Abstract: A catheter carries a functional component, like an ablating electrode, having a predetermined operating characteristic. The catheter also electronically retains an identification code that uniquely identifies the predetermined operating characteristic. The catheter is capable of transmitting the identification code to an external reader in response to a predetermined prompt. An associated apparatus, like an ablating energy source, reads the identification code and compares it to predetermined operating criteria. The apparatus will not permit interaction with the functional catheter component, if the identification code indicates that the functional characteristics of the catheter are not suited for the intended interaction. The catheter can also store usage information, to prevent reuse.

Abstract: An ultrasound transducer device is disclosed which is intended to be used for continuous imaging of a patient's heart or other body organs for diagnosis or monitoring. The device consists of a spherical transducer assembly held by a patch which is coated with adhesive for attaching to the body surface of a patient. Provision is made for the manual adjustment of the orientation of the transducer assembly while in place on a patient to adjust the area scanned by the transducer. An alternate embodiment of the device discloses provision for remote controlled adjustment of the transducer assembly orientation.

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 blood pressure monitor for determining a patient's blood pressure comprises a processor attached to a first input device for receiving an initial input representing the patient's absolute blood pressure, and a noninvasive sensor attached to the patient for measuring at least one physiological function. The processor executes a procedure for evaluating the initial input and the sensed physiological function to determine the patient's blood pressure. A method for determining a patient's blood pressure comprises the steps of storing an initial input representing a patient's absolute blood pressure, noninvasively sensing at least one of the patient's physiological functions, and evaluating the initial input and the sensed input to determine the patient's blood pressure.

Abstract: A series of devices for in vivo imaging of cellular architecture in a variety of tissues. A 200 MHz transducer is mounted on the tip of a cardiac catheter, gastroscope, colonoscope, bronchoscope, laparoscope or similar device, where it is moved mechanically to produce B-mode images of cells in the tissue. The ultrasound beam is focused in a subsurface region of tissue, and ultrasound which is backscattered from the focal zone is analyzed to produce images. Because heart motion may interfere with cardiac imaging, images are gated in mid-diastole for cardiac applications.

Abstract: A method and an apparatus for delivering controlled heat independently on separate channels to perform ablation to treat benign prosthetic hypertrophy or hyperplasia (BPH). The dual channel power system provides independent control of radio frequency energy to each of two stylets protruding from a catheter into a human prostate through the urethra. The energy is independently transferred directly into the respective tissue around the stylets in such a manner as to provide respective tissue ablation without damage to surrounding tissues. Automatic shut-off of both channels occurs when any one of a number of surrounding areas to include the urethra or surrounding mass or the adjacent organs exceeds predetermined safe temperature limits. Automatic shut off of the individual channels occurs when the temperature of the tissue proximal to the respective stylet exceeds respective predetermined values.

Abstract: An ablation electrode carries a temperature sensing element for measuring the temperature of the tissue being ablated. A thermal insulating element associated with the sensing element blocks the transfer of heat energy from between the temperature sensing element and the body. The temperature sensing element therefore measures temperature without being affected by the surrounding thermal mass of the electrode.

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 method and an apparatus for selectively coagulating blood vessels or tissue containing blood vessels involves the placement of the blood vessels or tissue containing blood vessels between the prongs of a forceps with the jaws of the forceps containing a plurality of electrodes which are energized by radio-frequency power. A plurality of sensors are associated with the electrodes and in contact with the vessels or tissue in order to measure the temperature rise of the tissue or blood vessels and to provide a feedback to the radio-frequency power in order to control the heating to perform coagulation of the vessels or tissue. In a further development, the upper prong of the device is split into two parts with a cutting blade between the two upper parts in order to provide for cutting of the coagulated vessels subsequent to the coagulation. The cutting may be accomplished either mechanically or with an electrosurgical cutting device.

Abstract: Systems for ablating tissue control radiofrequency power to an ablation electrode by relying upon actual phase sensitive power measurements, unaffected by phase shifts between radiofrequency voltage and current. The systems also detect these phase differences, if they develop, and integrate this factor in making their control decisions.

Abstract: A combination catheter for both detecting monophasic action potentials and ablating surface tissue in an in vivo heart of a patient is provided. The apparatus includes a catheter probe having a terminal tip portion and an electrode carried on the tip such that a portion of the tip electrode is exposed to ambient. A reference electrode is spaced along the tip from the first electrode for supplying a reference potential signal. An ablating electrode is located adjacent to but electrically insulated from both the tip and reference electrodes for providing electromagnetic energy to the tip. The electrodes are electrically connected to the proximal end of the catheter through individual conductors or wires that run through an insulated cable. An electronic filter is provided to permit the recording of MAPs during ablation without radiofrequency interference. The catheter may also include standard mapping and/or pacing electrodes.

Abstract: A catheter carries a functional component, like an ablating electrode, having a predetermined operating characteristic. The catheter also electronically retains an identification code that uniquely identifies the predetermined operating characteristic. The catheter is capable of transmitting the identification code to an external reader in response to a predetermined prompt. An associated apparatus, like an ablating energy source, reads the identification code and compares it to predetermined operating criteria. The apparatus will not permit interaction with the functional catheter component, if the identification code indicates that the functional characteristics of the catheter are not suited for the intended interaction. The catheter can also store usage information, to prevent reuse.

Abstract: An antenna assembly has an energy propagating region that is encapsulated in a material having a high dielectric constant for minimizing the loss of energy while having a high thermal conductivity for dissipating conductive heat patterns about the energy propagating region.

Abstract: An improved assembly for steering and orienting a functional element at the distal end of a catheter tube holds the functional element with its major axis aligned with the axis of the catheter tube for convenient steering to a tissue site. The mechanism can also pivot the functional element in response to an external force to orient the major axis of the functional element generally parallel to the plane of the tissue site, without bending the catheter tube.

Abstract: An improved assembly for steering and orienting a functional element at the distal end of a catheter tube holds the functional element with its major axis aligned with the axis of the catheter tube for convenient steering to a tissue site. The mechanism can also pivot the functional element in response to an external force to orient the major axis of the functional element generally parallel to the plane of the tissue site, without bending the catheter tube.

Abstract: A coaxial antenna assembly conducts a pressurized medium for absorbing heat along the coaxial cable.

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: Diseased tissue such as cirrhotic liver is differentiated from normal tissue by applying an ultrasound wave to the tissue, receiving backscattered ultrasound waves therefrom and bandpass filtering electrical signals generated from the backscattered wave. Assuming that the ultrasound wave has a spectrum and a center frequency, the bandpass is narrow relative to the spectrum and centered within the bounds of the spectrum of the ultrasound wave. The filtered signal will have an amplitude distribution for diseased tissue which is different from the amplitude distribution of normal tissue.

Abstract: For non-invasive diagnosis of conditions subsequent to a medical operative procedure, at the time of operation a "target" is sutured to tissue. Later, by use of an ultrasonic imaging system or other diagnostic instrument, the location of the target can be accurately determined. Thereupon, non-invasive techniques may be used in the target area to determine changes in physiology subsequent to implanting the target. For example, a target consisting of a fused array of small stainless steel balls is sutured to a coronary artery bypass graft. Later, to determine if the bypass graft is patent, by ultrasonic methods the location of the target and hence the bypass graft is determined. Then, using a Doppler-effect flowmeter, flow through the bypass graft may be measured and compared with prior measurements. The marking technique is also believed to be useful in postoperative determination of tumor growth at the locus of said marker.