Abstract: A hollow coaxial cable adapted for conduction of radio frequency (RF) energy, particularly microwave energy, has a proximal end and a distal end and comprises coaxial inner and outer conductors extending substantially the entire length of the cable from the proximal end to a distal end portion of the cable with a dielectric medium disposed between the inner and outer conductors. The inner conductor comprises an elongated electrically conductive tubular member having a hollow, axially extending lumen, and the outer conductor comprises an elongated electrically conductive tubular member disposed in a substantially coaxial relationship over at least a portion of the inner conductor. An ablating member which delivers radio frequency energy, particularly microwave energy, to body tissue is disposed at a distal end portion of the cable.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A radio-frequency based catheter system and method for ablating biological tissues within the body vessel of a patient comprises a radio-frequency (“RF”) generator for selectively generating a high frequency RF energy signal in a deployable catheter having an RF transmission line, an RF antenna mounted on the distal portion of the catheter, and a temperature sensor also mounted on a distal portion of the catheter for detecting temperature adjacent an ablation site. A control system adjusts the RF energy signal so that the detected temperature is at or close to a selected temperature setting or within a selected temperature range.

Abstract: A radio frequency energy transmission device comprises a hollow coaxial electrically conductive cable adapted for conduction of radio frequency (RF) energy, particularly microwave energy, for the ablation of biological tissue. The hollow cable has a proximal end and a distal end and comprises coaxial inner and outer conductors extending substantially the entire length of the cable from the proximal end to a distal end portion of the cable. The inner conductor comprises an elongated electrically conductive tubular member having a hollow, axially extending lumen, and the outer conductor comprises an elongated electrically conductive tubular member disposed in a substantially coaxial relationship over at least a portion of the inner conductor. Dielectricity to impede conduction between the inner and outer conductors is introduced with a vacuum or dielectric medium disposed between the inner and outer conductors.

Abstract: A radio-frequency based catheter system and method for ablating biological tissues within the body vessel of a patient comprises a radio-frequency (“RF”) generator for selectively generating a high frequency RF energy signal in a deployable catheter having an RF transmission line, an RF antenna mounted on the distal portion of the catheter, and a temperature sensor also mounted on a distal portion of the catheter for detecting temperature adjacent an ablation site. A control system adjusts the RF energy signal so that the detected temperature is at or close to a selected temperature setting or within a selected temperature range.

Abstract: A method for biological tissue ablation includes shaping a shapeable RF antenna to accommodate the contour of a body vessel adjacent a biological tissue load; generating a train of radio frequency (RF) energy pulses at an output frequency for transmission in a transmission line to the shapeable RF antenna adjacent the biological tissue load; sensing a reflected signal and a forward signal of the RF energy pulses; and adjusting output frequency of the RF energy pulses to effect a substantial match of transmission line impedance with shapeable RF antenna and biological tissue load impedance.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A preformed catheter set for production of linear ablation lines in the left and right atrium for treatment of atrial fibrillation includes at least a first catheter including a pre-shaped distal segment having a distal linear ablation antenna and a U-shaped curve portion proximal to the distal linear ablation antenna.

Abstract: A preformed catheter set for production of linear ablation lines in the left and right atrium for treatment of atrial fibrillation includes at least a first catheter including a pre-shaped distal segment having a distal linear ablation antenna and a U-shaped curve portion proximal to the distal linear ablation antenna.

Abstract: An improved radio-frequency based catheter system and method for ablating biological tissues within the body vessel of a patient comprises a radio-frequency (“RF”) generator for selectively generating high frequency energy in a deployable catheter having a RF co-axial transmission line with a hollow lumen, a RF antenna mounted on the distal portion of the catheter, and steering control lines in the lumen of the transmission line for steering catheter while being inserted into the body vessel and for deflecting the RF antenna to accommodate the contour of the body vessel where tissue ablation is needed. The RF generator having variable output frequency is adapted to generate and communicate RF energy to the RF antenna that minimizes reflected energy from the antenna-tissue interface. In application, the RF antenna establishes line of contact with the body vessel conformable to its internal contour to prescribe the precise tissue ablation pathway despite body vessel movements.

Abstract: An improved radio-frequency catheter system for ablating biological tissues of a body vessel in a patient including a catheter, a deployable antenna guide disposed at the distal portion of the catheter and a radio-frequency (“RF”) antenna mounted on the antenna guide. The RF antenna includes a axial passageway to accommodate the antenna guide, and is adapted to receive and transmit RF energy for tissue ablation. Upon deployment, the antenna guide acquires a loop configuration which establishes line contact with the body vessel conformable to its internal contour to prescribe the precise and affixed tissue ablation pathway despite body vessel movements. The RF antenna is carried by the antenna guide to be deployed along the established tissue ablation pathway. Alignment of the loop with the desired tissue ablation pathway is facilitated with the use of radio-opaque markers and intracardiac electrodes mounted along the antenna guide.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: An improved radio-frequency catheter system for ablating biological tissues of a body vessel in a patient including a catheter, a deployable antenna guide disposed at the distal portion of the catheter and a radio-frequency (“RF”) antenna mounted on the antenna guide. The RF antenna includes a helical coil which defines an axial passageway to accommodate the antenna guide, and is adapted to receive and transmit RF energy for tissue ablation. Upon deployment, the antenna guide acquires a loop configuration which establishes line contact with the body vessel conformable to its internal contour to prescribe the precise and affixed tissue ablation pathway despite body vessel movements. The RF antenna is carried by the antenna guide to be deployed along the established tissue ablation pathway. Alignment of the loop with the desired tissue ablation pathway is facilitated with the use of radio-opaque markers and intracardiac electrodes mounted along the antenna guide.

Abstract: A novel method and composition are provided for the replication and expression of exogenous genes in eukaryotic cells. A segment of a papilloma virus genome capable of extrachromosomal replication is linked to the foreign gene(s) using recombinant DNA techniques to provide a biologically functional replicon with a desired phenotypical property. The replicon is inserted into a eukaryotic cell by transformation, and the isolation of transformant provides cells for replication and expression of the DNA molecules present in the modified plasmid. The transforming region of the bovine papilloma virus provides a unique vector in that it provides both the capability of autonomous extrachromosomal replication but also the malignant transformed phenotype. Thus, genes which of themselves provide no selectable phenotypical property can be conveniently and efficiently introduced into eukaryotic cells and the transformants selected.