple configured to measure a first temperature of a cooling fluid and a second thermocouple configured to measure a second temperature of the cooling fluid, the radiometer configured to measure the noise temperature when the first temperature is substantially the same as the second temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A microwave ablation system comprising:
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a microwave applicator including an antenna configured to deliver microwave energy to ablate tissue; a microwave generator coupled to the microwave applicator via a transmission network and configured to generate a pulse-width modulated (PWM) microwave signal and transmit the PWM microwave signal to the antenna; a radiometer configured to measure a noise temperature propagating through the transmission network; and a controller configured to; control the radiometer to measure the noise temperature during each of the off times of the PWM microwave signal; determine a slope of magnitude of the noise temperature measurements; record a noise temperature measurement when the slope of magnitude of the noise temperature measurements represents solely the temperature of the tissue; determine whether the noise temperature measurements are greater than a predetermined noise temperature value; and shut off the PWM microwave signal or reduce the duty cycle of the PWM microwave signal if it is determined that any one or more of the noise temperature measurements is greater than the predetermined noise temperature value. - View Dependent Claims (9, 10)
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11. A microwave ablation system comprising:
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a microwave applicator including an antenna configured to deliver microwave energy to ablate tissue; a microwave generator coupled to the microwave applicator via a transmission network and configured to generate a microwave signal and transmit the microwave signal to the antenna; a radiometer configured to measure noise temperature from a signal propagating through the transmission network; a controller configured to turn off the microwave signal generated by the microwave generator for a predetermined period and to control the radiometer to measure noise temperature during the predetermined period; and a thermocouple configured to measure a temperature of the transmission network; wherein to obtain the noise temperature of the transmission network, the controller is configured to; record a first noise temperature measured by the radiometer at a time that the microwave signal turns off, record a second noise temperature measured by the radiometer at a time that the transmission network temperature reaches a predetermined temperature; and calculate the difference between the first noise temperature and the second noise temperature to obtain the noise temperature of the transmission network.
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Specification