JPH01250228A - Received beam former - Google Patents

Abstract

PURPOSE:To simultaneously form further many received sonic lines so as to reduce the number of parts, therefore, to reduce power consumption, by converting the signal received by a vibrator element to a light signal and delaying said light signal by a optical fiber to convert the same to an electric signal to form sonic lines. CONSTITUTION:The ultrasonic signal received by a vibrator element IL0 is amplified by a preamplifier A0 and the output signal thereof allows a light emitting diode LED0 on an element side to emit light which is, in turn, transmitted to photodiodes PD by optical fibers OF0-OF127. In the same way, the received signal of an element EL63 allows a light emitting diode LED63 to emit light which is, in turn, transmitted to a photodiode PD0 on an output side by an optical fiber 63F0. The length of each of the optical fibers OF0-63F0 is controlled in order to delay a light signal so as to form one sonic line and the output signal of an amplifier A0' forms the 0-th sonic line and, in the same way, the output signal of an amplifier A127' forms the 127-th sonic line. By this method, the optical fibers F connecting the light emitting photodiodes LED and the photodiodes PD constitute a perfect group formation.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an ultrasonic diagnostic apparatus that delays and adds the received signals of a sensor array composed of a plurality of transducer elements. Regarding receiving beamformer.

(Prior art) Ultrasonic diagnostic equipment irradiates ultrasound signals into the subject's body, receives sound waves reflected from various tissues and lesions of the subject, displays images, and provides diagnostic data. It is a device. There is a method of scanning the inside of a subject and observing each part by moving a probe, but a method of scanning the part to be inspected without moving the probe is to arrange many transducer elements, There is a phased array scanning method in which a beam of sound waves is created by electronically controlling the transmission time of the sound waves sent out from each element, and the beams are swayed and scanned by electronic control. This electronically controlled scanning method is widely used because scanning is easy.

(Problem to be Solved by the Invention) Conventionally, in this phased array type ultrasonic diagnostic apparatus, a different delay device is provided for each received signal of each element so that a sound ray is formed by the received signal. It performs phasing addition. This method of phasing and addition includes a one-way electric delay method that obtains different amounts of delay by switching delay lines with many analog switches, and a method that provides the amount of delay using digital words, which are cumbersome methods. I went there. Therefore, a considerable portion of the electronic components used in the device has been devoted to the receiving beamformer, which uses delay lines, analog switches, shift registers, and the like. Therefore, the power consumption was also considerable. Moreover, despite the use of such a large number of electrical components, the number of received ultrasound beams (hereinafter referred to as sound rays) that can be simultaneously synthesized is about four at most.

The present invention has been made in view of the above points, and an object thereof is to realize a receiving beamformer with a small number of parts and therefore low power consumption.

Furthermore, another object is to realize a receiving beamformer that simultaneously forms a large number of receiving acoustic rays.

<Means for Solving the Problems> The present invention, which solves the above-mentioned problems, provides an ultrasonic diagnostic apparatus that delays and adds the received signals of a transducer array composed of a plurality of transducer elements in a phased manner. The receiving beamformer includes a modulating light emitting means for converting a received electrical signal into an optical signal, and receiving and transmitting an optical signal from the light emitting means, and giving a required delay to the optical signal depending on the quality of the optical transmission path. It is characterized by comprising an optical fiber and a light receiving means for converting the optical signal transmitted from the nine fibers into an electrical signal proportional to the intensity of the optical signal.

(Operation) The signal received by the transducer element is converted into an optical signal by the light emitting means, and after receiving a required delay by the optical fiber, is converted into an electric signal by the light receiving means, thereby forming a sound ray.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention.

In the figure, EL is a transducer element that receives reflected waves, and includes 64 transducer elements from ELo to EuB6. A is a low-noise preamplifier that amplifies the output electrical signal of the resonator element El, and each EL
Ao is connected to o, and A83 is connected to ELag. L
ED is 64 light emitting diodes connected to each preamplifier Ao=Aa3, and each preamplifier AO to A
The high-frequency signals of the outputs of 63 are given in numerical order, and a DC bias is applied so that the signals above a certain value cause light to be emitted. F is an optical fiber that transmits the light emitted by each light emitting diode LED to the photodiode PD on the output side; 128 optical fibers from OFo to 0Ftzt are connected to LEDo, and 128 optical fibers from 1Fo to 1FK27 are connected to LEDz.
Similarly, 128 optical fibers are connected to each of the LEDs 2 to LEDas.

Photodiode PD is 128 of PDo"-PDtzv
There is an optical cable from the LEDo to the PDo.
o, OF+, − for PDl.

OF+2y is connected to PD+27. In addition, the optical cable from LED 63 is connected to 63 Fo to PDo.
, −, PDt 2 ? 63F+27 is connected to. The output signal of each photodiode PD is input to an amplifier A'. Amplifier A' is composed of 128 amplifiers Ao' to A127'.

The operation of the embodiment configured as described above will be explained by limiting it to the one-channel photodiode PDo. The ultrasonic signal received by the camera element ELo is sent to the preamplifier Ao.
is amplified. As the preamplifier Ao, a low-noise amplifier is used to maintain a good noise figure of the system. This output signal causes the light emitting diode LEDo to emit light. Optical fiber OF by light emission of light emitting diode LEDo
o~OF+ 27 transmits light to photodiode PD. If we consider only the photodiode PDo, LE
The light Do is transmitted by the optical fiber OFo. The light emitting diode LED+ emits light in response to the received signal of the element ELL, and the light is transmitted by the optical fiber IFo and reaches the photodiode PDo. Similarly element EL
The received signal a3 causes the light emitting diode LED63 to emit light and is transmitted to the photodiode PDo through the optical fiber 63Fo. Each optical fiber OFo, IFo.

The lengths of 2Fo, . . . , 63Fo are adjusted to give different delays so as to form one sound ray, and the output signal of the amplifier Ao' forms the 0th sound ray. Similarly, the output signal of amplifier AI' forms the first sound ray, and the output signal of amplifier A127' forms the 127th sound ray. In this way, the optical fibers F connecting the light emitting diode LED and the photodiode PD form a complete group. The length of the optical fiber OFo~63F+27 is O~2kn, which is assigned according to the delay time.

The delay time is a 67% reduction in the wavelength of light during optical fiber transmission.
Then, 1μS → 200m 10μS → 2kl Required quantity of optical fiber F - 64 x 128-8192 Required length of optical fiber F + 1k11 x 8192 (assuming the average as Ikl) "w82
00km Here, it is assumed that the long optical fiber F is wound around a drum.

Note that the present invention is not limited to this example. Second
The figure is a schematic configuration diagram of another embodiment of the present invention. In the figure, parts equivalent to those in FIG. 1 are given the same reference numerals.

In the figure, VDLo is a variable length delay line that delays the received signal of element ELo.
DLo=VDL3 is element E that constitutes the subarray
A delay amount is given to each received signal in order to locally phase the delay difference between Lo to E13. Reference numeral 1 designates an addition/synthesis circuit for phasing and adding the output signals of each of the variable length delay lines VDLo''-VDL3, and 2 an aperture control circuit for controlling the aperture of each sub-array. In order to reduce the number of layers, each subarray is grouped together to perform dynamic focus by delaying the received signal and dynamic aperture control by the aperture control circuit 2. In this example, the subarrays are grouped into four channels, so the optical fiber F
The required number of layers is as follows.

Required number of optical fibers F m -16X128-2048 Required length of optical fiber F -1ksx 2048 'e 2050 km (Effects of the Invention) As explained in detail above, according to the present invention, light can be used as a transmission medium. This makes it possible to realize a receiving beamformer with a simple configuration, low power consumption, and low m-sound. In particular, as the frequency to be handled increases, the total fiber length of the optical fiber F can be shortened, which is even more advantageous.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of one embodiment of the present invention, and FIG. 2 is a schematic diagram of another embodiment of the present invention. EL...Resonator element LED...Light emitting diode F...Optical fiber PD...Photodiode VDL...Variable length delay line...Addition synthesis circuit 2...Aperture control circuit

Claims (5)

[Claims] (1) Modulation that converts a received electrical signal into an optical signal in a receiving beamformer of an ultrasonic diagnostic device that delays each received signal of a transducer array made up of multiple transducer elements, and adds the phased signal. an optical fiber that receives and transmits an optical signal from the light emitting means and provides a required delay to the optical signal depending on the length of the optical transmission path; A receiving beamformer comprising: a light receiving means for converting the signal into an electric signal proportional to the intensity of the signal. (2) The optical fiber is arranged from each light emitting means to the light receiving means equal to the number of the desired ultrasonic beams so as to form all the desired ultrasonic beams. Receiving beamformer. (3) A light emitting diode is used for each element as the light emitting means, and the light receiving means is a photodiode provided for each desired ultrasonic beam, which is operated in a mode of adding biased incoherent light as a whole. The reception beamformer according to claim 1 or 2, characterized in that: (4) The light emitting means converts the received signal whose local phase is electrically phased in units of the subarrays of the vibrator elements into an optical signal, and the optical fiber is responsible for the delay of the main long section. The reception beamformer according to claim 1 or 2, characterized in that: (5) The receiving beamformer according to claim 4, wherein the electrical processing circuit of the sub-array performs dynamic processing such as electronic focusing and aperture width control.