Abstract: A miniaturized ultrasonic probe includes a housing encasing a motor, an ultrasonic transducer mounted for controlled rotation on the motor shaft, and an angular position sensor connected to the shaft. The housing has a radiating dome about the transducer and is sealed and wholly filled with an acoustically-transparent fluid. The transducer may be specially configured for use in continuous wave Doppler measurements of blood flow velocities and, for this purpose, may include a first portion for continuously transmitting an ultrasound beam and a second portion for continuously receiving backscattered ultrasound reflections of the transmitted ultrasound beam. The position sensor is implemented using a low mass variable-inductor arrangement. The resulting probe attains unusually rapid accelerations and changes in beam direction with highly accurate control of transducer orientation in a notably and advantageously miniaturized construction.

Abstract: A miniaturized ultrasonic probe comprises a housing encasing a motor, an ultrasonic transducer mounted for controlled rotation on the motor shaft, and an angular position sensor connected to the shaft. The housing has a radiating dome about the transducer and is sealed and wholly filled with an acoustically-transparent fluid. The dual frequency transducer operatively emits either of two ultrasonic frequency beams from opposed faces of a sandwich-like construction, and the position sensor is implemented using a low mass variable-inductor arrangement. The resulting probe attains unusually rapid accelerations and changes in beam direction with highly accurate control of transducer orientation, all in a miniaturized construction particularly well adapted for operative insertion in a human or animal body cavity or surgical site.

Abstract: Method and apparatus for synthesizing a continuous estimate signal of a Gaussian signal resulting from ultrasonic Doppler measurement on a fluid flow, from existing segments of the Gaussian signal. The segment signals are first stored and there is at the same time calculated a characteristic frequency parameter for each segment. The frequency parameter is combined with the first stored segment signal for transposition thereof to a base-band at or about the zero frequency point, and this base-band signal is used to generate coefficients in a controlled filter device which on the basis of a broad-band input signal gives a synthesized filter output signal which is a substantially Gaussian signal. The filter output signal is multiplied by a weighting or window function for smoothing the transitions between successive segments.

Abstract: A pulsed ultrasonic beam is swept over an image field and the backscattered signal is sampled for a multiplicity of timelags to obtain signals from a multiplicity of depths along the beam, the signals forming a two-dimensional set of range cells. A combination of the bandwidth and power of the signal from each range cell is utilized to identify those regions of the image field at which the blood velocity is sufficiently high that Doppler frequency aliasing occurs. These regions are then designated with a single color with strong contrast to the colors employed in the regions wherein the blood velocity is below this limit, so that the regions of high velocity flow are clearly delineated in the image. Where the velocity is sufficiently low that no frequency aliasing occurs, the mean Doppler shift is coded into a continuous distribution of colors for indicating the magnitude of the imaged velocities.

Abstract: Laser catheter delivery system for controlled ablation of atheroma, combining laser angioplasty and intra-arterial ultrasonic imaging. In laser ablation of atheroma, dosage and directing of the laser light beam represent critical problems, since accurate removal of the atheroma is required without damaging of the arterial wall.

Abstract: Method and apparatus for generating a multidimensional map of blood velocities in the circulatory system of living species, using the Doppler effect of backscattered ultrasound from the blood, with real time presentation on a display device, with the ability to select small sample volumes in the flow map where the information can be presented as a function of time together with the moving multidimensional map in real time. There is transmitted a pulsed ultrasonic beam which is swept in two or more dimensions through the region of the biological structure which is to be investigated. The backscattered ultrasonic signal is sampled in a number of depth volumes along each beam direction of the transmitted ultrasonic pulses. For each depth and beam direction there is determined a velocity parameter of the blood flow by means of the Doppler principle, and the velocity parameters from the whole region investigated are read into an image memory.

Abstract: An ultrasonic transducer probe having a mechanically steerable acoustic element includes a linear motor having a stationary magnet assembly and a coil bidirectionally linearly movable with respect to the magnet assembly. A mechanical arrangement formed of a pair of spaced apart, rotatably mounted pulleys and a flexible belt connecting the pulleys couples the coil and an ultrasonic transducer or acoustic element. The transducer element is mounted for rotation with at least one of the pulleys so that linear motion of the motor coil is converted to rotative motion of the transducer whereby the transducer and the ultrasonic beam it emits is caused to sweep through a selected angular sector. A position sensor formed of a supplemental stationary magnetic material and a position coil mounted for movement with the motor coil is utilized for detecting the linear position of the coil and, correspondingly, the angular orientation or position of the transducer element.

Abstract: Method and apparatus for ultrasonic blood flow velocity measurement based upon the doppler principle (doppler measurement), combined with simultaneous echo amplitude imaging by employing ultrasonic pulses (echo imaging). The method is used for investigation of living biological structures, in particular during movement, for example a heart function. The main application will be in hospitals and the like. The doppler measurement and the echo imaging is effected sequentially with so short intervals that the echo imaging is updated with a sufficiently high rate for obtaining an acceptable picture quality, with the doppler measurement occupying a substantial portion of the time. The information is presented in real time on a display screen. A control unit synchronizes the doppler measurement and the echo imaging, and there is incorporated one or more transducers in the equipment.