JPH0467854A - Ultrasonic image pickup device - Google Patents

Abstract

PURPOSE:To perform the image pickup of plural tomographic planes i.e. three- dimensional image pickup by the scan of an electronic linear or an electric sector at every scanning position by performing such aperture synthetic processing that reception signals for plural times at the scanning position by a scanning means are stored as adding. CONSTITUTION:A series of operations for ultrasonic wave transmission/reception are repeated at every sequential switching of electrode selection in electrode arrange ment A at a switch scanning circuit 2. The holding of reception data from a reception circuit 7 on memory space is always performed by developing on the circular arc of a concentric circle centering a position in accordance with a selected electrode, and also, it is performed as adding new data on a value held in each address of the memory space until then. In other words, the reception data is added and held at every shift of a voltage activation area in a direction of (x) i.e. a transmission/ reception wave aperture by an aperture synthesizing method. For example, when a reflection source exists at a position shown in C in a subject, a high value is added and held at a position equivalent to the circular arc a1 on the memory space in a transmission/reception wave by the selection of an electrode A1, and the high value is added and held at the position equivalent to the circular arc aj on the memory space in the transmission/reception wave by the selection of an electrode Aj.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electronic scanning type ultrasound diagnostic device and an ultrasound imaging device, and particularly to an electronic scanning type ultrasound diagnostic device and an ultrasound imaging device.

[Conventional technology]

Conventionally, in the method of dividing the ultrasound transducer constituting the electroacoustic transducer of an ultrasound probe into two dimensions and capturing three-dimensional images, it is necessary to The method used was to form independent electrodes and wire them. However, this method has a problem in that it becomes difficult to put it into practice as the number of oscillators increases. In order to solve this problem, a method was proposed in Japanese Patent Application Laid-Open No. 62-84, in which a rectangular electrode array was provided on both principal surfaces of an electrostrictive material plate to serve as a vibrator for an ultrasonic probe.
No. 697. Conventionally, piezoelectric materials, which have been widely used as transducer materials, are used in electroacoustic transducers of ultrasound probes, taking advantage of their property of generating voltage through mechanical displacement caused by ultrasound reception. In contrast, electrostrictive materials have the property of causing voltage fluctuations due to mechanical displacement only under a bias electric field. Further, since the electromechanical coupling coefficient changes greatly depending on the strength of the bias electric field, the electrostrictive material can also be regarded as a piezoelectric material whose electroacoustic conversion efficiency can be controlled by the bias electric field. If a vibrator is constructed by providing strip-shaped electrode arrays A and B that are perpendicular to each other or intersect at a certain angle, as shown in FIG. 5(a), each main By applying a bias electric field between electrodes selected from the plane, the electrostrictive material at the electrode intersection is selected as a vibrating element as shown in (b), and electroacoustic conversion occurs when receiving ultrasonic waves as voltage fluctuation between the electrodes. be able to. However, with this method, it is possible to converge the ultrasonic beam while performing electronic focusing using either electrode array A or H, and perform electronic scanning in real time. It is difficult to perform electronic scanning with precise focusing.

Problem to be Solved by the Invention 1 The above-mentioned prior art is based on the operating principle of an ultrasonic probe that uses an electrostrictive material vibrator with a crossed electrode arrangement as an electroacoustic transducer or the basic principle of the probe. Only the configuration is disclosed, and no consideration is given to the three-dimensional ultrasound imaging method, which takes into account the difficulty of simultaneously using both electrode arrays on both principal surfaces for electronic focusing and imaging in real time. First, it has not been possible to realize an ultrasonic diagnostic apparatus or an ultrasonic imaging apparatus equipped with the ultrasonic probe and capable of three-dimensional imaging. An object of the present invention is to provide an ultrasonic diagnostic device or an ultrasonic imaging device capable of three-dimensional stereoscopic imaging using an ultrasonic probe using an electrostrictive material provided with crossed electrodes as an electroacoustic transducer. The objective is to provide an imaging method. Another object of the present invention is to provide an electronic scanning method for the above diagnostic device or imaging device. Another object of the present invention is to provide a diagnostic device or an imaging device using the above imaging method. [Means for Solving the Problems] In order to achieve the above object, the present invention provides one of electrode arrays A and B that intersect with each other on both principal surfaces of a plate of electrostrictive material having crossed electrode arrays. A scanning means for selectively applying a bias voltage to each electrode is connected to the electrode array A, and an ultrasonic transmitting/receiving means having an electronic focusing function and a scanning function for the ultrasonic beam is connected to the other electrode array B. However, the ultrasonic transmitting/receiving means repeatedly performs transmitting/receiving using a plurality of electrodes in the electrode array B while performing so-called electronic linear scanning or electronic sector scanning, and the scanning means controls the electrode selection by the ultrasonic transmitting/receiving means. By applying a bias voltage to a smaller number of electrodes, the piezoelectrically induced portion of the vibrator is narrowed down to a small diameter and sequentially scanned in the arrangement direction of the electrode array A. A configuration in which three-dimensional imaging is performed by performing aperture synthesis in the arrangement direction of the electrode array A by adding and storing ultrasonic reception signals at a plurality of scan positions of the scanning means in a storage means for each scan position. It is characterized by the following points. More specifically, the ultrasonic transmitting/receiving means performs transmission and reception each time using all or some of the electrodes in the electrode array A, and applies a predetermined delay time distribution to the transmitted and received signals to transmit and receive the waves. It converges the receiving beam and includes means for sequentially changing the delay time distribution of the receiving signal during the receiving period after one transmission to move the convergence point of the receiving beam in the beam depth direction.

[Effect]

According to the above configuration, even if a certain part of the electrode array B is selected by the ultrasonic transmitting/receiving means, only the region of the electrode array A facing the part selected by the scanning means and to which the bias voltage is applied is electrified. Piezoelectric activity occurs in the strained material. Therefore, the directivity is weak in the arrangement direction of the electrode array A, that is, the ultrasonic beam that spreads in a fan shape in this direction is transmitted and received. Therefore, the echo signal intensity obtained at a certain point corresponds to the reflection from a point on the cross section selected by the ultrasonic transmitting/receiving means and on a circular arc with the center point at the center of the electrode to which the bias voltage is applied. do. Therefore, the echo signal intensity at each time point of the received signal is stored at each point on the arc of the storage area associated with this tomographic plane, and the received signals at multiple scan positions by the scanning means are added. A single tomographic image is obtained by performing aperture synthesis processing in which the images are stored while the images are being stored. This operation is performed for each scanning position of electronic linear or electronic sector scanning in the arrangement direction of the electrode array B by the ultrasonic transmitting/receiving means, so that imaging of multiple tomographic planes, that is, three-dimensional imaging is performed. If priority is given to scanning in the array direction of electrode array A, that is, while the beam scan in the array direction of electrode array B is fixed, the piezoelectric activity generating region is scanned by the scanning means and transmission and reception are repeated, and this is repeated in the direction of electrode array B. If this is repeated for each beam scanning position in the array direction, one tomographic image is completed first, and the other tomographic images are completed one after another. On the other hand, if priority is given to scanning in the array direction of electrode array B, in other words, beam scanning is performed in the array direction of electrode array B while fixing the scanning of the piezoelectric activity generation region by the scanning means, repeating transmission and reception, and transmitting and receiving the piezoelectric By repeating this for each scanning position of the active region, all tomographic images are gradually completed in parallel. Further, according to the configuration including the above-mentioned means for moving the convergence point of the received beam, it is possible to always perform aperture synthesis of the received signals from the reflection points near the focal region. Therefore, the resolution of each tomographic image in the direction perpendicular to the tomographic plane is improved, the image quality of each image is improved, and even if the tomographic image in the vertical direction is extracted after the image is completed, an image of sufficient quality can be obtained. Instead of this, the transmitting beam,
A method of repeating transmission and reception for each depth zone by changing the convergence point of both the receiving beam and the receiving beam can be considered, but there is a trade-off between the vertical resolution and the imaging time described above. Therefore, it is preferable to employ the above-mentioned means for moving the convergence point in order to obtain an image of sufficient quality within a practical imaging time.

【Example】

Next, the present invention will be explained in detail. As shown in FIG. 5(a), an electrostrictive ceramic composition (for example, P
b (Mg, Nb2,)O, -PbTiO, compositions whose phase transition temperature to ferroelectric is relatively near room temperature in relaxed ferroelectrics such as solid solution ceramics, etc.)
A rectangular plate, or a composite material in which the rectangular plate is divided into many parts vertically and horizontally and the spaces are filled with resin etc., is processed so that the resonance frequency in the thickness direction corresponds to the frequency of the ultrasonic waves being emitted or received. Let it be strain oscillator 1. Electrode arrays A and B divided into a plurality of strips are formed on each main surface of this rectangular plate. The electrodes may be formed, for example, by baking silver or electroless plating with copper, nickel, or the like. The electrode arrays A and B formed on both main surfaces are formed such that the electrode dividing directions on the two surfaces are perpendicular to each other. In such a vibrator, the electrode array A and the DC bias voltage generation circuit are connected by a switch scanning circuit, and the electrode array B and the transmitting and receiving circuits are connected by another switch scanning circuit. In each switch scanning circuit, from the electrode arrangement to which each is connected, as shown in FIG. 5(b), the electrodes A x g B,
) and connect them to the DC bias voltage generation circuit or the transmitter/receiver circuit, a DC bias electric field that induces piezoelectricity is applied to the electrode intersections, and they are also connected to the transmitter/receiver circuit, so they can selectively generate ultrasonic waves. It becomes possible to send and receive. FIG. 6(a) shows the appearance of the ultrasonic probe according to the present invention. The head, which transmits and receives ultrasonic waves, is covered with a protective film 12, and the casing 14 is provided with irregularities to make it easier to handle by hand. Also, on the back side, there is a signal line cable for connecting to the imaging device itself. FIG. 6(b) is an anatomical diagram of the head of the ultrasound probe. An electrostrictive material vibrator 1 provided with strip-shaped electrode arrays A and B that intersect with each other is adhered onto a back damping material 13, and has an electrode terminal array AL on the side surface. BL is provided. These are connected to respective switch scanning circuits by flexible printed wiring boards or the like. FIG. 1 is a conceptual diagram of the operation of the ultrasonic probe according to the present invention. A strip-shaped electrode array A provided on one main surface of the electrostrictive vibrator 1 is connected to a DC bias circuit 3 by a switch scanning circuit 2 or grounded. Further, each electrode of the strip-shaped electrode array B on the other main surface is connected to another matrix-like switch scanning circuit 4, and a series of a predetermined number of electrodes selected in 4 is passed through a delay circuit 5. Connected to transmitting circuit 6 and receiving circuit 7. In 22, the delay circuit 5 is inserted for each signal line connected to each selected electrode (however, in the illustrated example, each signal line commonly connected to electrodes at symmetrical positions centering on the center one of the selected electrode group) With this configuration, the focus controller 52 reads out the stored delay time distribution data and controls the delay time of each variable delay element. A delay time distribution is given to the transmitted pulses generated by the circuit 6 and distributed to each electrode, so that the ultrasonic pulses are focused on a desired region within the radiated space. Furthermore, when receiving ultrasonic echoes, the received signals from each electrode are added with a delay time distribution and transmitted to the receiving circuit 7, so that the received signal becomes a received signal of an echo from a desired area in space. do. That is, the delay circuit 5 performs electronic focusing in the y direction, and in the illustrated example, dynamic focusing can be performed by changing the delay time distribution during reception. The connection of the transmitting circuit, the receiving circuit, and the delay circuit is not limited to the configuration shown in the figure. For example, the receiving circuit 7 may be provided in plurality, and each terminal of the switch scanning circuit 4 and each terminal of the delay circuit 5 may be connected to each other. A connected configuration may also be used. Furthermore, for example, a plurality of transmitting circuits 6 may be connected directly to each terminal of the switch scanning circuit 4, and each transmitting circuit may output a transmitted wave pulse in response to a trigger input, so that the trigger signal to each transmitting circuit has a delay time distribution. A configuration with . Under such a configuration, at the start of ultrasonic beam scanning, the switch scanning circuit 2 to which the DC bias circuit 3 is connected selects the endmost electrode A1 from the electrode array A, and applies a bias voltage. be done. At the same time, a series of intersections indicated by circles in the matrix of the switch scanning circuit 4 are connected. In this state, the intersection of the electrode A selected by the switch scanning circuit 2 and the series of electrodes of the electrode arrangement B selected by the switch scanning circuit 4 is induced by the bias electric field to have piezoelectricity, and is electrically - Becomes capable of functioning as an ultrasonic transducer. After the transmitting pulse signal is output from the transmitting circuit 6, a delay time distribution is added to it by the delay circuit 5, and the pulse signal is outputted to a series of electrodes in the electrode array B via the switch scanning circuit 4. At this time, in the delay circuit 5, for a series of electrode arrays partially selected from the electrode array B by the switch scanning circuit 4, the signal output to the center electrode is given the longest delay time, and the signal output to both ends is A delay time distribution with a short delay time for the electrodes that are close to each other is selected. The shape of the wavefront when viewed from the X direction in Figure 1 at the moment when the intersection of electrode arrays A and B is excited and an ultrasonic pulse is emitted as a transducer is determined by the delay time distribution of the transmitted pulse. Ta. It becomes an arc whose radius is a certain focal length. As a result, the shape of the ultrasonic beam when viewed from the X direction converges to a certain focal distance from the center of the excitation portion of the vibrator. Furthermore, since each electrode in the electrode array A has a sufficiently narrow width in the array direction, the shape of the ultrasonic beam when viewed from the X direction is fan-shaped because the directivity of the transducer is small. Therefore, X
When viewed from the X direction, the convergence point of the ultrasonic beam exists on a circular arc whose radius is the focal length determined by the delay circuit 5, as shown by al in FIG. If the same delay time distribution is applied to the reception signal of each electrode during the echo reception period following this transmission, the reception signal input to the reception circuit 7 will form a fan-shaped reception beam shown by the arc a1 and the broken line in FIG. Shows echoes from reflective points within the pattern. Therefore, a two-dimensional storage space sufficient to hold all the signal values of one tomographic plane is provided on the storage circuit, and this is made to correspond to the cross section passing through the center electrode of the selected electrode array B. The values of the received data obtained at each point in time are developed and held on concentric arcs centered on the position corresponding to the electrode A1. However, in order to avoid an increase in the number of transmission repetitions and to increase the resolution in the direction perpendicular to the cross section (X direction), the delay time distribution is sequentially changed in multiple stages during the reception period after one transmission. The position of the convergence point of is moved in the beam depth direction,
Thus, the value of the received data at each point always indicates an echo from within or near the focal region of the X direction convergence. This series of ultrasound transmission and reception operations is repeated each time the switch scanning circuit 2 sequentially switches the selection of electrodes in the electrode array A. The reception data from the reception circuit 7 is always stored in the storage space as described above by expanding it on concentric arcs centered at the position corresponding to the selected electrode.
The new data is added to the value previously held at each address in the storage space and held. In other words, each time the piezoelectric active area, that is, the transmitting/receiving aperture shifts in the X direction, the received data is added and held using the aperture synthesis method. When transmitting and receiving waves by selecting electrode A, a large value is added and held at the position corresponding to arc a on the memory space, and when transmitting and receiving waves by selecting electrode AJ, a large value is added to the position corresponding to arc aJ on the memory space. Retained. By repeating such addition and holding, the value of the data at the point corresponding to the reflection source C increases in the storage space. In this way, when the repetition of transmitting and receiving waves and adding and holding data by sequentially selecting all the electrodes of electrode array A is completed, the data is reinforced in the storage space at the positions of all the reflection sources in the imaging area of the tomographic plane. , one tomographic image information can be obtained. Further, scanning for obtaining one tomographic image by such aperture synthesis method is repeated by switching the switch scanning circuit 4. That is, by connecting a series of intersections indicated by triangles among the intersections of the switch scanning circuit 4 and leaving the others open, the selected portion of the electrode array B is moved by one position in the scanning direction and connected. By repeating the operation of the aperture synthesis method described above using another storage space of the storage device and repeating this every time the switch scanning circuit 4 is switched, continuous imaging of a plurality of tomographic planes, that is, three-dimensional imaging is performed. Figures 2(a) and (b) show the vibrator in Figure 1. They are side views seen from the X direction and the X direction, respectively. (
A DC bias voltage is applied to A of the electrode arrangement A shown in b), and the other bias electrodes are grounded. Also,
In (a), a transmitting circuit, a receiving circuit, and a delay circuit are connected to some electrodes B to B7 of electrode array B by a switch scanning circuit. In order to converge the ultrasonic pulses to a certain part of the subject, excitation pulses are added to the sections B to B7 with a delay time distribution, and the ultrasonic pulses are transmitted. Thereafter, a delay circuit and a receiving circuit perform phasing and addition of the echo signals, that is, electronic focusing. The broken line shows how the focal point changes from a focus R1 at a far point in the subject to a focus R1 at a near point with respect to the vibration plane of the transducer due to the electronic focusing during reception. It is viewed in a plane along the length of. This situation is shown in (b) as seen from the arrangement direction of electrode arrangement B. The focal point of the electronic focus becomes omnidirectional in (b) because the width of the electrodes in electrode array A is small, and R1
,R,. R1 is a circular arc centered on electrode A1. The electrodes to which the bias voltage is applied are A1, A,, A,, . . ., A□. ..., one tomographic image is obtained by aperture-synthesizing the received signal strength on the storage space while moving sequentially from A to A, and (
, ), multiple tomographic images are scanned and three-dimensional imaging is performed by sequentially moving the electrodes to be simultaneously selected from electrode array B from Bi to B, ÷7t Bi, ~ Biass, etc. . In (b), when the width of the electrode A1 is small, the directivity approaches omnidirectionality, so the convergence region of the ultrasonic pulse becomes an arc, but in reality, when the width of the electrode is small, the ultrasonic pulse The radiation intensity of the sound waves decreases, causing problems when imaging a subject with large attenuation. Therefore, a method can be considered in which a bias voltage is simultaneously applied to a plurality of electrodes in the electrode array A to increase the radiation intensity of the ultrasonic waves. In such a case, the shape of the convergence zone of the ultrasonic pulse in (b) will no longer be arc-shaped because the directivity will become significant, but in this case, the received signal should be stored in consideration of the directivity function. By expanding spatially and adding and holding, aperture synthesis of tomographic images can be performed in the same way. The imaging area inside the subject obtained by such scanning is rectangular when viewed from the direction (a), but the area viewed from the direction (b) is determined by aperture synthesis, in which the received signal is expanded to what area. It depends on what you do. Therefore, the area can be a rectangular area or a fan-shaped area. Note that the number of signal electrodes that simultaneously perform transmission or reception and the number of bias electrodes that simultaneously apply DC bias voltage are not limited to those in this embodiment. However, in order to obtain a certain degree of resolution in the thickness direction of the tomographic image (Fig. 1, It is necessary to use a rectangular transmitting/receiving aperture to transmit and receive waves. At the same time, the number of electrodes selected from electrode array B is sequentially changed when ultrasonic waves are received, and the aperture of the vibrating part as seen in the It is also possible to improve resolution by setting a large aperture for reception and a small aperture for reception from nearby areas. Also, depending on the depth of the probe and the inside of the subject, ultrasonic waves are transmitted and received multiple times, and the number of signal electrodes (aperture size) is fixed at each time of transmission or reception. Alternatively, it is also possible to improve the resolution by dynamically changing it. On the other hand, the order in which the switch scanning circuit selects the electrodes to which bias voltages are applied for aperture synthesis of one tomographic image, and the order in which the electrode array B is switched in the case of scanning a plurality of tomographic images may be arbitrary. That is self-evident. In the above example, the ultrasonic scanning means in the arrangement direction of the electrode array B corresponds to linear electronic scanning in a conventional ultrasonic probe using a one-dimensional array of strip-shaped transducers. on the other hand,
In the above example, it is also possible to perform ultrasound scanning in the arrangement direction of electrode arrangement B by corresponding to sector-type electronic scanning in an ultrasound probe using a conventional one-dimensional array of strip-shaped transducers. be. 3(a) and 3(b) are side views of the vibrator shown in FIG. 1 viewed from the X direction and the X direction, respectively, when performing sector-type electronic scanning. As in the case of the linear type shown in FIG. 2, a DC bias voltage is applied to A of the electrode array A shown in (b), and the other bias electrodes are grounded. In addition, in (a), electrode arrangement B
A transmitting circuit, a receiving circuit, and a delay circuit are connected to all electrodes B□ to B1. Excitation pulses are applied to Bi to B with a delay time distribution so that the ultrasonic pulses converge from the transducer surface of the probe to a certain part of the fan-shaped scanning area inside the subject. After that, the delay circuit and the receiving circuit perform phasing and addition of the echo signals, that is, electronic focusing.
The change from the focal point to the nearby focal point S□ is seen in a plane perpendicular to the main surface of the vibrator and along the length direction of the electrode Ai. (b) shows this situation as seen from the arrangement direction of electrode arrangement B. As in the case of the linear type shown in Fig. 2, when the width of the electrodes in electrode array A is small, the focal point of the electronic focus becomes omnidirectional as shown in (b);
Yo, S□ becomes an arc centered on electrode A. One tomographic image is obtained by aperture synthesis. In addition, even if a bias voltage is simultaneously applied to multiple electrodes in the electrode array A to increase the radiation intensity of the ultrasonic waves, the received signals can be developed in the storage space and added and stored in consideration of the directivity function. Needless to say, it is possible to perform aperture synthesis of similar tomographic images. The electrodes to which bias voltage is applied are Ai, A2, and A.
1. ...IA+. ...By aperture-synthesizing the received signal strength on the storage space while moving sequentially with HAn, a single tomographic plane that spreads in the longitudinal direction of each electrode of electrode array B and forms a certain angle with the sound wave emission surface of the transducer is created. If the angle is sequentially changed by changing the delay time distribution as shown in (,), a plurality of tomographic images are scanned and three-dimensional imaging is performed. The area inside the subject that is imaged in this case is fan-shaped when viewed from the direction (a), but the area when viewed from the direction (b) is similar to the case of linear scanning. It can be rectangular or fan-shaped. In addition, even in this sector type scanning, the number of signal electrodes that simultaneously transmit or receive,
It goes without saying that the number of bias electrodes to which direct current bias voltages are simultaneously applied is not limited to the case of this embodiment and may be arbitrary. Furthermore, the order in which electrodes to which bias voltages are applied for aperture synthesis of one tomographic image is selected by the switch scanning circuit and the order in which the delay time distributions are applied when scanning a plurality of tomographic images may be arbitrary. FIG. 4 is a block diagram showing the overall configuration of an embodiment of the ultrasonic imaging apparatus of the present invention. Electrode array A that intersects each other ~
An electrostrictive vibrator 1 equipped with B-B is connected to a bias circuit 3 via a switch scanning circuit 2, and a delay circuit 5 and a transmitting circuit connected thereto via a matrix-type switch scanning circuit 4. 6 and a receiving circuit 7 are connected. According to the reference signal generator 91, the control circuit 92 selects the electrode to which the bias voltage is applied by the switch scanning circuit 2 from the electrode arrays B□ to B, and selects the electrode to which the bias voltage is applied to the part where the piezoelectricity of the electrostrictive vibrator 1 is induced by the bias voltage. to charge. After that, the transmitting circuit 6 generates an excitation pulse voltage and applies it to a selected series of electrodes in the electrode array B through B via the delay circuit 5 and switch scanning circuit 4 set by the control circuit 92. . As a result, the echo of the transmitted ultrasonic pulse is received again by the piezoelectric induction part of the same electrostrictive vibrator, and becomes an input to the delay circuit 5 via the switch scanning circuit 4 as a received signal, which performs phasing and addition using electronic focusing. The received signal becomes an input to the receiving circuit 7. The output amplified by the receiving circuit 7 is developed by a signal processing circuit 81 while sequentially adding and retaining its value in a storage space on a storage circuit 82. The control circuit 92 repeats the switching of the electrodes of the switch scanning circuit 2 on the bias voltage application side, the subsequent ultrasonic transmission/reception operation, and the development of the received signal value in the memory circuit 82, thereby scanning all of the electrode arrays A to An. Then, aperture synthesis to obtain one tomographic image is completed. Furthermore, the control circuit 92 switches the switch scanning circuit 4 to select a series of electrodes from the electrode arrays B to B, which have been moved by one position from the previous scanning time point, to obtain ten tomographic images again. Repeat aperture synthesis. As a result, a series of tomographic planes are held in the storage space of the memory circuit 82, and the monitor display circuit 83 displays arbitrary tomographic planes and recombined three-dimensional stereoscopic images. The block diagram in FIG. 4 is for the above-mentioned linear type scanning, but in the case of sector type scanning, the switch scanning circuit 4 is not provided, and the delay circuit 5 is used to control the delay time distribution to realize sector scanning. It must have the function to provide arrays B to B. The medical ultrasonic diagnostic device with this configuration can perform three-dimensional imaging of the heart from between the ribs using a probe as shown in Figure 6, and imaging of the heart from within a body cavity using a probe configured like an endoscope. Diagnostic methods that take three-dimensional images of prostate glands and prostate glands are already known to be highly useful. In particular, endoscope-type probes are required to be extremely compact, and mounting problems such as the number of wires to the transducer can be dramatically improved by adopting the configuration of the present invention. be done. In the three-dimensional imaging method in the above embodiment, while the switch scanning circuit 4 on the side that transmits and receives ultrasound waves is fixed, the switch scanning circuit 2 on the bias voltage application side is scanned to form a single tomographic image by aperture synthesis. Conversely, while the switch scanning circuit 2 on the bias voltage application side is fixed, the switch scanning circuit 4 on the side transmitting and receiving ultrasonic waves is electronically scanned to synthesize apertures of multiple tomographic planes. It is also possible to perform both at the same time. When the object to be examined is a still object, the time required to switch the application of the bias voltage is long, and the overall imaging time becomes long, so the latter imaging method is advantageous. Furthermore, in cases where the imaging device is a medical ultrasound diagnostic device, etc., the isochronism required for aperture synthesis is reduced due to the relative movement of the subject and the probe. The following method is preferable.

【Effect of the invention】

According to the present invention, there is provided an ultrasonic imaging device, ie, a medical ultrasonic diagnostic device or an ultrasonic flaw detection device, which can obtain tomographic image or three-dimensional image information inside a subject by ultrasonic echography. By realizing this device, the examiner can easily and quickly estimate the three-dimensional structure and tissue inside the subject, and can obtain tomographic images of the same site with high reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an imaging method and the configuration and function of circuit means connected to a vibrator, and FIG. 2 is a diagram for explaining an aperture synthesis method in the case of linear electronic scanning. FIG. 3 is a diagram explaining the aperture synthesis method in the case of sector-type electronic scanning, FIG. 4 is a block diagram explaining an embodiment of the imaging device of the present invention, and FIG. 5 is a diagram explaining the electrode configuration of the vibrator. FIG. 6 is an external view and a partially exploded view of the ultrasonic probe. 1... Electrostrictive vibrator, 11... Acoustic matching layer, 12...
・Protective film, 13... Rear braking material, 14... Housing, 2
, 4... Switch scanning circuit, 3... DC bias circuit, 5... Delay circuit, 6... Transmission circuit, 7... Receiving circuit, 81... Signal processing circuit, 82... Memory circuit, 83... Monitor circuit, 91... Reference signal generator, 92... Control circuit, A... Bias circuit side electrode array, B... Signal circuit side electrode array, AL, BL.・・・
Electrode terminal, , -No 1
Continuous V 9 Invitation circuit depth <b) Figure ((L) (Cross Cb) L

Claims (1)

[Claims] 1. On the first main surface of the electrostrictive material plate whose piezoelectricity is induced by a bias electric field, there are first strip-shaped strips arranged in a first direction.
The electrode array is arranged on the second main surface opposite to the first electrode array.
an ultrasonic probe comprising an electroacoustic transducer provided with a second strip-shaped electrode array arranged in a second direction intersecting the direction of the first electrode array; a first scanning means for selectively applying a bias voltage; and a first scanning means for selectively applying a bias voltage;
An ultrasonic imaging device comprising an ultrasonic transmitting/receiving means for applying a transmitting signal to at least some electrodes of an electrode array and receiving and processing received signals generated at these electrodes, and a storage means for storing the received signal that has been received and processed. In the ultrasonic transmitting/receiving means, the transmitting or receiving signal of each electrode is given a predetermined delay time distribution to converge the transmitting or receiving beam, and the beam position is determined by selecting the position or delay time distribution of the electrode group to be used. A second scanning means sequentially scans in the second direction, and the first scanning means scans the piezoelectricity of the vibrator by selecting a number of electrodes smaller than the number of electrodes selected at one time by the second scanning means. The inducing portion is scanned in the first direction, and the storage means stores reception signals from a plurality of scanning positions of the first scanning means for each beam scanning position of the second scanning means. An ultrasonic imaging device characterized in that three-dimensional imaging is performed by aperture synthesis by storing data while being added. 2. While the beam scanning in the second direction by the second scanning unit is fixed, the piezoelectrically induced portion of the vibrator is sequentially scanned in the first direction by the first scanning unit multiple times; A tomographic image is obtained by performing aperture synthesis in a first direction on the storage means, and by repeating this operation while scanning by the second scanning means, three-dimensional imaging is performed. The ultrasonic imaging device according to claim 1, wherein the ultrasonic imaging device performs the following steps. 3. While the scanning of the piezoelectric induced portion of the vibrator in the first direction by the first scanning unit is fixed, the beam scanning in the second direction by the second scanning unit is sequentially performed multiple times. 2. Transmission and reception of a plurality of tomographic planes by repeating this operation while scanning by the first scanning means to gradually obtain tomographic images of a plurality of tomographic planes by aperture synthesis.
The ultrasonic imaging device described in . 4. The ultrasonic transmitting/receiving means further includes delay time distribution changing means for sequentially moving the focal length of the receiving beam in the beam depth direction during a receiving period after one transmission. Ultrasonic imaging device. 5. The storage means is characterized in that the received signal is added only to fan-shaped positions centered on the position corresponding to the piezoelectric induced portion selected by the first scanning means of the electroacoustic transducer. The ultrasonic imaging device according to claim 1.