Abstract:
An electromagnetic surgical ablation probe having a tunable helical antenna element is disclosed. The probe includes a coaxial feedline having an inner conductor coaxially disposed within a dielectric, and an outer conductor coaxially disposed around the dielectric. The inner conductor and dielectric extend distally beyond a distal end of the outer conductor. A helical antenna element is operably coupled to a distal end of the inner conductor. During use, the antenna may be tuned by changing at least one dimension of the helical antenna element. Embodiments are presented wherein a dimensions of the helical antenna element is changed by state change of a shape memory alloy, by a change in temperature, by activation of a piston by fluidic pressure, by linear motion of a conical tip, and by a manual screw-type adjustment.
Abstract:
A microwave delivery device, including a coaxial feedline having an inner conductor, an inner dielectric insulator coaxially disposed about, the inner conductor, and an outer conductor coaxially disposed about, the inner dielectric, and a radiating portion operably coupled to a distal end. The radiating portion includes a radiating portion inner conductor operable coupled to and extending from a distal end of the coaxial feedline inner conductor, a shielding outer conductor helically wrapped about the radiating portion inner conductor and operably coupled to the coaxial feedline outer conductor; and a shielding dielectric positioned between the radiating portion inner conductor and the shielding outer conductor wherein the width of the shielding outer conductor varies according to the longitudinal position thereof along the coaxial feedline inner conductor, and a cap operably coupled to a distal end of the radiating portion inner conductor and the shielding outer conductor to provide an electrical connection therebetween.
Abstract:
A method of adjusting an ablation field radiating into tissue includes the initial step of providing a handheld device including a phased antenna array and an ultrasound transducer array. The method includes the steps of positioning a tissue-contact surface of the handheld device adjacent to tissue, activating the phased antenna array to deliver energy through the tissue-contact surface to generate an ablation field in targeted tissue, activating the ultrasound transducer array to acquire ultrasound image data representative of the targeted tissue during energy delivery into the targeted tissue by the phased antenna array, and selectively steering the focal point of energy delivery in tissue to adjust the ablation field radiating into tissue.
Abstract:
An electromagnetic surgical ablation probe having a tunable helical antenna element is disclosed. The probe includes a coaxial feedline having an inner conductor coaxially disposed within a dielectric, and an outer conductor coaxially disposed around the dielectric. The inner conductor and dielectric extend distally beyond a distal end of the outer conductor. A helical antenna element is operably coupled to a distal end of the inner conductor. During use, the antenna may be tuned by changing at least one dimension of the helical antenna element. Embodiments are presented wherein a dimensions of the helical antenna element is changed by state change of a shape memory alloy, by a change in temperature, by activation of a piston by fluidic pressure, by linear motion of a conical tip, and by a manual screw-type adjustment.
Abstract:
A microwave antenna having a curved configuration is described herein. The antenna portion is formed into various shapes whereby the antenna substantially encloses, by a partial or complete loop or enclosure, at least a majority of the tissue to be irradiated. When microwave energy is delivered through the antenna, the curved configuration forms an ablation field or region defined by the curved antenna and any tissue enclosed within the ablation region becomes irradiated by the microwave energy. The microwave antenna is deployed through one of several methods, and multiple curved antennas can be used in conjunction with one another. Moreover, RF energy can also be used at the distal tip of the antenna to provide a cutting tip for the antenna during deployment in tissue.
Abstract:
An electrosurgical device for directing energy to a target volume of tissue includes a coaxial feedline having an inner conductor, an outer conductor and a dielectric material disposed therebetween. A proximal cylindrical dielectric sleeve is coupled to the inner conductor at a distal end of the coaxial feedline. A distal cylindrical dielectric sleeve is coupled to the inner conductor. First and second dielectric segments are coupled to the inner conductor and disposed between the proximal cylindrical dielectric sleeve and the distal cylindrical dielectric sleeve. The device also includes an elongated shaft overlying the proximal cylindrical dielectric sleeve, the first dielectric segment, the second dielectric segment and the distal cylindrical dielectric sleeve. The elongated shaft includes an opening defined therethrough, wherein the opening is at least partially aligned with the first dielectric segment. A balun structure is disposed on the elongated shaft, at least partially overlying the opening in the elongated shaft.
Abstract:
High-strength microwave antenna assemblies and methods of use are described herein. The microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. Proximal and distal radiating portions of the antenna assembly are separated by a junction member. A reinforcing member is disposed within the junction member to increase structural rigidity.
Abstract:
An energy-delivery device suitable for delivery of energy to tissue includes an antenna assembly, a chamber defined about the antenna assembly, and a cable having a proximal end suitable for connection to an electrosurgical energy source. The energy-delivery device also includes a flexible, fluid-cooled shaft coupled in fluid communication with the chamber. The flexible, fluid-cooled shaft is configured to contain a length of the cable therein and adapted to remove heat along the length of the cable during delivery of energy to the antenna assembly.
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.
Abstract:
An electromagnetic surgical ablation probe having a tunable helical antenna element is disclosed. The probe includes a coaxial feedline having an inner conductor coaxially disposed within a dielectric, and an outer conductor coaxially disposed around the dielectric. The inner conductor and dielectric extend distally beyond a distal end of the outer conductor. A helical antenna element is operably coupled to a distal end of the inner conductor. During use, the antenna may be tuned by changing at least one dimension of the helical antenna element. Embodiments are presented wherein a dimensions of the helical antenna element is changed by state change of a shape memory alloy, by a change in temperature, by activation of a piston by fluidic pressure, by linear motion of a conical tip, and by a manual screw-type adjustment.