JPH11155863A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently receive a harmonic component generated according to the nonlinear behavior of an ultrasonic contrast medium when an ultrasonic wave is applied to the ultrasonic contrast medium. SOLUTION: A piezoelectric ultrasonic wave vibrator 3 for transmission and a high polymer piezoelectric vibrator 1 for receiving are stored in one case. The piezoelectric ultrasonic vibrator 3 has resonance frequency or antiresonance frequency which coincides in a resonance frequency of an ultrasonic contrast medium or a frequency having a specified relationship to the resonance frequency of the ultrasonic contrast medium, while the high polymer piezoelectric vibrator 1 is a non-resonance vibrator which can receive a harmonic component generated according to the nonlinear behavior of an ultrasonic contrast medium. An acoustic matching layer 2 is formed on the front of the transmitting piezoelectric ultrasonic vibrator 3, and the receiving high polymer piezoelectric vibrator 1 is superposed on the front thereof. Thus, only the region where the injected ultrasonic contrast medium exists such as a cancer tissue in which blood capillaries are concentrated in a blood vessel or its peripheral part in the human body can be extracted more clearly than the other region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe for an ultrasonic diagnostic apparatus for sharpening a diagnostic image using an ultrasonic contrast agent for medical diagnosis of a human body or the like.

[0002]

2. Description of the Related Art When an ultrasonic contrast medium is irradiated with ultrasonic waves,
By selectively extracting only the harmonic components generated based on the non-linear behavior of the ultrasound contrast agent, the presence of an injected ultrasound contrast agent such as cancerous tissue with concentrated blood vessels in the blood vessels and peripheral parts of the human body In recent years, an ultrasonic diagnostic apparatus using a so-called harmonic imaging method that renders only a part to be performed more clearly than other parts has attracted attention.

In the above-described ultrasonic diagnostic apparatus using the so-called harmonic imaging method, an ultrasonic probe employing a transmitting / receiving piezoelectric vibrator similar to that used in a conventional ultrasonic diagnostic apparatus is used. ing. By passing a scattered wave generated by an ultrasonic contrast agent received by the ultrasonic probe through a band-pass filter, only the second harmonic component contained in the scattered wave is extracted to realize the harmonic imaging method. doing.

[0004] Here, the second harmonic component refers to a component in the vicinity of twice the frequency of the ultrasonic wave applied to the ultrasonic contrast agent in the scattered wave.

[0005]

However, an ultrasonic probe used for realizing the above-described harmonic imaging method or ultrasonic angiography is used in a conventional ultrasonic diagnostic apparatus. The same transmitting / receiving piezoelectric ceramic vibrator as the ultrasonic probe is used. For this reason, only the fundamental frequency component (that is, the frequency component that matches the resonance frequency of the ultrasonic contrast agent) and the harmonic component that is an odd multiple of the fundamental frequency have the receiving sensitivity, and the receiving sensitivity to the second harmonic component is remarkable. Low. Therefore,
Second scattered wave scattered by the ultrasonic contrast agent
There is a problem that it is impossible to efficiently receive harmonic components.

In recent years, as an ultrasonic probe for harmonic imaging, two laminated piezoelectric ceramic vibrators having different thicknesses have a laminated structure, and these two laminated piezoelectric ceramic vibrators are electrically driven simultaneously. An ultrasonic probe of a type in which two piezoelectric ceramic vibrators simultaneously receive a signal at the time of reception has been proposed.

In the ultrasonic probe of this type, if the thickness of the thinner one of the two piezoelectric ceramic vibrators is made exactly half the thickness of the thicker one, The fundamental oscillator component can be transmitted and received by the thicker vibrator, and the second harmonic component can be transmitted and received by the thinner vibrator.

However, in this ultrasonic probe, since the transmitted ultrasonic signal already contains the second harmonic component, the second harmonic component contained in the received signal is not included. However, there is a problem that it is difficult to distinguish whether the microbubble is based on the non-linear behavior of the ultrasonic contrast agent or is originally included in the transmission signal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a high-frequency component generated based on the nonlinear behavior of an ultrasonic contrast agent when the ultrasonic contrast agent is irradiated with ultrasonic waves. The so-called harmonic imaging method that selectively extracts only the area where the injected ultrasound contrast agent exists, such as blood vessels in the human body and cancer tissues with concentrated capillaries around the body, more clearly than other areas It is an object of the present invention to provide an ultrasonic probe which can be realized in a practical manner.

[0010]

In order to achieve this object, the present invention is configured as follows.

The present invention is directed to an ultrasonic probe for an ultrasonic diagnostic apparatus for clarifying a diagnostic image using an ultrasonic contrast agent for medical diagnosis of a human body or the like.

An ultrasonic probe according to the present invention irradiates an ultrasonic contrast agent with an ultrasonic wave when irradiating the ultrasonic contrast agent with an ultrasonic wave, and a portion where the ultrasonic contrast agent injected in a human body exists. Probe for use in an ultrasonic diagnostic apparatus using a so-called harmonic imaging method that clearly depicts only the ultrasound probe, a transmitting ultrasonic transducer and a receiving ultrasonic transducer are provided in one case of the ultrasonic probe. The acoustic piezoelectric membrane vibrator is housed,
The transmission ultrasonic transducer, the resonance frequency of the ultrasonic contrast agent or a frequency having a specific relationship to the resonance frequency of the ultrasonic contrast agent, having a resonance frequency or anti-resonance frequency that matches, the The receiving ultrasonic vibrator is a non-resonant type vibrator, and is capable of receiving a harmonic component generated based on a non-linear behavior of the ultrasonic contrast agent.

That is, in the transmitting ultrasonic vibrator, the resonance frequency or the anti-resonance frequency coincides with the resonance frequency of the ultrasonic contrast agent or a designated frequency having a specific relationship with the resonance frequency of the ultrasonic contrast agent. By using such a resonance type ultrasonic transducer, it is possible to efficiently irradiate the ultrasonic pulse to the ultrasonic contrast agent, and a non-resonance type polymer piezoelectric transducer is used as the reception ultrasonic transducer. By using, the ultrasonic wave of any frequency component can be received, so that the fundamental wave component (coincides with the resonance frequency) compared to the conventional ultrasonic probe using the piezoelectric ceramic vibrator for both transmission and reception It is possible to receive not only the frequency component of an odd multiple thereof but also the scattered wave component of an arbitrary frequency including the second harmonic component without missing it.

Further, in the ultrasonic probe according to the present invention, since the second harmonic component is not essentially contained in the transmitted ultrasonic signal, the second harmonic contained in the received signal is apparent. It can be easily recognized that this is not based on the transmission signal but on the non-linear behavior of the microbubble ultrasonic contrast agent.

Further, the ultrasonic probe according to the present invention is characterized in that the transmitting piezoelectric ultrasonic vibrator and the receiving polymer piezoelectric vibrator are overlapped with each other.

Accordingly, the piezoelectric ultrasonic transducer for transmission and the polymer piezoelectric vibrator for reception are stacked in a single ultrasonic probe case as a laminated structure. Does not impair.

Further, in the ultrasonic probe according to the present invention, an acoustic matching layer is provided on a front surface of the transmitting piezoelectric ultrasonic transducer,
Further, a high-molecular piezoelectric vibrator for reception is superposed and disposed on the front surface thereof.

Further, when an acoustic matching layer is provided on the front surface of the transmitting piezoelectric ultrasonic vibrator, the acoustic impedance of the polymer piezoelectric vibrator is very similar to the acoustic impedance of the acoustic matching layer, or The acoustic impedance is set to be intermediate between the acoustic impedance of the acoustic matching layer and the acoustic impedance of the human body. Therefore, it is possible to more effectively detect the second harmonic component without causing the problem that the propagation of the transmitted ultrasonic pulse is obstructed by the receiving polymer piezoelectric vibrator even when transmitting the ultrasonic wave.

Further, another ultrasonic probe according to the present invention comprises:
Forming a transducer composite in which a piezoelectric ultrasonic transducer for transmission, an acoustic matching layer, and a polymer piezoelectric transducer for reception are sequentially laminated,
A plurality of transducer complexes are arranged in an array.

By sequentially switching the vibrator composites arranged in an array at a high speed, a diagnostic image of a blood vessel or a fine cancer tissue can be clearly described in real time.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows a configuration of an ultrasonic probe 11 according to an embodiment of the present invention. In the figure, a piezoelectric ultrasonic vibrator 3 is a transmitting ultrasonic vibrator. As the piezoelectric ultrasonic transducer 3, for example, lead zirconate titanate (so-called PZT), lead titanate,
Barium titanate and other various piezoelectric ceramic vibrators can be used, but have a resonance frequency in the MHz band that is the resonance frequency of microbubble ultrasonic contrast agents, including crystalline piezoelectric vibrators such as lead niobate Any piezoelectric vibrator may be used.

The acoustic matching layer 2 is provided for transmitting the ultrasonic pulse generated from the transmitting piezoelectric ultrasonic vibrator 3 to a portion to be diagnosed efficiently at the time of transmission. 3 is provided on the front surface. The acoustic matching layer 2 is made of a material having an acoustic impedance intermediate between the acoustic impedance of the transmitting piezoelectric ultrasonic vibrator 3 and the acoustic impedance of the human body or water. As such a material, a material obtained by mixing a metal oxide powder, a ceramic powder, or the like with an epoxy resin or other various polymer materials so as to have a required acoustic impedance is generally used. Further, the thickness of the acoustic matching layer 2 is processed so as to be about a quarter wavelength with respect to the transmission frequency.

The polymer piezoelectric vibrator 1 is a receiving ultrasonic vibrator. As the polymer piezoelectric vibrator 1, a piezoelectric material obtained by mixing a piezoelectric ceramic powder such as PZT with polyvinylidene fluoride (PVDF), a copolymer of polyvinylidene fluoride and trifluoroethylene, or a rubber or other polymer material is used. The acoustic impedance of rubber or the like is close to the acoustic impedance of the acoustic matching layer for transmission, or has an intermediate value between the acoustic impedance of the human body or water and the acoustic impedance of the acoustic matching layer, and its resonance frequency is very small. Any piezoelectric vibrator may be used as long as it is a sufficiently thin polymer piezoelectric film whose thickness is higher by about one digit or more than the resonance frequency of the bubble ultrasonic contrast agent.

The back plate 4 is a supporting material for supporting the piezoelectric ultrasonic vibrator 3 and is a member mounted on the back surface of the piezoelectric ultrasonic vibrator 3. The back plate 4 reflects an ultrasonic component radiated from the back surface of the piezoelectric ultrasonic vibrator 3 to the back plate 4 at an end face, returns to the piezoelectric ultrasonic vibrator 3 again, and measures an unnecessary ultrasonic component such as a human body. It is also necessary to have sufficient sound absorption performance to avoid radiating to the target. In general, a composite material in which fine particles having high scattering or sound absorption properties are mixed with a rubber-based material such as a ferrite rubber, a fluorine-based resin, or a thermosetting resin such as an epoxy resin is used.

In the ultrasonic probe 11 of the present invention, a resonance type piezoelectric ultrasonic vibrator 1 for transmission is disposed on the back plate 4 by means of bonding or the like, and a means such as molding or bonding is provided on the front surface thereof. Thus, an acoustic matching layer 2 for transmission is provided. Further, a receiving polymer piezoelectric vibrator 1 is disposed on the front surface of the acoustic matching layer 2 by means such as bonding. The transmitting HOT-side shield wire 6 is a lead wire on the HOT side for supplying a driving electric signal to the transmitting piezoelectric ultrasonic vibrator 3. The receiving HOT-side shield wire 5 is a lead wire on the HOT side for transmitting a received signal received by the receiving polymer piezoelectric vibrator 1 to a receiving circuit. Further, the GND lead 7 is a GND lead for both transmission and reception.

The ultrasonic probe 11 of the present invention has a structure in which a transmitting piezoelectric ultrasonic vibrator 3 and a receiving polymer piezoelectric vibrator 1 are present in the same case. Further, the driving voltage applied to the transmitting piezoelectric ultrasonic vibrator 3 is higher than the voltage level of the received signal by 40 dB or 60 dB or more. Therefore, if the drive signal of the transmitting piezoelectric ultrasonic vibrator 3 is electrostatically coupled to the receiving polymeric piezoelectric vibrator 1 or the receiving signal transmitting lead wire in the case, the measurement is disturbed and a large problem occurs. . Therefore, in the present embodiment, shield wires are used for the respective lead wires 5 to 7.

In addition, avoid the influence of the external incoming noise,
In order to avoid the emission of electromagnetic waves to the outside, a shield copper foil 8 is wound around the probe core and connected to the GND-side shield wire 7. FIG. 2 is a diagram showing an embodiment in which a shielding copper foil 8 is provided around the probe core.

FIG. 3 shows the configuration of an experimental system for confirming functions using the ultrasonic probe 11 of the present invention. In the present embodiment, a piezoelectric ceramic vibrator is used as the transmitting piezoelectric ultrasonic vibrator 3.

Using the pulsar circuit 20, the ultrasonic probe 11 of the present invention is driven to propagate underwater in the water tank, and the ultrasonic wave reflected from the metal perfect reflector is reflected by the same ultrasonic probe. After receiving the signal at 11 and amplifying it to an appropriate level so as not to lose the linearity at the receiver 31, the oscilloscope 32 displays the received waveform and further obtains a frequency spectrum by Fourier transform.

Using this experimental system, of the two types of piezoelectric vibrators built in the ultrasonic probe of the present invention,
Only the piezoelectric ceramic vibrator 3 for transmission is used for both transmission and reception, and the polymer piezoelectric vibrator 1 for reception is simply connected to the acoustic matching layer 2 without connecting any electric circuit to the piezoelectric vibrator 1 for reception. FIG. 4 shows an example of the frequency spectrum of the received waveform in the case of the usage method of acting as a part of.

In this case, the ultrasonic probe functions as a conventional transmitting / receiving ultrasonic probe for an ultrasonic diagnostic apparatus.
The resonance frequency of the transmitting piezoelectric ceramic vibrator 3 used in the experiment was 3.5 MHz, and the driving voltage was controlled so that the irradiation sound pressure was about 35 kPa. In this case, the second harmonic component at twice the transmission frequency could not be observed. Therefore, the ultrasonic probe according to the present invention,
Since the transmitted ultrasonic signal does not include a signal component corresponding to the second harmonic component, it is determined whether the second harmonic component included in the received signal is based on the nonlinear behavior of the microbubble ultrasonic contrast agent. Can be easily determined.

On the other hand, FIG. 5 shows the result of another function confirmation experiment conducted using the experiment system of FIG.
In the experiment in which the data shown in FIG. 5 was obtained, the ultrasonic probe 3 was used for transmitting ultrasonic waves,
This is an example of the frequency spectrum of the reflected wave from the perfect reflector measured under the same conditions as in the experiment of FIG. 4 using the receiving polymer piezoelectric vibrator 1 for reception. This data includes
The second harmonic component not observed in the data of FIG. 4 can be observed at about 6.2 MHz. This is a second harmonic component due to a non-linear effect generated based on underwater propagation, which is included in the reflected wave from the perfect reflector.

A comparison of the data of FIGS. 4 and 5 shows that the use of the ultrasonic probe according to the present invention makes it possible to detect the second harmonic component.

Next, FIG. 6 shows the configuration of an experimental system for detecting the second harmonic component contained in the scattered wave from the microbubble ultrasonic contrast agent using the ultrasonic probe 11 according to the present invention. Is shown. The above-described system uses the pulsar circuit 20 to drive the transmitting piezoelectric ceramic vibrator 3 in the ultrasonic probe 11 of the present invention to propagate through the water in the water tank, and to perform microbubble ultrasonic imaging in the sample container. The ultrasonic wave scattered from the agent sample solution 34 is received by the polymer piezoelectric vibrator 1 built in the same ultrasonic probe 11 and amplified by the receiver 31 to an appropriate level that does not break the linearity. 32 is a system that displays the received waveform and obtains a frequency spectrum by Fourier transform.

The resonance frequency of the microbubble ultrasonic contrast agent used here was about 3.5 MHz.

In this embodiment, the resonance frequency of the transmitting piezoelectric ceramic vibrator is set to 3.5 MHz so that an ultrasonic wave of about 3.5 MHz, which coincides with the resonance frequency of the microbubble ultrasonic contrast agent, can be emitted.

FIG. 7 shows an example of the frequency spectrum of the received waveform in this case. The resonance frequency of the transmitting piezoelectric ceramic vibrator 3 used in the experiment was 3.5 MHz, and the driving voltage was controlled so that the irradiation sound pressure was about 35 kPa. Also in this case, in the scattered wave spectrum of FIG. 7, a fundamental wave component was observed around 3.5 MHz, which is the same as the frequency of the irradiation ultrasonic wave, and a second harmonic component was observed around 7 MHz. Here, the harmonic generation efficiency is defined by the ratio of the amplitude of the second harmonic component to the amplitude of the fundamental wave component in the spectrum,
The frequency spectrum data of FIGS. 5 and 7 were compared. As a result, the harmonic generation efficiency based on the nonlinear effect due to underwater propagation in FIG. 5 was about minus 12 dB, but the harmonic generation efficiency of the spectrum of the scattered wave from the microbubble ultrasonic contrast agent in FIG. 7 was about minus 2 dB. Met.

Accordingly, the spectrum of the scattered wave from the microbubble ultrasonic contrast agent is about 10 dB larger than the harmonic generation efficiency generated by the non-linear effect accompanying the propagation in water in FIG. 5, and the ultrasonic probe of the present invention can be used. It is clear that the detection of the harmonic component based on the nonlinear behavior of the microbubble ultrasonic contrast agent is easily possible.

FIG. 8 shows a case where the ultrasonic probe of the present invention shown in FIG. 1 is used to irradiate an ultrasonic wave to the ultrasonic contrast agent, based on the nonlinear behavior of the ultrasonic contrast agent. By selectively extracting only the higher harmonic components, only the site where the injected ultrasound contrast agent is present, such as blood vessels in the human body or cancer tissue with concentrated capillaries in the periphery, is drawn more clearly than other sites. 1 shows a system configuration for realizing an ultrasonic diagnostic apparatus using a so-called harmonic imaging method.

The transmitting piezoelectric ceramic vibrator 3 built in the ultrasonic probe 11 of the present invention is driven by using the pulsar circuit 20 to irradiate the ultrasonic wave to the body to be diagnosed. The reflected wave from the boundary portion of each tissue in the body and the scattered wave from the injected microbubble ultrasonic contrast agent are received by the receiving polymer piezoelectric vibrator 1 built in the ultrasonic probe 11 of the present invention. I do. The received signal converted into a voltage signal by the receiving polymer piezoelectric vibrator 1 based on the received scattered wave is amplified by a preamplifier 13 to an appropriate level, and then sent to a harmonic extraction filter 14. The harmonic extraction filter 14 is a band-pass filter that can extract only the vicinity of a frequency component of interest included in scattered waves from the microbubble ultrasonic contrast agent, such as the second harmonic component and the third harmonic component. It is composed of circuits. Harmonic extraction filter 1
The output signal of No. 4 is a signal containing only a component near the frequency of the harmonic desired to be observed.

FIG. 9 shows how the scattered wave signal changes before and after the processing by the harmonic extraction filter 14. Before being subjected to the processing by the harmonic extraction filter 14, since the fundamental wave component is also included as shown in FIG. 9A, reflection from other tissue boundaries is also included in addition to the scattered wave from the contrast agent. Will be. On the other hand, since the waveform after processing by the harmonic extraction filter 14 contains only the harmonic component of interest, FIG.
As shown in (b), the signal is only from the portion where the smiling bubble ultrasonic contrast agent generating the harmonic component exists. Therefore, the output signal of the harmonic extraction filter 14 indicates only information on the portion where the microbubble ultrasonic contrast agent exists. This output signal is further amplified by the amplifier 15, processed by the detection circuit 16 and the signal processing unit 17, and displayed on a monitor 18. As a result, it becomes possible to clearly display, on the monitor 18, a minute cancer tissue or the like in which blood vessels and capillaries in which the ultrasonic contrast agent exists are distinguished from images of other organs.

As described above, according to the present invention,
The piezoelectric ceramic vibrator 3 for transmission and the polymer piezoelectric vibrator 1 for reception are contained in one case in the form of a laminated structure, so that the same operability as the conventional ultrasonic probe is maintained. By irradiating ultrasonic waves to the microbubble ultrasonic contrast agent, it becomes possible to efficiently detect the harmonic components contained in the scattered waves excited by this, an ultrasonic angiography system,
It is possible to provide an ultrasonic probe suitable for an ultrasonic diagnostic system using a nonlinear behavior of a microbubble ultrasonic contrast agent such as a harmonic imaging ultrasonic diagnostic apparatus and a flushing image ultrasonic diagnostic apparatus.

In the description of this embodiment, the ultrasonic probe in which the polymer piezoelectric vibrator 1 for reception is disposed on the front surface of the acoustic matching layer 2 for transmission has been intensively described.
The present invention also provides an ultrasonic probe having a configuration in which the polymer piezoelectric vibrator 1 for reception is provided directly on the front surface of the piezoelectric ceramic vibrator 3 for transmission without the acoustic matching layer 2 for transmission. Of course, it is included in the range.

Embodiment 2 FIG. 10 shows the configuration of an ultrasonic probe according to a second embodiment of the present invention. In the figure, a piezoelectric ultrasonic vibrator 3 is a transmitting ultrasonic vibrator. The acoustic matching layer 2 is provided on the front surface of the transmitting piezoelectric ultrasonic vibrator 3 so that the ultrasonic pulse generated from the transmitting piezoelectric ultrasonic vibrator 3 at the time of transmission can be efficiently incident on a portion to be diagnosed. It is arranged in. The polymer piezoelectric vibrator 1 is a receiving ultrasonic vibrator. The back plate 4 is a supporting material for supporting the piezoelectric ultrasonic vibrator 3, and the piezoelectric ultrasonic vibrator 3
This is a member to be mounted on the back of the device. The back plate 4 reflects an ultrasonic component radiated from the back surface of the piezoelectric ultrasonic vibrator 3 to the back plate at an end face, returns to the piezoelectric ultrasonic vibrator 3 again, and converts unnecessary ultrasonic components to a measurement object such as a human body. It is necessary to have a sufficient sound absorbing performance to avoid radiating the sound. The materials of the piezoelectric ultrasonic vibrator 3, the acoustic matching layer 2, and the polymer piezoelectric vibrator 1 are the same as those in the first embodiment, and thus the description thereof is omitted.

In the ultrasonic probe of the present invention, the resonance type piezoelectric ultrasonic vibrator 3 for transmission is disposed on the back plate 4 by means such as bonding, and the front surface thereof is formed by means such as molding or bonding. An acoustic matching layer 2 for transmission is provided.
Further, a receiving polymer piezoelectric vibrator 1 is disposed on the front surface of the acoustic matching layer 2 by means such as bonding. Especially,
In the ultrasonic probe according to the present embodiment, a transmitting piezoelectric ultrasonic vibrator 3, a transmitting acoustic matching layer 2, and a receiving polymer piezoelectric vibrator 1 are provided on a back plate 4. A large number of vibrator composites having a fine composite structure sequentially stacked are arranged in a one-dimensional array. The ultrasonic probe of the one-dimensional array structure of the present embodiment also basically irradiates ultrasonic waves to the microbubble ultrasonic contrast agent by the same mechanism as the ultrasonic probe of the first embodiment, Since it has a function of efficiently detecting harmonic components contained in the scattered wave from the microbubble ultrasonic contrast agent, a large number of transducer complexes arranged in an array form The electronic switches are sequentially switched at a high speed based on the instruction described above, whereby a diagnostic image of a blood vessel, a minute cancer tissue, or the like can be clearly described in real time.

Although the second embodiment has been described with respect to a case where the ultrasonic probes according to the present invention are arranged in a one-dimensional linear array, a convex array, a phased array, an annular array, and a two-dimensional array are used. Even if an array or any other arrangement is used, the ultrasonic probe with the structure in which the elementary probe, which is the basic configuration, has a polymer piezoelectric transducer for reception arranged in front of the piezoelectric ceramic transducer for transmission is also used. It is included in the invention.

[0047]

As described above, according to the ultrasonic probe of the present invention, a microbubble ultrasonic contrast agent is administered to a patient to be diagnosed, and then incorporated in the ultrasonic probe. Ultrasonic waves are radiated by the transmitting piezoelectric ultrasonic vibrator, and scattered waves scattered from the microbubble ultrasonic contrast agent in the body are scattered by the receiving polymer piezoelectric vibrator incorporated in the ultrasonic probe of the present invention. By receiving the signal, the second harmonic component contained in the scattered wave can be detected efficiently, and a microbubble ultrasonic wave such as an ultrasonic angiography system, a harmonic imaging ultrasonic diagnostic apparatus, and a flash image ultrasonic diagnostic apparatus An ultrasonic probe suitable for a system using the nonlinear behavior of a contrast agent can be provided.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an ultrasonic probe core according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a case where an ultrasonic probe core according to an embodiment of the present invention is shielded.

FIG. 3 is a diagram showing a configuration of an experimental system for confirming the function of the ultrasonic probe according to the present invention.

FIG. 4 is a diagram showing a reflection spectrum from a perfect reflector when a transmitting piezoelectric ceramic vibrator incorporated in the ultrasonic probe of the present invention is used for both transmission and reception (when used in a conventional method). .

FIG. 5 is a diagram showing a reception spectrum including a second harmonic component based on a non-linear effect of underwater propagation, obtained in a function confirmation experiment using the ultrasonic probe of the present invention.

FIG. 6 is a diagram showing a configuration of an experimental system for detecting a second harmonic component contained in a scattered wave from a microbubble ultrasonic contrast agent using the ultrasonic probe according to the present invention.

FIG. 7 is a scattered wave spectrum from a microbubble ultrasonic contrast agent measured using the ultrasonic probe of the present invention.

FIG. 8 is a configuration diagram of an embodiment of an ultrasonic angiography system using the ultrasonic probe of the present invention.

FIG. 9 is a diagram showing an example of a scattered signal before and after a harmonic extraction filter of an ultrasonic angiography system using the ultrasonic probe of the present invention.

FIG. 10 is a diagram showing a configuration of an ultrasonic probe according to a second embodiment in which the ultrasonic probes of the present invention are arranged in a one-dimensional array structure.

[Explanation of symbols]

1 polymer piezoelectric vibrator, 2 acoustic matching layer, 3 piezoelectric ultrasonic vibrator, 4 back plate, 5 receiving HOT side shield wire,
6 HOT side shield wire for transmission, 7 GND shield wire, 8 Copper foil for shield, 11 Ultrasonic probe, 12
Electrical switch, 13 preamplifier, 14 harmonic extraction filter, 15 amplifier, 16 detection circuit, 17 signal processing unit, 18 monitor, 19 controller, 20 pulsar circuit.

Claims (5)

[Claims] 1. An ultrasonic diagnostic apparatus using a so-called harmonic imaging method for irradiating an ultrasonic contrast agent with an ultrasonic wave to clearly depict only a portion of the human body where the ultrasonic contrast agent is present. In the ultrasonic probe, a transmitting ultrasonic vibrator and a receiving ultrasonic vibrator are accommodated in one case of the ultrasonic probe, and the transmitting ultrasonic vibrator includes the ultrasonic imaging. A resonance frequency of the agent or a frequency having a specific relationship to the resonance frequency of the ultrasonic contrast agent, a resonance frequency or an anti-resonance frequency, and the receiving ultrasonic vibrator has An ultrasonic probe, wherein the ultrasonic probe is capable of receiving a harmonic component generated based on a non-linear behavior of the ultrasonic contrast agent. 2. The ultrasonic probe according to claim 1, wherein said transmitting ultrasonic vibrator and said receiving ultrasonic vibrator are arranged in an overlapping manner. 3. The ultrasonic probe according to claim 2, wherein an acoustic matching layer is provided on a front surface of the transmitting ultrasonic vibrator, and a receiving ultrasonic vibrator is further arranged on the front surface of the acoustic matching layer. An ultrasonic probe characterized by the following. 4. The ultrasonic probe according to claim 1, wherein the transmitting ultrasonic transducer, the acoustic matching layer, and the receiving ultrasonic transducer are sequentially laminated. An ultrasonic probe, wherein a plurality of the transducer complexes are arranged in an array. 5. The ultrasonic probe according to claim 1, wherein the transmitting ultrasonic vibrator is a piezoelectric ultrasonic vibrator, and the receiving ultrasonic vibrator is An ultrasonic probe, which is a polymer piezoelectric vibrator.