JP2009265037A - Ultrasonic probe device and ultrasonic imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe device or the like, capable of attaining satisfactory ultrasonic imaging without limiting image resolution and observation object range by enabling control of the size of aperture length. <P>SOLUTION: The aperture length H is extended or contracted so as to be small when imaging a near range and to be large when imaging a far range. The attitude of each ultrasonic probe is controlled, in association with the extension and contraction of the aperture length, so that an imaging area is contained in the ultrasonic directivity angle width from each ultrasonic probe. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to the technical field of imaging an object in a medium using ultrasonic waves, and more particularly to an ultrasonic probe apparatus and an ultrasonic imaging apparatus capable of controlling the size of an opening.

  As a technique for visualizing an object in a medium using ultrasonic waves, for example, in seawater, an ultrasonic imaging apparatus represented by a fish finder (ultrasonic sonar) that detects a distant fish school is known. These transmit ultrasonic waves toward the seabed from a plurality of ultrasonic probes arranged in a row or in a row on the ship's bottom as a platform, and display the received waveform as the platform moves to the seabed. The method is to create a cross section of and to synthesize an image of a school of fish. Similarly, synthetic aperture sonar using ultrasonic sonar generates images as the platform moves. In these methods, it is necessary to move the platform and manage the moving position of the platform correctly. There is a need to.

In contrast to these techniques, there have been proposed devices and the like that can arrange ultrasonic probes in a matrix and generate images at once without moving the platform (see, for example, Patent Document 1 and Patent Document 2). ). Such an apparatus has a so-called planar antenna by arranging ultrasonic probes in a matrix. In these apparatuses, the relative positional relationship between the probes arranged in a matrix is fixed, and the probe density is unchanged.
Japanese Patent Application No. 4-206588 Japanese Patent Application No. 3-174098

  However, the conventional ultrasonic probe device and ultrasonic imaging device have the following problems.

  That is, in a synthetic aperture type ultrasonic imaging apparatus using an ultrasonic probe apparatus (matrix ultrasonic probe apparatus) in which ultrasonic probes are arranged in a matrix, the image resolution ΔX is from the probe to the imaging region. ΔX is proportional to L / H between the distance H and the diameter (opening length) L of the ultrasonic irradiation surface (opening) formed by the matrix ultrasonic probe. Therefore, a large matrix ultrasonic probe is required to image far distances with high resolution.

  If a short distance is imaged with a large matrix ultrasonic probe apparatus, that is, a matrix ultrasonic probe apparatus with a large opening length, the reflection of a specific ultrasonic probe becomes too strong, and the image quality may deteriorate. In other words, the ultrasonic probe density of the matrix ultrasonic probe apparatus is too rough when imaging a short distance. Further, if a long distance is imaged with a small matrix-like ultrasonic probe device, that is, a matrix-like ultrasonic probe device with a small opening length, the image resolution may be insufficient. This is due to the principle of the synthetic aperture that requires a large reception area in order to increase the resolution over a long distance.

  That is, there is a problem that the image resolution and the observation target distance are limited because the aperture length of the matrix ultrasonic probe apparatus is fixed.

  The present invention has been made in view of the above circumstances, and can control the size of the aperture length, and can realize good imaging with ultrasound without limiting the image resolution and the observation target distance. An object of the present invention is to provide an acoustic probe device and an ultrasonic imaging device.

In addition, as a well-known document relevant to this application, there exist the following, for example.
JP-A-4-206588 JP-A-3-174098

  In order to achieve the above object, the present invention takes the following measures.

  According to a first aspect of the present invention, a plurality of ultrasonic probes that each transmit an ultrasonic wave in response to a supplied drive signal, receive an ultrasonic wave, and generate an electric signal, and the plurality of ultrasonic waves The diameter of the ultrasonic irradiation surface formed by arranging the plurality of ultrasonic probes is changed by extending and contracting the installation means for arranging and installing the probes two-dimensionally. An ultrasonic imaging apparatus comprising: an expansion / contraction mechanism for generating an ultrasonic image using each electric signal generated by the plurality of ultrasonic probes.

  According to a second aspect of the present invention, a plurality of ultrasonic probes that each transmit an ultrasonic wave in response to a supplied drive signal and receive an ultrasonic wave to generate an electrical signal, and the plurality of ultrasonic waves The diameter of the ultrasonic irradiation surface formed by arranging the plurality of ultrasonic probes is changed by extending and contracting the installation means for arranging and installing the probes two-dimensionally. And an expansion / contraction mechanism.

  As described above, according to the present invention, it is possible to control the size of the aperture length, and it is possible to realize good imaging with ultrasound without limiting the image resolution and the observation target distance, and an ultrasound image. Can be realized.

  Hereinafter, first to third embodiments of the present invention will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

(First embodiment)
FIG. 1 shows a block diagram of an ultrasonic image processing apparatus 1 according to the first embodiment. As shown in the figure, the ultrasonic image processing apparatus 1 includes an ultrasonic probe device 10, an amplifier 12, an A / D converter 14, a distance signal calculation circuit 16, an image generation circuit 18, a transmitter 20, and a switching circuit 22. A transmission control unit 24, a display control unit 26, a display unit 28, an opening length control unit 30, a probe posture control unit 32, and an operation unit 34.

  The ultrasonic probe device 10 includes a plurality of ultrasonic probes 101, an opening length changing device 103, and a probe posture changing unit 104 arranged in a two-dimensional manner. The plurality of ultrasonic probes 101 are fixed to the opening length changing device 103 via the probe posture changing unit 104. Each ultrasonic probe 101 is formed of a piezoelectric element, generates an ultrasonic wave based on the supplied drive signal, and receives an ultrasonic wave to generate an electric signal having a predetermined waveform. The opening length changing device 103 has a mechanism for changing the opening length in accordance with a control signal from the opening length control unit 30. The probe posture changing unit 104 has a mechanism for changing the posture of each ultrasonic probe 101 with respect to the imaging target region S in accordance with a control signal from the probe posture control unit 32. The detailed configuration of the ultrasonic probe apparatus 10 will be described later.

  The amplifier 12 amplifies the received ultrasonic wave generated by each ultrasonic probe 101 and sends it to the A / D converter 14.

  The A / D converter 14 performs A / D conversion (analog / digital conversion) on the amplified received signal received from the amplifier 12.

  The distance signal calculation circuit 16 calculates the distance between the object to be imaged and each ultrasonic probe 101 based on the received signal after A / D conversion.

  Based on the positional information of each ultrasonic probe 101 and the calculated distance between the object to be imaged and the distance between each ultrasonic probe 101, the image generation circuit 18 generates an ultrasonic image related to the object for each ultrasonic probe 101. Generated for each channel. Here, the channel means a reception system including an amplifier 12, an A / D converter 14, a distance signal calculation circuit 16, and an image generation circuit 18 provided for each ultrasonic probe 101.

  The transmitter 20 repeatedly generates a drive signal for forming a transmission ultrasonic wave at a predetermined rate frequency fr Hz (period: 1 / fr second).

  The switching circuit 22 switches the switch according to the control signal from the transmission control unit 24 and supplies the drive signal from the transmitter 20 to the predetermined ultrasonic probe 101 at a predetermined timing.

  The transmission control unit 24 controls the selection of the ultrasonic probe 101 that supplies the drive signal from the transmitter 20, the control related to the supply timing (supply interval), and the reception timing control of the reflected ultrasonic waves by each ultrasonic probe 101. In particular, the transmission control unit 24 supplies a drive signal to each ultrasonic probe 101 (that is, ultrasonic transmission from each ultrasonic probe 101) according to an aperture synthesis function using the maximum / minimum distance described later, The timing of reception of reflected ultrasonic waves by the ultrasonic probe 101 is controlled.

  The display control unit 26 combines the ultrasonic images for each channel generated by the image generation circuit 18 and generates an ultrasonic image indicating the shape, internal structure, and the like of the imaging target.

  The display unit 28 displays the ultrasonic image generated by the display control unit 26 in a predetermined form.

  The opening length control unit 30 controls the opening length of the ultrasonic probe device 10 by expanding (stretching) or contracting the mechanism of the opening length changing device 103 under the control of the transmission / reception control unit 24. For example, when the distance between the imaging target region S and the ultrasonic probe apparatus 10 is L and the opening length of the ultrasonic probe apparatus 10 is H, L / H = constant. Thus, the mechanism of the opening length changing device 103 is expanded or contracted.

The probe posture control unit 32 controls the posture of each ultrasonic probe 101 by driving the mechanism of the probe posture changing unit 104 under the control of the transmission / reception control unit 24. For example, when the imaging target region S is a disk having a diameter L1 at a distance L from the ultrasonic probe device 10, the probe posture control unit 32 has an ultrasonic probe device having an opening length H. The probe orientation is such that the ultrasonic probe 101 that transmits and receives the ultrasonic wave having the directivity angle θ _c at the tip position 0.5H of 10 has the direction of θ _o defined by the following equations (1), (2), and (3). The mechanism of the changing unit 104 is controlled.

  By controlling the aperture length control unit 30 and the probe posture control unit 32, for example, when the short distance is imaged, the aperture length H is reduced, and when the long distance is imaged, the aperture length H is increased. The image resolution is kept constant.

  The operation unit 34 includes various switches, buttons, a trackball 13s, a mouse 13c, a keyboard 13d, and the like for incorporating various instructions, condition setting instructions, various image quality condition setting instructions, and the like from the operator into the apparatus main body 1. ing.

(Opening length control function)
Next, the opening length control function of the ultrasonic imaging apparatus 1 will be described. This function expands and contracts the aperture length so that the aperture length H is reduced when imaging a short distance and the aperture length H is increased when imaging a long distance. Further, the posture of each ultrasonic probe is controlled in conjunction with the expansion and contraction of the opening length so that the imaging region is included in the ultrasonic directivity angle width from each ultrasonic probe. With these functions, the resolution of the image can be kept constant regardless of the distance to the imaging target.

  FIG. 2A is a view of the expanded state of the ultrasonic probe apparatus 10 as viewed from the front, and FIG. 2B is a view of the contracted and expanded state of the ultrasonic probe apparatus 10 as viewed from the front. As shown in each figure, the ultrasonic probe 101 is installed on a telescopic rod 105, and the telescopic rod 105 is connected to each other by a coupling member 107. As each telescopic rod 105 expands and contracts, the opening surface and the opening length can be expanded and contracted.

  Since each of the ultrasonic probes 101 has a diameter of about several centimeters to several tens of centimeters, the ultrasonic probes 101 may overlap with each other when the opening length is contracted. In such a case, as shown in FIG. It is necessary to prevent the ultrasonic probes 101 from overlapping each other in the contracted state. Therefore, the ultrasonic probes 101 are not installed in the same number for each of the telescopic rods 105 as shown in FIG. 2A, but arranged so as not to overlap in the contracted state as shown in FIG. Is done.

2A and 2B, a total of 64 ultrasonic probes 101 are arranged, and 32 telescopic rods 105 are arranged. In addition, three telescopic rods 105 form one set, and each set of telescopic rods 105 includes four, one, and two patterns of ultrasonic probe elements (see region r _{1 in} FIG. 2A). ) or 3, 1, are installed in the two pattern reference area _{r 2} (FIG. 2 (a)). However, without being limited to this example, the number of ultrasonic probes 101, the number of telescopic rods 105, and the number of ultrasonic probes 101 arranged on each telescopic rod 105 can be arbitrarily set.

3A is a diagram showing a developed state of the region r ₁ in FIG. 2A, and FIG. 3B is a diagram showing a contracted state of the region r ₁ in FIG. 2A. is there. As shown in each drawing, the telescopic rod 105 is coupled by a wire 111 for feeding and a coupling portion 113, and the feeding wire 111 is fed by the rotation of the drive mechanism 115.

  The telescopic rod 105 has a link mechanism 109 that changes the posture angle of each ultrasonic probe 101 as it expands and contracts. The link mechanism 109 controls the posture angle of each ultrasonic probe 101 so as to satisfy a predetermined condition according to the size of expansion / contraction so as to satisfy a predetermined condition. A typical example of the link mechanism 109 includes a rack and pinion mechanism that changes the angle of the ultrasonic probe 101 in synchronization with the expansion / contraction length of the expansion / contraction rod 105. However, any mechanism may be used as long as it can convert the expansion / contraction / contraction motion of the telescopic rod 105 into a rotational motion without being limited to the example.

  The resolution in imaging an object in a medium using ultrasonic waves will be described with reference to FIGS. 4, 5 (a), and (b). For example, when the ultrasonic probe 101 is arranged in the form shown in FIG. 2A, the opening length is H, and the distance between the imaging target region S and the opening surface of the ultrasonic probe apparatus 10 is L. In this case, in the image resolution ΔX, ΔX and L / H are proportional to each other between the distance H from the ultrasonic probe 101 to the imaging region S and the size L of the ultrasonic probe apparatus 10. Therefore, when performing short-distance imaging, it is necessary to increase the arrangement density of the ultrasonic probes 101 as shown in FIG. Further, when imaging at a long distance, it is necessary to reduce the arrangement density of the ultrasonic probes 101 as shown in FIG.

  On the other hand, the arrangement density of the ultrasonic probes 101 is limited. This is due to the directivity of the ultrasonic probe 101. Moreover, in order for the transmitted ultrasonic wave to be reflected by a distant reflector and detected by the ultrasonic probe 101 as a reflected wave, it is necessary to increase the intensity of the transmitted ultrasonic wave. In order to increase the intensity of the transmitted ultrasonic wave, there is a method of enlarging the ultrasonic probe 101 itself. However, as the diameter of the ultrasonic probe 101 becomes larger than the half wavelength of the waveform of the transmitted ultrasonic wave, the ultrasonic wave transmitted by the ultrasonic probe 101 has a directivity waveform that is strongly emitted to the front surface of the probe 101. Therefore, if there is no observation area in the radiation range (within the directivity angle) of the emitted waveform, the reflected signal is too weak to be received. In other words, there is a limit to the installation range of the ultrasonic probe 101 that can transmit an effective reflected wave in a certain imaging range, and the remaining ultrasonic probes 101 arranged other than that contribute to grasping the shape of the reflector by aperture synthesis. become unable.

That is, when the imaging region S is determined, the ultrasonic probe 101 that can transmit ultrasonic waves in the imaging region S is limited by the directivity of the ultrasonic waves transmitted from the ultrasonic probe 101. In the example shown in FIG. 6, an imaging region S is included in each directivity angle θ _a , θ _b , θ _c , θ _{d of the} ultrasonic wave transmitted from each of the ultrasonic probes 101a, 101b, 101c, 101d. . On the other hand, the bottom of the ultrasonic probe 101e originating ultrasonic each directional angle θ in _e from, there is only a part of the imaging area S. When the ultrasonic probe 101 having such directivity is used, the ultrasonic probe 101 that contributes to the actual aperture synthesis is limited to a part of all the probes, no matter how much the aperture length of the ultrasonic probe apparatus 10 is increased. It will be. As described above, since the individual ultrasonic probes 101 have directivity, the arrangement range of the ultrasonic probes 101 involved in aperture synthesis is limited.

Therefore, the ultrasonic probe apparatus 10 according to the present embodiment and the ultrasonic imaging apparatus 1 including the ultrasonic probe apparatus 10 control the posture of each ultrasonic probe 101 in order to avoid this limitation. That is, the orientation (posture) of each ultrasonic probe 101 is controlled so that the imaging region S enters each directivity angle of each ultrasonic probe 101 as shown in FIG. For example, the ultrasound probe 101a, the probe position controller 21, for example, adjusting the angle theta _A only to the image region S is within the directional angle of the ultrasound probe 101 by inclining the lower side with respect to the vertical direction In addition, the probe posture changing unit 104 is controlled. The ultrasonic waves transmitted from all the ultrasonic probes 101 can reach the imaging region S by such posture control of each ultrasonic probe 101. As a result, the entire ultrasonic probe 101 can contribute to aperture synthesis, and the resolution can be increased by increasing the size of the aperture length.

  Note that the posture control of the ultrasonic probe 101 is not limited to the above example. The angle of the ultrasonic probe 101 with respect to the vertical direction may be adjusted by deforming the telescopic rod 105 to which the ultrasonic probe 101 is fixed. FIG. 8 shows an example in which the deforming rod 121 is deformed so as to become a part of an arc with a predetermined curvature around the imaging region S. Also by such a method, the angle of the ultrasonic probe 101 with respect to the vertical direction can be adjusted, and the ultrasonic probe 101 can always face the direction of the imaging region S. In particular, the advantage of the attitude control of the ultrasonic probe 101 is not required to be controlled for each ultrasonic probe 101, can be adjusted by a unified driving mechanism, and the positional accuracy of each ultrasonic probe 101 is also improved. It is easy to maintain.

In order to minimize the curvature of the spherical surface in the example shown in FIG. 8, if the imaging region S planned to be imaged by one ultrasonic transmission / reception falls within the directivity angle width of each ultrasonic probe 101. Good. As shown in FIG. 9, the minimum adjustment angle θ _A (= θ _o ) of the ultrasonic probe 101a for causing the imaging region S to be within the directivity angle width can be obtained by the relational expression of Expression (1). it can. Here, L1 is expressed by equation (2), and H is expressed by equation (3). That is, a sound wave from the ultrasonic probe 101 having the directivity angle θ _c at the position 0.5H at the extreme end of the opening surface is formed in a disk-shaped imaging region S having a radius H1 that is separated from the ultrasonic probe device 10 by L. In order to irradiate, the direction of the ultrasonic probe 101 may be set to θ _o .

When only the direction of the ultrasonic probe 101 is adjusted, it is sufficient to select the direction θo of the ultrasonic probe 101 that satisfies the equation (3) not considering the distance L1 and the following equation (4). It is.

(effect)
According to the configuration described above, the aperture length is expanded and contracted so that the aperture length H is reduced when imaging a short distance and the aperture length H is increased when imaging a long distance. Can do. In particular, when the opening length of the ultrasonic probe device is H and the distance between the ultrasonic probe device and the imaging target region is L, the L / H is constant so that L / H is constant. The opening length H is controlled according to the distance L. Therefore, ultrasonic imaging with a constant image quality can be realized regardless of the distance to the image target region. In particular, the posture of each ultrasonic probe is controlled so that the imaging region is included in the ultrasonic directivity angle width from each ultrasonic probe in conjunction with expansion and contraction of the opening length. Thereby, all the ultrasonic probes can be contributed to imaging, and the resolution of the image can be kept constant regardless of the distance to the imaging target.

  In addition, the ultrasonic probe device has a strong structure that can be expanded and contracted an arbitrary number of times by an opening length changing device using an extendable rod or the like. Therefore, the opening length can be freely controlled even in a medium having high resistance such as in the sea.

  As an observation means that is very similar to an aperture synthesis method using ultrasonic waves, an antenna having a deployment function is often used in a synthetic aperture radar using radio waves. For example, various space antennas are known as deployable antennas for use in communication with the ground and various observations. These satellite antennas are contracted for storage at launch, but need only be deployed once, and are not expanded and contracted multiple times. Also, because it is deployed in outer space without obstacles, it can be said that there is no problem even if the structure is weak. Furthermore, in order to use a radio wave as an antenna, elements that transmit and receive the wavelength of the radio wave are arranged in a planar shape, and it is not necessary to manipulate the arrangement density of the elements. Further, since the aperture synthesis is performed by the movement of the artificial satellite itself as the platform, it is not necessary to change the direction of the antenna element. Therefore, compared with these antennas, this ultrasonic probe apparatus can execute expansion / contraction at a desired number of times at an arbitrary timing and has a remarkable strength.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The ultrasound imaging apparatus 10 according to the present embodiment is an example of controlling the aperture length and posture by inclining the ultrasound irradiation surface (that is, the aperture surface) of the ultrasound probe device 10 with respect to the image target region S. It is.

  FIGS. 10A and 10B are views showing a side view of the ultrasonic probe apparatus 10 according to the present embodiment. As shown in the figure, in the ultrasonic probe apparatus 10, the ultrasonic probes 101 are arranged in a matrix with respect to a flat plate 121 via a probe attitude changing unit 104. The base on which the ultrasonic probes 101 are arranged is not limited to the flat plate 121 and may be a grid-like solid frame, for example, in order to reduce the influence from waves or the like.

When the opening length of the ultrasonic probe apparatus 10 is increased, the flat plate 121 is disposed so as to face S as shown in FIG. 10A, and each ultrasonic probe 101 and the flat plate 121 are arranged. And the probe posture changing unit 104 are controlled so that each of the ultrasonic probes 101 faces the imaging region. On the other hand, in the case of shortening the opening length to tilt the flat plate 121 so as to form, for example, horizontal and angle theta _e as shown in Figure 10 (b). At this time, the posture of each ultrasonic probe 101 is controlled so that all the ultrasonic probes 101 contribute to imaging. For example, as shown in FIG. 11, when the distance from the ultrasonic probe device 10 to the disk-shaped imaging region having the diameter H1 is L, the control is performed at the extreme end of the opening surface of the ultrasonic probe device 10. to at positions 0.5H irradiated with ultrasonic waves for directional angle theta _c for the image irradiation area S, tilting the angle θo only the ultrasound probe 101 which is given by the following equation (5).

In addition, L1 and H in Formula (5) are given by the following Formulas (6) and (7), respectively.

  Even with the configuration described above, the same effects as those of the first embodiment can be realized.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The ultrasonic imaging apparatus 10 according to the present embodiment controls the arc length (or radius) of a circular frame on a concentric circle having different sizes, in which a plurality of ultrasonic probes 101 are arranged, thereby the ultrasonic probe. This is an example of controlling the opening length of the device 10.

  FIG. 12A is a view of the deployed state of the ultrasonic probe apparatus 10 according to the present embodiment as viewed from the front, and FIG. 12B is a view of the contracted and deployed state as viewed from the front. As shown in each figure, the ultrasonic probe apparatus 10 has a plurality of annular frames 123 arranged concentrically and provided with a plurality of ultrasonic probes 101. Each annular frame 123 has a mechanism (details will be described later) that can be expanded and contracted while the center position is fixed. Therefore, the opening length of the ultrasonic probe device 10 can be expanded (enlarged) and contracted by expanding and contracting along the radial direction of each annular frame 123.

  In the example shown in FIGS. 12A and 12B, the ultrasonic waves in which six, six, six, and twelve ultrasonic probes 101 are installed in each annular frame 123 in order from the inside. A probe device 10 is shown. However, the installation configuration may be any configuration as long as the ultrasonic probes 101 are not in contact with each other in the contracted state illustrated in FIG. Further, the number of the annular support members 125 is not particularly limited.

  FIG. 13 is a view for explaining the expansion and contraction mechanism of the annular frame 123. For explanation, FIG. 14A and FIG. 14B show what is developed by cutting FIG. 13 at 125. FIG. As shown in FIGS. 13, 14 (a), (b), the ring frame 123 has an opening length control unit 30 that determines the angle θ formed by the frame members 123 a, 123 b and the frame members 123 a, 123 b connected at the connection part 123 c. It is a pantograph which has the opening / closing device 123d controlled according to the signal from. For example, when the opening / closing device 123d increases the angle θ in accordance with the signal from the opening length control unit 30, the frame members 123a and 123b connected to each other as shown in FIG. The arc length (or radius) of 123 increases, and as a result, the opening length of the ultrasonic probe apparatus 10 increases. On the other hand, when the opening / closing device 123d decreases the angle θ according to the signal from the opening length control unit 30, the connected frame members 123a and 123b contract as shown in FIG. 123 arc length (or radius) decreases, and as a result, the opening length of the ultrasonic probe apparatus 10 decreases.

  As shown in FIGS. 14A and 14B, the connecting member 123c changes in length in synchronization with the pantograph arc length (that is, when the opening / closing device 123d increases the angle θ). Becomes longer and decreases when the angle θ is decreased.) The ultrasonic probe apparatus 10 according to the present embodiment performs posture control of each ultrasonic probe 101 in conjunction with opening length control by a pantograph mechanism, using the property of the connecting member 123c.

  FIGS. 15A and 15B are views for explaining the posture control of each ultrasonic probe 101 in conjunction with the opening length control by the pantograph mechanism. As shown in FIG. 15A, the connecting member 123c includes a hatching portion 123e having a pinion mechanism, and a rack 123f that is coupled to the hatching portion 123e and on which the ultrasonic probe 101 is installed. When the angle θ is increased by the opening / closing device 123d and the annular frame 123 is expanded, the posture of the installed ultrasonic probe 101 changes downward as shown in FIG. 15B, for example, in conjunction with the expansion. Further, when the angle θ is decreased by the opening / closing device 123d and the annular frame 123 contracts, the posture of the installed ultrasonic probe 101 is interlocked with the expansion and contraction, for example, from FIG. 15B to FIG. 15A. To change.

It should be noted that the relationship between the number of teeth of the rack 123f and the pinion mechanism and the radius needs to have sufficient conditions to change the direction so as to satisfy the above-described formulas (1), (2), and (3). Needless to say. Furthermore, as shown in the first embodiment, when the distance L1 is not considered, the direction of the ultrasonic probe 101 is that of the ultrasonic probe 101 that satisfies the expressions (3) and (4) described above. It is sufficient to select the orientation θ _o . In this case, the direction of the ultrasonic probe 101 is an angle determined by the size length H of the opening.

  Further, the posture control mechanism of the ultrasonic probe apparatus 101 shown in FIGS. 15A and 15B is merely an example. Therefore, in order to control the posture, for example, a configuration having a posture driving mechanism for each ultrasonic probe 101 (that is, individually) may be used.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  As described above, according to the present invention, it is possible to control the size of the aperture length, and it is possible to realize good imaging with ultrasound without limiting the image resolution and the observation target distance, and an ultrasound image. Can be realized.

FIG. 1 shows a block diagram of an ultrasonic image processing apparatus 1 according to the first embodiment. 2A and 2B illustrate the expanded state and the contracted state of the ultrasonic probe apparatus 10 from the front. 3A is a diagram showing a developed state of the region r ₁ in FIG. 2A, and FIG. 3B is a diagram showing a contracted state of the region r ₁ in FIG. 2A. is there. FIG. 4 is a diagram for explaining the resolution in imaging an object in a medium using ultrasonic waves. FIGS. 5A and 5B are diagrams for explaining the resolution in imaging an object in a medium using ultrasonic waves. FIG. 6 is a diagram for explaining the positional relationship between the directivity angle of the ultrasonic probe and the imaging region S. FIG. FIG. 7 is a diagram for explaining an example of posture control of the ultrasonic probe. FIG. 8 is a diagram for explaining another example of posture control of the ultrasonic probe. FIG. 9 is a diagram for explaining the adjustment angle θ _c for causing the imaging region S to exist within the directivity angle width of the ultrasonic probe. FIGS. 10A and 10B are side views of the ultrasonic probe apparatus 10 according to the second embodiment. FIG. 11 is a diagram for explaining posture control of the ultrasonic probe 101 of the ultrasonic probe apparatus 10 according to the second embodiment. 12A and 12B are front views of the ultrasonic probe apparatus 10 according to the third embodiment. FIG. 13 is a view for explaining the expansion and contraction mechanism of the annular frame 123. FIGS. 14A and 14B are views for explaining the expansion and contraction mechanism of the annular frame 123. FIG. FIG. 15 is a diagram for explaining posture control of each ultrasonic probe 101 in conjunction with opening length control by the pantograph mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic imaging apparatus, 10 ... Ultrasonic probe apparatus, 12 ... Amplifier, 14 ... A / D converter, 16 ... Distance signal arithmetic circuit, 18 ... Image generation circuit, 20 ... Transmitter, 22 ... Switching circuit, 24 ... Transmission control unit, 26 ... Display control unit, 28 ... Display unit, 30 ... Opening length control unit, 32 ... Probe posture control unit, 34 ... Operation unit, 101 ... Ultrasonic probe, 103 ... Opening length changing device, 104 DESCRIPTION OF SYMBOLS ... Probe posture change part, 105 ... Telescopic rod, 107 ... Connection member, 109 ... Link mechanism, 111 ... Wire, 113 ... Connection part, 115 ... Drive mechanism, 121 ... Deformation rod, 123 ... Ring frame, 125 ... Ring Support member

Claims (8)

A plurality of ultrasonic probes, each transmitting ultrasonic waves in response to a supplied drive signal, receiving ultrasonic waves and generating electrical signals;
Installation means for arranging and installing the plurality of ultrasonic probes in a two-dimensional manner;
An expansion and contraction mechanism that changes the diameter of the ultrasonic irradiation surface formed by arranging the plurality of ultrasonic probes by extending and contracting the installation means;
Image generating means for generating an ultrasound image using each electrical signal generated by the plurality of ultrasound probes;
An ultrasonic imaging apparatus comprising:   The installation means is contracted as the distance between the ultrasonic irradiation surface and the imaging target region is reduced, and the installation means is extended as the distance between the ultrasonic irradiation surface and the imaging target region is increased. The ultrasonic imaging apparatus according to claim 1, further comprising control means for controlling the expansion / contraction mechanism.   The control means follows the distance L so that L / H is constant when the diameter of the ultrasonic irradiation surface is H and the distance from the ultrasonic irradiation surface to the imaging target region is L. The ultrasonic imaging apparatus according to claim 2, wherein the expansion / contraction mechanism is controlled.   The installation of at least one ultrasonic probe is performed in conjunction with expansion or contraction of the installation means so that an imaging target region is included in the directivity angle width of the ultrasonic wave transmitted from each of the plurality of ultrasonic probes. 3. The ultrasonic imaging apparatus according to claim 1, further comprising posture control means for controlling a posture with respect to the means. A plurality of ultrasonic probes, each transmitting ultrasonic waves in response to a supplied drive signal, receiving ultrasonic waves and generating electrical signals;
Installation means for arranging and installing the plurality of ultrasonic probes in a two-dimensional manner;
An expansion and contraction mechanism that changes the diameter of the ultrasonic irradiation surface formed by arranging the plurality of ultrasonic probes by extending and contracting the installation means;
An ultrasonic probe apparatus comprising:   The installation means is contracted as the distance between the ultrasonic irradiation surface and the imaging target region is reduced, and the installation means is extended as the distance between the ultrasonic irradiation surface and the imaging target region is increased. 6. The ultrasonic probe apparatus according to claim 5, further comprising control means for controlling the expansion / contraction mechanism.   The control means follows the distance L so that L / H is constant when the diameter of the ultrasonic irradiation surface is H and the distance from the ultrasonic irradiation surface to the imaging target region is L. The ultrasonic probe apparatus according to claim 6, wherein the expansion / contraction mechanism is controlled.   The installation of at least one ultrasonic probe is performed in conjunction with expansion or contraction of the installation means so that an imaging target region is included in the directivity angle width of the ultrasonic wave transmitted from each of the plurality of ultrasonic probes. 7. The ultrasonic probe apparatus according to claim 5, further comprising posture control means for controlling the posture with respect to the means.

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