JP2012011118A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus preventing a temperature rise in an ultrasonic probe to eliminate deterioration of harmonic images caused by variation of the amount of amplification of a built-in amplifying part, variation of thermal noise, etc. without limiting the use of the ultrasonic probe.SOLUTION: The ultrasonic diagnostic apparatus including the ultrasonic probe includes a transmitting/receiving part having a plurality of transmitting/receiving elements for transmitting/receiving ultrasonic waves; the amplifying part having a plurality of amplifiers for amplifying received signals received by the transmitting/receiving part; and a change-over switch having a plurality of switches for switching a connection state of the amplifying part and transmitting/receiving part. The apparatus further includes a control part for controlling the amount of amplification of the amplifying part based on the connection state of the amplifying part and transmitting/receiving part switched by the change-over switch. The temperature rise in the ultrasonic probe is thereby prevented to eliminate the deterioration of harmonic images caused by the variation of the amount of amplification of the built-in amplifying part, the variation of thermal noise, etc. without limiting the use of the ultrasonic probe.

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus that receives an ultrasonic reflected wave transmitted from an ultrasonic probe to a subject and generates an ultrasonic image inside the subject.

  An ultrasonic diagnostic apparatus is a medical imaging device that non-invasively obtains a tomographic image of a soft tissue in a subject from a body surface by an ultrasonic pulse reflection method. Compared to other medical imaging equipment, this ultrasound diagnostic device has many features such as small size, low cost, high safety without exposure to X-rays, and blood flow imaging using the Doppler effect. It is widely used in the circulatory system (coronary artery of the heart), digestive system (gastrointestinal), internal medicine system (liver, pancreas, spleen), urological system (kidney, bladder), and obstetrics and gynecology.

  A piezoelectric effect of a piezoelectric element is generally used for a transmission / reception element of an ultrasonic probe used in such a medical ultrasonic diagnostic apparatus in order to transmit / receive ultrasonic waves with high sensitivity and high resolution.

  On the other hand, tissue harmonic imaging (THI) diagnosis using ultrasonic harmonic signals is becoming a standard diagnostic modality because a clear diagnostic image that cannot be obtained by conventional B-mode diagnosis is obtained.

  THI diagnosis has a low sidelobe level compared to the fundamental wave, a good S / N and a good contrast resolution, and a high frequency results in a narrower beam width and better lateral resolution. The sound pressure is small at the distance, and since there is little fluctuation in the sound pressure, multiple reflections do not occur, the attenuation beyond the focal point is the same as the fundamental wave, and the harmonic ultrasonic wave has a greater depth than the fundamental wave ultrasonic wave. It has many advantages that it can be taken.

  Therefore, for example, Patent Document 1 discloses a wideband and high-sensitivity reception using an organic piezoelectric element such as polyvinylidene fluoride (PVDF) or polyvinylidene fluoride / 3-fluoroethylene (P (VDF / 3FE)). A method for constructing a piezoelectric element has been proposed. This facilitates THI diagnosis.

  By the way, if the ultrasonic probe is continuously used, the temperature in the probe rises and exceeds the upper limit value of the temperature of the contact surface to the subject, or the characteristics of the element that transmits and receives ultrasonic waves deteriorates. There are problems such as.

  In recent years, in order to reliably transmit a received signal, a probe incorporating an amplifier in an ultrasonic probe has been provided. However, since the amplifier is built in, the temperature in the sealed ultrasonic probe further increases due to the power consumption of the amplifier.

  Furthermore, since the number of elements that transmit and receive ultrasonic waves has been increased, it is necessary to install a changeover switch that connects the transmitter and receiver elements and the output cable of the ultrasonic probe within the ultrasonic probe. However, the temperature rise in the ultrasonic probe due to the increase in power consumption tends to become more severe.

  In order to solve these problems, for example, in Patent Document 2, the temperature of the transmission / reception surface is estimated from the temperature detected by the temperature sensor provided in the ultrasonic probe, and transmission restriction is performed based on the estimated temperature of the transmission / reception surface. A method of performing is disclosed.

  Patent Document 3 discloses a control method that includes a temperature sensor that detects the temperature of the surrounding environment and that can use the ultrasonic probe only within the operating environment temperature.

  Further, Patent Document 4 discloses a method of controlling the operation of the receiving circuit to be stopped in a predetermined period in order to suppress the temperature rise of the ultrasonic probe to be small.

JP 2008-188415 A Japanese Patent Laid-Open No. 2003-052693 JP 2010-000137 A JP 2009-148424 A

  However, in the methods disclosed in Patent Documents 2, 3, and 4, the use of the ultrasonic probe is limited in any of the methods, so that the diagnosis is interrupted, and the ultrasonic probe is given to the user and the subject. The inconvenience of having to wait until the temperature drops is forced. In addition, the operation of the built-in amplifier becomes unstable due to temperature changes in the ultrasonic probe, and the harmonic signal contains a large amount of fluctuation noise due to fluctuations in amplification amount and fluctuations in thermal noise. It has been found that there is also a problem that deteriorates.

  The present invention has been made in view of the above circumstances, and prevents an increase in temperature in the ultrasonic probe, and without limiting the use of the ultrasonic probe, fluctuations in amplification amount of the built-in amplification unit and thermal noise An object of the present invention is to provide an ultrasonic diagnostic apparatus in which the ultrasonic image is less deteriorated due to fluctuations or the like.

  The object of the present invention can be achieved by the following constitution.

1. A transmission / reception unit having a plurality of transmission / reception elements for transmitting and receiving ultrasonic waves;
An amplifying unit having a plurality of amplifiers for amplifying the received signal received by the transceiver unit;
In an ultrasonic diagnostic apparatus comprising an ultrasonic probe comprising a changeover switch having a plurality of switches for switching a connection state between the amplification unit and the transmission / reception unit,
An ultrasonic diagnostic apparatus comprising: a control unit that controls an amplification amount of the amplification unit based on a connection state between the amplification unit and the transmission / reception unit switched by the changeover switch.

2. The controller is
An amplification amount determination voltage table for determining an amplification amount of the amplification unit based on a connection state between the amplification unit and the transmission / reception unit;
2. The ultrasonic diagnostic apparatus according to claim 1, further comprising: a voltage control unit that outputs an amplification amount determination voltage that controls an amplification amount of the amplification unit based on the amplification amount determination voltage table.

3. The controller is
Based on a connection state between the amplification unit and the transmission / reception unit, an amplification amount determination voltage table for determining an amplification amount of the amplification unit is generated,
2. The ultrasonic diagnostic apparatus according to claim 1, further comprising: a voltage control unit that outputs an amplification amount determination voltage for controlling the amplification amount of the amplification unit based on the generated amplification amount determination voltage table.

4). 4. The ultrasonic diagnostic apparatus according to 3 above, wherein the voltage control unit calculates the amplification amount determination voltage table according to the following (formula 1). here,
Vgd (β) = α × {N− (γ−β)} ² (1)
However,
Vgd (β): Amplification amount determination voltage data of the β-th amplifier (in the amplification amount determination voltage table) α: Amplification constant N: Number of transmission / reception of ultrasonic waves γ: Number of amplifiers in the amplification unit β: Number of amplifiers in the amplification unit It is.

5. The ultrasonic diagnostic apparatus has a plurality of operation modes,
The controller is
5. The ultrasonic diagnostic apparatus according to any one of 2 to 4, further comprising an amplification amount determination voltage table for each operation mode.

6). The amplifying unit is a variable gain amplifier having an amplification amount determination terminal whose amplification amount is determined by an input voltage,
6. The ultrasonic diagnostic apparatus according to claim 1, wherein the amplification amount determination voltage of the voltage control unit is input to an amplification amount determination terminal of the amplification unit.

  7). The ultrasonic diagnostic apparatus according to any one of 1 to 6, wherein the transmission / reception unit is an organic piezoelectric element thin film.

8). The transmission / reception unit receives a reflected wave of a harmonic that is an integral multiple of the fundamental frequency component of the transmitted ultrasonic wave,
8. The ultrasonic diagnostic apparatus according to any one of 1 to 7, further comprising an image processing unit that forms an ultrasonic image based on the reflected wave of the harmonic.

  According to the present invention, a transmission / reception unit having a plurality of transmission / reception elements for transmitting / receiving ultrasonic waves, an amplification unit having a plurality of amplifiers for amplifying a reception signal received by the transmission / reception unit, and a connection state between the amplification unit and the transmission / reception unit In an ultrasonic diagnostic apparatus having an ultrasonic probe having a changeover switch having a plurality of switches for switching between, the amplification amount of the amplification unit is controlled based on the connection state between the amplification unit and the transmission / reception unit switched by the changeover switch By providing a control unit that prevents the temperature inside the ultrasound probe from rising, and without limiting the use of the ultrasound probe, an ultrasound image due to fluctuations in the amount of amplification in the built-in amplification unit, fluctuations in thermal noise, etc. It is possible to provide an ultrasonic diagnostic apparatus with little deterioration of the above.

It is a schematic diagram which shows the external appearance structure of the ultrasound diagnosing device in each embodiment of this invention. It is a schematic diagram which shows an example of the transmission / reception element in each embodiment of this invention. It is a schematic diagram which shows an example of a structure of the ultrasonic probe in each embodiment of this invention. It is a block diagram which shows an example of the internal structure of 1st Embodiment of an ultrasound diagnosing device. It is a block diagram which shows an example of a structure of the receiving part of the ultrasonic probe of 1st Embodiment. It is a schematic diagram which shows the relationship between the format of an ultrasonic probe and the intensity | strength of a reflected wave. It is a schematic diagram which shows the receiving element used at the time of reception of an ultrasonic wave. It is a schematic diagram which shows the structure of the part which supplies the amplification amount determination voltage of the control part in the 1st example of the control method of the amplification amount of 1st Embodiment. It is a schematic diagram which shows the structure of the part which supplies the amplification amount determination voltage of the control part in the 2nd example of the control method of the amplification amount of 1st Embodiment. It is a block diagram which shows the internal structure of 2nd Embodiment of an ultrasonic diagnosing device. It is a block diagram which shows the internal structure of the ultrasonic probe of 2nd Embodiment. It is a schematic diagram which shows the structure of the part which supplies the amplification amount determination voltage of the control part in 2nd Embodiment. It is a schematic diagram which shows the structure of the amplification part in 2nd Embodiment.

  Hereinafter, the present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant description may be omitted.

  First, the configuration of the ultrasonic diagnostic apparatus according to each embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing the external configuration of the ultrasonic diagnostic apparatus according to each embodiment of the present invention. It is.

  In FIG. 1, the ultrasonic diagnostic apparatus S is composed of an ultrasonic diagnostic apparatus main body 1, an ultrasonic probe 2, a cable 3, and the like. The ultrasonic diagnostic apparatus main body 1 includes, for example, an operation unit 11 for inputting data such as a command for instructing the start of diagnosis and personal information of the subject, various information input by the operation unit 11, and the ultrasonic probe 2. A display unit 15 or the like for displaying an internal state image (ultrasonic image) in the subject generated based on the received signal is provided.

  The ultrasonic probe 2 transmits an ultrasonic wave (ultrasonic signal) to a subject such as a human body (not shown), and receives a reflected wave (echo, ultrasonic signal) of the ultrasonic wave reflected in the subject. Generate a received signal.

  The cable 3 connects the ultrasonic diagnostic apparatus main body 1 and the ultrasonic probe 2, transmits a transmission signal from the ultrasonic diagnostic apparatus main body 1 to the ultrasonic probe 2, and receives signals generated by the ultrasonic probe 2. Is transmitted to the ultrasonic diagnostic apparatus main body 1.

  Next, a transmitting / receiving element used for the ultrasonic probe will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing an example of a transmitting / receiving element in each embodiment of the present invention. Here, a method of separately providing a transmitting element and a receiving element will be described.

  In FIG. 2, the transmitting / receiving element 21 includes a backing layer 211, a piezoelectric part 212 having an electrode and a piezoelectric body provided on the backing layer 211, an acoustic matching layer 213 provided on the piezoelectric part 212, and an acoustic matching layer 213. The acoustic lens 214 and the like provided in

  The piezoelectric unit 212 includes a transmission element 212a, an intermediate layer 212b disposed on the transmission element 212a, a reception element 212c disposed on the intermediate layer 212, and the like. The transmitting element 212 a is configured by placing a transmitting piezoelectric element 218 and a transmitting piezoelectric element 218 having electrodes 217 on both surfaces thereof on a flexible substrate (hereinafter referred to as FPC) 215. Similarly, the receiving element 212c is configured by placing the receiving piezoelectric element 219 and the receiving piezoelectric element 219 with electrodes 217 on both surfaces thereof on the FPC 216.

(Backing layer 211)
The backing layer 211 is an ultrasonic absorber that supports the piezoelectric portion 212 and can absorb unnecessary ultrasonic waves. As the backing material used for the backing layer 211, natural rubber, ferrite rubber, a material obtained by pressing a powder of tungsten oxide, titanium oxide, ferrite or the like into an epoxy resin, vinyl chloride, polyvinyl butyral (PVB), ABS resin, Polyurethane (PUR), polyvinyl alcohol (PVAL), polyethylene (PE), polypropylene (PP), polyacetal (POM), polyethylene terephthalate (PET), fluororesin (PTFE) polyethylene glycol, polyethylene terephthalate-polyethylene glycol copolymer, etc. A thermoplastic resin or the like can be used.

  A preferable backing material is made of a rubber-based composite material and / or an epoxy resin composite material, and the shape thereof can be appropriately selected according to the shape of the ultrasonic probe 2 including the transmission / reception element 21 and the transmission / reception element 21. .

  As the rubber-based composite material, a material containing a rubber component and a filler is preferable. A hardness from A70 in a spring hardness tester (durometer hardness) according to JIS K6253 to D70 in a type D durometer. In addition, various other compounding agents can be added as necessary.

  Examples of rubber components include ethylene propylene rubber (EPDM or EPM), hydrogenated nitrile rubber (HNBR), chloroprene rubber (CR), silicone rubber, EPDM and HNBR blend rubber, and EPDM and nitrile rubber (NBR) blend rubber. NBR and / or HNBR and high styrene rubber (HSR) blend rubber, EPDM and HSR blend rubber, and the like are preferable.

  More preferably, ethylene propylene rubber (EPDM or EPM), hydrogenated nitrile rubber (HNBR), EPDM and HNBR blend rubber, EPDM and nitrile rubber (NBR) blend rubber, NBR and / or HNBR and high styrene rubber (HSR) ) Blend rubber, EPDM and HSR blend rubber, and the like. As the rubber component of the present embodiment, one of rubber components such as vulcanized rubber and thermoplastic elastomer may be used alone. However, a blend rubber obtained by blending two or more rubber components such as a blend rubber is used. It may be used.

  The filler to be added to the rubber component can be selected in various forms together with the blending amount from those usually used to those having a large specific gravity. For example, zinc oxide, white titanium, bengara, ferrite, alumina, tungsten trioxide, yttrium oxide and other metal oxides, calcium carbonate, hard clay, diatomaceous earth clays, calcium carbonate, barium sulfate and other metal salts, glass Examples include powders, various fine metal powders such as tungsten and molybdenum, and various balloons such as glass balloons and polymer balloons.

  These fillers can be added at various ratios, preferably 50 to 3000 parts by weight, more preferably about 100 to 2000 parts by weight, or about 300 to 1500 parts by weight with respect to 100 parts by weight of the rubber component. preferable. These fillers may be added alone or in combination of two or more.

  Other compounding agents can be added to the rubber-based composite material as necessary. Examples of such compounding agents include vulcanizing agents, cross-linking agents, curing agents, auxiliaries, and deterioration inhibitors. , Antioxidants, colorants and the like. For example, carbon black, silicon dioxide, process oil, sulfur (vulcanizing agent), dicumyl peroxide (Dicup, crosslinking agent), stearic acid and the like can be blended. These compounding agents are used as necessary, but the amount used is generally about 1 to 100 parts by mass with respect to 100 parts by mass of the rubber component, but may be appropriately changed depending on the overall balance and characteristics. You can also.

  As an epoxy resin composite agent, it is preferable to contain an epoxy resin component and a filler, and various compounding agents can be added as necessary. Examples of the epoxy resin component include bisphenol A type, bisphenol F type, resol novolak type, novolac type epoxy resin such as phenol-modified novolak type, naphthalene structure-containing type, anthracene structure-containing type, fluorene structure-containing type, etc. Type epoxy resin, hydrogenated alicyclic epoxy resin, liquid crystalline epoxy resin and the like. Although the epoxy resin component of this invention may be used independently, you may mix and use two or more types of epoxy resin components like a blend resin.

  As the filler added to the epoxy component, any of those similar to the filler mixed with the rubber component to composite particles prepared by pulverizing the rubber-based composite agent can be preferably used. Examples of the composite particles include particles in which silicone rubber is filled with ferrite and pulverized with a pulverizer to a particle size of about 200 μm.

  When using an epoxy resin composite, it is necessary to add a crosslinking agent. For example, chain aliphatic polyamines such as diethylenetriamine, triethylenetetramine, dipropylenediamine, and diethylaminopropylamine, N-aminoethylpiperazine, mensen Cyclic aliphatic polyamines such as diamine and isophoronediamine, aromatic amines such as m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone, polyamide resin, piperidine, NN-dimethylpiperazine, triethylenediamine, 2,4, Secondary and tertiary amines such as 6-tris (dimethylaminomethyl) phenol, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2-methylimidazole, 2-ethylimid Sol, imidazoles such as 1-cyanoethyl-2-undecylimidazolium trimellitate, liquid polymercaptan, polysulfide, phthalic anhydride, negligible trimellitic acid, methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutyrate Examples of the acid anhydride include tenenyltetrahydrophthalic anhydride and methylhexahydrophthalic acid.

  The thickness of the backing layer 211 is preferably approximately 1 to 10 mm, and particularly preferably 1 to 5 mm.

(Transmitting element 212a and receiving element 212c)
The transmitting element 212a and the receiving element 212c in this embodiment each have an electrode and a piezoelectric element, can convert electrical signals into mechanical vibrations and mechanical vibrations into electrical signals, and can transmit and receive ultrasonic waves. It is a possible element. Piezoelectric elements are electromechanical transducers that contain a piezoelectric material that can convert electrical signals into mechanical vibrations and mechanical vibrations into electrical signals. Examples of the piezoelectric material include inorganic piezoelectric ceramics such as lead zirconate titanate (PZT) ceramics and PbTiO3 ceramics, organic polymer piezoelectric materials such as polyvinylidene fluoride (PVDF), crystal, and Rochelle salt. The thickness of the piezoelectric material is generally in the range of 100 μm to 500 μm. A piezoelectric material is used as a piezoelectric element with electrodes attached to both sides thereof.

(Electrode 217)
As a material used for the electrode 217 attached to the piezoelectric material, gold (Au), platinum (Pt), silver (Ag), palladium (Pd), copper (Cu), aluminum (Al), nickel (Ni), Tin (Sn) etc. are mentioned.

  As a method for attaching the electrode 217 to the piezoelectric material, for example, a base metal such as titanium (Ti) or chromium (Cr) is formed to a thickness of 0.02 to 1.0 μm by sputtering, and then the metal element is mainly used. And a metal material made of an alloy thereof and a metal material thereof, and a method of forming a part of the insulating material to a thickness of 1 to 10 [mu] m by sputtering or other appropriate methods as necessary.

  Electrodes can be formed by screen printing, dipping, or thermal spraying using a conductive paste in which fine metal powder and low-melting glass are mixed, as well as sputtering. The electrode 217 is provided on the entire surface of the piezoelectric material surface or a part of the piezoelectric material surface on the piezoelectric material according to the shape of the transmitting / receiving element 21.

  In a preferred embodiment, the piezoelectric part 212 and the backing layer 211 are laminated via an adhesive layer. As an adhesive for forming the adhesive layer, an epoxy-based adhesive can be used.

  An electrode 217 is in contact with a part of the surface of the piezoelectric portion 212 on the backing layer 211 side and a part of the surface on the acoustic matching layer 213 side, and the backing layer 211 and the electrode 217 are laminated via an adhesive layer. Some parts may be included.

(Acoustic matching layer 213)
The acoustic matching layer 213 in the present embodiment matches the acoustic impedance between the piezoelectric unit 212 and the subject, and is made of a material having an acoustic impedance intermediate between the piezoelectric unit 212 and the subject. Materials used for the acoustic matching layer include aluminum, aluminum alloy (for example, AL-Mg alloy), magnesium alloy, macor glass, glass, fused quartz, copper graphite, polyethylene (PE), polypropylene (PP), and polycarbonate (PC). , ABC resin, polyphenylene ether (PPE), ABS resin, AAS resin, AES resin, nylon (PA6, PA6-6), PPO (polyphenylene oxide), PPS (polyphenylene sulfide: glass fiber can be included), PPE (polyphenylene ether) ), PEEK (polyetheretherketone), PAI (polyamideimide), PET (polyethylene terephthalate), PC (polycarbonate), epoxy resin, urethane resin, and the like.

  Preferably, a thermosetting resin such as an epoxy resin is used which is molded by adding zinc white, titanium oxide, silica, alumina, bengara, ferrite, tungsten oxide, yttrium oxide, barium sulfate, tungsten, molybdenum or the like as a filler. be able to.

  The acoustic matching layer 213 may be a single layer or a plurality of layers, but preferably has two or more layers. The layer thickness of the acoustic matching layer 213 needs to be determined to be λ / 4 where λ is the wavelength of the ultrasonic wave. If this is not satisfied, a plurality of unnecessary spurious noises appear at frequency points different from the original resonance frequency, and the basic acoustic characteristics greatly vary. As a result, an increase in reverberation time and a decrease in sensitivity and S / N due to waveform distortion of the reflected echo are undesirable. The thickness of the acoustic matching layer 213 is generally in the range of 30 μm to 500 μm.

(Acoustic lens 214)
The acoustic lens 214 is at the forefront of the transmitting / receiving element 21 and is used to focus the ultrasonic beam. The acoustic impedance of the acoustic lens 214 is substantially the same as that of a living tissue. By making the acoustic lens 214 convex, the ultrasonic beam can be focused according to Snell's law.

  In the transmission / reception element 21 described above, the configuration including the transmission element 212a and the reception element 212c separately has been described. The arrangement of the transmitting element 212a and the receiving element 212c may be either an arrangement in which the elements are arranged one above the other or an arrangement in which the elements are arranged in parallel. The thickness of the transmitting element 212a and the receiving element 212c when stacked is preferably 40 to 150 μm.

  The transmitting / receiving element 21 is not limited to the configuration including the transmitting element 212a and the receiving element 212c separately. For example, in FIG. 2, the receiving element 212c (the receiving piezoelectric element 219 and the electrode 217), the FPC 216, The transmitting element 212a may be used as a transmitting / receiving element.

  Next, an example of the configuration of the ultrasonic probe in each embodiment of the present invention will be described with reference to FIG. 3A and 3B are schematic views showing an example of the configuration of the ultrasonic probe in each embodiment of the present invention. FIG. 3A is a schematic view of the appearance of the ultrasonic probe, and FIG. 3B is an internal view of the ultrasonic probe. It is a block diagram.

  3A, the appearance of the ultrasonic probe 2 is as follows. The housing 29, the acoustic lens 214 of the transmitting / receiving element 21 disposed at the tip of the housing 29, the cable 3 connected to the rear end of the housing 29, and the like. Consists of. The user of the ultrasonic probe 2 uses the housing 29 while pressing the acoustic lens 214 against the subject.

  In FIG. 3B, the transmitting / receiving element 21 including the acoustic lens 214, the substrate 25, the connector 26, the cable 3, and the like are disposed inside the housing 29 of the ultrasonic probe 2.

  An FPC 24 is connected to the transmission / reception element 21, and the FPC 24 and the substrate 25 are connected by a connecting portion 24a. A changeover switch 22 composed of a plurality of switch elements and an amplifying unit 23 composed of a plurality of amplifier elements are mounted on the substrate 25. By mounting the amplification unit 23 at a position away from the transmission / reception element 21, it is possible to prevent the heat generated by the amplification unit 23 from adversely affecting the transmission / reception element 21. The substrate 25 and each coaxial cable 27 of the cable 3 are connected by a connector 26.

  The substrate 25 and the coaxial cable 27 may be directly connected to the substrate 25 by soldering or the like. Alternatively, the coaxial cable 27 is connected to another substrate by soldering or using a coaxial cable connector, and the substrate 25 and the coaxial cable 27 are connected by the substrate connector provided on the separate substrate and the connector provided on the substrate 25. It may be configured.

  Further, when the ultrasonic probe 2 is provided with the temperature sensor 28 as in the second embodiment described later, for example, the temperature sensor 28 is provided as in the example of FIGS. 3A and 3B, for example. Can be arranged.

  In this example, three temperature sensors 28 are arranged. The temperature sensor 28 a is disposed in the vicinity of the center of the array of the amplifiers 23 and detects the temperature of the amplifiers 23. The temperature sensor 28b is disposed at a position close to the acoustic lens 214 of the transmitting / receiving element 21, and detects the temperature of the acoustic lens 214 that the subject feels on the skin. The temperature sensor 28c is disposed at a position that is not gripped by the user, for example, at a side surface position in the housing 29, and detects the outside air temperature.

  Next, the configuration of the first embodiment of the ultrasonic diagnostic apparatus of the present invention will be described using FIG. 4 and FIG. FIG. 4 is a block diagram illustrating an example of the internal configuration of the first embodiment of the ultrasonic diagnostic apparatus.

  In FIG. 4, as described above, the ultrasound diagnostic apparatus S includes the ultrasound diagnostic apparatus body 1, the ultrasound probe 2, the cable 3, and the like. The ultrasonic diagnostic apparatus main body 1 includes a transmission unit 12, a reception unit 13, an image processing unit 14, a control unit 16, a storage unit 17, the above-described operation unit 11, a display unit 15, and the like. The ultrasonic probe 2 includes a transmission / reception unit 21, a changeover switch 22, an amplification unit 23, and the like.

  As described above, the operation unit 11 inputs data such as a command to start diagnosis and personal information of the subject. The transmission unit 12 supplies a transmission signal 121 to a predetermined transmission / reception element of the transmission / reception unit 21 of the ultrasonic probe 2 via the cable 3 and the changeover switch 22, thereby ultrasonic waves to the predetermined transmission / reception element of the transmission / reception unit 21. Drive to generate.

  The reception unit 13 receives a signal 21 r of an ultrasonic reflected wave received by a predetermined transmission / reception element of the transmission / reception unit 21 of the ultrasonic probe 2 via the changeover switch 22 and the cable 3, and is received by the amplification unit 23. 231 is received.

  Based on the reception signal 231 received by the reception unit 13, the image processing unit 14 generates an image of an internal state in the subject, that is, an ultrasonic image. The display unit 15 displays various information input by the operation unit 11 described above and an ultrasonic image in the subject generated by the image processing unit 14. The storage unit 17 stores the ultrasonic image in the subject generated by the image processing unit 14.

  The control unit 16 controls the overall operation of the ultrasound diagnostic apparatus S by controlling the operation unit 11, the transmission unit 12, the reception unit 13, the image processing unit 14, the display unit 15, and the storage unit 17 according to each function. Do.

  Further, the control unit 16 supplies a switch control signal Sc for controlling the changeover switch 22 to the changeover switch 22 of the ultrasonic probe 2 via the cable 3, and controls the amplification amount of the amplification unit 23 to the amplification unit 23. An amplification amount determination voltage Vg to be supplied is supplied. By controlling the amplification amount of the amplification unit 23 by the amplification amount determination voltage Vg, the heat generation of the amplification unit 23 can be suppressed and the temperature in the ultrasonic probe 2 can be controlled within a predetermined range.

  FIG. 5 is a block diagram illustrating an example of a configuration of a receiving unit of the ultrasonic probe according to the first embodiment.

  In FIG. 5, as described above, the receiving unit of the ultrasonic probe 2 includes the receiving element 212c, the changeover switch 22, the amplifying unit 23, and the like.

  In the example of FIG. 5, the receiving element 212c is composed of 192 piezoelectric elements PZ from PZ0 to PZ191, and the changeover switch 22 is a bidirectional switch MUX having 64 three-to-one input / output relationships from MUX0 to MUX63. The amplification unit 23 is composed of 64 amplifiers AM from AM0 to AM63. Each amplifier AM of the amplifying unit 23 is a variable gain amplifier that can control the amplification amount by applying the amplification amount determination voltage Vg to the amplification amount determination terminal 233.

  The number of the piezoelectric elements PZ of the receiving element 212c, the number of the switches MUX of the changeover switch 22, and the number of the amplifiers AM of the amplifying unit 23 are merely examples, and the ultrasonic diagnostic apparatus in which the ultrasonic probe 2 is used. And may be determined appropriately according to the diagnosis system. Further, it is not dependent on the type of the ultrasonic probe 2 and can be applied to any ultrasonic probe such as a linear probe, a convex probe, and a sector probe.

  At the time of receiving the ultrasonic wave, the changeover switch 22 receives the ultrasonic wave received by the continuous 64 piezoelectric elements PZ among the 192 piezoelectric elements PZ of the receiving element 212c according to the switch control signal Sc supplied from the control unit 16. A reflected wave signal 21 r is input to each of the 64 amplifiers AM of the amplifier 23. The amplification unit 23 controls the amplification amount of each of the 64 amplifiers AM in accordance with the amplification amount determination voltage Vg supplied from the control unit 16, and an amplification output obtained by amplifying the reflected wave signal 21 r is received as a reception signal 231 to the reception unit 13. Send.

  It is possible to generate an ultrasonic image by repeating transmission and reception of ultrasonic waves while sequentially shifting and switching the changeover switch 22 according to the switch control signal Sc, that is, sequentially shifting and switching the piezoelectric elements PZ of the receiving element 212c. it can.

  Here, the relationship between the form of the ultrasonic probe and the intensity of the reflected wave will be described with reference to FIG. FIG. 6 is a schematic diagram showing the relationship between the form of the ultrasonic probe and the intensity of the reflected wave. FIG. 6 (a) shows the intensity of the transmitted wave, and FIG. 6 (b) shows the intensity of the reflected wave of the linear probe. 6C shows the intensity of the reflected wave of the convex probe, and FIG. 6D shows the intensity of the reflected wave of the sector probe.

  In FIG. 6A, the ultrasonic wave transmitted from the transmission / reception unit 21 of the ultrasonic probe 2 has directivity, and the intensity I of the main peak T shows the eggplant type intensity as shown. Accordingly, the intensity I (θ) of the main peak T in the direction inclined by the angle θ with respect to the normal line of the transmission / reception unit 21 is a function of the angle θ. The transmitted ultrasonic wave has secondary lobe side lobes Ts on both sides of the main peak T.

  In FIG. 6B, the linear probe transmits ultrasonic waves perpendicularly to the planar transmission / reception unit 21, so that the piezoelectric element PZ is sequentially shifted and switched in the direction of the arrow F by the method shown in FIG. By transmitting and receiving the ultrasonic waves shown in FIG. 6 (a), the intensity R of the reflected wave is strong at the center and weak at both sides as shown in the upper part of the figure. Here, the horizontal axis Δ in the figure indicates the position of the piezoelectric element PZ of the transmission / reception unit 21. The same applies hereinafter.

  In FIG. 6 (c), the convex probe transmits ultrasonic waves vertically to the spherical transmitter / receiver 21, so that the piezoelectric element PZ is sequentially shifted in the direction of arrow F by the method shown in FIG. When the ultrasonic waves shown in FIG. 6 (a) are transmitted and received while switching, the intensity R of the reflected wave is strong at the center and weak at both sides as shown in the upper part of the figure.

  On the other hand, in FIG. 6D, the sector probe transmits the ultrasonic wave in a sector shape by deflecting the synthesized wavefront of the ultrasonic wave generated by the transmission / reception unit 21, and therefore the intensity R of the reflected wave is the intensity of the transmitted wave. Depending on the deflection angle α, when α = 0, the intensity is strong at the center and weak at both sides like the linear probe or convex probe, but the deflection angle α becomes large (for example, α = α1 or α = in the figure). -Α1), and as shown by the broken line in the figure, one end is strong, the center is medium strength, and the other end is weak. Here, the receiving element of the transmission / reception unit 21 is not shifted and switched, but is fixedly displayed in accordance with a second example of the control method of the amplification amount of the amplification unit 23 described later in FIG. Yes.

  As described above, the characteristics of the intensity distribution of the reflected wave are different depending on the type of the ultrasonic probe. Therefore, when generating the ultrasonic image, the amplification unit 23 amplifies the ultrasonic wave in accordance with the type of the ultrasonic probe. By controlling the amount, a better ultrasound image can be generated. In the following, two examples of the control method of the amplification amount are shown according to the type of the ultrasonic probe.

  Next, a first example of a method for controlling the amplification amount of each amplifier AM of the amplification unit 23 when receiving an ultrasonic wave will be described with reference to FIGS. 7 and 8. FIG. 7 is a schematic diagram showing a receiving element used when receiving an ultrasonic wave. The first example is a method applied to the above-described linear probe and convex probe.

  In FIG. 7, during the first transmission / reception of ultrasonic waves, the selector switch 22 selects 64 continuous piezoelectric elements PZ from PZ0 to PZ63 among the 192 piezoelectric elements PZ of the receiving element 212c as the transmission / reception range. Send ultrasonic waves and receive reflected waves of ultrasonic waves.

  At this time, in the case of the linear probe and the convex probe, as described with reference to FIGS. 6B and 6C, the reflected waves are reflected in the piezoelectric elements PZ0 and PZ63 at the end of the reception range of the reflected waves and in the vicinity thereof. Therefore, it is necessary to sufficiently amplify the reflected wave by increasing the amplification amount of the amplifier AM of the amplification unit 23. On the other hand, since the reflected wave is strong in the piezoelectric element PZ31 corresponding to the center of the reception range of the reflected wave and its vicinity, it is not necessary to increase the amplification amount of the amplifier AM of the amplifying unit 23 too much.

  On the other hand, at the 32nd transmission / reception of ultrasonic waves, the changeover switch 22 selects 64 continuous piezoelectric elements PZ from PZ31 to PZ94 among the 192 piezoelectric elements PZ of the receiving element 212c as the transmission / reception range. Transmits sound waves and receives reflected ultrasonic waves.

  At this time, since the reflected wave is weak in the piezoelectric elements PZ31 and PZ94 corresponding to the end of the reflected wave reception range and in the vicinity thereof, it is necessary to increase the amplification amount of the amplifier AM of the amplifying unit 23 to sufficiently amplify the reflected wave. is there. On the other hand, since the reflected wave is strong in the piezoelectric element PZ63 corresponding to the center of the reception range of the reflected wave and its vicinity, it is not necessary to increase the amplification amount of the amplifier AM of the amplifying unit 23 too much.

  That is, it is necessary to increase the amplification amount of the amplifier AM of the amplifying unit 23 at both ends of the reception range selected by the changeover switch 22 and in the vicinity thereof. There is no need to make it bigger.

  Therefore, in the first embodiment, the amplification amount of the amplifier AM of the amplifying unit 23 connected to both ends of the piezoelectric element PZ in the reception range selected by the changeover switch 22 and the piezoelectric element PZ in the vicinity thereof is increased, and reception is performed. The amplification amount of the amplifier AM of the amplification unit 23 connected to the piezoelectric element PZ in the vicinity of the center of the range is reduced.

  The amplification amount of the amplifier AM of the amplifying unit 23 connected to the piezoelectric element PZ located between the both ends and the center of the reception range depends on the position of the piezoelectric element PZ, and the amplifier AM connected to the piezoelectric elements PZ at both ends. And the amplification amount of the amplifier AM connected to the central piezoelectric element PZ.

  Specifically, as shown in FIG. 5, the amplification amount determination voltage Vg is applied from the control unit 16 to the amplification amount determination terminals 233 of each of the 64 amplifiers AM0 to AM63 of the amplification unit 23. The amount of amplification is controlled for each amplifier AM.

  As a result, it is possible to reduce the extra power consumption that has been generated because the amplifier AM that has conventionally amplified a large amount of amplification is uniformly amplified, and the temperature inside the ultrasonic probe 2 can be prevented from rising.

  FIG. 8 is a schematic diagram illustrating a configuration of a portion that supplies an amplification amount determination voltage of the control unit in the first example of the amplification amount control method according to the first embodiment, and FIG. FIG. 8B is a schematic diagram showing the configuration of the amplification amount determination voltage table. FIG.

  8A, the control unit 16 includes a voltage control unit 161, an amplification amount determination voltage table 162, and the like, and controls the amplification amount of each amplifier AM of the amplification unit 23. The voltage control unit 161 includes a voltage determination control unit 1611, an amplification amount determination voltage generation unit 1612, and the like.

  The voltage determination control unit 1611 determines 64 amplification amount determination voltage data Vgd for each amplifier AM from the amplification amount determination voltage table 162 based on the ultrasonic transmission / reception frequency N, and sends the amplification amount determination voltage generation unit 1612 to the amplification amount determination voltage generation unit 1612. Send.

  The amplification amount determination voltage generation unit 1612 generates 64 amplification amount determination voltages Vg for each amplifier AM based on the amplification amount determination voltage data Vgd received from the voltage determination control unit 1611, and each amplifier of the amplification unit 23 Supply to AM.

  As shown in FIG. 5, the reflected wave signal 21r of the ultrasonic wave received by the 64 piezoelectric elements PZ selected by the changeover switch 22 of the receiving element 212c of the ultrasonic probe 2 is the amplifier of the amplifying unit 23. The signals are amplified by the amplification amount determined by the amplification amount determination voltage Vg input from AM0 to AM63 and applied to the amplification amount determination terminal 233 of each amplifier AM, and output as the received signal 231. Here, it is assumed that the amplifier AM has a large amplification amount when the amplification amount determination voltage Vg is high and small when the amplification amount determination voltage Vg is low.

  In FIG. 8B, the amplification amount determination voltage table 162 is a look-up table (LUT) composed of amplification amount determination voltage data Vgd of the amplifiers AM0 to AM63 of the amplification unit 23 corresponding to the number N of ultrasonic transmission / reception. is there. The amplification amount determination voltage table 162 may be provided in the storage unit 17.

  In the illustrated example, during the first transmission / reception of the ultrasonic wave, the value of the amplification amount determination voltage data Vgd of the amplifiers AM0 and AM63 connected to the piezoelectric elements PZ0 and PZ63 at both ends of the reception range is high, The value of the amplification amount determination voltage data Vgd of the amplifier AM31 connected to the piezoelectric element PZ31 is low.

  On the other hand, at the 32nd transmission / reception of ultrasonic waves, the value of the amplification amount determination voltage data Vgd of the amplifier AM31 connected to the piezoelectric element PZ31 at the end of the reception range is high and is connected to the piezoelectric elements PZ63 and PZ64 at the center of the reception range. The values of the amplification amount determination voltage data Vgd of the amplifiers AM63 and AM0 are low. However, the amplification amount determination voltage table 162 is not limited to this.

  In addition, since the power consumption and the necessary amplification amount are different for each operation mode (for example, B-mode, power Doppler mode, color Doppler mode, M-mode, and these combined modes) of the ultrasonic probe 2, each operation mode is different. May have a separate amplification amount determination voltage table 162.

Further, for example, when the ultrasonic probe used differs depending on the diagnostic site, for example, the setting values such as the number of amplification units 23 and the number of transmissions / receptions for each ultrasonic probe to be used are read. May be used to calculate and generate the amplification amount determination voltage table 162. here,
Vgd (β) = α × {N− (γ−β)} ² (1)
However,
Vgd (β): Amplification amount determination voltage data of the β-th amplifier (in the amplification amount determination voltage table) α: Amplification constant N: Number of times of transmission / reception of ultrasonic waves γ: Number of amplifiers AM in amplification unit 23 β: Amplification unit 23 This is the number of the amplifier AM. The amplification constant α may be appropriately determined by experiments or the like. As described above, (Expression 1) is applied to linear probes and convex probes.

  Next, a second example of the control method of the amplification amount of each amplifier AM of the amplification unit 23 at the time of receiving ultrasonic waves will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating a configuration of a part that supplies an amplification amount determination voltage of the control unit in the second example of the amplification amount control method according to the first embodiment. FIG. 9A illustrates the control unit. FIG. 9B is a schematic diagram showing the configuration of the amplification amount determination voltage table. The second example is a method applied in the case of the sector probe described above.

  Here, for easy understanding, the receiving element 212c in FIG. 5 is made up of 64 piezoelectric elements PZ from PZ0 to PZ63, and each piezoelectric element PZ and each amplifier AM (AM0 to AM63) of the amplifying unit 23 are provided. It is assumed that the bidirectional switch MUX (MUX0 to MUX63) of the changeover switch 22 is fixedly connected on a one-to-one basis.

  9A, similarly to FIG. 8A, the control unit 16 includes a voltage control unit 161 and an amplification amount determination voltage table 162, and controls the amplification amount of each amplifier AM of the amplification unit 23. The amplification amount determination voltage Vg to be output is output. The voltage control unit 161 includes a voltage determination control unit 1611, an amplification amount determination voltage generation unit 1612, and the like.

  The voltage determination control unit 1611 determines 64 amplification amount determination voltage data Vgd for each amplifier AM from the amplification amount determination voltage table 162 based on the deflection angle α of the transmission wave determined by the control unit 16, and amplifies it. It transmits to the quantity determination voltage generation part 1612.

  The amplification amount determination voltage generation unit 1612 generates 64 amplification amount determination voltages Vg for each amplifier AM based on the amplification amount determination voltage data Vgd received from the voltage determination control unit 1611, and each amplifier of the amplification unit 23 Supply to AM.

  As shown in FIG. 5, the reflected wave signal 21r of the ultrasonic wave received by the 64 piezoelectric elements PZ of the ultrasonic probe 2 is input to the amplifiers AM0 to AM63 of the amplifying unit 23 and amplified by each amplifier AM. The signal is amplified by the amplification amount determined by the amplification amount determination voltage Vg applied to the amount determination terminal 233 and output as the reception signal 231. Here, it is assumed that the amplifier AM has a large amplification amount when the amplification amount determination voltage Vg is high and small when the amplification amount determination voltage Vg is low.

  In FIG. 9B, the amplification amount determination voltage table 162 is a look-up table (LUT) composed of amplification amount determination voltage data Vgd of the amplifiers AM0 to AM63 of the amplification unit 23 corresponding to the ultrasonic deflection angle α. is there. The amplification amount determination voltage table 162 may be provided in the storage unit 17.

  In the illustrated example, when the ultrasonic deflection angle α = −45 °, the value of the amplification amount determination voltage data Vgd of the amplifier AM0 connected to the piezoelectric element PZ0 at one end of the reception range is low, and the piezoelectric at the other end is piezoelectric. The value of the amplification amount determination voltage data Vgd of the amplifier AM63 connected to the element PZ63 is high, and the value of the amplification amount determination voltage data Vgd of the amplifier AM31 connected to the piezoelectric element PZ31 at the center of the reception range is an intermediate value. The opposite is true for the deflection angle α = 45 °.

  On the other hand, when the ultrasonic deflection angle α = 0 °, the value of the amplification amount determination voltage data Vgd of the amplifier AM31 connected to the piezoelectric elements PZ0 and PZ63 at both ends of the reception range is high, and the piezoelectric value at the center of the reception range is high. The value of the amplification amount determination voltage data Vgd of the amplifier AM31 connected to the element PZ31 is low. However, the amplification amount determination voltage table 162 is not limited to this.

  In order to extend the second example described above to a method of scanning while switching the connection between the receiving element 212c and the amplifying unit 23 with the changeover switch 22 as shown in FIG. The amplification amount determination voltage table 162 may be expanded to have a plurality of lookup tables for each transmission / reception frequency N in FIG. 8B for each ultrasonic deflection angle α.

  Further, the amplification amount determination voltage table 162 may be calculated and generated based on the deflection angle α and the number N of transmission / reception, as in the above-described first example (formula 1).

  As described above, according to the first embodiment, a transmission / reception unit having a plurality of transmission / reception elements for transmitting / receiving ultrasonic waves, and an amplification unit having a plurality of amplifiers for amplifying reception signals received by the transmission / reception unit, In an ultrasonic diagnostic apparatus having an ultrasonic probe including a changeover switch having a plurality of switches for switching a connection state between an amplification unit and a transmission / reception unit, the connection state between the amplification unit and the transmission / reception unit switched by the changeover switch Based on this, by providing a control unit that controls the amplification amount of the amplifier of the amplification unit, the temperature increase in the ultrasonic probe is prevented, and the amplification amount of the built-in amplification unit is restricted without restricting the use of the ultrasonic probe. Therefore, it is possible to provide an ultrasonic diagnostic apparatus in which harmonic images are not deteriorated due to fluctuations in noise and fluctuations in thermal noise.

  Next, the configuration of the second embodiment of the ultrasonic diagnostic apparatus of the present invention will be described with reference to FIGS. FIG. 10 is a block diagram showing an internal configuration of the second embodiment of the ultrasonic diagnostic apparatus.

  In FIG. 10, the second embodiment of the ultrasonic diagnostic apparatus S is different from the first embodiment shown in FIG. 4 in that a temperature sensor 28 is built in the ultrasonic probe 2 and measurement is performed by the temperature sensor 28. The temperature signal 281 indicating the internal temperature of the ultrasonic probe 2 is input to the control unit 16, the configuration of the amplification unit 23 described later is different, and the amplification amount determination voltage of the control unit 16 described later Three points are different in the configuration of the portion for supplying Vg. Others are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 11 is a block diagram illustrating an internal configuration of the ultrasonic probe according to the second embodiment.

In FIG. 11, in the second embodiment, the amplifier AM constituting the amplifying unit 23 is a normal operational amplifier, unlike the first embodiment. Further, the power supply voltages V ⁺ and V ^{− of} each amplifier AM constituting the amplification unit 23 are variable and controlled by the amplification amount determination voltage Vg of the control unit 16. Details will be described later. Others are the same as those of the first embodiment shown in FIG.

  FIG. 12 is a schematic diagram illustrating a configuration of a portion that supplies an amplification amount determination voltage of the control unit according to the second embodiment, and FIG. 12A illustrates a configuration of a portion that supplies the amplification amount determination voltage of the control unit. FIG. 12B is a schematic diagram showing a structure of temperature aging data.

  12A, the control unit 16 includes a voltage control unit 161, temperature change data 163, and the like, and controls the amplification amount of the amplification unit 23. The voltage control unit 161 includes a voltage determination control unit 1611, an amplification amount determination voltage generation unit 1612, and the like.

  For example, the voltage determination control unit 1611 receives the temperature signal 281 of the temperature sensor 28 shown in FIG. 10 every predetermined time (for example, 10 seconds) after the ultrasonic probe 2 is turned on, and generates the temperature signal 281. Based on this, the temperature Tp of the transmitting / receiving unit 21 and the amplifying unit 23 which are the main heat sources in the ultrasonic probe 2 is acquired and added to the temperature change data 163.

  Next, the amplification amount determination voltage data Vgd is determined using a control method such as PID control or PI control based on the acquired current temperature Tp and the temporal change data of the temperature Tp acquired in the past, This is added to the temperature change data 163 and transmitted to the amplification amount determination voltage generation unit 1612.

  The control target temperature To when determining the amplification amount determination voltage data Vgd may be a uniquely determined temperature (for example, 40 ° C.). More preferably, a temperature at which the patient does not feel a large temperature difference between the outside air temperature and the contact surface of the ultrasonic probe 2 based on the difference from the outside air temperature may be set as the control target temperature To.

The amplification amount determination voltage generation unit 1612 generates the amplification amount determination voltage Vg based on the amplification amount determination voltage data Vgd received from the voltage determination control unit 1611 and supplies the amplification amount determination voltage Vg to the amplification unit 23. As will be described later with reference to FIG. 13, the amplification amount determination voltage Vg is a voltage that controls the power supply voltages V ⁺ and V ⁻ of the amplification unit 23.

  In FIG. 12B, the temperature aging data 163 is stored in the ultrasonic probe 2 acquired by the voltage determination control unit 1611 every predetermined time (for example, 10 seconds) after the ultrasonic probe 2 is turned on. Is a data table of the temperature Tp of the current and the amplification amount determination voltage data Vgd at that time. The temperature change data 163 may be provided in the storage unit 17.

  According to the illustrated example, the temperature Tp in the ultrasonic probe 2 gradually increases as time elapses after the power of the ultrasonic probe 2 is turned on, and correspondingly, the amplification amount determination voltage data It can be seen that Vgd also changes gradually.

  FIG. 13 is a schematic diagram illustrating the configuration of the amplification unit according to the second embodiment. FIG. 13A is a circuit diagram illustrating the configuration of the amplification unit according to the second embodiment. FIG. 13C is a schematic diagram showing the power consumption of the amplification unit.

In FIG. 13A, in the second embodiment, each amplifier AM constituting the amplifying unit 23 is an inverting amplifier using an operational amplifier. The ultrasonic reflected wave signal 21r received by the transmitting / receiving unit 21 of the ultrasonic probe 2 is input to the non-inverting input (−) of the operational amplifier via the resistor R1, and is determined by the ratio of the resistor R2 and the resistor R1. Is amplified by the amplification amount to be output as the received signal 231. As the power source of the operational amplifier, the power source voltages V ⁺ and V ⁻ generated from the amplification amount determining voltage Vg described above are used.

Here, the positive power supply voltage V ⁺ and the negative power supply voltage V ⁻ of each amplifier AM of the amplification unit 23 are values obtained by multiplying the amplification amount determination voltage data Vgd by a predetermined coefficient k from a predetermined power supply voltage value + Vcc, respectively. And a voltage obtained by adding a predetermined power supply voltage value -Vcc to a value obtained by multiplying the amplification amount determination voltage data Vgd by a predetermined coefficient j. here,
V ⁺ = + Vcc−k × Vgd
V ⁻ = −Vcc + j × Vgd
It is. The predetermined coefficients k and j may be appropriately determined by actual measurement or the like.

The ultrasonic reflected wave signal 21r received by the transmitter / receiver 21 of the ultrasonic probe 2 is usually a signal having both positive and negative voltages. Therefore, the power consumption _PT of the amplifying unit 23 is as shown in FIGS. 13 (b) and 13 (c).
P _T = Icc × (V ⁺ −V ⁻ ) + Io × (V ⁺ −Vo) (2 formulas)
Or
P _T = Icc × (V ⁺ −V ⁻ ) + Io × (Vo−V ⁻ ) (3 formulas)
It becomes.

Therefore, from (Equation 2) and (Equation 3), the difference (V ⁺ −V ⁻ ) between the power supply voltages of the amplifying unit 23 and the difference (V ⁺ −Vo) between the output Vo and the power supply voltage of the amplifying unit 23 or By reducing (Vo−V ⁻ ), the power consumption _PT of the amplifying unit 23 can be reduced, and the heat generation of the amplifying unit 23 can be suppressed. Therefore, by using the above-described V ⁺ and V ⁻ as the power supply voltage of the amplifying unit 23, heat generation of the amplifying unit 23 can be suppressed.

  Even in this case, when the amplitude of the output Vo of the amplifying unit 23 is small, the signal is not distorted, and only when the amplitude of the output Vo is large, the linearity of the output is lost and the state becomes saturated. That is, the amplification amount determination voltage Vg is determined so that the amplification amount of the amplification unit 23 is suppressed only when the amplitude of the output Vo is large.

  As described above, according to the second embodiment, a transmission / reception unit having a plurality of transmission / reception elements for transmitting / receiving ultrasonic waves, an amplification unit having a plurality of amplifiers for amplifying reception signals received by the transmission / reception unit, In an ultrasonic diagnostic apparatus including an ultrasonic probe having a changeover switch having a plurality of switches for switching a connection state between an amplification unit and a transmission / reception unit, a temperature sensor is incorporated in the ultrasonic probe and is detected by the temperature sensor. By providing a control unit that controls the power supply voltage of the amplifier of the amplification unit based on the temporal change of the temperature in the ultrasonic probe, the temperature rise in the ultrasonic probe is prevented and the use of the ultrasonic probe is limited Therefore, it is possible to provide an ultrasonic diagnostic apparatus in which there is no deterioration of the harmonic image due to fluctuations in the amount of amplification of the built-in amplification unit and fluctuations in thermal noise.

Further, the power supply voltages (V ⁺ and V ⁻ ) of the amplifying unit 23 are controlled based on the history of the temperature Tp in the ultrasonic probe 2 by combining the first embodiment and the second embodiment. At the same time, by controlling the amplification amount of the amplifier AM of the amplification unit 23 based on the connection state between the amplification unit 23 and the transmission / reception unit 21 switched by the changeover switch 22, the power consumption of the amplification unit 23 can be suppressed more efficiently. It is possible to prevent a rise in the temperature in the ultrasonic probe 2 and to limit the use of the ultrasonic probe 2 without the use of the ultrasonic probe 2. The ultrasonic diagnostic apparatus S without deterioration can be provided.

  Here, the organic piezoelectric element thin film used for the ultrasonic probe 2 and its operation will be briefly described. The organic piezoelectric element thin film is used as an electromechanical conversion element that receives an ultrasonic wave reflected inside a subject and converts it into an electric signal. For example, a polymer of vinylidene fluoride or vinylidene fluoride is used. It is composed of a thin film of an organic piezoelectric material such as a (VDF) copolymer, a copolymer of vinylidene fluoride and trifluoroethylene.

  The reflected wave reflected inside the subject is not only the fundamental reflected wave of the fundamental frequency component of the transmitted ultrasonic wave but also a frequency component of a harmonic that is an integral multiple of the fundamental frequency, for example, twice or three times the fundamental frequency. Also, reflected waves such as second harmonic components such as 4 times, third harmonic components, and fourth harmonic components are included.

  That is, since harmonics of the fundamental wave are received, it is possible to form an ultrasonic image by the above-described harmonic imaging technique, and the ultrasonic probe 2 and the ultrasonic diagnosis in the first and second embodiments described above. The apparatus S can provide a more accurate ultrasonic image. In particular, since the second and third harmonics having relatively high power are received, a clearer ultrasonic image can be provided.

  As described above, according to the present invention, a transmission / reception unit having a plurality of transmission / reception elements for transmitting / receiving ultrasonic waves, an amplification unit having a plurality of amplifiers for amplifying reception signals received by the transmission / reception unit, and an amplification unit In an ultrasonic diagnostic apparatus comprising an ultrasonic probe comprising a change-over switch having a plurality of switches for switching a connection state between the transmission / reception unit and the transmission / reception unit, based on the connection state between the amplification unit and the transmission / reception unit switched by the change-over switch By providing a control unit that controls the amplification amount of the amplification unit, it is possible to prevent a rise in temperature in the ultrasonic probe, and to limit the use of the ultrasonic probe, and to prevent fluctuations in the amplification amount of the built-in amplification unit and heat It is possible to provide an ultrasonic diagnostic apparatus in which no harmonic image is deteriorated due to noise fluctuation or the like.

  It should be noted that the detailed configuration and detailed operation of each component constituting the ultrasonic diagnostic apparatus according to the present invention can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus main body 2 Ultrasonic probe 3 Cable 11 Operation part 12 Transmission part 121 Transmission signal 13 Reception part 14 Image processing part 15 Display part 16 Control part 161 Voltage control part 1611 Voltage determination control part 1612 Amplification amount determination voltage generation part 162 Amplification amount determination voltage table 163 Temperature change data 17 Storage unit 21 Transmission / reception unit 21r (Ultrasonic) reflected wave signal 22 Changeover switch 23 Amplification unit 231 Reception signal 233 Amplification amount determination terminal 28 Temperature sensor 281 Temperature signal S Ultrasonic wave Diagnosis device PZ transmission / reception element MUX switch AM amplifier Vg amplification amount determination voltage Vgd amplification amount determination voltage data Sc switch control signal N number of transmission / reception V ⁺ (amplification unit 23) positive power supply voltage V ⁻ (amplification unit 23) negative power supply Voltage

Claims (8)

A transmission / reception unit having a plurality of transmission / reception elements for transmitting and receiving ultrasonic waves;
An amplifying unit having a plurality of amplifiers for amplifying the received signal received by the transceiver unit;
In an ultrasonic diagnostic apparatus comprising an ultrasonic probe comprising a changeover switch having a plurality of switches for switching a connection state between the amplification unit and the transmission / reception unit,
An ultrasonic diagnostic apparatus comprising: a control unit that controls an amplification amount of the amplification unit based on a connection state between the amplification unit and the transmission / reception unit switched by the changeover switch. The controller is
An amplification amount determination voltage table for determining an amplification amount of the amplification unit based on a connection state between the amplification unit and the transmission / reception unit;
The ultrasonic diagnostic apparatus according to claim 1, further comprising: a voltage control unit that outputs an amplification amount determination voltage that controls an amplification amount of the amplification unit based on the amplification amount determination voltage table. The controller is
Based on a connection state between the amplification unit and the transmission / reception unit, an amplification amount determination voltage table for determining an amplification amount of the amplification unit is generated,
The ultrasonic diagnostic apparatus according to claim 1, further comprising: a voltage control unit that outputs an amplification amount determination voltage for controlling the amplification amount of the amplification unit based on the generated amplification amount determination voltage table. The ultrasonic diagnostic apparatus according to claim 3, wherein the voltage control unit calculates the amplification amount determination voltage table according to the following (formula 1). here,
Vgd (β) = α × {N− (γ−β)} ² (1)
However,
Vgd (β): Amplification amount determination voltage data of the β-th amplifier (in the amplification amount determination voltage table) α: Amplification constant N: Number of transmission / reception of ultrasonic waves γ: Number of amplifiers in the amplification unit β: Number of amplifiers in the amplification unit It is. The ultrasonic diagnostic apparatus has a plurality of operation modes,
The controller is
5. The ultrasonic diagnostic apparatus according to claim 2, further comprising an amplification amount determination voltage table for each operation mode. The amplifying unit is a variable gain amplifier having an amplification amount determination terminal whose amplification amount is determined by an input voltage,
The ultrasonic diagnostic apparatus according to claim 1, wherein the amplification amount determination voltage of the voltage control unit is input to an amplification amount determination terminal of the amplification unit.   The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission / reception unit is an organic piezoelectric element thin film. The transmission / reception unit receives a reflected wave of a harmonic that is an integral multiple of the fundamental frequency component of the transmitted ultrasonic wave,
The ultrasonic diagnostic apparatus according to claim 1, further comprising an image processing unit that forms an ultrasonic image based on the reflected wave of the harmonic.

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