Abstract: A method of treatment of tissue with focussed ultrasound comprises placing adjacent the tissue to be treated a reflector of ultrasound or an ultrasound energy conversion device which converts received ultrasound energy to heat, stores the heat and then releases the heat over time into the tissue to be treated. An ultrasound transducer is then oriented with its focal point adjacent the reflector or ultrasound energy conversion device. The tissue is then irradiated with high intensity focussed ultrasound while the reflector or ultrasound energy conversion device is in place.

Abstract: A catheter assembly comprises a stylus including a first generally conically shaped end tapering to a point at a predetermined angle and a second end. A cannula includes a first lumen for slidably receiving the stylus. The cannula includes a first end having an end wall and a second end. A catheter includes a second lumen for slidably receiving the cannula, a first end and a second end. The first end of the catheter includes an end wall having an outer surface tapered at the predetermined angle and an inner surface. The stylus, cannula, and catheter are configured so that the stylus, cannula, and catheter are aligned when the stylus, cannula and catheter are assembled for insertion into a patient's body.

Abstract: An apparatus and a method for non-invasively decomposing a calculus in a human body include a mechanism for, and the step of, locating the calculus, a mechanism for, and the step of, delivering to the site of the calculus a chemical species known to reduce the calculus, and a mechanism for, and the step of, generating an unfocussed beam of ultrasound radiation for insonating the calculus for enhancing the chemical dissolution of the calculus through the interaction of the calculus, the chemical species and the ultrasound radiation.

Abstract: A method and an apparatus for ultrasound imaging at different frequencies using a single ultrasound transducer. The transducer has a single characteristic frequency. The method and apparatus involve driving the transducer with pulses having different rise times through different coupling circuits having different impedance characteristics. Between pulses, the same transducer and coupling circuit which were used during the pulse transmission "listen" for echoes from the structure being ultrasonically investigated. It is believed that the combination of different pulses having different rise times and different coupling circuits having different characteristics enhances different ones of the frequencies contained in the Fourier spectrum of the driving pulse and suppresses others. This enables the operator to investigate a structure ultrasonically with a single transducer at different frequencies which illuminate different characteristics of the structure to greatest advantage.

Abstract: An improved composition for dissolution of renal calculi is disclosed. The composition includes citric acid, preferably at about 10 to about 15% by weight, and an effective amount of a pharmacologically acceptable chelating agent such as EDTA in a sterile aqueous solution having a pH between about 3 and about 4.5. In vivo irrigation with the improved formulation, optionally in combination with incident ultrasound therapy promotes rapid stone dissolution with minimal complications for the patient.

Abstract: It has been observed that attenuation of a transmitted or reflected beam of ultrasound in tissue irradiated with such a beam having a power intensity in the tissue in the non-linear range will change measurably as the tissue temperature changes. Based upon this observation, a method and apparatus for non-invasive thermometry include periodically interrogating the tissue with an ultrasonic beam having a power intensity sufficient such that the power intensity of the beam in the tissue is in the non-linear range. Attenuation coefficients based upon the attenuation of the power intensity of the ultrasonic beam due to the tissue are then periodically determined. Temperature changes in the tissue are determined based upon differences between the determined attenuation coefficients.

Abstract: A method is provided for enhancing ultrasound detection of implantable or insertable devices which can be placed in bodies. The method includes the steps of providing a space in the device having a substantially gas-impermeable wall, and filling the space with a gas. A medically implantable or insertable device having an enhanced ultrasound detectability is also provided. The device includes a substantially gas-impermeable portion which defines a space. The space is filled with a gas or mixture of gases to enhance ultrasound detection, and determination of the location of the device.

Abstract: A heat-sterilizable ultrasonic surgical scanner includes an ultrasonic transducer and a permanent magnet motor for moving the transducer along an arcuate path. The scanner further includes a housing for the ultrasonic transducer and the motor. The housing includes an acoustically transparent window for transmitting ultrasonic energy from and into the housing. A resilient diaphragm permits expension and contraction of a coupling fluid with which the housing is filled without causing fluid loss from the housing due to leakage. The resilient diaphragm is mounted at a location remote from the acoustically transparent window.

Abstract: A puncturing device for insertion into the body, which has an ultrasonically coded displacement scale of gaseous inclusions regularly spaced along the length of the device. Owing to the acoustic reflectiveness of the gaseous inclusions, the precise location of the puncturing device can be directly and readily detected by an ultrasound visualization system. The acoustically reflective displacement scale enables the calibration of distances to be made directly from the ultrasound viewing screen. Located at the tip of the puncturing device is a gaseous inclusion which reveals the precise location of the tip of the device in the body.

Abstract: A heat-sterilizable ultrasonic surgical scanner includes an ultrasonic transducer and a permanent magnet motor for moving the transducer along an arcuate path. The scanner further includes a housing for the ultrasonic transducer and the motor. The housing includes an acoustically transparent window for transmitting ultrasonic energy from and into the housing. A resilient diaphragm permits expansion and contraction of a coupling fluid with which the housing is filled without causing fluid loss from the housing due to leakage. The resilient diaphragm is mounted at a location remote from the acoustically transparent window.

Abstract: A system for driving an ultrasonic transducer for use in ultrasound imaging of a target includes a charging voltage generator, a first impedance for coupling the charging voltage generator to a terminal of the transducer to permit the transducer to charge sufficiently slowly from the charging voltage source so that charging strain is not coupled from the transducer to the target, and a switch coupled to the transducer. Closing of the switch permits the transducer to discharge sufficiently rapidly that discharging strain is coupled from the transducer to the target. A system for processing return echoes includes a return echo-related signal processor. The return echoes impinge upon, and cause voltage signal related to the return echoes to appear across the terminals of, the transducer.

Abstract: The present invention relates to an ultrasound visualization system which has a capability of microscopic examination of tissue within the body without the need for removal of the tissue. A transducer, capable of producing and receiving high frequency acoustical beams is positioned within a needle. The acoustical beams are directed radially from the needle and are focused on a point which is outside of the needle and in the tissue. The microscope can be operated in either the pulse echo or pulse reflection mode. The needle can be inserted into a patient, and the acoustical beams are scanned to produce highly magnified images of cellular features of internal tissue or features of tissue architecture and structure helpful to the determination of tissue pathology.

Abstract: A digital video image splitter permits the top portion of a closed-circuit television (CCTV) display to be shifted right (delayed) or left (advanced) with respect to the stationary bottom portion of the display. The user controls the vertical level (distance from top to bottom of display) at which the split is seen on the display, and the amount of shift from controls in the system. Shifting of the image permits the width of an object displayed on the display to be measured. By matching opposite edges of the object in the display, the width of the displayed object is equal to the amount of shift. A single raster line at the level of the split is available as digitized image intensity data, and represents the intensity profile of the video display, including the object being measured, along that raster line.

Abstract: A direct water coupling device for ultrasound scanning of the human breast in a supine position. A tank, which has an open top and an open bottom and has a bottom edge which is shaped so as to conform to the shape of a human body about the perimeter of the breast area, is placed in a sealed position about the breast while the patient is in a supine position. A strapping apparatus maintains the device in position while the tank is filled with water and the ultrasound scan is performed.

Abstract: A method and apparatus employing zero order Raman-Nath diffraction information to visualize the longitudinal character of an acoustic field. The method includes the steps of directing a first portion of a beam of coherent light at normal incidence to a reflective mirror, propogating an acoustic field within a medium to interact with the first portion of the beam, detecting signals derived from the acousto-optical interaction from which phase change and amplitude change information in the reflected zero order diffraction component of the laser beam can be derived after its return pass through the acoustic field and then generating a two-dimensional raster scan representation of the acoustic field from the detected light signals.

Abstract: The activity of conventional iron-based ammonia synthesis catalysts is enhanced by supplying alkali to the finished catalyst by vapor transpiration, either during preparation of the catalyst or during its use in synthesis operation, or during both. The catalyst used may contain one or more conventional promoters, including alkali embodied in the catalyst during its manufacture. The vapor transpiration provides increased effective alkali at the catalyst surfaces in the form of a inorganic compound, such as the hydroxide or carbonate or hydride. It avoids the problem of loss of surface area which would result from adding more alkali during manufacture of the catalyst. Vapor transpiration conditions, especially the relative temperatures of the vaporization chamber and hence the alkali vapor partial pressure in the catalyst chamber, are controlled to achieve an effective deposition while avoiding pore blockage or reduction of surface area.

Abstract: A digital electronic system for improving the resolution of dynamic range-handling capacity for received ultrasound in reflection or transmission imaging systems. This system provides a means for preventing loss of structural detail in the display by minimizing the overlapping of signals resulting from the transducer bandwidth and pulse length. It also makes use of a (positive or negative) peak detector to recognize and print as a single point the presence of point targets. With the present technology, a point target may be represented in a B-mode display on several successive scan lines resulting in an abnormally large representation on the display. The actual target is represented by the peak point of the envelope of a series of scan lines in which the point target is displayed. The objective is to print only one point which corresponds with the actual position of the point target with an intensity that corresponds to the intensity of the received signal.

Abstract: A dental x-ray aligning system in which various Hall effect sensors, mounted on a dental x-ray apparatus, detect the magnetic field strength resulting from a magnet which is attached to an x-ray film plate located within the mouth of a patient. By measuring and comparing the relative magnetic field strengths, the present invention can indicate when the dental x-ray apparatus is properly aligned, and can also indicate the direction in which the apparatus should be moved to obtain alignment, and the distance between the apparatus and the film plate. The present invention also includes means for adjusting the collimation of the dental x-ray apparatus.

Abstract: A digital electronic system for improving the resolution and dynamic range-handling capacity for received ultrasound in reflection or transmission imaging system. This system provides a means for preventing loss of structural detail in the display by minimizing the overlapping of signals resulting from the transducer bandwidth and pulse length. It also makes use of a (positive or negative) peak detector to recognize and print as a single point the presence of point targets. With the present technology, a point target may be represented in a B-mode display on several successive scan lines resulting in an abnormally large representation on the display. The actual target is represented by the peak point of the envelope of a series of scan lines in which the point target is displayed. The objective is to print only one point which corresponds with the actual position of the point target and with an intensity that corresponds to the intensity of the received signal.

Abstract: An anchor incorporating an arrangement for releasing the anchor when it becomes snagged on large rocks or other objects. One embodiment includes a blocking element which is positioned in the elongated anchor body to prevent the anchor arms from moving out of a radially extending position to a position in which they extend longitudinally of the body. The blocking element is spring biased into its blocking position and has a sleeve thereon which is also spring biased to a position wherein the sleeve holds the anchor arms away from the blocking element. A sharp jerk on the anchor line causes the blocking element to move in the elongated anchor body out of blocking position releasing the anchor. Another embodiment includes a blocking element similarly positioned in an elongated anchor body. A striker element is mounted on the anchor body and connected to the anchor line and is spring biased to a position spaced from the blocking element.