54 results about "Ablation zone" patented technology

An ablation catheter comprises a catheter body extending longitudinally between a proximal end and a distal end along a longitudinal axis; and an ablation element assembly comprising ablation elements connected to the catheter body, each ablation element to be energized to produce an ablation zone. The ablation elements are distributed in a staggered configuration such that the ablation zones of the ablation elements span one or more open arc segments around the longitudinal axis, but the ablation zones of all ablation elements projected longitudinally onto any lateral plane which is perpendicular to the longitudinal axis span a substantially closed loop around the longitudinal axis. Since the ablation zones do not form a closed loop, the risk of renal artery / vein stenosis is reduced or eliminated. Since the ablation zones of all ablation elements projected longitudinally onto any lateral plane span a substantially closed loop, substantially complete renal denervation is achieved.

An ablation apparatus comprises an ultrasonic transducer which includes a piezoelectric element having a cylindrical shape; a plurality of external electrodes disposed on the outer surface of the piezoelectric element; and at least one internal electrode disposed on the inner surface of the piezoelectric element. The at least one internal electrode provides corresponding internal electrode portions that are disposed opposite the external electrodes with respect to the piezoelectric element, the external electrodes and the at least one internal electrode to be energized to apply an electric field across the piezoelectric element. The ultrasonic ablation zones of the external electrodes are distributed in a staggered configuration so as to span one or more open arc segments around the longitudinal axis, and the ultrasound ablation zones of all external electrodes projected longitudinally onto any lateral plane which is perpendicular to the longitudinal axis span a substantially closed loop around the longitudinal axis.

Multi-phase RF ablation employing a two-dimensional or three-dimensional electrode array produces a multitude of currents paths on the surface of the ablation zone. This results in a uniform lesion with a size defined by the span of the electrode array. An orthogonal electrode catheter array suitable for cardiac ablation is used in conjunction with a two-phase RF power source to produce uniform square-shaped lesions of size 1.2 cm2. Lesions of larger size are created by successive adjacent placement of the square-shaped lesions. A temperature sensor at the electrode tip allows monitoring of ablation temperature and regulation of thereof to minimize the electrode tips from being fouled by coagulum. In another embodiment, an external auxiliary electrode is used in combination with the catheter electrodes. This also produces lesions of greater depth. In yet another embodiment, ablation is performed with a sequence of elementary electrode-electrical configurations.

System for increasing a target zone for electrical ablation includes a treatment control module executable by a processor. The control module directs a pulse generator to apply pre-conditioning pulses to subject tissue cells in a pre-conditioning zone to electroporation, the pre-conditioning zone being smaller than a target ablation zone. After the pre-conditioning pulses have been applied, the control module directs the pulse generator to apply treatment pulses to electrically ablate the tissue cells in the target ablation zone. The pre-conditioning pulses cause the pre-conditioning zone to have a much higher conductivity so that the zone acts as a larger electrode area when the treatment pulses are applied, which results in a much larger target ablation zone than otherwise possible.

A laser beam delivery system and a method for ablating tissue, e.g., for reshaping a cornea of an eye is provided. The laser beam delivery system directs a laser beam on the tissue to be ablated in a predetermined pattern according to the principles of the present invention. The laser beam is incrementally scanned to subsequent laser beam ablation points or spots in the ablation zone in accordance with the predetermined pattern. The laser beam ablates tissue at the spots in the predetermined pattern in an arranged order. In one aspect of the present invention, the radii of the predetermined pattern is varied between scans of the laser beam until a predetermined reshaping is achieved by ablation. In another aspect of the present invention, every other, every third, every fourth, etc. laser beam spot in a predetermined pattern is ablated, and the scans are repeated for unablated points until all spots are ablated. In yet another aspect of the present invention, one or more layers in each of a plurality of annular ablation zones may be fully ablated before ablation in other annular ablation zones is performed.

Systems and methods are provided for modeling and for providing a graphical representation of tissue heating and electric field distributions for medical treatment devices that apply electrical treatment energy through one or a plurality of electrodes. In embodiments, methods comprise: providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to tissue through a plurality of electrodes; modeling electric and heat distribution in the tissue based on the parameters; and displaying a graphical representation of the modeled electric and heat distribution. In another embodiment, a treatment planning module is adapted to generate an estimated target ablation zone based on a combination of one or more parameters for an irreversible electroporation protocol and one or more tissue-specific conductivity parameters.

An energy delivery probe and method of using the energy delivery probe to treat a patient is provided herein. The energy delivery probe has at least one probe body having a longitudinal axis and at least a first trocar and a second trocar. Each trocar comprises at least two electrodes that are electrically insulated from each other, and each electrode is independently selectively activatable. An insulative sleeve is positioned in a coaxially surrounding relationship to each of the first trocar and the second trocar. The probe also has a switching means for independently activating at least one electrode. The method involves independently and selectively activating the first and second electrodes to form an ablation zone, then repeating the ablation by delivering energy to a second set of electrodes, producing one or more overlapping ablation zone, and eliminating the need to reposition the ablation probes.

A method is provided for ablating brain tissue of a living mammal comprising: placing first and second electrodes in a brain of the living mammal; applying a plurality of electrical pulses through the first and second placed electrodes which are predetermined to: cause irreversible electroporation (IRE) of brain tissue of the mammal within a target ablation zone; and cause a temporary disruption of a blood brain barrier (BBB) within a surrounding zone that surrounds the target ablation zone to allow material in a blood vessel to be transferred to the surrounding zone through the temporarily disrupted BBB. Such methods are useful for delivering large molecule material within a blood vessel of the brain across the BBB, where the large molecule is otherwise blocked by the BBB from passing through the blood vessel into the brain.

A system for monitoring ablation size is provided and includes a power source including a microprocessor for executing at least one control algorithm. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. A radiation detection device is operably disposed on the microwave antenna. The radiation detection device is configured to generate a voltage corresponding to a radius of the ablation zone, wherein the radiation detection device is in operative communication with at least one module associated with the power source. The at least one module triggers a signal when a predetermined threshold voltage is measured corresponding to the radius of the ablation zone.

Methods for treating tissue with irreversible electroporation and immunotherapy are described. The methods include placing a probe in tissue within a human body, wherein the probe has at least a first electrode, applying a plurality of electrical pulses through the first electrode and a second electrode, causing irreversible electroporation (IRE) of the tissue within a target ablation zone, and administering one or more exogenous agents into the tissue within the target ablation zone or to the human, thereby stimulating or otherwise modulating an immune system response within the body.

A method for laser treatment of the eye using one or more diffractive optical elements for producing unique treatment segments within an ablation zone on the eye. The treatment segments may be annular, pie-shaped, or have other geometries or patterns selected to apply energy in a particular manner, usually in a non-overlapping manner so that energy dosages can be precisely controlled. In a first embodiment of the method, a single diffractive optical element is used and a beam expander expands or converges the beam to achieve the different treatment segments. In a second embodiment, a plurality of diffractive optical elements are used, each of which produces a single treatment segment.

A system for monitoring ablation size is provided. The system includes a power source including a microprocessor for executing at least one control algorithm. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. A series of thermal sensors is operably disposed adjacent a radiating section of the microwave antenna and extends proximally therefrom. The thermal sensors corresponding to a radius of the ablation zone, wherein each thermal sensor generates a voltage when a predetermined threshold tissue temperature is reached corresponding to the radius of the ablation zone.

A system and method for selectively treating aberrant cells such as cancer cells through administration of a train of electrical pulses is described. The pulse length and delay between successive pulses is optimized to produce effects on intracellular membrane potentials. Therapies based on the system and method produce two treatment zones: an ablation zone surrounding the electrodes within which aberrant cells are non-selectively killed and a selective treatment zone surrounding the ablation zone within which target cells are selectively killed through effects on intracellular membrane potentials. As a result, infiltrating tumor cells within a tumor margin can be effectively treated while sparing healthy tissue. The system and method are useful for treating various cancers in which solid tumors form and have a chance of recurrence from microscopic disease surrounding the tumor.

A method and apparatus for intrastromal refractive surgery is disclosed wherein tissue at selected locations within the stroma of the cornea is photoablated using a pulsed laser beam. The apparatus includes an optical system for forming a shaped laser beam having a waist at a predetermined distance from the optical system. The pulse duration and pulse energy of the laser beam are selected to cause ablation to occur in front of the waist (i.e. between the waist and the optical system). To achieve this, a pulse energy is used that exceeds the minimum pulse energy required for ablation at the waist. By ablating in front of the waist, a relatively large ablation zone (per pulse) is created (compared to ablation at the waist). Furthermore, while the laser is scanned through the cornea to effectuate a refractive change, the optical system maintains a uniform waist for the laser beam.

An energy delivery probe and method of using the energy delivery probe to treat a patient is provided herein. The energy delivery probe has at least one probe body having a longitudinal axis and at least a first trocar and a second trocar. At least a portion of each trocar is disposed with the at least one probe body. The distance between the first trocar and the second trocar is adjustable between a first position and a second position. Each of the deployed electrodes has an energy delivery surface of a sufficient size to create a volumetric ablation zone between the deployed electrodes. The energy delivery probe is connected to an energy source. At least one cable couples the energy delivery probe to the energy source.

A system for monitoring ablation size is provided and includes a power source including a microprocessor for executing at least one control algorithm. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. An ablation zone control module is in operative communication with a memory associated with the power source. The memory includes one or more data look-up tables including data pertaining to a control curve varying over time and being representative of one or more electrical parameters associated with the microwave antenna. Points along the control curve correspond to a value of the electrical parameters and the ablation zone control module triggers a signal when a predetermined threshold value of the electrical parameter(s) is measured corresponding to the radius of the ablation zone.

A system for monitoring ablation size is provided and includes a power source including a microprocessor for executing at least one control algorithm. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. An ablation zone control module is in operative communication with memory associated with the power source. The memory includes one or more data look-up tables including one or more electrical parameter associated with the microwave antenna. The one or more electrical parameters corresponding to an ablation zone having a radius. The one or more electrical parameters include a threshold value, wherein when the threshold value is met the power source is adjusted to form an ablation zone of suitable proportion.

Systems and methods for three-dimensional guidance and monitoring of a cryotherapy procedure, including virtually performing the procedure. A method of virtually performing a cryotherapy procedure includes: selecting a target object from three-dimensional image data displayed in three dimensions; selecting a three-dimensional ablation zone; selecting, from a library of virtual cryoprobe needles, a cryoprobe needle with a three-dimensional ablation zone that corresponds to the selected ablation zone; comparing the location of the target object with the selected ablation zone, the location of the ablation zone encompassing the target object to the greatest extent being an optimal location, determining, via a processor, a virtual trajectory for the virtual cryoprobe needle from an entry site to the target object when the ablation zone of the virtual cryoprobe needle is in the optimal position; and calculating a result of the procedure based on the target object, the selected ablation zone, the selected needle, and a duration of treatment. Guidance may also optionally be provided during an actual cryotherapy procedure, based upon three dimensional image data and / or data from one or more sensors, for example according to the results of the virtual cryotherapy procedure.

A system for monitoring ablation size is provided. The system includes a power source including a microprocessor for executing one or more control algorithms. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. A plurality of spaced-apart electrodes is operably disposed along a length of the microwave antenna. The plurality of spaced-apart electrodes is disposed in electrical communication with one another and each of the plurality of spaced-apart electrodes has a threshold impedance associated therewith corresponding to the radius of the ablation zone.

A microwave applicator for insertion into living body tissue for use in microwave coagulation and ablation treatments includes a microwave transmission line extending between an attachment end of the applicator and an antenna toward an insertion end of the applicator with an outer conductive sleeve forming an enclosed fluid space around the transmission line. A fluid circulation system circulates fluid in the fluid space. A portion of or all of the circulating fluid can be injected into tissue that surrounds the applicator body from approximately the proximal end of a desired heating zone produced by microwave energy radiated from the antenna along the applicator body toward the proximal end of the applicator to hydrate and wet the tissue outside the proximal end of the desired heating zone to reduce the drying of this tissue and limit extension of the heating and ablation zone proximally along the applicator body.