1156 results about "Conductive fluid" patented technology

An electrosurgical system comprises a radio frequency generator (1), an electrosurgical instrument (E1), and a fluid enclosure (42). The generator (1) has a radio frequency output for delivery of power to the electrosurgical instrument (E1) when immersed in an electrically-conductive fluid. The electrosurgical instrument (E1) has an electrode assembly (32) at the distal end thereof, the electrode assembly comprising a tissue treatment electrode (34), and a return electrode (38) axially spaced therefrom in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode. The fluid enclosure (42) is adapted to surround an operation site on the skin of a patient or an incision leading to a cavity surgically created within the patient's body. The fluid enclosure (42) includes sealing means (44) for sealing against the patient's tissue, and the fluid enclosure includes at least one port (50a, 52a) through which the electrosurgical (E1) is insertable, and through which the electrically-conductive fluid can enter and / or leave the enclosure.

An electrosurgical system comprises a radio frequency generator (1), an electrosurgical instrument (E1), and a fluid enclosure (42). The generator (1) has a radio frequency output for delivery of power to the electrosurgical instrument (E1) when immersed in an electrically-conductive fluid. The electrosurgical instrument (E1) has an electrode assembly (32) at the distal end thereof, the electrode assembly comprising a tissue treatment electrode (34), and a return electrode (38) axially spaced therefrom in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode. The fluid enclosure (42) is adapted to surround an operation site on the skin of a patient or an incision leading to a cavity surgically created within the patient's body. The fluid enclosure (42) includes sealing means (44) for sealing against the patient's tissue, and the fluid enclosure includes at least one port (50a, 52a) through which the electrosurgical (E1) is insertable, and through which the electrically-conductive fluid can enter and / or leave the enclosure. The fluid enclosure device of the present invention can also be used to treat tumours within the colon. The enclosure, which includes a proximal and a distal bung, is inserted into the colon in a deflated condition and then inflated with a conductive fluid or gas. The colon can be supported against the pressure of the fluid or gas with a pressure sleeve that has been inserted to surround the region of the colon being treated. An electrosurgical instrument is then inserted into the colon and manipulated to vaporize the tumor.

A system and method are disclosed for removing a uterus using a fluid enclosure inserted in the peritoneal cavity of a patient so as to enclose the uterus. The fluid enclosure includes a distal open end surrounded by an adjustable loop, that can be tightened, a first proximal opening for inserting an electrosurgical instrument into the fluid enclosure, and a second proximal opening for inserting an endoscope. The loop is either a resilient band extending around the edge of the distal open end or a drawstring type of arrangement that can be tightened and released. The fluid enclosure is partially inserted into the peritoneal cavity of a patient in a deflated condition and then manipulated within the peritoneal cavity over the body and fundus of the uterus to the level of the uterocervical junction. The loop is tightened around the uterocervical junction, after which the enclosure is inflated using a conductive fluid. The loop forms a pressure seal against the uterocervical junction to contain the conductive fluid used to fill the fluid enclosure. Endoscopically inserted into the fluid enclosure is an electrosurgical instrument that is manipulated to vaporize and morcellate the fundus and body of the uterus. The fundus and body tissue that is vaporized and morcellated is then removed from the fluid enclosure through the shaft of the instrument, which includes a hollow interior that is connected to a suction pump The fundus and body are removed after the uterus has been disconnected from the tissue surrounding uterus.

The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to brain, liver, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accordance with the present invention includes a source of super-cooled fluid for selectively providing super-cooled fluid to the target tissue to cause a temporary cessation of cellular or electrical activity, a supply of conductive or electrolytic fluid to be provided to the target tissue, and alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering super-cooled fluid to the target tissue to cause a temporary cessation of cellular or electrical activity, evaluating whether the temporary cessation of cellular or electrical activity is the desired cessation of cellular or electrical activity, and if so, delivering a conductive fluid to the predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and / or the fluid flow in response to the measured parameters.

The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to liver, lung, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accord with the present invention includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering a conductive fluid to a predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and / or the fluid flow in response to the measured parameters.

The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to liver, lung, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accord with the present invention includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering a conductive fluid to a predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and / or the fluid flow in response to the measured parameters.

An instrument for thermally-mediated therapies in targeted tissue volumes or for volumetric removal of tissue. In one embodiment, the instrument has an interior chamber that includes a diffuser structure for diffusing a biocompatible conductive fluid that is introduced under high pressure. The interior chamber further includes surfaces of opposing polarity electrodes for vaporizing the small cross-section diffused fluid flows created within a diffuser structure. In one embodiment, the diffuser structure includes a negative temperature coefficient of resistance material between the opposing polarity surfaces. The NTCR structure can self-adjust the lengths of current paths between the opposing polarities to insure complete vaporization of the volume of flow of conductive fluid. The non-ionized vapor phase media is ejected from a working surface of the instrument and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. In another embodiment, the instrument provides voltage means for converting the non-ionized vapor phase media into an ionized media or plasma for applying energy to body structure.

Methods and apparatus for selectively applying electrical energy to a target location within a patient's body, particularly including tissue in the spine. In a method of the invention high frequency (RF) electrical energy is applied to one or more active electrodes on an electrosurgical probe in the presence of an electrically conductive fluid to remove, contract or otherwise modify the structure of tissue targeted for treatment. In one aspect, a dura mater and spinal cord are insulated from the electrical energy by an insulator positioned on a non-active side of the probe. In another aspect, a plasma is aggressively formed in the electrically conductive fluid by delivering a conductive fluid to a distal end portion of the probe and aspirating the fluid from a location proximal of the return electrode. In another aspect, a distal end of an electrosurgical probe having at least one electrode on a biased, curved, bent, or steerable shaft is guided or steered to a target site within an intervertebral disc having a disc defect for treatment of tissue to be treated at the target site by the selective application of electrical energy thereto.

Systems and methods are provided for applying a high frequency voltage in the presence of an electrically conductive fluid to create a relatively low-temperature plasma for ablation of tissue adjacent to, or in contact with, the plasma. In one embodiment, an electrosurgical probe or catheter is positioned adjacent the target site so that one or more active electrode(s) are brought into contact with, or close proximity to, a target tissue in the presence of electrically conductive fluid. High frequency voltage is then applied between the electrode terminal(s) and one or more return electrode(s) to generate a plasma adjacent to the active electrode(s), and to volumetrically remove or ablate at least a portion of the target tissue. The high frequency voltage generates electric fields around the active electrode(s) with sufficient energy to ionize the conductive fluid adjacent to the active electrode(s). Within the ionized gas or plasma, free electrons are accelerated, and electron-atoms collisions liberate more electrons, and the process cascades until the plasma contains sufficient energy to break apart the tissue molecules, causing molecular dissociation and ablation of the target tissue.

A sensing and ablation electrode includes bifurcated sensing limbs separated by an ablation web. The electrode is disposed on the distal end of a catheter. The sensing limbs each support an array of sensors that are individually wired for mapping and post ablation efficacy testing. The web includes a pair of pliable membranes that define a lumen and are adapted to collapse the cross-section of the electrode. One membrane defines a plurality of apertures for dispersing a conductive fluid medium as a virtual electrode. The sensors and the apertures all lie within substantially the same plane.

An elongated, flexible, flat conductive tape can be applied to any surface to be monitored for water or other liquid leaks, and electrically connected to any suitable type of conventional electrically operated leak detector. A pair of parallel spaced conductors is disposed on one side of the tape that run longitudinally along the length thereof. The conductors are spaced from one another by a small distance to insure that only a small quantity of water or other conductive liquid is necessary to bridge the gap between the conductors, and create an electrical short circuit or substantial impedance reduction between the two. In addition, the conductors are preferably as flat as possible to insure that liquid can freely flow transversely across them without being impeded thereby. Both of these features insure that the detector tape can sense even very small quantities of liquid, thereby generating an early warning of a leak condition before extensive damage results. A liquid responsive visible indication is also provided on the tape to identify the location along the tape where water or other leaking liquid has come in contact therewith, and eliminates the need for using an expensive sensing device to locate the source of a leak.

An ablation catheter employing one or more manifold arrangements to convey a conductive fluid medium to a target tissue. The manifold includes at least one inlet port in fluid communication with a fluid supply lumen running along at least a portion of the catheter. The inlet port or ports are in fluid communication with a larger outlet port. The outlet ports provide an outlet for the fluid to flow out of the catheter and against the target tissue. As such, the combination of at least the inlet port with the outlet port provides a flow path for fluid within the fluid lumen to flow through the manifold and to outside of the catheter. An electrode is arranged in the flow path of fluid within or adjacent the manifolds. As such, fluid may be energized and conduct ablation energy to the target tissue to ablate the tissue.

Systems and methods are provided for applying a high frequency voltage in the presence of an electrically conductive fluid to create a relatively low-temperature plasma for ablation of tissue adjacent to, or in contact with, the plasma. In one embodiment, an electrosurgical probe or catheter is positioned adjacent the target site so that one or more active electrode(s) are brought into contact with, or close proximity to, a target tissue in the presence of electrically conductive fluid. High frequency voltage is then applied between the active electrode(s) and one or more return electrode(s) to non-thermally generate a plasma adjacent to the active electrode(s), and to volumetrically remove or ablate at least a portion of the target tissue. The high frequency voltage generates electric fields around the active electrode(s) with sufficient energy to ionize the conductive fluid adjacent to the active electrode(s). Within the ionized gas or plasma, free electrons are accelerated, and electron-atoms collisions liberate more electrons, and the process cascades until the plasma contains sufficient energy to break apart the tissue molecules, causing molecular dissociation and ablation of the target tissue.

A method and apparatus for creating a virtual electrode to ablate bodily tissue. The apparatus includes an outer tube, a first electrode, an inner tube and a second electrode. The outer tube is fluidly connected to a source of conductive fluid and defines a proximal end and a distal end. The distal end includes an opening for delivering conductive fluid from the outer tube. The first electrode is disposed at the distal end of the outer tube for applying a current to conductive fluid delivered from the outer tube. The inner tube is coaxially received within the outer tube and is connected to a source of conductive fluid. The inner tube defines a proximal end and a distal end, with the distal end forming an opening for delivering conductive fluid from the inner tube. Finally, the second electrode is disposed at the distal end of the inner tube for applying a current to conductive fluid delivered from the inner tube. With this configuration, upon final assembly, the distal end of the outer tube is axially spaced from the distal end of the inner tube such that the first electrode is spaced from the second electrode. As a result, a bi-polar virtual electrode can be established.

Methods and apparatus for ablating a target tissue are discussed. Such methods and apparatus include those that simplify tissue ablation. For example, a tissue ablation device having an actuator, such as a trigger mechanism, coupled to a power source and an electrode is discussed. A single step of engaging the actuator causes the electrode to be introduced into the target tissue and causes energy to be delivered from the power supply to the tissue via the electrode. By way of additional example, a tissue ablation device having an actuator coupled to a fluid source and an electrode is discussed. A single step of engaging the actuator causes conductive fluid to flow from the fluid source to the target tissue location and causes the electrode to be introduced to the target tissue location. The fluid source may be a conductive fluid, such as saline, which may increase the efficiency of ablation. Various other configurations and methods that simplify tissue ablation are also discussed.

A wearable therapeutic device that includes a garment configured to contain an external defibrillator. The garment is configured to house at least one of an alarm module and a monitor and to house a first therapy electrode and a second therapy electrode. The garment is also configured to releasably receive a receptacle that contains a conductive fluid proximate to at least one of the first therapy electrode and the second therapy electrode, and to electrically couple the receptacle with the garment.

An electrosurgical apparatus for treating body tissue, comprising an active and a return electrode, a vacuum inlet located near the active electrode, and at least one pinhole defined on the apparatus near the return electrode that is adapted to provide a conductive fluid bridge between the active and return electrodes during use regardless of the orientation of the electrodes relative to the tissue, without flooding the electrodes or the tissue. Also, a method and system of performing a dry field surgical procedure comprising applying ablative energy to a target tissue wherein the target tissue is not flooded or submerged in electrically conductive fluid; and maintaining a fluid bridge between the electrodes regardless of the orientation of the shaft. Advantageously, since the conductive fluid bridge is maintained for any orientation of the electrodes relative to the tissue without flooding, the instrument can be used to treat tissue from any orientation without breaking the fluid bridge.

Certain embodiments provide a system including a heater. The heater includes one or more electrical conductors. The heater is configured to generate a heat output during application of electrical current to the heater. The heater includes a ferromagnetic material. A conduit at least partially surrounds the heater. A fluid is located in a space between the heater and the conduit. The fluid has a higher thermal conductivity than air at standard temperature and pressure (STP) (0° C. and 101.325 kPa). The system is configured to provide (a) a first heat output below a selected temperature when time-varying electrical current is applied to the heater, and (b) a second heat output near or above the selected temperature when time-varying electrical current is applied to the heater.

A flexible diagnostic device has a measurement cell that is sandwiched between the conductive surfaces of two conductive-coated insulating layers. At least one of the conductive surfaces is scored with an insulating pattern, so that the flow of a conductive fluid sample into the cell can be monitored.

An ablation catheter including a shaft supporting one or more partially or completely exposed braided electrodes that may be positioned against a target tissue to ablate the tissue. The shaft may be precurved in a loop-like shape or any other shape to assist in positioning the electrode against a target tissue. The shaft may include a fluid lumen to direct a fluid material, which may be conductive, through one or more apertures or ports. The ports are adapted to direct the fluid past portions of the braided electrode to cool the electrode, flush blood away from the electrode, and to transfer ablation energy to the target tissue. Ablation energy may be delivered directly by the electrode and by way of a conductive fluid contacting the electrode. The shaft may further include a second lumen to provide a housing for a control wire that may be used to control the shape of the shaft.

The disclosure describes a method and a system that may be used to provide feedback on the progress of ablation therapy. The system includes a first needle that penetrates a target tissue to deliver radio frequency energy, with or without a conductive fluid, that heats and ablates the target tissue and a second needle that penetrates the target tissue and detects a tissue property indicative of the ablation progress. Temperature, impedance, or another parameter may be the tissue property detected and measured by the system. In addition, more than one sensor may be positioned on the first or second needle. The system may provide real-time monitoring of the tissue property or use the tissue property measurement to automatically terminate the ablation therapy. In particular, the system may be used to treat benign prostatic hypertrophy.

A surgical apparatus for delivering a conductive fluid to a target site for subsequent formation of a virtual electrode to ablate bodily tissue at the target site by applying a current to the delivered conductive fluid. The surgical apparatus includes an elongated device forming a helical needle. The helical needle is configured to engage bodily tissue and is hollow for delivering conductive fluid from a fluid source. Finally, the helical needle terminates in a needle tip. In one preferred embodiment, an electrode is associated with the helical needle for applying a current to conductive fluid delivered from the helical needle. During use, following delivery of conductive fluid, the electrode applies a current to the delivered conductive fluid for creating a virtual electrode. The virtual electrode ablates bodily tissue contacted by the conductive fluid.

Systems and methods are provided for applying a high frequency voltage in the presence of an electrically conductive fluid to create a relatively low-temperature plasma for ablation of tissue adjacent to, or in contact with, the plasma. In one embodiment, an electrosurgical probe or catheter is positioned adjacent the target site so that one or more active electrode(s) are brought into contact with, or close proximity to, a target tissue in the presence of electrically conductive fluid. High frequency voltage is then applied between the active electrode(s) and one or more return electrode(s) to non-thermally generate a plasma adjacent to the active electrode(s), and to volumetrically remove or ablate at least a portion of the target tissue. The high frequency voltage generates electric fields around the active electrode(s) with sufficient energy to ionize the conductive fluid adjacent to the active electrode(s). Within the ionized gas or plasma, free electrons are accelerated, and electron-atoms collisions liberate more electrons, and the process cascades until the plasma contains sufficient energy to break apart the tissue molecules, causing molecular dissociation and ablation of the target tissue.

A system, device and method for thermally affecting tissue are provided. The system includes a pump / controller unit having a pump for pumping a thermally conductive fluid through the system, a fluid chiller for thermally treating the conductive fluid, a controller circuitry for measuring and controlling the temperature of the conductive fluid, and a fluid circulation path having an extension tubing set for circulating the thermally conductive fluid, a thermal application device having at least one flow passage that is in fluid communication with the tubing set, a thermal exchanger element in fluid communication with the tubing set that interfaces with the fluid chiller, where the tubing set operably interfaces with a pump to enable the pump to circulate a thermally conductive fluid through a fluid circulation path. The fluid circulation path may have various sensors providing temperature and pressure readings to the pump / controller unit.

Virtual-electrode catheters and methods for using such virtual-electrode catheters are disclosed. For example, bipolar and multipolar, virtual-electrode catheters having at least one internal electrode and at least one surface electrode, and methods of using these catheters for treatment of cardiac arrhythmias via, for example, radiofrequency (RF) ablation are disclosed. The catheters may comprise a catheter body with an internal lumen extending within it and adapted to flowingly receive a conductive fluid. An exit feature defining a flow path from the internal lumen to the catheter's outer surface may exist through a sidewall of the catheter body. A conductor is mounted within the internal lumen adjacent to the exit feature and is adapted to deliver treatment energy to the tissue via the conductive fluid in the internal lumen. At least one surface electrode is mounted on the outer surface of the catheter body adjacent to the exit feature.

Systems and methods are provided for applying a high frequency voltage in the presence of an electrically conductive fluid to create a relatively low-temperature plasma for ablation of tissue adjacent to, or in contact with, the plasma. In one embodiment, an electrosurgical probe or catheter is positioned adjacent the target site so that one or more active electrode(s) are brought into contact with, or close proximity to, a target tissue in the presence of electrically conductive fluid. High frequency voltage is then applied between the active electrode(s) and one or more return electrode(s) to non-thermally generate a plasma adjacent to the active electrode(s), and to volumetrically remove or ablate at least a portion of the target tissue. The high frequency voltage generates electric fields around the active electrode(s) with sufficient energy to ionize the conductive fluid adjacent to the active electrode(s). Within the ionized gas or plasma, free electrons are accelerated, and electron-atoms collisions liberate more electrons, and the process cascades until the plasma contains sufficient energy to break apart the tissue molecules, causing molecular dissociation and ablation of the target tissue.