JPH0255049A - Phased array ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To reduce the number of transmitting/receiving circuits and the number of signal lines by providing a variable resistor means controlling the passage of the received signal and controlled with its internal resistance value by the control signal, a passing signal selecting means connected in parallel with the variable resistor means, and an opening control means in the thickness direction made of fixed impedance inserted between the junction of both means and the ground. CONSTITUTION:The transmitted signal of a transmitting circuit 4A excites vibrators 11A and 11B via a high-voltage passing diode circuit 13 and directly excites a vibrator 12, ultrasonic waves are concurrently transmitted from three vibrators in the thickness direction. Among the reflected signals returned from an object to the vibrators 11A, 11B and 12, the signal received by the vibrator 12 enters a receiving circuit 4B, the signals received by the vibrators 11A and 11B enter an FET 14. The received signals are weak and can not pass the high-voltage passing diode circuit 13, only the received signal of the center vibrator 12 is inputted to the receiving circuit 4B. The opening value in the thickness direction of a probe 1 can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a phased array ultrasonic diagnostic apparatus, and more specifically, a method for controlling the frontage in the thickness direction of an image sensor divided in the thickness direction of an arrayed transducer. This invention relates to an improved ultrasonic diagnostic device.

(Prior Art) A sound field scanning method used in a phased array ultrasound diagnostic device controls the phase or delay time of a high-frequency electrical signal applied to an ultrasound probe having a large number of piezoelectric transducers. A device that scans by changing the direction of ultrasound transmitted from an ultrasound probe, and then restores the received signal, which is converted into an electrical signal, by performing the reverse processing of the transmission. It is. An example of a conventional wave transmitting/receiving circuit of this ultrasonic diagnostic apparatus is shown in FIG. In the figure, 1 is a probe consisting of many transducers that convert electrical signals into ultrasonic signals and transmit them, and receive reflected waves and convert them into electrical signals. It is composed of a child row 2Δ, an inner transducer row 2B, and a central central transducer row 3, and has a structure having a plurality of transducers in the arrangement direction. The first row of vibrations 2A and 2B are connected to the same wave transmitting/receiving circuit consisting of a transmitting circuit 4A and a receiving circuit 4B, and the central transducer row 3 is connected to a transmitting/receiving circuit consisting of a transmitting circuit 5A and a receiving circuit 5B. has been done. In this way, the transducer rows 2A and 2B at both ends in the thickness direction and the central transducer row 3 are controlled separately, and the operation mode determines whether only the central transducer row 3 is operated or all the transducer rows are operated. By selecting , it is possible to distinguish between focusing on short distances and focusing on long distances.

(Problem to be Solved by the Invention) By the way, in the conventional device shown in FIG. 3, two systems of wave transmitting and receiving circuits are used to control the aperture in the thickness direction, so the scale of the entire wave transmitting and receiving circuit becomes extremely large. Therefore, the number of signal lines associated therewith increases correspondingly to the number of wave transmitting/receiving circuits. If it is further divided into multiple stages in the thickness direction, more wave transmitting/receiving circuits and signal lines will be required, resulting in a larger scale.
It is inevitable that the device will become larger and the cost will increase.

The present invention has been made in view of the above points, and its purpose is to be able to control the opening in the thickness direction with a simple circuit, and to
The object of the present invention is to realize a phased array ultrasonic diagnostic device that can reduce the number of required wave transmitting/receiving circuits, signal lines, etc.

(Means for Solving the Problems) The present invention solves the above problems by providing a phased array ultrasonic diagnostic apparatus having arrayed transducers divided in the thickness direction, the internal resistance of which is controlled by a control signal. variable resistance means for controlling passage of the received signal; passing signal selection means connected in parallel to the variable resistance means exhibiting low impedance to high voltage signals and high impedance to weak signals; The present invention is characterized by comprising a thickness direction aperture control means consisting of a fixed impedance inserted between a connection point between the variable resistance means and the passing signal selection means and the ground.

(Function) The transmitting signal from the transmitting circuit excites all the transducers arranged in the thickness direction to transmit ultrasonic waves, and among the reflected waves from the five reflectors, the aperture control means is inserted. The input of the reception signal received by the rotor to the reception circuit is controlled by the control signal of the aperture control means, and the aperture control in the thickness direction is performed by the input of the control signal at the time of wave reception.

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

FIG. 1 is a circuit diagram of an embodiment of the present invention. In the figure, parts equivalent to those in FIG. 3 are given the same reference numerals. The probe 1 shown in FIG. 1 has three rows of transducers in the thickness direction, and only one channel of a large number of transducers, which differ depending on the application, is displayed in the horizontal direction. In the figure, 11A″″, 11
B is a vibrator provided on the outside and inside in the thickness direction, and both are connected in parallel. Reference numeral 12 denotes a vibrator provided at the center in the thickness direction, and is connected to a connection point between the wave transmitting circuit 4A and the wave receiving circuit 4B. 13 is a high-voltage passing diode circuit in which diodes that operate at high voltage are connected in antiparallel to allow a high-voltage signal, which is a transmitting signal, to pass through, but not to pass a weak receiving signal; FE that controls the passage of weak received signals by changing internal impedance
T is connected in parallel to the high voltage passing diode circuit 13, and the transducers 11A, 11B, the wave transmitting circuit 4A and the wave receiving circuit 4
It is inserted between the connection point of B. 15 is a fixed resistor for discharging the charges accumulated in each vibrator.

Next, the operation of the embodiment configured as described above will be explained.

The transmission signal that has undergone amplification and other processing in the transmission circuit 4A is
The vibrators 11A and 11B are excited through the high-pressure passing diode circuit 13, and the vibrator 12 is directly excited to simultaneously transmit ultrasonic waves from the three vibrators in the thickness direction. Among the reflected signals reflected from the target object and returned to the imagers 11A, 11B, and 12, the signal received by the transducer 12 enters the receiving circuit 4B as it is, and is received by the transducers 11A, 11B. The resulting signal is input to FET14. Since the received signal is weak, it cannot pass through the high voltage passing diode circuit 13. The internal resistance between the drain and the source of the FETI 4 changes according to a control signal input to the gate, and performs on/off control for the received signal. When FET 1.4 is on, the received signal passes through and is input to the receiving circuit 4B,
When the FET 14 is off, the received signal does not pass through, and only the received signal from the central vibrator 12 among the three vibrators is input to the wave receiving circuit 4B. Therefore, by controlling the FET 14 with a control signal, the aperture value of the probe 1 in the thickness direction can be effectively controlled.

Note that the present invention is not limited to the above embodiments. FIG. 2 is a diagram showing a circuit according to another embodiment of the present invention, where (a) is the circuit diagram, and (b) is a diagram showing details of the aperture control circuit in the circuit of (a). .

In the figure, parts equivalent to those in FIG. 1 are given the same reference numerals. In the figure, 16A and 16B are transducers provided outside the transducers 11A and 11B in the thickness direction of the probe 1, and 17
A is an aperture control circuit connected in series to the parallel circuit of vibrators 11A and 11B, 178G, tffl actuators 16A and 16;
This is an aperture control circuit connected in series to eight parallel circuits.

The aperture control circuits 17△ and 17B are connected to the high voltage passing diode circuit 13 and the FE as shown in the aperture control circuit 17 in FIG.
It consists of a TI4 parallel circuit, and a fixed resistor 8 is inserted between this circuit and ground. The circuit of this embodiment shows an example in which the probe 1 is divided into multiple stages in the thickness direction, and the transducers 11A and 11B on both sides of the central transducer 12 are connected to the frontage control circuit 17A. , vibrator 16
Δ, 16B are connected to the aperture control circuit 17B. The aperture value of the probe 1 can be changed by controlling the aperture control circuits 17A and 17B, respectively. As is clear from FIG. 2, the number of aperture control circuits may be increased each time the number of divisions in the thickness direction increases. The high voltage passage diode circuit 13 of the aperture control circuit 17 may be any circuit as long as it has low impedance against high voltage (or the FET 14
Any other circuit may be used as long as it is a variable resistance circuit controlled by a control signal.

As explained above, according to this embodiment, aperture control in the thickness direction can be performed by using only one transmitter/receiver circuit for one channel in the array direction, and the array type vibrator is not divided in the thickness direction. It can be realized with the same configuration as the transmitter/receiver circuit.

The transducers in the same thickness direction of all channels in the arrangement direction can be controlled by the same control signal, and the transmission/reception signal and the aperture t(J tlO signal) can be realized with a smaller configuration than in the past.

(Effects of the Invention) As described above in detail, according to the present invention, the aperture control in the thickness direction can be performed with a simple circuit, and the number of wave transmitting/receiving circuits and the number of signal lines associated therewith can be reduced. It is possible,
The practical effects are significant.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is a circuit diagram of another embodiment of the present invention, and FIG. 3 is a diagram of a conventional wave transmitting/receiving circuit. 1... Probe 4A, 5A... Wave transmitting circuit 4B, 5B... Wave receiving circuit 1△, 11B, 12.16A, 16B... Vibrator 3.
...High voltage passing diode circuit 4...FET 15...Fixed resistor 7.
17△, 17B...Aperture control circuit patent applicant Yokogawa Medical Systems Co., Ltd. 11B8+ Cocoon diagram Figure 3

Claims (1)

[Claims] (1) In a phased array ultrasonic diagnostic device having an array type transducer divided in the thickness direction, a variable resistance means for controlling the passage of a received signal whose internal resistance value is controlled by a control signal, and a high voltage signal passing signal selection means connected in parallel to the variable resistance means exhibiting a low impedance to the weak signal and high impedance to the weak signal; and a connection point between the variable resistance means and the passing signal selection means and the ground. 1. A phased array ultrasonic diagnostic apparatus comprising: a fixed impedance inserted into the thickness direction aperture control means; (2) The phased array ultrasonic diagnostic apparatus according to claim 1, wherein the resistance value of the variable resistance means constituting the thickness direction aperture control means is controlled by the same control signal for all channels in the arrangement direction.