Abstract: An external ultrasonic probe includes a transducer array including multiple transducers arranged along an azimuth direction, the multiple transducers transmitting and receiving ultrasonic waves; and a covering material having a projecting surface touchable with a living body, formed of a single member, covering an entire front-surface side of the transducer array, and covering at least a part of a side-surface side of the transducer array. In a section dividing a width of the transducer array in the azimuth direction substantially into two equal parts, a width between two points on the projecting surface falling down from a top of the projecting surface by 2 mm is larger than a width of the transducer array in an elevation direction. A difference between the width between the two points and the width of the transducer array in the elevation direction is 5 mm or less.

Abstract: Object detection may include transmitting, by a first device, a first pulse into an environment using a wide field configuration of an ultrasonic sensor array, detecting a presence of an object in the environment based on a detected echo based on the first pulse. In response to detecting the presence of the object, a targeted configuration of the ultrasonic sensor array is determined, and a second pulse is transmitted into the environment based on the second pulse, wherein a characteristic of the object is determined based on a detected echo from the second pulse.

Abstract: The present invention is aimed to provide, as an acoustic lens propagating a sonic wave having a wavelength ? of 100 ?m or less, an acoustic lens capable of exhibiting excellent acoustic characteristics in response to the wavelength ? of the sonic wave to be propagated and a production method thereof. The acoustic lens is an acoustic lens 1 to be used for propagating a sonic wave having a wavelength ? of 100 ?m or less, wherein the acoustic lens contains a silicone resin and silica particles, an average primary particle diameter of the silica particles is 15 nm or more, and a particle diameter (D90) of 90% of a cumulative percentage in cumulative particle size distribution of the silica particles is less than ? of the wavelength ? of the sonic wave to be propagated.

Abstract: The disclosure provides a focusing method of optical machine of projector, a focusing device and an optical machine. The focusing method comprises steps of: detecting deformation amount of lens of an optical machine; and controlling and adjusting a focal length of the lens of the optical machine according to the deformation amount of the lens of the optical machine. In the he focusing method, by detecting the deformation amount of the lens of the optical machine in real time and controlling to adjust the focal length of the lens of the optical machine in real time according to the deformation amount of the lens of the optical machine, the adjustment precision of the focal length of the lens of the optical machine can be greatly improved.

Abstract: A method and system for investigating structure near a borehole are described herein. The method includes generating an acoustic beam by an acoustic source; directing at one or more azimuthal angles the acoustic beam towards a selected location in a vicinity of a borehole; receiving at one or more receivers an acoustic signal, the acoustic signal originating from a reflection or a refraction of the acoustic wave by a material at the selected location; and analyzing the received acoustic signal to characterize features of the material around the borehole.

Abstract: Tunable polymer-based sonic structures (“TuPSS”) are made up of sonic structures and polymers. The TuPSS has three general requirements: a) The sonic structure is composed of one or materials engineered to behave as a lens, filter, cloak, or dampener; b) Stimulus sensitive polymer is incorporated into the sonic structure; and c) The actuation of the polymer tunes the acoustic behavior of the structure in a predictable manner. The tunable polymer-based sonic structures utilize stimuli-driven physical properties of the polymers in these acoustic structures to produce a stimulus driven, or tunable, sonic structure or device. The sonic structures actively modulate mechanical vibrations that propagate through the structures, but are passive in that they do not produce mechanical vibrations. The stimuli for the structures include electric, magnetic, electromagnetic, chemical, thermal, and shaking/orientation.

Abstract: A subsea sonar unit includes an acoustic transducer. The acoustic transducer transmitting an acoustic beam defining an acoustic propagation path for acoustic signals to or from the transducer, and the unit also includes a housing at least a part of which being oil filled and positioned in the propagation path of the beam. The housing is acoustically transparent in the direction of the acoustical beam and has an outer surface with a known shape in the propagation path. The unit also includes a corrective lens, the corrective lens being mounted in the propagation path between the transducer and the housing part the interface between which defining a first surface having a shape relative to the cross section of the acoustic beam in the propagation path essentially corresponding to the shape of the housing surface relative to the beams cross section at the housing surface in the propagation path.

Abstract: A subsea sonar unit includes an acoustic transducer. The acoustic transducer transmitting an acoustic beam defining an acoustic propagation path for acoustic signals to or from the transducer, and the unit also includes a housing at least a part of which being oil filled and positioned in the propagation path of the beam. The housing is acoustically transparent in the direction of the acoustical beam and has an outer surface with a known shape in the propagation path. The unit also includes a corrective lens, the corrective lens being mounted in the propagation path between the transducer and the housing part the interface between which defining a first surface having a shape relative to the cross section of the acoustic beam in the propagation path essentially corresponding to the shape of the housing surface relative to the beams cross section at the housing surface in the propagation path.

Abstract: Provided is an acoustic lens composition which comprises 40 wt % or more of silicone rubber and 15 to 60 wt % of a zinc oxide powder, suppresses ultrasonic attenuation, and has superior molding properties.

Abstract: The disclosure is directed to a system for variably refracting, and is transparent for, ultrasound as well as for light. By choosing liquids with the right optical and acoustical properties, it is possible to variably refract (including focusing and deflecting or steering) ultrasound while not affecting the refraction of light, or vice versa. Two lenses in series, or preferably one lens, allow for variably refracting ultrasound and light.

Abstract: Disclosed is an ultrasonic lens configuration permitting the production of an acoustic field from low frequency ultrasound waves with predictable regions of energy concentration. The lens comprises at least three adjacent convex surface contours. Each surface contour corresponds to an arc of an ellipse. The first surface contour is within the center of the lens and is flanked by two adjacent contours. The flanking contours correspond to arcs from two symmetrical ellipses having semi-latus rectums at least equal to the semi-latus rectum of the ellipse to which the first, central, contour corresponds. The contours of the lens are arranged such that the flanking contours extend past the first contour by positioning the contours so that if the ellipses to which they correspond were drawn the ellipses of the flanking contours directly adjacent to the first contour would have their centers aligned on a plane parallel to and not below the major or minor axis of the ellipse of the first contour.

Abstract: The apparatus comprises an ultrasonic vibration generator (1) and a lens (2) affixed thereto adapted to focus the ultrasonic vibration at a predetermined zone. It may be used to destroy certain types of cancerous cell which lie close beneath the surface, such as skin cancers and other melanomas. Other cosmetic skin treatments may also be carried out, such as restructuring collagen molecules in order to tighten and restructure skin tissue, depilation and to destroy dyed tissue and thereby aid removal of unwanted tattoos.

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: An apparatus for generating acoustic waves has an acoustic transducer with a first electrode serving as a membrane and adjoining an acoustic propagation medium and a second electrode spaced from the first, between which an electrolyte is situated. The acoustic transducer is fashioned transparent to X-rays.

Abstract: An acoustic lens having two or more regions, each region having a different acoustic index of refraction. The lens may have a simple, non-compound, surface in which both regions form different sections of the same convex or concave curve with the same functional dependence. The transition between the two regions may be gradual or abrupt. The attenuation and other characteristics of the lens may be tailored to provide apodisation and to filter out unwanted frequencies.

Abstract: The preferred embodiments described herein provide an improved ultrasound transducer and method of manufacture thereof. In one preferred embodiment, a method of manufacturing an ultrasound transducer is provided comprising the acts of supporting a layer of piezoelectric material with a window and separating the layer of piezoelectric material into at least two elements by dicing through the layer of piezoelectric material and at least partially into the window. In another preferred embodiment, an ultrasound transducer is provided comprising a first transducer element, a second transducer element, and a window coupled with the first and second transducer elements and comprising a kerf positioned between the first and second transducer elements.

Abstract: An ultrasonic probe includes a piezoelectric element for transmitting and receiving ultrasonic waves and an acoustic lens provided on an ultrasonic transmission/reception side of the piezoelectric element. The acoustic lens is formed in an acoustic lens shape by vulcanization formation through addition of 2,5-dimethyl-2,5-di-t-butyl peroxy hexane as a vulcanizing agent to a composition prepared by addition of silica (SiO2) particles in an amount of 40 wt % to 50 wt % to silicone rubber with a dimethylpolysiloxane structure including vinyl groups. Thus, the ultrasonic transmission and reception sensitivity is improved and the degradation in frequency characteristics is diminished. Consequently, higher resolution of an ultrasonic image and higher sensitivity can be achieved.

Abstract: An ultrasonic probe includes a piezoelectric element for transmitting and receiving ultrasonic waves and an acoustic lens provided on an ultrasonic transmission/reception side of the piezoelectric element. The acoustic lens is formed in an acoustic lens shape by vulcanization formation through addition of 2,5-dimethyl-2,5-di-t-butyl peroxy hexane as a vulcanizing agent to a composition prepared by addition of silica (SiO2) particles in an amount of 40 wt % to 50 wt % to silicone rubber with a dimethylpolysiloxane structure including vinyl groups. Thus, the ultrasonic transmission and reception sensitivity is improved and the degradation in frequency characteristics is diminished. Consequently, higher resolution of an ultrasonic image and higher sensitivity can be achieved.

Abstract: A device for converting mechanical vibrations into a digital signal uses a iaphragm having a reflective surface with a plurality of reflective facets disposed on a face of the diaphragm. The diaphragm is mounted such that it will be displaced a distance proportional to the external stimulus, such as acoustic energy, it receives. A light source provides a continuous optical beam which is directed onto the reflective surface and reflected by the surface onto an optical detector, which in turn, produces an electrical signal identifying the position on the detector illuminated by the reflected beam. As the diaphragm vibrates in response to the external stimulus receive, the optical beam will be reflected in different directions thereby changing the position that the beam strikes the optical detector. A microprocessor receives the electrical signals from the optical detector and produces a digital signal corresponding to the displacement of the diaphragm.

Abstract: This invention is a composite acoustic lens that can be steered internally through electrical control. It can collect and direct acoustic energy from a plane wave to focus it on a transducer. It can also take the nearly omnidirectional output from a standard acoustic transducer and direct its energy in a plane wave. In the receive role the lens increases the effective signal-to-noise ratio of the array; in the transmit role it reduces the output energy that is responsible for reverberation. The lens is steerable by virtue of its material: it is electrorheological. Its bulk modulus, and the resulting speed of sound, can be changed electrically. Controlling the gradient of the index of refraction allows the steering to be adjusted precisely, continuously, and quickly. It is held by a container of plastic material that matches the acoustic impedance of water and minimizes the presence of near-field scatterers.

Abstract: An acoustic lens system is constructed so that at least one surface of acoustic lenses constituting the acoustic lens system is an aspherical surface, which has such a shape that curvature moderates progressively in separating from the axis of the acoustic lens system, and an acoustic beam stop is provided therein. As a result, aberrations can be favorably corrected even when the angle of view and the numerical aperture are increased and this brings about the acoustic lens system suitable for an objective lens of an acoustic system for securing an image of an object having a two-dimensional size in particular.

Abstract: An ultrasonic transducer having a transducer element which generates ultrasonic energy propagating along a transducer axis with a predetermined speed of propagation, and a lens acoustically coupled to the transducer element and having an input face positioned to receive the ultrasonic energy, wherein the lens includes electrorheological fluid with voltage dependent acoustic properties therein for enabling the speed of propagation to be selectively controlled as the ultrasonic energy passes through the lens. The transducer may include a focusing lens, a steering lens, or a combination thereof for selectively controlling the focusing and/or steering of the ultrasonic energy within a region of interest in an object to be inspected therewith. A voltage control device is used to controllably apply voltage to the lens to control the propagation speed as the ultrasonic energy passes therethrough.

Abstract: The process comprises the steps of calculating, by varying the opening angle of a cluster, a first group of reference points of x, z coordinates in an incidence plane of the beam, so that the times taken by the ultrasounds to pass through the reference points and through the focal point are identical, then calculating a second group of reference points of y, z coordinates in a plane perpendicular to the incidence plane, defining two polynomials of degree 4 by polynomial interpolation by the method of least squares of the two previously calculated groups of points of the following form: f(x)-ax.sup.4 +bx.sup.3 +cx.sup.2 +dx g(y)=a'y.sup.4 +b'y.sup.3 +c'y.sup.2 +d'y, determining the x, y and z coordinates of the points of the output surface by the relation z=f(x)+g(y), and producing the output surface by means of the coordinates.

Abstract: An ultrasonic probe including one or more piezoelectric ceramic elements mounted on an acoustically damping support body. Desired acoustic signals are transmitted and received through a front portion of the probe while unwanted acoustic signals are dampened by the support body at the rear portion of the probe. The present invention generates and efficiently focusses a main lobe of a beam of the acoustic signals. Furthermore, the invention provides for apodization of the acoustic beam to reduce extraneous acoustic signals corresponding to side lobes of the acoustic beam. Each element has a respective rear face and a respective first piezoelectric ceramic layer integral therewith to provide efficient acoustic coupling between the element and the acoustically damping support body. The respective first piezoelectric layer of each element includes shallow grooves disposed on the respective rear face of each piezoelectric element.

Abstract: The acoustic lens system is used for ultrasonic imaging in an ultrasonic system which displays an image of an object while transmitting ultrasonic waves and receiving the ultrasonic waves reflected from the object, and has a half field angle .omega. expressed as follows: ##EQU1## wherein the reference symbol v.sub.0 represents the velocity of sound in the medium located on the incidence side of the first lens surface and the reference symbol v.sub.1 designates the velocity of sound in the medium located on the emergence side of the first lens surface. Accordingly, the acoustic lens system according to the present invention is remarkably excellent in the performance thereof in respect of field angles, aberrations, aperture angles, attenuation, etc., and has an advantage to permits further reducing acoustic attenuation and preventing spurious images from being formed due to multiple reflections by arranging antireflection films on the lens surfaces.

Abstract: An acoustic device has an acoustic wave propagating medium exhibiting elastic abnormality in the vicinity of a Curie temperature. It is desirable that such an acoustic wave propagating medium be formed of a ferroelectric substance or a high-elastic substance and, in particular, have a Curie temperature at normal temperatures. For example, such ferroelectric substance is a solid solution expressed by Cs(Pb.sub.1-x Sr.sub.x)(Cl.sub.1-y Br.sub.y).sub.3 or (Bi.sub.1-x Dy.sub.x)VO.sub.4. By changing values of x and y appropriately, the Curie temperature of the solid solution can be varied, and an acoustic wave propagating medium meeting the purpose of use can be obtained. In such an acoustic wave propagating medium, an elastic coefficient C.sup.P at the time of constant polarization differs greatly from an elastic coefficient C.sup.E at the time of a constant electric field in the vicinity of the Curie temperature. Accordingly, the propagation velocity of acoustic waves is greatly different, too.

Abstract: An acoustic lens for the transformation of a planar wave into a spherical segment-shaped wave, and vice versa, is disclosed. In order to avoid aberrations, the lens is fashioned rotationally symmetrical relative to its center axis and biconcavely, the lens surface adjoining the medium in which the planar wave propagates is produced by the rotation of a section of a straight line, the lens surface adjoining the medium in which the spherical segment-shaped wave propagates is produced by the rotation of a section of an ellipse, and the angle between the straight line and the center axis as well as the angle between the major half-axis of the ellipse and the center axis are selected such that a planar or spherical segment-shaped wave entering into the lens propagates in the lens as a conical wave whose aperture angle is equal to double the angle at which the minor half-axis of the ellipse intersects the center axis.

Abstract: An acoustic lens system is constructed so that at least one surface of acoustic lenses constituting the acoustic lens system is an aspherical surface, which has such a shape that curvature moderates progressively in separating from the axis of the acoustic lens system, and an acoustic beam stop is provided therein. As a result, aberrations can be favorable corrected even when the angle of view and the numerical aperture are increased and this brings about the acoustic lens system suitable for an objective lens of an acoustic system for securing an image of an object having a two-dimensional size in particular.

Abstract: A transducer apparatus and method for generating sonic sound waves having a far field wavefront amplitude pattern in a Bessel or Gaussian distribution is disclosed. The transducer includes a piezoelectric element having uniformly poled dipoles formed therein. An unpoled backing body having the same dielecctric constant as the piezoelectric element contacts and is attached to the piezoelectric element. An indentation shaped to produce a beam amplitude distribution of a predetermined function is formed on the backing body.

Abstract: A generator for acoustic waves has a source of acoustic waves with which acoustic waves can be introduced into an acoustic propagation medium and a liquid lens having a variable focal length which is arranged in the acoustic propagation medium, the liquid lens having two lens walls and a lens liquid situated therebetween. At least one of the lens walls is deformable for the purpose of varying the focal length. The liquid lens has a central opening, so that the lens walls have an outer and an inner edge, and the outer edge of the deformable lens wall is fixed and the inner edge is displaceable in the direction of the center axis of the liquid lens for the purpose of varying the focal length.

Abstract: A pressure pulse source, of the type suitable for generating shockwaves, has a positive lens for focusing the pressure pulses onto a focal zone. The positive lens has an acoustic exit face which has a shape, in a focusing zone, for focusing the pressure pulses and a shape, in at least one measurement zone, which deviates from the shape in the focusing zone. A pressure sensor containing a piezoelectric polymer foil is disposed at the measurement zone. The pressure sensor, or a number of such pressure sensors, generate signals which are used to monitor the pressure pulses emerging from the positive lens, such as by acquiring their peak value.

Abstract: A preferred embodiment of a large diameter solid ultrasonic imaging transducer is illustrated in FIG. 5 with alternate embodiments illustrated in FIGS. 6-9. The large diameter solid ultrasonic imaging lens 100 has a diameter preferably greater than six inches with a focal length-to-diameter ratio of between 1 and 2. The lens 100 has concave surfaces 108 and 110, and is composed of a homogenous material that has an ultrasonic impedance of less than twice that of water and has a density less than the water. Preferably, the velocity of the ultrasonic sound through homogenous plastic material is less than twice that of water. One or both of the concave surfaces 108 and 110 have surfaces that are without a constant radius and curvature, but however are composed of separate radius of curvatures for each small increment of lens surface to properly focus the ultrasound at a desired focal length "L".An alternate embodiment is illustrated in FIG.

Abstract: A conical ultrasonic wave deflection system has an ultrasonic transducer for ultrasonic microscopy using surface waves and/or Lamb waves in an object. A conical wave front is directed onto the object via a deflection element. An inactive axial circular disk is provided between the ultrasonic transducer and the object to minimize unnecessary interference from undeflected waves. A frustoconical lens with a blocked top face, or a conical metal reflector with a ring transducer on the transducer side can be provided as the deflection element. The arrangement is highly compatible with ultrasonic microscopes. Matching to a critical angle .theta. of the object is achieved by selection of the appropriate ultrasonic frequency.

Abstract: An ultrasonic probe comprising an acoustic lens (20) having a concave lens surface (21) formed on one side of a lens body, and a piezoelectric transducer (23) disposed on the other side of the acoustic lens, ultrasonic waves generated by applying voltage to the piezoelectric transducer being focused through the lens surface to detect the reflected waves of the ultrasonic waves from a sample (26) by the piezoelectric transducer for obtaining information about the surface or interior of the sample. The lens surface (21) of the acoustic lens (20) is defined by an etch profile (15) formed by etching a substrate material (11) which makes up the lens body.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver paris of crystals.

Abstract: An ultrasonic probe comprising an acoustic lens (20) having a concave lens surface (21) formed on one side of a lens body, and a piezoelectric transducer (23) disposed on the other side of the acoustic lens, ultrasonic waves generated by applying voltage to the piezoelectric transducer being focused through the lens surface to detect the reflected waves of the ultrasonic waves from a sample (26) by the piezoelectric transducer for obtaining information about the surface or interior of the sample. The lens surface (21) of the acoustic lens (20) is defined by an etch profile (15) formed by etching a substrate material (11) which makes up the lens body.

Abstract: An acoustic filter is provided for attenuating or suppressing the negative pressure half-waves of an elastic wave, comprising an enclosure containing a liquid whose saturating vapor tension is close to the atmospheric pressure. A pump causes the liquid to flow and a regulator fixes its temperature.

Abstract: An elastic pulse generator including a piezo-electric or magnetrostrictive transducer which is focussing or associated with a focussing device, having a plurality of elementary emitting surfaces generating elastic signals. These signals are superimposed, after propagation over a certain distance, in a focal region. Several groups of elementary emitting surfaces are periodically exciting at a predetermined rate with respective separate electric signals. The emitting surfaces belong to transducer elements electrically isolated from each other and having different transfer functions. Delay lines are provided for phase shifting the elastic signals emitted by the transducer elements.

Abstract: A temperature compensation system that adjusts the temperature of an acoustic lens fluid in a prescribed manner to maintain the index of refraction of the fluid constant relative to the surrounding water thereby maintaining the focal length of the lens constant over its operating temperature range. The system comprises two temperature sensors, a programmed lens fluid temperature prescriber and an error amplifier all cooperating to direct a servomechanism system to adjust a temperature control system to either heat or cool the lens fluid to the prescribed temperature so that its index or refraction and focal length are held constant.

Abstract: An automatic ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver pairs of crystals.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver pairs of crystals.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage container which may or may not contain various quantities of ice. The system includes a housing, a front and a rear pair of separate transmitter and receiver crystals mounted in the housing with a lens on the lower surface of each crystal. Each crystal is located within a separate non-ferrous metal tube. Polyurethane foam fills the space within the housing and the tubes.

Abstract: A liquid column (2) is placed between two high-frequency ultrasound sources (6) in the field of a standing wave produced by the sources. Each source produces a convergent beam that compensates for a substantial part of the attenuation of the ultrasound energy that occurs at higher frequencies. It is thereby possible to increase considerably the axial distance along the standing wave over which streaming effects due to acoustic pressure are absent or negligible. It is also possible to increase the angle of convergence to compensate for divergence of the outputs from the sources.

Abstract: An ultrasound liquid level detector system for automatically controlling the dispensing of a post-mix beverage, including microprocessor-controlled circuitry for monitoring and implementing the automatic dispensing process. The microprocessor is interfaced with an ultrasonic transducer which transmits ultrasonic wave energy towards the container to be filled and receives reflected ultrasonic wave energy, the characteristics of which are analyzed within the microprocessor to implement control functions of the automatic dispensing process. Dispensing automatically begins as a container is inserted under the ultrasonic transducer into a proper position beneath a post-mix beverage dispenser nozzle. The transducer continuously measures the distance between the top or lip of the container and a liquid/foam interface of a carbonated beverage being dispensed into the container. Dispensing stops when the transducer senses a predetermined level of carbonated beverage within the container.

Abstract: A shock wave source for disintegrating a calculus has a centrally disposed cavity in which a locating system for identifying the position of the calculus is disposed. The shock wave source has an emission surface, from which shock waves are emitted into a coupling agent in the shock wave source. The emission surface is angled in the direction of shock wave propagation, so that the shock waves emitted therefrom diverge. A focusing element is provided which focuses the shock waves onto the calculus, the focusing element having a structure which, in addition to focusing the shock waves, compensates for the divergence of the shock waves. Due to the divergence of the shock waves, the central cavity in which the locating system is disposed is maintained free of shock waves.

Abstract: An acoustic filter is provided for attenuating or suppressing the negative pressure half-waves of an elastic wave, comprising an enclosure containing a liquid whose saturating vapor tension is close to the atmospheric pressure. A pump causes the liquid to flow and a regulator fixes its temperature.

Abstract: An underwater communicator comprising a transmitter for transmitting acoustical energy between mediums having differing impedance. The transmitter includes first and second ends. The first end is exposed to a first medium while the second end is exposed to a second medium. In the preferred embodiment, the transmitter is formed from a material having a substantially identical impedance to the second medium. An acoustical lens is positioned adjacent the first end of the transmitter. The acoustical lens has a substantially planar front face and a substantially concave shaped rear face. The acoustical lens includes a plurality of spaced vertically extending plates. The vertically extending plates form a substantially right angle with the front face of the acoustical lens. A plurality of spaced plates intersect the vertically extending plates and form an acute angle with the front face of the acoustical lens, thereby forming a plurality of inclined passageways.

Abstract: A detector for detecting the acceleration, the velocity or the displacement of a point is described. The detector includes a light source, at least two photoelectric elements spaced apart from each other over a predetermined distance and a focusing optical system disposed between the light source and the photoelectric elements; the combination being particularly suited for use as an optical seismic detector for detecting and mapping an underground stratum structure.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes a pair of piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level. The control module includes a microcomputer and associated circuitry.

Abstract: A differential property sensitive acoustic lens for non-destructive materials evaluation is described which in a preferred embodiment comprises first and second substantially semicylindrical shaped portions of fused silica disposed in closely spaced relationship along an axial plane, a substantially spherical depression defined in one end of each semicylindrical portion and a flat defined on each semicylindrical portion at the other end, a piezoelectric transducer attached to the flat of each semicylindrical portion, and a paraffin coated aluminum film of preselected thickness disposed between and in laminar contact with the semicylindrical portions for preventing acoustic and electrical cross talk between the transducers and between the semicylindrical portions.