Abstract: An electrode catheter is provided for ablation of arrhythmogenic tissue in a malperforming heart and includes an elongated catheter tube having longitudinally spaced apart proximal and distal ends. At least one electrode for ablation of the arrhythmogenic tissue in a targeted region of the patient is carried on the catheter tube, preferable at or proximate the distal end of the catheter tube. One such electrode may be located at the distal tip of the catheter and configured in the shape of a generally flat disk that substantially conforms to the contour of the targeted region and such that the ratio of the surface area of the tissue-contacting end face to that of a side wall portion of the electrode is greater than 1.0.

Abstract: An endometrial ablation apparatus and method wherein an RF current having a frequency of between 250 kHz and 100 MHz is passed through the entire surface of an endometrium in order to provide heating of the endometrium. An electroconductive expandable member such as a balloon is used as the medium for passing the current and causing the heating of the endometrium. The temperature of the endometrium is raised to a temperature between 45.degree. C. and 90.degree. C. and preferably not above 70.degree. for a time sufficient to destroy the cells of the lining while maintaining the average temperature of the myometrium at a temperature below approximately 42.degree. C. The expandable balloon is connected to a power source which provides the radio frequency power having the desired characteristics to selectively heat the endometrial lining to the desired temperature.

Abstract: A catheter for radio frequency ablation with a cooled electrode for use in tissue having a surface comprising an elongate member having proximal and distal extremities. A metal conducting electrode secured to the distal extremity of the elongate member and having a chamber therein. A conductor extends through the elongate member from the proximal to the distal extremity for supplying radio frequency energy to the electrode. The elongate member has a lumen in the distal extremity which is in communication with the chamber. A coolant is disposed in the chamber and in contact with the electrode for dissipating heat created in the electrode by the application of radio frequency energy thereto.

Abstract: A catheter for use in an electrophysiological procedure to ablate a site includes a metallic tip having a first work function and energized by a source of RF energy. The RF energy return path is through a relatively large plate of a metallic material having a second work function and disposed at a location removed from the ablation site. The difference in work functions of the tip and the plate, operating in the presence of an electrolyte represented by the intermediate tissue, produces an exchange of electrical charges through chemical reaction to create a galvanic cell. By loading the galvanic cell with a shunt resistor, it becomes a current source providing a current linear with and highly dependent on the tissue temperature at the ablation site. This accurate representation of the tissue temperature at the ablation site is used to regulate the RF energy applied to maintain the tissue at the ablation site at a predetermined temperature during the ablation procedure.

Abstract: A method of locating infarcted myocardial tissue in a beating heart includes the step of inserting an impedance measuring tip of a catheter into the chamber of the beating heart, particularly the left or right ventricle, and measuring the impedance of the endocardium at various locations within the chamber of the beating heart. The values measured are compared to impedance values with a predetermined range of values to identify an infarcted area of myocardium and distinguish such area from normal myocardium. The measurements are also compared to a range of values for an infarction border zone. In accordance with the invention, the infarction border zone may be located. The infarction border zone is a significant source of arrhythmia, and particularly of ventricular tachycardia.

Abstract: A catheter for radio frequency ablation with a cooled electrode for use in tissue having a surface comprising an elongate member having proximal and distal extremities. A metal conducting electrode secured to the distal extremity of the elongate member and having a chamber therein. A conductor extends through the elongate member from the proximal to the distal extremity for supplying radio frequency energy to the electrode. The elongate member has a lumen in the distal extremity which is in communication with the chamber. A coolant is disposed in the chamber and in contact with the electrode for dissipating heat created in the electrode by the application of radio frequency energy thereto.

Abstract: Apparatus and methods are provided for performing an in situ characterization of a tissue mass which may be normal, malignant, or benign, and, based on the measured characteristics of the tissue mass, therapeutically treating the tissue mass to cause necrosis of the tissue. In an illustrative preferred embodiment, the characterization of the tissue is accomplished by measuring an electrical property of the tissue, such as electrical impedance, while treatment is accomplished by supplying heat to the tissue to induce cauterization.

Abstract: A method and apparatus for ablation of body tissue. A catheter provided with a hollow needle is employed both for mapping the location to be ablated by injection of an excitability reducing agent and for ablating tissue, employing RF energy in conjunction with an injected, conductive fluid.

Abstract: The invention relates to a catheter comprising a tubular body with a distal end. A proximal catheter end is provided with a connector. A flexible catheter section is defined at the distal end. The wall of the flexible section comprises an elongated, flexible heating element extending in the longitudinal direction of the catheter, wherein at least one electric conductor for the heating element extends from the heating element to adjacent the proximal end. The heating element is preferably an element which can be exited by high frequency electromagnetic oscillations.

Abstract: A system for checking the initial calibration of a temperature measuring device that provides a temperature measuring signal in a catheter includes a comparison unit for comparing the magnitude of the temperature signal to a reference value indicating the normal body temperature of the patient. The treatment procedure is disabled if the magnitude of the temperature signal is not within a predetermined range of the reference value.

Abstract: A method of ablating tissue in the heart to treat atrial fibrillation introduces into a selected atrium an energy emitting element. The method exposes the element to a region of the atrial wall and applies ablating energy to the element to thermally destroy tissue. The method forms a convoluted lesion pattern comprising elongated straight lesions and elongated curvilinear lesions. The lesion pattern directs electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation. The method emulates the surgical maze procedure, but lends itself to catheter-based procedures that do not require open heart surgical techniques. A composite structure for performing the method is formed using a template that displays in planar view a desired lesion pattern for the tissue. An array of spaced apart element is laid on the template.

Abstract: This continuation-in-part patent application follows the original parent patent application which described a general method of denervation of the nerves in and around the intervertebral disc to relieve back pain using heating from a probe which is inserted within the intervertebral disc. The probe in the original application can be connected to a power source to deliver energy to the disc, thereby heating the disc and denervating the nerves associated with the disc, with consequent relief of various kinds of discogenic pain. This continuation-in-part illustrates other embodiments of the invention described in the parent patent application. In particular, it describes other embodiments of heating methods to denervate the disc, as well as thermal cooling or cryogenic methods to denervate the disc. These methods can be either percutaneous or carried out during open interoperative intervention of the disc.

Abstract: An apparatus and method are provided for control contraction of tissue that includes collagen fibers. The apparatus includes a handpiece, and an electrode with an electrode proximal end associated with the handpiece. A distal end of the electrode has a geometry that delivers a controlled amount of energy to the tissue for a desired contraction of the collagen fibers. This is achieved while dissociation and breakdown of the collagen fibers is minimized. The handpiece, with electrode, is adapted to be introduced through an operating cannula in percutaneous applications. Additionally, an operating cannula may be included in the apparatus and be attached to the handpiece. The apparatus and method provides for a desired level of contraction of collagen soft tissue without dissociation or breakdown of collagen fibers.

Abstract: An endometrial ablation device and a method of manufacturing and using the device. An RF current is passed through an endometrium to heat it. An electroconductive expandable member such as a balloon is used as the medium for passing the current and causing the heating of the endometrium. The power delivered from a power source to the balloon is selectively provided to a plurality of electrode area segments on the balloon with each of the segments have a thermistor associated with it whereby temperature is monitored and controlled by a feedback arrangement from the thermistors. The selective application of power is provided on the basis of a switching arrangement which provides either monopolar or bipolar energy to the electrodes. The method of manufacturing the ablation device includes using commercially available stretchable sheet material or providing a mandrel or support base and coating the mandrel or base with an uncured emulsion. The emulsion is then cured to form a bladder-like coating.

Abstract: A method of locating infarcted myocardial tissue in a beating heart includes the step of inserting an impedance measuring tip of a catheter into the chamber of the beating heart, particularly the left or right ventricle, and measuring the impedance of the endocardium at various locations within the chamber of the beating heart. The values measured are compared to impedance values with a predetermined range of values to identify an infarcted area of myocardium and distinguish such area from normal myocardium. The measurements are also compared to a range of values for an infarction border zone. In accordance with the invention, the infarction border zone may be located. The infarction border zone is a significant source of arrhythmia, and particularly of ventricular tachycardia.

Abstract: Systems and methods form curvilinear lesions in tissue within the body. The systems and methods expose tissue to electrode arrays with intersecting energy emitting elements. The systems and methods apply ablating energy for emission by the elements to create intersecting curvilinear lesion patterns in the tissue.

Abstract: A catheter for radio frequent ablation of tissue which includes a flexible elongate member having proximal and distal extremities. The flexible elongate member is provided with a lumen in the distal extremity. A metal conducting electrode is secured to the distal extremity of the elongate member and has first and second extremities. The electrode is provided with a chamber therein which is in communication with the lumen. A conductor extends through the elongate member from the proximal to distal extremities for supplying radio frequency energy to the electrode. Coolant is disposed in the chamber and in contact with the electrode for dissipating heat created in the electrode by the application of radio frequency energy thereto. A sleeve made from an electrically insulating material extends over at least the first extremity of the electrode.

Abstract: A device for ablating tissue within the body has an element with an energy emitting region helically wound about and along the axis of the element. The element emits energy to create a lesion in body tissue. A sheath of a non-energy emitting material is movable over the region to adjust the impedance of the region.

Abstract: Presbyopia and hyperopia are treated by a method which increases the amplitude of accommodation by increasing the effective working distance of the ciliary muscle in the presbyopic eye. The effective working distance of the ciliary muscle can be increased by expanding the sclera in the region of the ciliary body. This expansion is accomplished by suturing to the sclera a relatively rigid band having a diameter slightly greater than that of the sclera in the region of the ciliary body, by weakening the sclera overlying the ciliary body, by surgical procedures or treatment with enzymes, heat or radiation, whereby intraocular pressure expands the weakened sclera, or by surgical alloplasty. The effective working distance of the ciliary muscle can also be increased by shortening the zonules by application of heat or radiation, by repositioning one or both insertions of the ciliary muscle or by shortening the ciliary muscle.

Abstract: A cardiovascular electrode catheter for use in arrhythmia ablation procedures has a dumbbell-shaped large-tip electrode having an annular recess or indentation. The annular recess divides the electrode into a ball-shaped distal portion and a generally cylindrical proximal portion. Both the distal and proximal portions of the electrode have a diameter substantially the same as that of the catheter body. The recess enables the electrode to grip the mitral or tricuspid annulus or the atrial or ventricular myocardial wall to improve ablation procedures.

Abstract: A recording and ablation catheter system for creating linear lesions in the right atrial chamber of a heart is disclosed which includes an array of readily controlled electroded arcuate distal working catheter shapes that are easily deployed to contact the inner wall surface of the right atrial cardiac chamber in a manner that enables easy recording and mapping of impulses and thereafter facilitates sustained contact so that linear lesions can be produced from an array of mapping and ablation electrode devices serially spaced along the working catheter shape.

Abstract: An apparatus is provided for treating cutaneous vascular lesions in a target area of a patient. The apparatus has a lower housing having a bottom with an opening therethrough, and an upper housing adapted to be connected in liquid tight engagement to the lower housing. The upper housing has a top with an opening therethrough and substantially in alignment with the opening of the lower housing. A pair of glass windows are provided one positioned in the opening of the lower housing, and the other positioned in the opening of the upper housing. The apparatus further comprises at least one fenestrated wall adapted to be removably positioned in the lower housing to form a first and a second chamber when the upper and lower housings are connected together. The first chamber is adapted to receive a cooling medium, and the second chamber prevents the cooling medium from obstructing the passage of a laser beam between the pair of glass windows.

Abstract: A mapping and ablation distal vascular catheter arrangement is disclosed which is suitable for association with a vascular catheter system and which includes a segmented mapping/ablation electrode system in which the lesion size including length, width and depth is made flexible and the ability to discretely map localized electrical activity using the same is preserved. The electrode system includes a plurality of serially spaced individual electrodes on the surface of a distal working catheter area which can be utilized together to produce the effect of an elongated segmented ablation electrode or individually utilized to map local electrical activity. A control system or device is provided that allows the individual electrodes to be connected to one or more receiving/recording/display devices in any desired pattern. That is, recording or mapping may be conducted using any configuration of electrodes for receiving signals.

Abstract: A method of locating infarcted myocardial tissue in a beating heart includes the step of inserting an impedance measuring tip of a catheter into the chamber of the beating heart, particularly the left or right ventricle, and measuring the impedance of the endocardium at various locations within the chamber of the beating heart. The values measured are compared to impedance values with a predetermined range of values to identify an infarcted area of myocardium and distinguish such area from normal myocardium. The measurements are also compared to a range of values for an infarction border zone. In accordance with the invention, the infarction border zone may be located. The infarction border zone is a significant source of arrhythmia, and particularly of ventricular tachycardia.

Abstract: An endometrial ablation apparatus and method wherein an RF current having a frequency of between 250 kHz and 100 MHz is passed through the entire surface of an endometrium in order to provide heating of the endometrium. An electroconductive expandable member such as a balloon is used as the medium for passing the current and causing the heating of the endometrium. The temperature of the endometrium is raised to a temperature between 45.degree. C. and 90.degree. C. and preferably not above 70.degree. for a time sufficient to destroy the cells of the lining while maintaining the average temperature of the myometrium at a temperature below approximately 42.degree. C. The expandable balloon is connected to a power source which provides the radio frequency power having the desired characteristics to selectively heat the endometrial lining to the desired temperature.

Abstract: The present invention relates to a technique of relieving back pain by heating of an intervertebral disc. The heating is illustrated by a percutaneous technique where a needle or electrode is inserted into the disc under X-ray or other imaging control and subsequently used to elevate the temperature of the disc. Above a certain temperature, the innervation related to the disc is destroyed to the point that back pain related to that innervation can also be eliminated. Specific examples of methods and apparatus to achieve such disc heating are given. Among the methods are use of radiofrequency heating and direct current heating, use of stimulation and impedance monitoring to improve target control, and the use of temperature monitoring to determine and quantify the appropriate disc temperature to achieve the desired clinical results.

Abstract: A catheter for radio frequency ablation with a cooled electrode for use in tissue having a surface comprising an elongate member having proximal and distal extremities. A metal conducting electrode secured to the distal extremity of the elongate member and having a chamber therein. A conductor extends through the elongate member from the proximal to the distal extremity for supplying radio frequency energy to the electrode. The elongate member has a lumen in the distal extremity which is in communication with the chamber. A coolant is disposed in the chamber and in contact with the electrode for dissipating heat created in the electrode by the application of radio frequency energy thereto.

Abstract: A medical probe device for reducing tissue mass in a selected portion of the body comprises a torquable catheter having a control end and a probe end. The probe end includes a stylet guide means with a flexible tip and a tip directing means extending from the control end to the flexible tip for changing the orientation of the central axis of the stylet guide means for directing a flexible stylet outward through the stylet port and through intervening tissue to targeted tissues. A stylet is positioned in the said stylet guide means. The stylet can be an RF electrode, microwave antenna, biopsy means, fluid supply means or combination thereof. Preferably, the stylet is a non-conductive sleeve having an electrode lumen and a second lumen therein, the electrode lumen terminating at a distal port in the distal end of the non-conductive sleeve, a radiofrequency electrode being positioned in said electrode lumen for longitudinal movement therein through the distal port.

Abstract: A medical probe device comprises a catheter having a stylet guide housing with one or more stylet ports in a side wall thereof and guide means for directing a flexible stylet outward through the stylet port and through intervening tissue at a preselected, adjustable angle to a target tissue. The total catheter assembly includes a stylet guide lumen communicating with the stylet port and a stylet positioned in said stylet guide lumen for longitudinal movement from the port through intervening tissue to a target tissue. The style can be an electrical conductor enclosed within a non-conductive layer, the electrical conductor being a radiofrequency electrode. Preferably, the non-conductive layer is a sleeve which is axially moveable on the electrical conductor to expose a selected portion of the electrical conductor surface in the target tissue. The stylet can also be a microwave antenna. The stylet can also be a hollow tube for delivering treatment fluid to the target tissue.

Abstract: A catheter for radio frequency ablation with a cooled electrode for use in tissue having a surface comprising an elongate member having proximal and distal extremities. A metal conducting electrode secured to the distal extremity of the elongate member and having a chamber therein. A conductor extends through the elongate member from the proximal to the distal extremity for supplying radio frequency energy to the electrode. The elongate member has a lumen in the distal extremity which is in communication with the chamber. A coolant is disposed in the chamber and in contact with the electrode for dissipating heat created in the electrode by the application of radio frequency energy thereto.

Abstract: An apparatus and method for performing diagnostics and intravascular therapies. A guidewire anemometer can be used to measure the velocity of fluid flowing through the vasculature. An in-line anemometer can be used to measure the volumetric flow rate of fluid transported out of a patient's body. A heated balloon catheter can be used to deliver heat therapy no a vessel wall in a patient's vasculature.

Abstract: A thin, elongate and flexible ablation catheter, suitable for delivery to an internal organ, comprises a fluid delivery lumen centrally located within the catheter, and first and second electrodes disposed on an outer surface of the catheter. The electrodes preferably are helically oriented about the catheter. At least one of the electrodes is in communication with a source of electrosurgical energy so as to deliver ablative electrosurgical energy to tissue. The lumen communicates with a fluid supply source such that fluid is conveyed through the lumen and is discharged to adjacent tissue during the delivery of ablative energy. The fluid delivered through the lumen assists in optimizing the electrode temperature. A method and apparatus is also provided to regulate the fluid flow rate based on monitored electrode temperature and/or tissue impedance.

Abstract: Intravesical electromotive administration of specified dye substances for localisation and treatment of occult bladder cancers, is disclosed. Innocuous dye substances will provide differential staining of cancerous and normal urothelium; and anticancer dye substances will demonstrate differential staining and also initiate therapy of cancerous lesions. The addition of vasodilating agents will accentuate the differential staining and further promote therapy of the cancerous sites.

Abstract: An endometrial ablation method comprising passing sufficient RF current having a frequency of from 250 kHz to about 100 MHz through substantially the entire surface of the endometrium to heat the endometrium, in a single operation, to a temperature within the range of from 45.degree. C. to 90.degree. C. and preferably not above 70.degree. C. for a time sufficient to destroy the cells of the lining while maintaining the average temperature of the myometrium at a temperature below about 42.degree. C. The apparatus comprises a electroconductive expandable member such as a balloon for extending the organ and effecting electrical contact with the endometrial lining to be destroyed. The balloon is connected to a power source adapted to provide radiofrequency electric power having the desired characteristics to selectively heat the endometrial lining to the desired temperature. The balloon can be an electroconductive elastomer such as a mixture of a polymeric elastomer and electroconductive particles.

Abstract: A urethral inserted applicator for prostate hyperthermia includes a multi-tube, balloon type catheter. The catheter includes first and second closed end fluid dry tubes, respectively, for a helical coil electrode type applicator, and an electromagnetic field compatible temperature sensor for measuring the temperature of the prostate tissue, and an open fluid receiving tube enabling urine drainage from the bladder. A radiofrequency source supplies electromagnetic energy to the applicator. A control unit contains a comparator which is connected to the temperature sensor and a temperature reference device for comparing the actual tissue temperature level with a desired temperature level and output control signals to the radiofrequency generator for controlling the output to the applicator. The coil type applicator is an elongated coil connected to the center conductor of a coaxial cable.