Tissue ablation apparatus and method using ultrasonic imaging
AssigneeMedwaves, Inc.
InventorTheodore C. Ormsby
Life of this patent
Estimating the term…
Abstract
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.
Claims27
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;
- and
- the 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.
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;
- and
- the 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.
Dependencies are inferred from the claim text.