A process for selective graphic representation and/or evaluation of the Doppler spectrum of objects limitedly resistant to sonic intensity, for example biological organs and tissues, by an ultrasonic process wherein a material is introduced in the examination area to be acoustically irradiated, nonlinear oscillations are produced in the examination area by irradiated ultrasonic waves and the signal is evaluated by an ultrasonic converter. Also, a circuit for carrying out the above process is disclosed.

Ultrasonic processes and circuits for performing them

Sonic excitation is used to locate, without contact, an object or defect beneath a surface. Defects may include, for example, damage and flaws in load bearing concrete structures wrapped in plastic, fiberglass or composite sheathing, while buried objects amenable to detection include landmines or above-ground mines.

Acoustic detection of hidden objects and material discontinuities

To reduce the cost while maintaining the real time environment in receiving ultrasonic waves in an ultrasonic receiving apparatus which is capable of reducing changes in detection sensitivity due to environmental changes in the ultrasonic detecting element The ultrasonic receiving apparatus comprises a light source for generating broadband light, an ultrasonic detecting element including an ultrasonic sensing portion that expands and contracts in response to a received ultrasonic wave and has optical reflectance that changes in accordance with expansion and contraction thereby performing intensity modulation on the light, spectrum-separating means for spectrum-separating the light, first photo-detecting means having a plurality of photoelectric conversion elements for detecting the light for plural wavelength components, and second photo-detecting means for detecting a selected wavelength component included in the light on the basis of a detection result of the first photo-detecting means

Ultrasonic receiving apparatus and ultrasonic receiving method

An ultrasonic probe for detecting ultrasonic waves in a two-dimensional manner without necessity of electric-wiring works to a large number of very fine elements and without increasing of crosstalk and electric impedance. The ultrasonic probe is equipped with an ultrasonic transmitting function and can be provided in low cost. The ultrasonic probe includes an ultrasonic detecting element having a reception plane capable of receiving ultrasonic waves, for modulating light on the basis of ultrasonic waves applied to respective positions of the reception plane, and at least one ultrasonic transmitting element for transmitting ultrasonic waves.

Ultrasonic probe and ultrasonic diagnosing apparatus using the same

Acoustic imaging apparatus wherein a beam of high frequency acoustic energy is directed to the object to be imaged to create variations in the transmitted acoustic energy which variations are then detected by a plurality of small particles suspended in the beam path for motion in response to radiation pressure produced by the incident acoustic energy, thus providing a visible image with high contrast sensitivity and excellent image resolution.

Acoustic imaging apparatus

An acousto-optical method and apparatus for monitoring individual constituents of differing acoustical transparency in a multi-constituent flow through a conduit. The conduit is acoustically coupled to an external acoustic source of fixed frequency and an external acoustic wave transmission medium in a manner such that acoustic wave energy from the source is transmitted laterally through a section of the conduit into the acoustic medium to produce within the medium distorted acoustic waves containing information representing each constituent present within the conduit section. This acoustic information is transformed to equivalent light information by a light-sound wave interaction yielding a light sideband which may be optically processed to image the constituents or converted to an electrical output representing the constituents.

Acousto-optical multi-constituent flow monitoring method and apparatus

An object situated in an acoustic medium, such as water or soil, characterized by relatively high acoustic absorption is optically imaged by a novel acousto-optical imaging technique. Relatively low frequency acoustic waves which are subject to relatively low attenuation by the ambient medium are transmitted through the medium to the object and emanate from the object as distorted acoustic waves containing information defining an image of the object. These distorted acoustic waves are received by an acousto-optical coupling medium which is excited by relatively high frequency and large amplitude acoustic waves. The distorted low frequency acoustic waves and high frequency waves undergo non-linear interaction to produce in the coupling medium resultant acoustic wave sets having frequencies equal to the sum and difference, respectively, of the low and high frequencies and each containing essentially the same image information as the distorted waves. A monochromatic light beam is projected through the coupling medium to impinge the wave fronts of one resultant wave set, preferably the sim wave set, at an oblique angle which causes Bragg diffraction of the light waves by the acoustic waves, such that the light waves emerging from the coupling medium form an optical image of the object.

Low frequency parametric acousto-optical imaging method and apparatus

An underwater acousto-optical imaging system for receiving water-borne acoustic waves representing an image of an object in the water and converting the image information to a corresponding optical image of the object. The acoustic waves are focused by an acoustic lens into a Bragg coupling medium wherein a monochromatic light beam is Bragg diffracted by the acoustic waves to produce a modulated light side band defining the optical image. A television camera converts this optical image to electrical signals for viewing of the image at a remote video monitoring station. The imaging system may be driven in a scanning motion for operation in a search made and may include an acoustic source for generating acoustic probing waves which reflect from objects in the water back to and are converted to optical images by the imaging system.

R Aprahamian

Papers

Acousto-optical multi-constituent flow monitoring method and apparatus

Low frequency parametric acousto-optical imaging method and apparatus

Acousto-optical underwater imaging system