Microwave ablation system with dielectric temperature probe
View Patent ↗An electromagnetic surgical ablation system having a generator adapted to selectively provide surgical ablation energy to an ablation probe, and methods of operating same, are disclosed. The system includes a controller operatively coupled to the generator, and a tissue sensor probe operatively coupled to the controller. The tissue sensor provides a tissue temperature and at least one tissue dielectric property to the controller. During an electromagnetic tissue ablation procedure, the controller monitors tissue temperature and the at least one tissue dielectric property to determine tissue status, and to activate and deactivate the generator in accordance therewith.
1. An ablation system, comprising:
a generator adapted to selectively provide ablation energy to an ablation probe;
an ablation probe operably coupled to the generator and adapted to receive the ablation energy from the generator and to deliver the ablation energy to tissue;
a controller operatively coupled to the generator, including:
a processor;
a memory operatively coupled to the processor;
a database operatively coupled to the processor and configured to store a tissue status lookup table having a first dimension representative of tissue temperature, a second dimension representative of tissue permittivity, and a third dimension representative of tissue loss factor;
a tissue sensor probe operatively coupled to the controller and having a distal end and a proximal end, including:
a dielectric sensor disposed at a distal end of the tissue sensor probe and configured to transmit a test signal to tissue, receive at least a portion of a reflected test signal from tissue, and provide a dielectric sensor signal corresponding to a measured tissue permittivity and loss factor;
a temperature sensor disposed at a distal end of the tissue sensor probe and configured to provide a temperature sensor signal corresponding to a measured temperature of tissue;
wherein a dielectric sensor circuit is operatively coupled to the processor and is adapted to receive the dielectric sensor signal from the tissue sensor probe; and
a temperature sensor circuit is operatively coupled to the processor and is adapted to receive the temperature sensor signal from the tissue sensor probe; and
wherein the processor is configured to utilize each of the measured tissue temperature, the measured tissue permittivity, and the measured tissue loss factor as indices into the tissue status lookup table to identify a tissue status.
2. The ablation system in accordance with claim 1 , wherein the dielectric sensor is selected from the group consisting of a time domain reflectometry dielectric sensor, a broadband vector reflectometry dielectric sensor, and a scattering parameter analysis dielectric sensor.
3. The ablation system in accordance with claim 1 , wherein the temperature sensor is selected from the group consisting of a fluoroptic temperature sensor, a thermocouple, a thermistor, and an infrared thermometer.
4. The ablation system in accordance with claim 1 , wherein the tissue sensor probe includes an absorbent sleeve disposed on an outer surface of the tissue sensor probe.
5. The ablation system in accordance with claim 1 , wherein the tissue sensor probe includes a handle disposed at a proximal end of the tissue sensor probe.
6. The ablation system in accordance with claim 5 , wherein the handle includes a grip-enhancing feature.
7. The ablation system in accordance with claim 1 , further comprising an actuator operatively coupled to the controller and configured to selectively activate the generator.
8. The ablation system in accordance with claim 7 , wherein the actuator is selected from a group consisting of a handswitch, a footswitch, and an orally-activated switch.