JPS6337664B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to the transmission of ultrasonic devices such as ultrasonic diagnostic devices that transmit and receive ultrasonic signals to and from a specimen and obtain tomographic images of the specimen from the received signals. The present invention relates to an ultrasonic measuring device suitable for obtaining high-resolution tomographic information.

[Conventional technology]

Conventionally, ultrasonic diagnostic or flaw detection devices have been known that transmit an ultrasonic beam inside a specimen such as a human body or a metal object, and obtain tomographic information by receiving reflected signals and scattered signals obtained from the tomographic position of the specimen. ing.

In such ultrasonic devices, the ultrasonic beam to be transmitted is generally converged at a predetermined focal position and the beam diameter is narrowed to improve the on-axis resolution of the beam in the beam transmission direction - so-called azimuth resolution. .

FIG. 8 is a diagram explaining the principle of such an ultrasonic measuring device.

In the figure, 1 is a probe, 1A and 1B are ultrasound beams, 1a1 and 1b1 are convergence positions (hereinafter referred to as focal points), 1c is a transmission center line, and 2 is a specimen.

Further, the ultrasonic beams 1A and 1B have center frequencies of different frequencies _f1 and _f2 , respectively.
Explain the operation. A probe 1 is brought into contact with a specimen 2 and the probe 1 is simultaneously driven at a plurality of different frequencies.

At this time, the ultrasonic beam 1A is controlled to be focused on the focus 1a1, and the ultrasonic beam 1B is controlled to be focused on the focus 1b1. These ultrasonic beams 1A and 1B are reflected within the specimen and received by the probe 1. A discrimination filter (not shown) is connected to the probe 1, and received signals are distinguished and extracted for each ultrasonic beam.
It is considered to be fault information.

Therefore, the ultrasonic beam 1A can irradiate a beam with a narrow diameter in a range _l1 near the focal point 1a1, and by extracting only information in this range _l1 , the extracted information has a better resolution. .

Moreover, since the ultrasonic beam 1B has a narrow beam diameter in the range _l2 , a signal with good resolution of information in that part can be obtained. Therefore, taking into consideration the speed of sound in the specimen 2 and the distance from each focal position 1a1, 1b1 to the transducer, the period for receiving the reflected signals of the tomographic plane within the range _l1 measured from the transmission time is the beam 1A. During the reception period corresponding to range _l2 , only the received signals from beam 1B are extracted, and by combining these, clear tomographic information can be obtained.

FIG. 9 is a diagram showing an example of beam diameter characteristics of an ultrasonic beam. In the figure, the vertical axis shows the beam diameter, and the horizontal axis shows the distance from the transmission position to the focal point.

The probe used to measure the figure has a cross section of 13 mm.
32 transducers (piezoelectric vibrators) in ×13mm
We used probes arranged in parallel. The figure also shows the beam diameter characteristics at a sound pressure of -6 dB when the so-called phased array method is used to converge the beam by giving a phase difference to the activation signal of each transducer, and the focal length is set to 100 mm. According to the figure, for example, when a beam having a beam diameter of 5 mm is to be used effectively, only received signals within a distance range of about 52 mm to 132 mm are selectively extracted from the signals of the beam.

That is, this range of 52 mm to 132 mm corresponds to l ₁ and l ₂ shown in FIG.

Returning to Figure 8 again.

In order to receive signals in the range l ₁ and l ₂ in FIG. 8, signals of different frequencies corresponding to the respective depth portions l ₁ and l ₂ are used.

Therefore, the ultrasonic waves emitted from the probe 1 require time to emit the first frequency signal and time to emit the second frequency signal, which is preferable from the viewpoint of high-speed signal processing. It wasn't.

Therefore, in order to improve this, conventionally, the 10th
A probe as shown in the figure has been devised.

FIGS. 10a and 10b show perspective exploded cross-sectional views of the probe.

In FIG. 10a, the transducer 1 is composed of a piezoelectric element 1A' that transmits the A-system ultrasonic beam 1A in FIG. 8 described above, and a piezoelectric element 1B' that transmits the B-system ultrasonic beam 1B. Ru.
Also, each piezoelectric element 1A' has a convergence point O on the central axis 1C.
It has a spherical surface with radius R as the center and is formed into a donut shape with an outer diameter of φ ₁ and an inner diameter of φ ₂ .
Further, the piezoelectric element 1B' has a radius of at least φ ₂ or less, and has a concave surface having a convergence point position different from that of the piezoelectric element 1A'.

With this configuration, by generating different frequencies in the piezoelectric elements 1A' and 1B', it is possible to emit signals of different frequencies at the same time, and high-speed signal processing is realized.

Furthermore, a device as shown in FIG. 10b has been proposed for the same purpose.

FIG. 10b shows a probe used when creating a convergence point using the phased array method.

That is, the probe 1 is connected to the transducer group 1A0~
1An and transducer groups 1B0 to 1Bn are arranged alternately. Further, the transducer groups 1A0 to 1An transmit and receive the A-system ultrasonic beam 1A having signal components in a predetermined frequency band, and the transducer groups 1B0 to 1Bn transmit and receive the A-system ultrasonic beam 1A having a signal component in a predetermined frequency band. The probe 1 transmits and receives an ultrasonic beam having a signal component.
is composed of

[Problem that the invention seeks to solve]

By the way, the inventor of the present invention has discovered that when the structure is as shown in FIGS. 10a and 10b, there is a problem in that so-called side lobes become large.

This will be explained using FIG. 11.

The figure shows an arc P 1 -P ₁ created on a plane formed by the x-axis x1C and the y-axis y, with the radius being the point O, which is the convergence point, and the distance R to the transducer in Fig. _10a. ′ shows the sound pressure above.

The horizontal axis indicates the angle θ between the central axis 1C and the straight line connecting the center and the point x on the arc P ₁ -P ₁ ' in degrees.

The vertical axis is standardized with the sound pressure on the central axis 1C as a value of "1".

Furthermore, in the figure, the wavy line indicates the directivity characteristic when irradiated from the transducer 1A' shown in Figure 10a,
The solid line has the same outer diameter φ ₁ as the above-mentioned donut-shaped transducer 1A', and the same curvature as the transducer 1A'. indicates the directivity when received. According to the figure, the sidelobe S of the characteristic (solid line) of a commonly used transducer is lower than the sidelobe S' of the donut-shaped transducer.

That is, when a donut-shaped transducer is used, an ultrasonic signal with a high sound pressure can be supplied to the convergence point O by the main lobe M, but an ultrasonic signal with a peak is also supplied to other positions. becomes.

For this reason, if a method using a donut-shaped transducer is applied to the ultrasound device as described above, the signal of tomographic information at the side lobe S' position will increase, which will affect the tomographic information at the main lobe M position. becomes.

The deterioration of the tomographic information signal due to this side lobe is the same in the case of FIG. 10b as shown in FIG. 11.

The conventional configuration as described above is disclosed in Japanese Patent Application No. 55-142598.
(Japanese Unexamined Patent Publication No. 57-66746).

The purpose of the present invention is to solve these drawbacks.
An object of the present invention is to provide an ultrasonic transmitting device that can minimize side lobes.

[Means for solving problems]

In order to achieve the above object, the present invention proposes that the cause of sidelobes is that transducers that transmit ultrasound beams of different frequencies are arranged in a mixed manner on the transmitting surface of the probe (the surface on which the transducers are provided). When transmitting multiple ultrasound beams at the same time as in the past, the ultrasound beams are transmitted in such a way that there is virtually no splitting of the ultrasound emission surface, and the gap between the transducers is complemented. It is designed to weaken the robe.

〔Example〕

Figures 1a and 1b are a front view and a side sectional view of an embodiment of the invention.

In the figures, the same parts as those used in the above-described drawings are indicated by the same symbols.

Moreover, 3a, 3b are piezoelectric vibration elements 4a, 4b, 4
C is a matching layer that matches the acoustic impedance of the piezoelectric vibrating elements 3a and 3b and the acoustic impedance of the specimen, and 5a and 5b are backing materials that transmit information from the piezoelectric vibrating element to the side opposite to the specimen side. absorbing ultrasonic signals, 6
a, 6b, and 6c are electrodes; 6a, 6b are driving electrodes; and 6c is a grounding electrode.

In addition, the piezoelectric vibrator 3a has a resonance frequency of 2.5MHz,
The piezoelectric vibrator 3b uses PZT with a resonance frequency of 3MHz (3.5+2.5/2MHz), and the matching layers 4a and 4c
is an epoxy resin with an acoustic impedance of 3.0×10 ⁶ [Kg/m ²・S], and the matching layer 4b has an acoustic impedance of
Fused quartz of 13.0×10 ⁶ [Kg/m ² ·S] was used as the backing materials 5a and 5b, and epoxy resin containing metal powder was used. Note that the electrodes 6a, 6b, and 6c were all formed from silver paste. Furthermore, the distance R of the piezoelectric vibrator 3a from the center of the spherical surface of the vibrator is 80 mm, the distance R of the piezoelectric vibrator 3b is 40 mm, and the transducer 1
A′ has an inner diameter φ ₁ of 6.5 mm, an outer diameter φ ₂ of 13 mm, and transducer 1B′ has a diameter of 6.4 mm, and each thickness is λ/, where λ is the wavelength of the resonant frequency of each vibrator. 4.

FIG. 2 shows the transmission and reception characteristics of each transducer 1A', 1B'. Note that the horizontal axis represents frequency, and the vertical axis represents transmission/reception efficiency. Also, curve a is transducer 1
A' characteristic, curve b is the characteristic of transducer 1B'.

According to the diagram, the frequency band that transducer 1A' can transmit and receive is higher than that of transducer 1A'.
It is clear that it is smaller than B′.

In addition, as a comparison example of the prototype example 1 with the above configuration, a donut-shaped transducer 1A' without the transducer 1B' in FIG. 1 and a transducer 1B' as a prototype example 2 are used. We have created a transducer that has the same resonant frequency as the transducer.

Figure 3 shows the frequency of each of these transducers.
When driven at 2MHz, R = 80 in Q in Figure 10
The results of measuring the sound pressure at a position above the arc P-P' of mm are shown.

Further, curve a shows the characteristics of the first prototype, curve b shows the characteristics of the comparative example, and curve c shows the characteristics of the second prototype.

Note that the vertical axis in the figure shows the value normalized by the sound pressure on the central axis.

According to the figure, it is found that curve a has a larger side lobe than curve c, and a smaller side lobe value than curve b.

In other words, the side lobes of the prototypes according to the present invention are smaller than those of the donut-shaped comparative examples.

Also, A of the transducer shown in FIG. 10b
Each transducer in transducer groups 1A0 to 1An of the system is constructed with the same structure as transducer 1A', and transducer group 1B of system B is configured.
When each of the transducers 0 to 1Bn had the same structure as transducer 1B', a sound pressure characteristic similar to curve c was obtained.

FIG. 4 is a block diagram of an embodiment of the present invention. Further, FIG. 5 is a diagram for explaining the frequency characteristics, and the description will be made with reference to FIG.

Explain the operation.

The timer 8 is supplied with a clock CL of a predetermined period from a clock generation source (not shown). The timer 8 counts the clock cl and outputs a pulse p every time it counts a value corresponding to the transmission cycle. This pulse p is supplied to the driver 9. The driver 9 creates an impulse signal using this pulse p. The impulse signal is supplied to each transducer 1A', 1B' via the switch section 7, and causes the transducer 1A', 1B' to emit an ultrasonic beam.

The switch 7 connects the output line of the driver 9 to the electrodes of the transducers 1A' and 1B' only when an impulse signal is supplied from the driver 9, and connects the output line of the driver 9 to the electrodes of the transducers 1A' and 1B' during other periods.
are configured to connect to the transducers 1A', 1B'.

When the ultrasonic signals are received by the transducers 1A' and 1B', received signals converted into electrical signals are obtained from the transducers 1A' and 1B'. Of these signals, the signal obtained from transducer 1B' is supplied to switch 10 via switch 7, and the signal obtained from transducer 1A' is supplied to filter 11A.

On the other hand, the output pulse p of timer 8 is
is supplied to The timer 10' has a function of counting the above-mentioned period _t3 . That is, the clock cl is counted from the time when the output pulse p is supplied, and the output is set to level "0" until the counted value reaches a value corresponding to period _t3 , and then level "1" (after _t3 ). shall be.
This output is supplied to the switch 10, and the switch 10 sends the input signal to the filter 11B when the output level is "0", and sends the input signal to the signal line obtained from the transducer 1A' when the output level is "1". Connect the lines.

That is, until the period _t3 passes from the time when the pulse p is output, the signal in the band shown in FIG. 5e, which will be described later, is extracted by the high bass filter 11B having a high frequency function. High pass filter 11B
The extracted signal is amplified by an amplifier 12B and supplied to an automatic gain control section 13B.

On the other hand, the pulse output p of the timer 8 is
is supplied to reset the counter 14. After being reset by this reset pulse, the counter 14 counts the clock CL and outputs the counted value. The count value of the counter 14 is supplied to the control circuit 15. The control circuit 15 includes a gain control section 13A,
13B is supplied with a signal for adjusting and controlling the gain according to the counter value.

It is generally known that the deeper the depth of the reflected position within the specimen, the greater the attenuation of the received signal, and the higher the frequency, the greater the attenuation.

Therefore, the gain adjustment sections 13A and 13B change over time.
That is, the overall gain is increased each time the count value of the counter 14 changes due to the input of the clock cl to the counter 14, and the gain is changed such that the higher the frequency, the higher the gain.

Therefore, the received signal corrected for the attenuation within the specimen is supplied to its output. The analog-to-digital converters 16A and 16B convert the analog output of the gain adjustment unit AGC into digital data.

On the other hand, the switch 17 receives the output of the timer 10' whose level changes in the period _t3 as described above. The switch 17 is set to
The output of the system's analog-to-digital converter 16B is given to the memory 15 as write data.

The memory 18 has storage addresses that correspond one-to-one to display addresses on a display screen of a display device (not shown).

Therefore, the write data applied via the switch 17 is stored at different storage addresses depending on the time at which it is received. This storage address is output from the address generation section 19 which converts the count value of the counter 14 mentioned above into a storage address. The address data generated by the address generation section 19 is supplied to the memory 18 by the memory control section 20 at the write timing of the memory 18. Furthermore, the memory control unit 20
is supplied with the count value of the display scanning counter 21. The counter 21 is a counter that counts up in synchronization with the display scan of the display device, and outputs a count value corresponding to the display address scanned and displayed.

The memory control unit 20 alternately repeats a write operation and a read operation for the memory 18. During the write operation, the memory control unit 20 supplies the address output from the address generator 19 to the memory 18, and during the read operation, it supplies the address output from the address generator 19 to the memory 18.
The count value of is given to the memory 18.

The memory 18 retrieves the digital data of the received signal stored as described above from the storage address according to the count value given during the read operation, and
The signal is supplied to the digital-to-analog converter 22. The digital-to-analog converter 22 converts this digital value into an analog signal and supplies it to the display device as a luminance signal.

When the period _t3 has elapsed, the output level of the timer 10' changes. As a result, the switches 10 and 17 are switched to the opposite side.

That is, the switch SW10 connects the input signal line to the input signal line of the filter 11A, and the switch 17 connects the output signal line of the analog-to-digital converter 16A to the write data supply line to the memory 18.

Therefore, the filter 11A is supplied with a signal having the frequency component shown in FIG. 5c.

The filter 11A extracts only the frequency component signal shown in FIG. 5g from this signal.

Thereafter, the data is similarly amplified and converted into digital data, which is then supplied to the memory 18 via the switch 17.

Therefore, after the period _t3 , the memory 18 stores the signals transmitted and received by the transducers 1A' and 1B'.

In the embodiment described above, the transmission and reception characteristics of the transducers 1A' and 1B' are adjusted so that both transducers can be driven over long distances. The transmission and reception characteristics of both may be made wideband, and the frequency band of the signal supplied to and driven by each transducer 1A', 1B' may be adjusted.

However, in this case as well, transducer 1A' is connected to ultrasonic transducer 1 with a narrow frequency band.
It is necessary to send out ultrasonic waves from B′ that encompass this frequency band and have a wide band.

FIGS. 5a to 5g are diagrams illustrating frequency bands of signals according to an embodiment of the present invention.

In each figure, the horizontal axis is frequency and the vertical axis is signal strength. In addition, As and Ar are the transmission wave characteristics of the transducer (hereinafter referred to as the A-system transducer) that transmits and receives the A-system ultrasonic beam (shown as 1A in Figure 1) during transmission and reception. The received wave characteristics, Bs and Br are B-system ultrasonic beams (1 in Figure 1).
Transmission wave characteristics and reception wave characteristics of the transducer (hereinafter referred to as B-system transducer) that transmits and receives (shown as B), Fh is the wave characteristic of the high-pass filter, and Fl is the wave characteristic of the low-pass filter. shows.

Furthermore, the mark [*] indicates the wave characteristics when the respective transmission and reception wave characteristics are combined. For example, “As＊
"Ar" is the transmission wave characteristic of the A-system transducer.
This shows the wave characteristics when a signal waved by As is waved by the received wave characteristics Ar of an A-system transducer.

Explain the operation.

First, when the A-system and B-system transducers are driven at the same time, ultrasonic waves having components as shown in Figure 5a are transmitted to the specimen side due to the wave characteristics As and Bs of each transducer during transmission. Sent.

That is, the frequency band having the signal component of the ultrasound beam transmitted by the B-system transducer includes the frequency band of the ultrasound beam signal transmitted by the A-system transducer.

Therefore, both the A-system and B-system transducers transmit signals of the same frequency component at the same time.

Next, regarding the operation during reception, the time taken for the ultrasonic signal to travel back and forth between the convergence point of the A-system transducer and the transmission position is t ₂ , and the time taken for the ultrasonic signal to travel back and forth between the convergence point of the B-system transducer and the transmission position is t 2 . The time it takes for the ultrasonic signal to travel back and forth between the positions is t ₁ , and the distance between the convergence point of the A-system transducer and the transducer is that of the B-system transducer. A case where the length is longer will be explained using FIGS. 5d to 5g as an example. During the period t3, which is longer than _t1 and shorter than _t2 from the transmission time, a high-pass filter having the wave characteristic Fh shown in FIG. 5d is connected only to _the B-system transducer.

In other words, if the transmission time is t ₀ , then B during the period t ₀ to _{t 3}
The signal obtained from the transducer of the system is a signal waveformed by the wave characteristics As*Br and Bs*Br.

On the other hand, when the wave characteristic Fh of the high-pass filter shown in FIG. 5d is applied to the waveformed signal, a signal in the area shown by the solid line in FIG. 5e is extracted. In other words, shallow depth tomographic information of the ultrasound beam transmitted by the B-system transducer can be extracted.
At this time, the received signal from the A-system transducer is ignored. Next, during the period after time _t3 , a low-pass filter having a wave characteristic Fl shown in FIG. 5f is applied to the output signals of the A-system and B-system transducers.

That is, first, the signals obtained from the A-system and B-system transducers have wave characteristics As*Ar, As*Br,
This is a signal waved by Bs*Ar and Bs*Br.

On the other hand, when the filter Fl is applied, only the necessary components of the reflected ultrasonic waves for the ultrasonic beam with a deep focal depth can be extracted as shown by the solid line in FIG. 5g. As a result, the B
Since the transducer of the system transmits and receives components in the same phase and same frequency band as that of the A system, it becomes equivalent to a probe that transmits and receives the ultrasonic beam of the A system from the entire aperture surface.

FIG. 6 is a block diagram of another embodiment of the invention.

In the figures, the same parts as those used in each of the figures described above are designated by the same reference numerals.

In addition, T ₁ to Tn are each transducers,
Items with wideband frequency wave characteristics, 9
1 and 92 are driving parts, and the driving part 91 is the above-mentioned A.
The drive unit 92 outputs a signal with a frequency obtained by the wave characteristics of the transducer of the system A, and the drive unit 92 outputs a signal with a frequency obtained by the wave characteristics of the transducer of the system B, which has a wave band including the wave band of the system A. 23 is a timer that outputs a signal of
The timer 8 in FIG. 72 is a counter for dynamically focusing the received signal by setting the delay time of each of the variable delay circuits 251 to 257 according to the time value;
A multiplexer 71 counts the pulses p, and connects each output signal line of the variable delay circuits 251 to 257 to the signal lines of seven adjacent transducers corresponding to the count value of the counter 72, such as a transducer. It is connected to the signal lines _T1 to _T7 .

Explain the operation.

Drive units 91 and 92 are simultaneously driven by pulse p.

At the same time, the timer 23 starts counting, the counter 72 counts up, and the multiplexer 71
Let be the connection system function shown by the dotted line in the figure.

On the other hand, during this transmission, delay circuits 251 to 257
The delay circuits 252, 256, 257 are arranged so that the depth of focus is at point 1a, and the delay circuits 253, 254,
255, respective delay amounts are set by the delay amount control unit 24 so that the depth of focus is at point 1b. At the time of reception, the focus is set to move on axis 1C'.

Therefore, each drive signal generated from the drive sections 91 and 92 is transmitted through the switch 7 to the delay circuits 251 to 25.
57 and drive transducers T ₁ -T ₇ via multiplexer 71 .

Ultrasonic beams 1A and 1B transmitted by the transducers _T1 to _T7 are reflected within the specimen and are received by each of the transducers _T1 to _T7 . These received signals are passed through the multiplexer 71, delayed by the amount of delay set to vary with time as described above, focused, and synthesized for each system. 10 and a low-pass filter 11A. Next, when the pulse p is input, the driving parts 91, 9
2. The timer 23 and counter 72 operate.

As the counter 72 counts up, the multiplexer 71 selects the transducers _T1 to Tn.
The connection system is one step shifted from the dashed line position. In other words, the delay circuit 251 is
T ₂ , delay circuit 252 to transducer T ₃ ,
The connection system is such that the delay circuit 253 is connected to the transducer T ₄ and the delay circuit 254 is connected to the transducer T ₅ (the same applies hereinafter).

Thereafter, the ultrasonic beams 1A and 1B are scanned repeatedly in the same manner.

Furthermore, in the above embodiments, two types of ultrasonic signals having different frequency characteristics are transmitted and received, but three or more types may be used.

FIGS. 7a and 7b are diagrams showing frequency characteristics of three or more types of ultrasonic beams.

As in the case of the two types, as shown in FIG. 7 a or b, the frequency characteristics of the ultrasonic waves emitted from inside the aperture diameter of the transmitted ultrasonic beam are wider, and the frequency characteristics of the outer ultrasonic beams are included. With such a configuration, the azimuth resolution is further improved.

In addition, for a sample with large attenuation as described in this example, it is recommended to consider that the frequency band handled by each transducer is narrower as the distance increases, and that it is placed in a lower frequency range. suitable.

This is because, as described above, the higher the frequency, the greater the attenuation caused by the specimen, and the lower the frequency of the ultrasound signal, the more it can be received without attenuation. On the contrary, it is preferable to use a low frequency ultrasound signal for obtaining tomographic information at a short distance for a specimen with low attenuation, and a high frequency for a long distance. This is because the beam of high-frequency ultrasound is less likely to diverge than that of low-frequency ultrasound, so it can be narrowed down.

〔Effect of the invention〕

As explained above, according to the present invention, an ultrasonic measuring device with small side lobes can be obtained.

In addition, by making the B-system transducer include the frequency band of the wave characteristics of the A-system transducer, signal components such as impulses are uniformly distributed over the entire band as a signal for driving each transducer. It is also possible to downsize the device by providing only one means for generating a signal.

Furthermore, by making the drive part independent from the transducer side and configuring the drive part to regulate the frequency band, all transducers can be of the same structure and material, and the probe Manufacturing becomes easier.

Furthermore, if the measuring device of the present invention is applied to a diagnostic device that extracts and examines tomographic information of a specimen, the tomographic information with less noise due to side lobes can be used for examination, thereby allowing accurate diagnosis.

In addition, during reception, the output components of the inner transducer are first extracted, and then the output components of the outer and inner transducers are extracted, allowing accurate tomographic information to be extracted over a wide range using a thin ultrasonic beam. be able to.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the present invention, FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of the present invention, FIG. 4 is an embodiment of the present invention, FIG. 5 is an explanatory diagram of the present invention, and FIG. The figures are other embodiments of the present invention, Fig. 7 is an explanatory diagram of the present invention, Fig. 8 is an explanatory diagram of a conventional example, Fig. 9 is an explanatory diagram of a conventional example, and Fig. 10 is an explanatory diagram of a conventional example.
The figure shows a conventional example, and FIG. 11 is an explanatory diagram of the conventional example. In the figure, 1A and 1B are ultrasound beams, 1A', 1
B' is the transducer, 2 is the specimen, 3a, 3b
is a vibrator, 4a, 4b, 4c are matching layers, 5a,
b, c are backing materials, and 6a, b, c are electrodes.

Claims (1)

[Claims] 1. In an ultrasonic measuring device that transmits and receives ultrasonic signals of frequencies in different bands and has first and second ultrasonic transducers separated from each other, the first ultrasonic transformer means for transmitting an ultrasonic signal of a first frequency component from the transducer; and means for transmitting an ultrasonic signal of a second frequency component having a wider band including the first frequency component from the second ultrasonic transducer. and extracting the first frequency component of the first and second ultrasonic transducers according to the depth of diagnosis, or extracting the first frequency of the second frequency components of the second ultrasonic transducer. An ultrasonic measuring device comprising means for extracting components not included in the components, and composition means for synthesizing outputs of the extraction means according to depth.