摘要:
A system for determining field of ablation is disclosed. The system includes a power source configured to generate electromagnetic energy and an energy applicator coupled to the power source. The energy applicator is configured to be inserted into tissue and to provide electromagnetic energy to a target volume. The system also includes an imaging apparatus configured to generate a uniform magnetic field and at least one variable magnetic field around the tissue. The imaging apparatus obtains an image of a field of ablation within the target volume in response to a trace RF pulse supplied by the power source through the energy applicator to the target volume simultaneously with an excitation RF pulse generated by the imaging apparatus and the at least one variable magnetic field.
摘要:
A coaxial cable, including an inner conductor and an outer conductor surrounding the inner conductor and a thermally responsive material positioned between the outer conductor and the inner conductor. The outer conductor is in a generally concentric relationship to the inner conductor and the inner and outer conductors are adapted to connect to an energy source. A thermal change in the thermally responsive material alters the generally concentric relationship between the outer conductor and the inner conductor.
摘要:
The present disclosure relates to devices and methods for the treatment of tissue with microwave energy. The devices and methods disclosed herein incorporate an antenna assembly comprising outer and inner conductors having a dielectric material interposed therebetween, a sealing barrier, and a cooling system to minimize the likelihood that the antenna assembly will overheat.
摘要:
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.
摘要:
A microwave ablation system is provided. The microwave ablation system includes a power source. A microwave antenna is adapted to connect to the power source via a coaxial cable that includes inner and outer conductors having a compressible dielectric operably disposed therebetween. The inner conductor in operative communication with a radiating section associated with the microwave antenna. The outer conductor includes a distal end transitionable with respect to each of the inner conductor, compressible dielectric and radiating section from an initial condition wherein the distal end has a first diameter to a subsequent condition wherein the distal end has second diameter. Transition of the distal end from the initial condition to the subsequent condition enhances the delivery of microwave energy from the power source to the inner conductor and radiating section such that a desired effect to tissue is achieved.
摘要:
A microwave surgical ablation probe having an arrangement of coolant channels in fluid communication with a cooling chamber disposed within the distal end of the probe is disclosed. A hypotube having one or more longitudinal ribs extending radially inward from an inner surface thereof is coaxially disposed around a coaxial feedline. The longitudinal ribs of the hypotube engage an outer sheath of the feedline to define a fluid inflow channel to deliver coolant to the cooling chamber, and a fluid outflow channel to receive fluid from the cooling chamber. The cooling chamber may be formed from porous ceramic or porous metallic material that provides structural support to the probe while permitting coolant to circulate therethrough. The probe includes dielectric and choke members that are adapted to control the microwave radiation pattern (e.g., ablation shape), and which may provide improved coupling of the probe to tissue.
摘要:
A method of fabricating a microwave antenna assembly is disclosed. The fabrication method includes providing a proximal portion having an inner conductor and an outer conductor, the inner conductor extending at least partially therein. The method further includes providing a distal portion disposed distally of the proximal portion, with the inner conductor extending at least partially therein. A high strength material may be injected from an inflow slot to an outflow slot of the distal portion such that the material is disposed in-between the inner conductor and a ceramic layer. The material bonds the distal portion and the ceramic layer to the proximal portion while providing mechanical strength to the distal portion.
摘要:
A method of fabricating a microwave antenna assembly is disclosed. The fabrication method includes providing a proximal portion having an inner conductor and an outer conductor, the inner conductor extending at least partially therein. The method further includes providing a distal portion disposed distally of the proximal portion, with the inner conductor extending at least partially therein. A high strength material may be injected from an inflow slot to an outflow slot of the distal portion such that the material is disposed in-between the inner conductor and a ceramic layer. The material bonds the distal portion and the ceramic layer to the proximal portion while providing mechanical strength to the distal portion.
摘要:
The microwave antenna assembly includes a feedline electrically connected to an elongated shaft by a choke electrical connector. The feedline includes an inner conductor, an outer conductor, an elongated shaft and a choke electrical connector. The inner conductor is disposed in coaxial arrangement with the inner conductor and forms a dielectric supply lumen therebetween. The elongated shaft at least partially surrounding the feedline and form a dielectric return lumen therebetween. The choke electrical connector surrounds at least a portion of the feedline and electrically connects the feedline outer conductor to the elongated shaft. A low-loss dielectric fluid is supplied between the inner conductor and the outer conductor of the feedline and forms a dielectric barrier therebetween. The low-loss dielectric fluid also forms a dielectric barrier between the outer conductor of the feedline and the elongated shaft and the choke electrical connector forms a plurality of apertures extending therethrough, the apertures forming at least a portion of the dielectric return lumen.
摘要:
A microwave antenna probe incorporating a high-strength antenna coupler is described herein. The microwave antenna has a radiating portion connected by a coaxial feedline to a source of therapeutic energy, e.g., a microwave generator. Proximal and distal radiating portions of the antenna assembly are separated by a microwave antenna coupler. In embodiments, the described antenna coupler is generally cylindrical in shape and includes a central section having a diameter substantially equivalent to the radiating sections. The coupler includes end sections of a smaller diameter than the central section that are dimensioned to fit within the ends of the radiating section. The end portions include a groove that is adapted to receive a corresponding rib formed within the respective ends of the radiating section. The coupler includes an axial opening defined therein into which a tubular collar in fixed using an interference fit. The outward forces of the collar and the inward forces of the radiating section places the coupler under compression, which improves the strength of the coupler, and the strength of the overall probe assembly.