Hitachi Medical Corporation

Hitachi, Ltd.

Shizuo Ishikawa

Kageyoshi Katakura

Toshio Ogawa

Hisashi Nishiyama

Ryuichi Shinomura

Shinichiro Umemura

Hiroshi Kanda

Yutaka Sato

Satoshi Tamano

Koji Tanabe

Yukio Ito

Yuichi Miwa

Hiroshi Ikeda

Toshio Kondo

Hiroshi Masuzawa

Tsuyoshi Mitake

Koichi Yokosawa

Chitose Nakaya

Shinichi Kondo

Noriyoshi Ichikawa

Shuzo Sano

A needle-like ultrasonic probe includes an inner needle received in a hollow, tubular outer needle for rotation about an axis thereof. The inner needle has a pointed distal end, and a notch is formed in an outer peripheral surface of that portion of the inner needle which is located adjacent to the distal end thereof. At least one ultrasonic transducer, as well as an acoustic lens for converging an ultrasonic wave, produced by the ultrasonic transducer, onto a point near to the outer peripheral surface of the inner needle, is provided in the notch. A filler, having an outer surface conforming to the outer peripheral surface of the inner needle, is fitted in the notch. With this construction, after the inner needle is smoothly stuck into a living tissue, even if it is rotated and axially moved, the living tissue is less affected or damaged by the inner needle.

Needle-like ultrasonic probe for ultrasonic diagnosis apparatus, method

An ultrasound signal processor has a receiving signal digitizing circuit, waveform conversion circuit for mixing a produced digital signal by a reference signal, a cumulation circuit for performing a cumulation processing of a series of converted signals, a delay circuit subject to the cumulation processing, and a circuit for adding delayed signals, whereby the frequency of the receiving signal is shifted to a lower frequency and thereafter subjected to a cumulation processing which perform over-sampling technique so that the accuracy of an analog to digital conversion can be improved drastically. The ultrasound signal processor further has a circuit for converting a receiving signal into a low frequency signal by analog-mixing and a circuit for passing a low frequency component of the analog-converted signal, whereby a higher frequency receiving signal can be digitized even if the digitizing circuit has a insufficient sampling rate.

Ultrasound signal processor

An ultrasonic flow mapping apparatus transmits and reflects waves from sampling points on a two-dimensional cross-section. The waves are detected while transmitting repeatedly ultrasonic pulses. The phase shifts of different reflected waves are calculated, and displayed in color to show a distribution of blood flow velocity. Artifact due to reflected waves from body organs, which remain even by using MTI filters, is detected from phase signals, which have not passed through the MTI filters, and the artifact is removed by lowering display brightness for a sampling point corresponding to a relevant detection output.

Apparatus for ultrasonic color flow mapping

A pulse doppler apparatus transmits a ultrasonic sound wave at transmission intervals T and T+Ts alternately and iteratively, detects the phase difference attributable to the doppler shift in the reflected sound wave signal at the interval T and the phase difference in the reflected signal at the interval T+Ts sequentially, detects the difference between both phase differences, and transforms the difference into a doppler frequency. The apparatus includes an MTI filter which exerts the same filtering characteristics on the reflected sound signals at both intervals T and T+Ts.

Pulse doppler flow speed meter

A flow meter, in which pulsed continuous ultrasonic wave is transmitted towards an object at predetermined intervals T to obtain a phase vector from a reception signal of wave reflected by the object and which calculates a Doppler frequency from the average value of phase differences between phase vectors at the sampling interval T to obtain a signal indicating the speed of the object, comprising a phase difference calculator by the auto-correlation method, by which a plurality of phase difference vectors indicating phase differences between phase vectors are added, the argument of the sum vector thus obtained representing the average phase difference, or a phase difference calculator by the 2-axial-component method, by which a phase difference is divided into 2 axial components, a cosine value and a sine value, and the average phase difference is obtained by using the average value for each of the components, and a phase difference calculator by the phase difference averaging calculator, by which a plurality of phase differences are added, as they are, to obtain the average thereof, in order to obtain a phase difference average value having small errors by switching them.

Ultrasonic doppler flow meter

A ultrasonic Doppler meter for measuring the speed of a moving body by measuring the phase shift due to the Doppler effect on received signals, comprising a transmitting/receiving unit transmitting ultrasonic bursts with a constant time interval towards the moving body and receiving reflected waves; a unit for measuring a phase difference vector representing a difference between phases of received signals corresponding to two successive transmitted pulses; a unit for calculating a difference between phase differences on the basis of two successive phase difference vectors stated above; and an accumulation unit for adding the difference between phase differences to a preceeding phase difference vector so as to obtain the speed of the moving object.

Ultrasonic doppler meter

An ultrasonic Doppler blood flow meter comprises a transmit-receive transducer transmitting ultrasonic wave toward and into a living body and receiving an echo signal, quadrature detectors detecting a real (R) component and an imaginary (I) component of the receiving echo signal respectively, A/D converters converting analog output signals of the quadrature detectors into digital signals respectively, a converter subjecting the R and I components to quadrature transformation to generate output signals representing the absolute value and phase angle (.theta.) respectively of the received echo signal, and a signal processing circuit calculating the mean value of the differences (.DELTA..theta..sub.i =.theta..sub.i -.theta..sub.i-1) between the phase angles (.theta..sub.i) and their preceding ones (.theta..sub.i-1) detected when the ultrasonic wave is transmitted and the echo signal is received a predetermined number of times. In the signal processing circuit, the phase angle differences (.DELTA..theta.) are each resolved into an X-axis component (cos .DELTA..theta.) and a Y-axis component (sin.DELTA..theta.), and, after calculation of the mean values X and Y of n consecutive X-axis and Y-axis components respectively, the mean Doppler shift phase angle .DELTA..theta.=tan.sup.-1 (Y/X) is calculated on the basis of the calculated mean values X and Y.

Ultrasonic doppler blood flow meter

An ultrasonic diagnosis apparatus includes a circuit unit for obtaining an envelope signal of a received ultrasonic signal, an A/D converter for A/D converting the envelope signal, and a circuit unit responsive to the output from the A/D converter for emphasizing the high frequency components of the envelope signal through a digital signal processing.

Ultrasonic diagnosis apparatus

A probe which is inserted into a lumen to obtain an ultrasonic tomogram using mechanical scanning is disclosed. A cylindrical acoustic case is filled with a liquid medium which transmits sound waves, and an elliptical ultrasonic transducer is immersed therein in such a manner that it can be rotated by a motor. The diameter of the transducer parallel to its axis of rotation is greater than that perpendicular to the axis of rotation, so that the lateral resolution parallel to the axis of rotation is improved, as well as the sensitivity.

Growing community of inventors

Kanagawa, Japan

Shizuo Ishikawa