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A coaxial cable apparatus which transmits radio frequency (RF) energy for the ablation of biological tissues has inner and outer coaxial conductors extending from a proximal portion to a distal portion. An RF antenna is disposed at the distal portion of the cable and transmits RF energy for ablation

A coaxial cable apparatus which transmits radio frequency (RF) energy for the ablation of biological tissues has inner and outer coaxial conductors extending from a proximal portion to a distal portion. An RF antenna is disposed at the distal portion of the cable and transmits RF energy for ablation of a tissue region to be treated. At least one ultrasonic transducer is also disposed at the distal portion of the cable to direct ultrasonic frequency energy to a tissue region. The ultrasonic transducer detects reflected ultrasonic signals from the tissue region and provides a signal output which varies dependent on the density of tissue over the monitored tissue region. The reflected ultrasonic signal can be monitored before, during, and after ablation treatment.

대표청구항 ▼

1. A hollow coaxial cable apparatus for transmission of radio frequency (RF) energy for the ablation of biological tissues, comprising: a hollow coaxial electrical cable having a proximal portion and a distal portion and comprising inner and outer coaxial conductors extending between the proximal po

1. A hollow coaxial cable apparatus for transmission of radio frequency (RF) energy for the ablation of biological tissues, comprising: a hollow coaxial electrical cable having a proximal portion and a distal portion and comprising inner and outer coaxial conductors extending between the proximal portion and the distal portion;an outer casing extending over the coaxial conductors from the proximal portion to the distal portion of the cable;an RF antenna disposed at the distal portion of the cable which transmits RF energy to a tissue region to be treated;a first array of ultrasonic transducers disposed at the distal portion of the cable which directs ultrasonic energy radially outwards from the cable over a predetermined angle to the tissue region, and which detects reflected ultrasonic signals and provides a signal output according to the reflected ultrasonic signals;first and second conductive leads extending from the proximal portion of the cable to the ultrasonic transducer, at least the first conductive lead comprising one of the coaxial conductors; andthe outer casing having a distal portion extending over the RF antenna and ultrasonic transducer array which has a window of ultrasonic and microwave transparent material aligned with the transducer array, the remainder of the distal portion of the casing being of microwave and ultrasound absorbing material. 2. The apparatus of claim 1, further comprising a power supply and control assembly connected to the proximal portion of the cable, the assembly comprising an RF signal generator module which communicates with the RF antenna through the coaxial conductors, and an ultrasonic signal generator and a signal processing module connected to the ultrasonic transducer through the first and second conductive leads, the signal processing module processing output signals from the transducer to provide information on a monitored tissue region. 3. The apparatus of claim 1, wherein the cable has a central lumen extending from the proximal portion to the distal portion of the cable, and the second conductive lead comprises a wire extending from the transducer through the central lumen. 4. The apparatus of claim 1, further comprising a temperature sensor disposed at the distal portion of the cable which detects temperature in the vicinity of a tissue region to be treated. 5. The apparatus of claim 1, wherein the angle is 360 degrees. 6. The apparatus of claim 1, wherein the predetermined angle is 180 degrees. 7. The apparatus of claim 1, wherein the RF antenna has a central longitudinal axis and the transducers are spaced radially about the central axis of the antenna. 8. The apparatus of claim 1, wherein the transducers are disposed on an outer surface of the inner conductor. 9. The apparatus of claim 1, wherein the transducers are disposed on an outer surface of the outer conductor in the vicinity of the proximal portion of the RF antenna. 10. The apparatus of claim 1, further comprising a second array of ultrasonic transducers disposed at the distal portion of the cable and axially spaced from the first array. 11. The apparatus of claim 10, wherein the outer conductor terminates at a distal portion spaced rearwardly from the distal end of the cable and the inner conductor has a portion which projects from the distal portion of the outer conductor, and the first and second arrays are disposed at axially spaced locations on the projecting portion of the inner conductor. 12. The apparatus of claim 10, wherein the outer conductor terminates at a distal portion spaced rearwardly from the distal portion of the cable and the inner conductor has a distal portion which projects from the distal portion of the outer conductor, the first array is located on the distal portion of the outer conductor and the second array is located on the distal portion of the inner conductor. 13. The apparatus of claim 1, wherein the ultrasonic transducer array is a circular array which directs ultrasonic energy radially outwards through an angle of 360 degrees, and the distal portion of the casing which extends over the RF antenna and ultrasonic transducer array is formed of ultrasonic and microwave transparent material. 14. The apparatus of claim 1, wherein the RF antenna has a distal end and a proximal end and is selected from the group consisting of a helical coil antenna, a monopole antenna, and a pair of spaced electrically conductive microstrips. 15. The apparatus of claim 14, wherein the ultrasonic transducer is located adjacent the distal end of the RF antenna. 16. The apparatus of claim 14, wherein the ultrasonic transducer is located adjacent the proximal end of the RF antenna. 17. The apparatus of claim 14, wherein the RF antenna comprises a helical coil antenna which surrounds an area and the ultrasonic transducer is located in the area surrounded by the antenna. 18. The apparatus of claim 1, wherein the cable has a central lumen which is closed at the distal end of the cable. 19. The apparatus of claim 1, wherein the cable has a central lumen which is open at the distal portion of the cable. 20. The apparatus of claim 1, wherein the RF antenna transmits microwave energy at a frequency from approximately 300 Megahertz and up. 21. A radio frequency ablation system, comprising: an elongated hollow coaxial cable having a proximal portion and a distal portion;a radio frequency (RF) antenna disposed at the distal portion of the cable which directs RF energy outwardly from the cable for ablation of biological tissue;inner and outer coaxially aligned, circumferentially spaced, electrically conductive tubular members extending from the proximal portion to the RF antenna;at least one ultrasonic transducer array disposed on an outer surface of one of the electrically conductive tubular members at the distal portion of the cable, the ultrasonic transducer array being configured to direct ultrasonic signals from the distal portion to a monitored biological tissue region and to receive ultrasonic signals reflected from the monitored biological tissue region;the ultrasonic transducer array comprises a series of transducers arranged at spaced intervals around an arc co-axial with the RF antenna and subtending a predetermined angle of no more than 180 degrees, whereby the transducers project ultrasonic signals radially outwardly through a predetermined angular range;a power supply and control assembly connected to the cable, the assembly comprising an RF signal generator module which communicates with the RF antenna through the conductive tubular members, an ultrasonic transducer power supply module which communicates with the ultrasonic transducer array and provides power to generate the ultrasonic signals, and a reflected ultrasonic signal processor module which receives output signals from the ultrasonic transducer array and which processes the output signals to provide information on the tissue in the monitored tissue region; andthe RF antenna being configured to transmit RF energy from the distal end portion of the cable through a predetermined angular range coincident with the angular range of the ultrasonic transducer array. 22. The system of claim 21, wherein the power supply and control assembly further comprises a control module which adjusts the output energy directed from the RF antenna onto a tissue site being treated based on information received from the ultrasonic transducer array. 23. The system of claim 21, further comprising a temperature sensor disposed at the distal portion of the cable which detects temperature in the vicinity of a tissue region during treatment, the power supply and control assembly further comprising a temperature output module which receives detected temperature signals from the temperature sensor and compares the output signals with a preset temperature setting, and a control module which adjusts the RF output energy from the RF antenna based on the detected temperature. 24. The system of claim 23, wherein the control module adjusts the RF output energy based on both the detected temperature and the reflected ultrasonic signals received by the ultrasonic sensor assembly. 25. The system of claim 21, wherein the ultrasonic transducer array is unidirectional. 26. The apparatus of claim 1, wherein the ultrasonic transducer array comprises a series of transducers arranged at spaced intervals around an arc co-axial with the RF antenna and subtending a predetermined angle of no more than 180 degrees. 27. The system of claim 21, further comprising an outer casing having a distal portion extending over at least the RF antenna and ultrasonic transducer array which has a window of ultrasonic and microwave transparent material aligned with the transducer array and extending around said predetermined angle, the remainder of the distal portion of the casing being of microwave and ultrasound absorbing material.