Abstract: A handheld acoustic shock wave or pressure pulse applicator device has a body structure and an applicator head. The body structure has a proximal end and a distal end with a longitudinal axis extending between the ends. The applicator head is at the distal end. the head emits pressure pulses or shock waves at an inclined angle relative to the longitudinal axis of the body structure. The applicator head has a balloon or lens or membrane through which the emitted pressure pulses or shock waves pass. The lens or membrane is configured to be coupled directly or indirectly to an exposed soft tissue surface of a palate inside a patient's mouth to direct emitted pressure pulses or shock waves to the brain. The applicator device can be configured with the inclined obtuse angle fixed between 150 degrees and 90 degrees or can be adjustable between 180 degrees and 90 degrees.

Abstract: A valvuloplasty system comprises a balloon adapted to be placed adjacent leaflets of a valve. The balloon is inflatable with a liquid. The system further includes a shock wave generator within the balloon that produces shock waves. The shock waves propagate through the liquid and impinge upon the valve to decalcify and open the valve.

Abstract: A bipolar ionization device in which fiberglass is used as the dielectric. In one embodiment, a fiberglass board is used, with the anode on one side of the board and the cathode on the other side of the board. A number of flat boards can be stacked, with spacing between them to allow air flow to scavenge ions, with stanchions providing both mounting and electrical connections to the ionization devices. In another embodiment, a fiberglass tube is used, with the cathode inside the tube and the anode outside the tube.

Abstract: An electrohydraulic shock-wave therapy apparatus comprising a variable voltage source and a controller that controls the voltage source for accurate adjustment of the shock wave pressure. The invention, in various embodiments, also includes various methods, optionally closed loop as well as open loop based, for determining the shock pressure while compensating for burnout and or erosion that normally suppress the pressure after some thousands of sparks. This way the effective lifetime of the electrodes is dramatically extended. The control is further used for significantly increasing the effective therapeutic area of the apparatus by adjusting the shock pressure value close to the maximal safe value.

Abstract: A method for operating an impulsive type seismic energy source in a firing sequence having at least two actuations for each seismic impulse to be generated by the source. The actuations have a time delay between them related to a selected energy frequency peak of the source output. One example of the method is used for generating seismic signals in a wellbore and includes discharging electric current through a spark gap disposed in the wellbore in at least one firing sequence. The sequence includes at least two actuations of the spark gap separated by an amount of time selected to cause acoustic energy resulting from the actuations to have peak amplitude at a selected frequency.

Abstract: A wellbore seismic source includes a sparker electrically coupled to a power source. The sparker is disposed in a pressure-sealed canister, wherein the canister is at least partially filled with liquid. At least one of the pressure of the liquid and the energy discharged by the power source through the sparker is selected to cause emission of acoustic energy at a selected frequency.

Abstract: The generator device is proposed for seabed survey, comprising a generator line, including electrodes, a hoist, hydraulic pump, air compressor, and at least one hose joined to the generator line, situated optionally inside or outside the line. The hose includes a through hydro-channel therein, a stationary end connected to the pump or alternatively to the compressor, and a running end furnished with a discharge valve. Connecting to the compressor ensures positive floatation of the generator line, whereas connecting to the pump ensures negative floatation thereof. In preferred embodiments, the device comprises a hydraulic clutch and a faucet. The hose communicates with the pump and compressor through the clutch and faucet, ensuring alternative communication of the hose's hydro-channel with water or air for filling thereof. The generator line comprises a dipole including one power braiding, and an initial part including two power braidings, the braidings are connected to the electrodes.

Abstract: A device, in particular a therapy device, for the application of acoustic shock waves aimed at a region to be treated in a human or animal body and comprising a housing with a coupling surface for coupling the shock waves into the body to be treated, a shock wave generating device and a means suitable for focusing the shock waves, in which the shock wave generating device and the means suitable for focusing the shock waves are enclosed in a housing and designed such that they can be moved relative to the coupling surface.

Abstract: A wellbore seismic source includes a sparker electrically coupled to a power source. The sparker is disposed in a pressure-sealed canister, wherein the canister is at least partially filled with liquid. At least one of the pressure of the liquid and the energy discharged by the power source through the sparker is selected to cause emission of acoustic energy at a selected frequency.

Abstract: Described is a device for generating an acoustic signal in an electrically conductive medium such as salt water. The device of the present invention has a broadband frequency response and supports high bandwidth data transmission. Reliability is improved in comparison to conventional underwater acoustic transmitters as the device includes no moving components. In one embodiment, the device includes a parallel and alternating arrangement of electrodes and magnets. Neighboring electrodes have different voltages and neighboring magnets have opposite pole configurations such that the magnetic fields overlap the currents between the electrodes in the medium. The currents or the magnetic fields are modulated according to a data signal to generate an acoustic signal in the medium.

Abstract: A method for underwater exploration which makes use of a parabolic transmitter (1) and a parabolic receiver (3), the transmitter (1) and the receiver (3) being both open at their lower side and immersed below the seawater surface. The electric breakdown discharge occurring between both electrodes (15) of the transmitter (1) generates a primary signal and a pulse which is called “cavitation bubble pulse.” The method consists in enhancing the signal (23) produced by the implosion of the cavitation bubble, to the detriment of the primary signal (13?), by appropriately adjusting the value of the “spark gap” (distance d between the electrodes) so as to optimize the delay time (t) and consequently the acoustic efficiency of the transmitter, by transferring the electrostatic energy to the bubble implosion signal.

Abstract: Disclosed is a device for producing an intracorporeal pressure pulse comprising a pressure pulse source configured to generate a collimated pressure pulse and an acoustic lens including at least one ring-shaped focusing section configured to focus a pressure pulse generated by the pressure pulse source substantially to the vicinity of the central axis of the ring-shaped focusing section.

Abstract: A reflector (14) reflects energy emitting from an energy source (16) and focuses and directs it to a target. An aperture stop or suppressor disk (18) is positioned between the energy source (16) and target. The outer periphery of the aperture stop or suppressor disk (18) is an irregular curve (FIGS. 12 and 13). This shape of the periphery prevents diffraction enhancement to the direct wave. In another emobidment, the suppressor disk (18) is replaced by a suppressor member (18?) that is directly mounted on a frame portion of the energy source (16). This energy source (16) includes a spark-gap, or the like, and an open frame (36) that surrounds the spark-gap (52) or the like. This frame (32) includes a pair of laterally spaced apart frame members (42, 44) on the side of the frame (36) that faces the target (F2). The suppressor member (18?) is connected to these frame members (32, 44). It may have longitudinal grooves (48, 50) in its side edges into which the frame members (42, 44) snap-fit.

Abstract: An apparatus for generating an acoustic signal which has a dielectric substrate having opposed first and second sides. A pair of electrodes are mounted on the first surface of the substrate so that the electrodes are spaced apart from each other. A high voltage power source is electrically connected to the electrodes to produce a high voltage electric potential between the electrodes and this high voltage electric potential is less than a level sufficient to create a surface arc discharge along the first surface of the dielectric substrate. An electrical conductor strip is mounted to the second side of the substrate.

Abstract: An acoustic source for infrasonic electromagnetic wave exploration including: an electrically conductive, generally cylindrical tubular member for containing an electrically conductive fluid, the tubular member having a closed top end, an open bottom end, an interior wall and an internal diameter; an electrode axially positioned within the tubular member, wherein the electrode is axially positioned within the tubular member at a distance equivalent to about three times the internal diameter of the tubular member to enable the acoustic source to produce high energy acoustic waves having a substantial portion of acoustic wave energy in the infrasonic frequency range; means for electrically connecting the electrode to the negative electrical pole of an external source of DC electric power; and means for electrically connecting the tubular member to one of: a positive electrical pole of the external source of DC electric power; an electrical ground; and a combination of the above.

Abstract: A non-explosive acoustic source utilizes the combustion of aluminum and water to generate an acoustic pulse. The operation of the non-explosive acoustic source relies on a water/aluminum reaction to generate a burst pressure. The source may be deployed as a single charge or as one element of a multiple charge array and is configurable to explode at variable depths with variable energy levels. The inherent safety of the non-explosive acoustic source obviates the necessity for auxiliary safety features or procedures to protect against inadvertent explosion. As a result, the non-explosive acoustic source facilitates the implementation of sonic detection systems and reduces the operational costs associated with such systems.

Abstract: A pressure-pulse therapy apparatus, including a dome-shaped reflector, at least one ring section, a central x-axis, an open end, a flexible diaphragm capping the open end, a fluid medium within the reflector and diaphragm, a pressure-pulse source immersed in the fluid medium and located on the x-axis for generating a primary pressure pulse, and a power supply for the pressure-pulse source. The reflector includes a center section that has a predetermined first curvature and associated reflective characteristics to reflect the primary pressure pulse to form a first subordinate pressure pulse of a compound pressure pulse. The ring section is substantially concentric with the center section and has a predetermined second curvature and associated reflective characteristics to reflect the primary pressure pulse to form at least one additional subordinate pressure pulse of the compound pressure pulse.

Abstract: An impulsive acoustic and radiation source is provided that maintains a constant electrode gap to provide efficient and long life operation. In one implementation the electrodes have a “toaster” arrangement. In another implementation the electrodes have a double annulus arrangement. The electrode gap may be maintained by interposing a non-electrically conducting material between the electrodes. In another implementation the electrode gap is maintain by the insertion of electrodes into a base. Also, the electrodes may be coated with a non-electrically conduction material. In alternative implementation, efficient and long life operation is achieved by feeding a material between widely spaced electrodes. In certain implementations an exothermic material is fed to increase the strength of the impulse from the sparker. Also, reflectors and enclosures are employed that increase the output utilization of the source.

Abstract: A device for generating shock waves, specifically for medical applications, has electrodes arranged in a liquid medium, a high voltage being applied to the electrodes to generate an electrical breakdown. Particles added in powder form are suspended in the liquid medium. In order to maintain the particles in suspension, a thixotropic additive is added to the liquid medium.

Abstract: A device for generating shock waves, specifically for medical applications, has electrodes arranged in a liquid medium, a high voltage being applied to the electrodes to generate an electrical breakdown. Particles added in powder form are suspended in the liquid medium. In order to maintain the particles in suspension, a thixotropic additive is added to the liquid medium.

Abstract: The thermohydraulic principle is utilized for generating intensive ultrasonic fields. At least two electrodes which enclose a volume with an electrolyte are driven by a power pulse generator. The electrolyte volume to be heated by the electrical pulse is delimited to such an extent that the electrical power to be applied can be controlled by semiconductor switching elements.

Abstract: The present invention relates to a electrode assembly and related method that includes a insulator assembly, an electrode assembly, a charging system, a mechanism for measuring electrical voltages, a mechanism for adjusting the distance between inner and outer electrode tips, and a controller. The insulator assembly includes an insulator body having a hollow central portion with a threaded inner wall. The insulator assembly includes inner and outer conductors that are electrically connected to the charging system and are physically connected to inner and outer electrodes, respectively. The electrodes are positioned such that their longitudinal axes are aligned and the tips of the electrodes are in relatively close physical proximity. The distance between the tips is defined as the spark gap. The charging system charges a capacitor that discharges and forms a spark across the spark gap.

Abstract: A projector (10) for creating electrohydraulic acoustic and pressure waves comprising an energy source (21) (such as a capacitor) within approximately one meter of an electrode array (23). Larger projectors may be formed by arraying the projectors, and still larger projectors by arraying them.

Abstract: A device for generating acoustic shock waves, comprising at least two electrodes which form a spark discharge gap G in a fluid volume and a reflector for the acoustic shock waves generated during the spark discharge made of an electrically conductive material, and wherein the power to one of the electrodes is supplied by way of the reflector.

Abstract: The invention concerns a method and device for generating shock waves by spark discharge between electrodes which are intermittently fed with electric current in a fluid medium such as water. The shock waves are focused on the object to be shattered in a body. According to the invention, conductive, semiconductive or polarisable particles (15) are introduced into the fluid medium (14) between the electrodes (3, 4) and retained there owing to the fact that the medium (14) and the particles (15) it contains are accommodated in a casing (11) around the electrodes (3, 4), said casing (11) being permeable to the shock waves. A voltage breakdown in the form of a spark discharge is attained even in cases in which the distance between the electrodes has increased beyond an otherwise critical extent.

Abstract: Acoustic shock waves for medical uses are generated by an electrical discharge between two electrodes, which are mounted in a liquid medium. A catalyst is added to the liquid medium in the area of the electrodes; this catalyst partially or completely catalytically converts the gas which forms upon application of the voltage to the electrodes back into its original state or partially or completely prevents the formation of the gas.

Abstract: An efficient sparker for a pulse powered underwater acoustic source for msweeping is capable of repetitive discharges at about 15 Hz for at least one hour without replacement or maintenance. The sparker has a tubularly-shaped cathode spaced apart from an elongate anode that coaxially extends the length of the tubularly-shaped cathode and a cylindrically-shaped insulator that fills the space between the cathode and anode. The cathode, anode, and insulator are secured to a collar and are shaped to have minimal drag when towed through the water at speeds up to 35 knots. The configuration and selection of fabrication materials for the sparker assure that a nominal constant gap is maintained between the cathode and anode.

Abstract: A seismic source for crosshole testing comprises a hammer rod supported by axial bearings in the ends of a cylindrical housing. Fasteners attach a down-blow hammer to the hammer rod inside the housing. A helical spring inside the housing biases the hammer rod in a downward direction. A hammer cable, attached to the upper end of the hammer rod, raises the hammer rod against gravity and spring pressure until an up-blow hammer attached to the hammer rod below the cylindrical housing strikes the bottom end cap which serves as an anvil. Relaxation of the hammer cable tension results in the down-blow hammer striking the anvil. The device provides compression waves and highly repeatable and selectable-phase shear waves. The device is simple, light and operable by a single person.

Abstract: An array system, which provides a unipolar acoustic impulse with a broad spectral response underwater, utilizes a vertical array of airgun or electrical spark sources whose individual peak source strengths are essentially constant over the array length, but whose individual source periods vary with depth. The array of sources produces in each instance a near-unipolar, impulsive signature with a broad pedestal-like spectrum. The system may be used for underwater object location and also for seismic exploration.

Abstract: An acoustic impulse source has been developed and used to simulate the high coustic output of detonation driven acoustic sources. While detonation driven acoustic sources are capable of producing large acoustic signals (>160 dB) at 10s and 100s of meters from the source, their laboratory use is limited due to the combustion byproducts. The present invention is capable of reproducing the downrange detonative source acoustic signals (170 dB) at short range, on the order of 1 meter, without noxious or large thermal byproducts. The present invention relies on the plasma formation resulting from electrical arc discharge in air to generate thermal impulses and the resultant acoustic signals. Utilizing multiple plasma channels and timing control of the formation of said channels, the present invention achieves increased efficiency and the ability to tailor the acoustic output signal to match the desired detonation source characteristic output.

Abstract: A submersible ultrasonic emitter is integrated with a dissolved oxygen (DO) or other aquatic probe so that biofouling of the sensor's membrane is minimized. Sonification, that is, exposure to ultrasound, precludes the need to use other biofouling elimination procedures such as water/air jets, chemical treatments, or biocides. The invention can be configured to readily integrate with existing probes from a variety of manufacturers, and eliminates membrane cleaning as the maintenance interval constraint for field or laboratory deployed sensors.

Abstract: An impulsive acoustic radiation source includes an enclosure disposed about an impulse generator to control the generated acoustic spectrum. In some implementations, the impulse source includes electrically nonconducting materials disposed so as to provide a compact means to complete the electrical circuit. In certain implementations, the impulse source includes a restrictor that mechanically guides a "cavity" produced by the pulsed electrical discharge. In other implementations, multiple impulse sources are disposed within an enclosure having walls or other means to define an enclosure for each specific source. Arrangements of multiple impulse sources connected in series and driven by a single circuit and having a reflector disposed about the impulse source or sources are disclosed.

Abstract: An energy converter for generating high-power pulses includes a housing defining a chamber having an open side; an electrode assembly supported in the chamber; a power supply for applying a voltage to the electrode assembly; a fluid medium accommodated in the housing and being in contact with the electrode assembly for receiving pulses from the electrode assembly; and a diaphragm attached to the housing and closing the open side of the housing for encapsulating the electrode assembly and the fluid medium in the chamber. The diaphragm has an inner surface oriented toward the chamber and is in contact with the fluid medium. The diaphragm further has an outer surface oriented away from the chamber and is arranged for contacting a substance to be comminuted, whereby mechanical pulses transmitted from the fluid medium to the diaphragm are applied by the diaphragm to the substance to be comminuted.

Abstract: Acoustical shock waves are generated by electrical sparks within a gap between electrodes adjustably positioned for exposure to water adjacent a surface immersed therein. High voltage electrical energy derived from a constant current power supply, is stored in a capacitor for rapid. application to the electrodes by discharge during cyclic periods of short duration under remote control in order to render the acoustical shock waves so generated effective in preventing biofouling of the surface by organisms in the water.

Abstract: A method and apparatus for increasing the density and strength of bone, particularly for preventing or treating osteoporosis, by subjecting the bone to unfocussed compressional shock waves.

Abstract: The invention relates to a device for generating shock waves by means of a park gap by using two electrodes. At a spark gap, apart from the desired shock waves, low frequency sound parts are generated. These sound parts have a disturbing effect during therapy. According to the invention, for the reduction of the low frequency sound parts it is provided to arrange the electrodes in a pressure-tight tube surrounding them.

Abstract: Water is treated with sound waves produced by means of a submerged plasma sparking device (16) to mitigate detrimental effects of aquatic organisms in the water. For example, the incrustation of zebra mussels may be reduced by killing the zebra mussels or creating an environment hostile to them. The plasma sparking device may have a main storage circuit (14) which includes liquid dielectric capacitors or cryogenically cooled field coils for storage. Moreover, the electrodes (50) of the plasma sparking device may be of aluminum or an aluminum alloy.

Abstract: A method of and an apparatus for the high-resolution sea bottom prospecting, in which an electroacoustic paraboloidal transducer is placed into water, the electrodes of which are near the focus of the paraboloid and are connected both to a capacitor bank the capacitance of which may be varied at will and to a supply circuit for the generation of an electroacoustic discharge between said electrodes. As the capacitance varies the delay time between the primary pulse or underwater prospecting pulse and the cavitation pulse is recorded at any discharge, and at the same time dominant frequency of the prospecting signal spectrum is determined. Afterwards capacitance values are set so as to provide both cavitation pulses the contribution of which to the resulting pulse is minimum and a dominant frequency spectrum as broad as possible.

Abstract: A water system is provided for an extracoporeal lithotripter. The reflector is aimed downwardly and has a spark gap at the first focus point thereof for generating a shock wave. A rubber diaphragm spans the lower end of the reflector. A water reservoir is provided along with pipes and a pump for circulating water from the reservoir to the reflector and back. A vacuum pump maintains pressure below ambient in the reservoir, the reflector and connecting pipes to control downward ballooning of the diaphragm.

Abstract: An acoustic source for seismic exploration has a generally cylindrical tube ith spaced upper and lower closed ends. An insulated continuous conductor has a first portion with an exposed internal conductive end within the tube and a second portion extending therefrom through the upper end. A selectively closeable port is operably associated with the tube for permitting the tube to be filled and maintained filled with a conductive solution. A gas vent has a first open end within the tube adjacent the upper end and a second end exteriorly disposed of the tube.

Abstract: A source of seismic waves operable within a borehole filled with liquid crises a module supported by a cable. The module includes means to generate a high voltage and to charge a bank of capacitors, and means to connect the capacitors across a pair of electrodes forming a spark gap. The electrodes are immersed in liquid at the same pressure as the borehole liquid and acoustically continuous with it, and are separated by a gap of width between 0.5 and 20 mm. If the gap is greater than about 5 mm, both the electrodes should be covered with insulation except at the positions where the spark is to be formed. The module can operate automatically at considerable depths and at high pressures.

Abstract: An apparatus for comminuting concretions in a patient's body includes a liquid filled focusing chamber, defined by a reflector (2) with an inner wall having the form of an open revolution ellipsoid, which has its open end closed by a bellows (4,6) intended for placing against the patient's body. A spark gap (8) is disposed at the first focus (F.sub.1) of the ellipsoid reflector for generating a shock wave intended to be focused at the second focal area (F.sub.2) of the ellipsoid. The reflector wall thickness is formed such that resonance of the waves reflected on the inside and outside of the ellipsoid reflector occurs in said second focal area at a predetermined frequency.

Abstract: The ignition of spark gaps for the production of shockwaves in the contactless comminution of concrements, using a capacitor discharge is improved by providing at least for some time prior to the ignition proper a voltage much smaller than the breakthrough voltage for producing a small current between the electrodes that prepares a channel in the discharge gap.

Abstract: A medical electrode arrangement for urological use, has a core with an aperture going therethrough. This aperture receives a first electrode. A cage is defined by at least a side wall having first and second ends. The first end has a receiving unit for receiving a second electrode. An inner space of said cage is situated between the first and second ends and is surrounded by the side wall. The inner space is adapted to receive the core with a first electrode and a second electrode. A plurality of openings penetrating through the side wall of the core and extend from the first end toward the second end.

Abstract: Apparatus for triggering shock waves for therapeutic purposes, and generated with the aid of spark discharge in a liquid includes a signal analyzer disposed for receiving the ECG signal from a patient, a pulse generator being connected to this analyzer for sending a trigger signal shortly after the occurrence of the R peak in the ECG signal. An electromagnetically manoeuvreable, moving auxiliary electrode (14) is disposed for motion towards or into a fixed electrode gap (8, 10) in response to the trigger signal for connecting the spark gap (4, 6) to high voltage by making the electrode gap conductive.

Abstract: A method of and a system for remotely controlling an adjustable, electrodeless arc discharge acoustic pulse transducer for borehole and underwater operations using high-energy arc discharges to generate high power seismic and acoustic pulses capable of being easily and remotely adjusted in time duration and magnitude such that they can be customized to create waveforms of preferred shapes. The transducer has an insulating ceramic barrier which contains a biconical aperture separating two bodies of electrolyte through which the two zones of liquid make contact and electrically adjustable circuits for switching supplemental amounts of stored electrical energy into the arc discharge circuit at successively delayed time intervals to lengthen the arc discharge current pulse to create the desired waveform shape for detecting variations in the geological features of the formations being probed or for use in ocean acoustic or sonar applications.

Abstract: The invention relates to an electrical discharge circuit between two electrodes. The circuit includes switch means connected in parallel between the electrodes and constituting a switch that is closed for low frequency currents and that is open for high frequency currents. The discharge circuit may be used to detect and correct the position of an electrode at will, in manner that is simple, reliable, cheap, and suitable for being automated.

Abstract: A spark gap unit that is easy to manufacture and significantly lighter than previously used spark gap units for generating underwater shock waves, particularly for non-invasive lithotrispy, has an internal conductor with an inner electrode, an insulation which at least partially envelops the internal conductor, and an external conductor with a bow and an outer electrode. The internal conductor is significantly shorter than the external conductor, and the external conductor at the rearward end of the spark gap unit projects beyond the internal conductor. The internal conductor, the insulation, and the external conductor are coaxially arranged. An outside diameter of the internal conductor is relatively small in comparison to an inside diameter of the external conductor. The spark gap unit has a hollow space inside the insulation, this hollow space being open in the direction of a rearward end of the spark gap unit.

Abstract: An arrangement for the comminution of concrements of various kinds in the body of living being, uses an underwater or submerged arc gap with spark discharge, and an electrical energizing circuitry for that arc gap, a plurality of electrode assemblies from which one is selected to be used in the equipment is connected to the energizing circuit; the electrode assemblies are basically similarly configured and each has an ohmic resistor which is connected directly in series with one of the electrodes, the resistance value for the resistors in the electrode assemblies of the plurality are different, and in each instance much lower than the resistance of the unignited gap, but of comparable magnitude with the resistance of a fully developed plasma channel in the gap following ignition by the energizing circuit.

Abstract: The present invention relates to a method and device for discharging an electric current between two electrodes, comprising considerably reducing the resistance to the passage of electric current at least between the electrodes so as to bring it to a resistance value near to or slightly higher than the critical resistance by interposing a conductive electrolyte between electrodes. This improves the rate of discharge of an electric current produced between the electrodes, by eliminating substantially completely the latency time.