JPH0370492B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mechanical scanning ultrasonic probe ( (hereinafter abbreviated as MSP).

Configuration of Conventional Examples and Problems There are various methods of obtaining ultrasonic tomographic images by mechanically scanning ultrasonic beams in a fan shape, and the most common example is shown in FIG. Figure 1A shows the overall configuration diagram.
Figure B is a side view of the rotor (rotating body) 1 shown in Figure 1A for actually fan scanning the ultrasonic beam, and Figure 1C is a switch circuit for selecting and operating the piezoelectric vibrator. This shows that the parts within the broken lines rotate.

In FIGS. 1A, B, and C, a rotor 1 has three piezoelectric vibrators 2a, 2b, 2c arranged at equal intervals on its outer surface.
, reed switches 3a, 3b, 3c for selectively switching the piezoelectric vibrators 2a, 2b, 2c, and a secondary coil 6b provided on the rotating shaft of the rotor 1 to constitute a rotary transformer. The rotor 1 includes a rotation drive unit 9 such as a motor, and a belt 8.
rotated by. On the other hand, the rotation of the rotation drive section 9 is controlled to be maintained at a constant rotation speed based on a signal from the rotation control detector 10. 11 is a housing. The rotary transformer 6 provided on the rotating shaft of the rotor 1 is composed of a primary coil 6a and a secondary coil 6b, and transmits and receives signals in a non-contact manner.

Transmission and reception operations by this MSP will be explained below.
As the rotor 1 rotates, the reed switch 3a is closed depending on the relative position between the fixed permanent magnet 7 and the reed switch 3a, and the piezoelectric vibrator 2a is selected.
Naturally, at this time, the piezoelectric vibrator 2a needs to face the living body at a desired position. Next, a connection cable 12 with a transmission signal processing/display unit (not shown)
A transmission signal that drives the piezoelectric vibrator 2a is applied to the primary coil 6a of the rotary transformer 6 through the transmission signal. The signal is magnetically transmitted to the secondary coil 6b.
and drives the piezoelectric vibrator 2a. Ultrasonic pulses generated from the piezoelectric vibrator 2a are radiated to the living body through the acoustic window material 5 filled with a sound wave propagation medium.
The ultrasonic reflected pulse signal generated in the living body is guided to the transmitting/receiving signal processing/display section through a path opposite to that of the transmitting signal. This operation is repeated while rotating the piezoelectric vibrator 2a to obtain a fan-shaped ultrasonic tomographic image. Here, the reed switch 3a needs to be closed until the piezoelectric vibrator 2a completes the fan-shaped scanning at the desired angle, and this can be achieved by appropriately setting the shape or installation position of the fixed permanent magnet 7. .

Similarly, piezoelectric vibrator 2b and reed switch 3b, piezoelectric vibrator 2c and reed switch 3c
The above operations are repeated for each combination. That is, each time the rotor 1 rotates once, the three piezoelectric vibrators 2a, 2b, 2c are sequentially activated by the reed switch 3.
A, 3b, and 3c are selectively transmitted and received by opening and closing to obtain a fan-shaped ultrasonic tomographic image.

By the way, the biggest problem with the MSP based on such a configuration is that the reed switches 3a, 3b, and 3c have a short lifespan. Generally, the opening/closing life of a reed switch is said to be about ^107cm .
Assuming that the rotor 1 of the MSP rotates at 600 rpm, each reed switch opens and closes 10 times per second, so it will fail in about 280 hours, and it must be said that the reliability of the device is extremely low. This has been the biggest problem especially in medical devices that require high reliability.

Purpose of the Invention The present invention uses an electronic switch with a semi-permanent lifespan in place of the reed switch used in the conventional MSP described above, thereby significantly extending the lifespan, which was the biggest problem with conventional MSPs, and improving reliability. Its purpose is to significantly improve sexual performance.

Composition of the Invention The present invention achieves the above-mentioned object, and includes a signal transmission unit that incorporates a high voltage withstand electronic switch into a rotating support and transmits the power supply and control signals of the semiconductor switch, and transmitting and receiving signals applied to the piezoelectric vibrator. A highly reliable MSP is provided by selectively applying the transmission/reception signals from the signal transmission section to each piezoelectric vibrator using an electronic switch.

DESCRIPTION OF EMBODIMENTS FIG. 2 is a side view showing an embodiment of the rotor 13 according to the present invention. Each piezoelectric vibrator 2a,
Lead wires 14 taken out from one of the electrodes 2b and 2c are connected to semiconductor switches 15, respectively. This semiconductor switch 15 has a withstand voltage of 100 to 200V, and is HV10 (manufactured by Supertex).
It is a chip. Note that the other electrode of each piezoelectric vibrator is connected to a common ground. The semiconductor switch 15 includes a connection line 1 for transmitting and receiving signals.
6a, a connection line 16b for supplying power, and a connection line 16c for transmitting digital signals for controlling the switch. Although these various connection lines are represented by one line in FIG. 2, in this embodiment there is actually one connection line 16a, four connection lines 16b, and three connection lines 16c. It's a book. However, if the decoder is built into the rotor, only two are required. Furthermore, integrators, specifically capacitors 17 and 18, are added to the connection lines 16b and 16c to protect against instantaneous interruptions. The switch operation is similar to the conventional MSP described above, in which the terminal 19 corresponding to each piezoelectric vibrator and the common terminal 20 are connected when each piezoelectric vibrator 2a, 2b, 2c is at a desired position relative to the living body. Let me do it.
Note that FIG. 2 is for explanation only, and in reality, the semiconductor switch 15, capacitors 17, 18, or connection lines 16a, 16b, 16c are all connected to the rotor 1.
Built in 3.

FIG. 3 shows a concrete connection example of the various signal or power supply connection lines mentioned above.
Since the overall configuration of the MSP is almost the same as that shown in FIG. 1A, only the lower part of FIG. 1A is shown. The rotor 13 based on this embodiment is attached to a rotating shaft 21, which is supported by two bearings 4 provided on the acoustic window material 5 and the housing 11, and is supported by a belt 8. Driven. The various connection wires 16a, 16b, 16c shown in FIG. 2 pass through the rotating shaft 21 and are connected to each electrode 23 of the slip ring 22. The slip ring 22 is attached to the rotating shaft 21 and rotates in response to the rotation of the rotating shaft 21. In addition, the slip ring 22
The electrodes 23 are arranged concentrically around the rotating shaft 21, and the number of electrodes 23 is basically the same as the number of connection lines. A needle 24 is in contact with the electrode 23 with a predetermined pressure, and guides various signals and power to a transmit/receive signal processing/display unit (not shown).

FIG. 4 is a configuration diagram of an MSP showing a second embodiment of the present invention. The difference from Fig. 3 is the method of transmitting various signals and power, and the rotary transformer 25
a, 25b and the slip ring 22 are used. Ideally, it is desirable to transmit various signals and power in a non-contact manner, and in particular, non-contact transmission is desirable as a method of transmitting and receiving signals with a dynamic range of 100 dB or more. Therefore, in FIG. 4, the transmitted and received signal 26 is transmitted to the rotary transformer 2.
5a and 25b, and a slip ring 22 is used to provide control signals and power for the semiconductor switch. Of course, the semiconductor switch control signals may be transmitted using the rotary transformers 25a and 25b, and in that case, rotary transformer pairs corresponding to the number of signals are provided. Specifically, a plurality of rotary transformer pairs are provided concentrically.
Note that the rotary transformer 25a is fixed, and the other rotary transformer 25b is attached to the rotating shaft 21 and rotates.

The lifespan of the MSP based on these examples is determined by the lifespan of the slip ring, but it has been confirmed that it has operated for more than 3000 hours without failure, compared to the lifespan of the conventional MSP of about 300 hours. about 10 compared to
This means that the lifespan will be more than doubled. In addition, by introducing a structure in which only the DC power supply was used to transmit signals through the slip ring, standards for slip ring accuracy and performance were relaxed, and as a result, the life of the MSP could be further extended.

Effects of the Invention In summary, the present invention provides a support body in which a plurality of piezoelectric vibrators are arranged at a predetermined angle, an electronic switch for selectively applying transmission/reception signals to these piezoelectric vibrators, and a drive for rotating the support body. The present invention provides a mechanical scanning ultrasound probe (MSP) comprising a signal transmission section that transmits transmission/reception signals, power supply, and control signals to the piezoelectric transducers, and a signal transmission section that is connected to a plurality of transducers. In addition to achieving miniaturization by reducing the number of connection wires used in conventional mechanical scanning ultrasonic probes, it has the exceptional effect of significantly extending the life span and significantly increasing reliability, which was the biggest problem with conventional mechanical scanning ultrasonic probes. .

[Brief explanation of drawings]

Figure 1A is an overall configuration diagram of a conventional mechanical scanning ultrasonic probe, Figure 1B is a side view of the rotor of the same probe,
Fig. 1C is a switch circuit diagram of the same probe, Fig. 2 is a side view of the rotor of the mechanical scanning ultrasonic probe according to the first embodiment of the present invention, and Fig. 3 is a rotor of the same probe. 4 is a schematic diagram of a rotor portion of a mechanical scanning ultrasonic probe according to a second embodiment of the present invention. 13...Rotor (support body), 15...Semiconductor electronic switch, 16a, 16b, 16c...Connection wire, 22...Slip ring, 25a, 25b...
...Rotary transformer.

Claims (1)

[Scope of Claims] 1. A support that includes a plurality of piezoelectric vibrators arranged at a predetermined angle and includes an electronic switch that selectively applies transmission and reception signals to the piezoelectric vibrators, and a drive unit that rotates the support. , sending and receiving signals to the piezoelectric vibrator;
A mechanical scanning ultrasonic probe that includes a power supply and a signal transmission section that transmits a control signal. 2. The mechanical scanning ultrasonic probe according to claim 1, wherein the signal transmission section is a slip ring. 3. The mechanical scanning ultrasonic probe according to claim 1, wherein the signal transmission section is comprised of a slip ring and a rotary transformer.