Medwaves, Inc.

Other

Xytronyx, Inc.

George L Leung

Theodore C Ormsby

Ming-Fan Law

Gwo Jenn Shen

Peter Chu

Russell Chung

Ming Fan Law

Gregory Kent Feld

Gerald Odstrchel

Shen Gwo Jenn

An ablation system which transmits radio frequency (RF) energy for the ablation of biological tissues has a transmission line and an RF antenna disposed at the distal portion of the transmission line. An RF signal generator supplies RF energy to the proximal end of the cable for transmission to the antenna, and an electrically tunable transformer is connected between the signal generator and the antenna. The transformer is tuned based on detection of the reflected power level from the antenna so as to reduce or minimize reflected power, thereby increasing RF energy coupling between the antenna and tissue.

Electrically tunable tissue ablation system and method

An RF ablation system has a hollow conductive coaxial cable comprising inner and outer coaxial tubular conductors, and an ablating member mounted at the distal end portion of the cable for delivery of radio frequency energy including microwaves to the target body tissue. The inner conductor has a central lumen and extends at least up to the ablating member. At least one electromagnetic tracking sensor coil with a magnetic core is located in the central lumen at the distal end portion of the cable, close to the distal tip of the cable, and connected to a signal processing unit. An electromagnetic field generator positioned in the vicinity of a patient undergoing treatment generates an electromagnetic field which induces a voltage in the sensor coil. The signal processing unit uses the induced voltage to calculate the position and orientation of the distal end portion or tip of the catheter in a patient's body.

Radio frequency ablation system with tracking sensor

An ablation device which transmits radio frequency (RF) energy for the ablation of biological tissues has elongate 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 device and transmits RF energy for ablation of a tissue region to be treated. Reflection of energy from the tissue or the ablation point is reduced by providing multiple layers of dielectric media about the antenna, or by providing a gradual transition point from the conductors to the antenna tip, by means of a longitudinally stepped dielectric layer transformer.

Radio frequency based ablation system and method with dielectric transformer

A coaxial cable apparatus which transmits radio frequency (RF) energy for the ablation of biological tissues has inner and outer coaxial conductors extending substantially the entire length of the cable from a proximal end portion to a distal end portion. An RF antenna is disposed at the distal end portion of the cable and transmits RF energy for ablation of a tissue region to be treated. An angioplasty balloon is disposed over the RF antenna and communicates with a fluid supply and extraction passageway extending through the cable to allow the balloon to be inflated for an angioplasty procedure including tissue ablation, and to be deflated after the procedure is complete.

Angioplasty and tissue ablation apparatus and method

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.

Hollow conductive coaxial cable for radio frequency based tissue ablation system

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.

Radio frequency-based catheter system with improved deflection and steering mechanisms

Radio-frequency-based catheter system with improved deflection and steering mechanisms

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.

Radio-frequency based catheter system and method for ablating biological tissues

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.

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.

Preformed catheter set for use with a linear ablation system to produce ablation lines in the left and right atrium for treatment of atrial fibrillation

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 (&ldquo;RF&rdquo;) 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. The catheter, as well as the antenna can be provided with steering or deflection mechanism for navigation through the body vessel passageways. A hollow co-axial cable is provided for the delivery of RF energy.

Radio-frequency based catheter system and hollow co-axial cable for ablation of body tissues

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 (&ldquo;RF&rdquo;) 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. The catheter system is provided with steering mechanism for navigation through the body vessel passageways.

Radio-frequency based catheter system for ablation of body tissues

Method for determining the presence of an aminotransferase (AT.sub.1), other than aspartate aminotransferase (AST), in a biological sample. The method includes contacting the sample with an amino donor substrate for AT.sub.1, an amino acceptor substrate for AT.sub.1, cysteine sulfinic acid (CSA) in excess, a second aminotransferase (AT.sub.2), different from AT.sub.1, in excess, and an indicator for the presence of sulfite ions, under conditions in which the concentration of said AT.sub.1 can be determined by the amount of the indicator which forms a detectable signal.

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San Diego, CA, United States of America

George L Leung