JP2017124053A - Acoustic wave probe and analyte information acquisition device - Google Patents

Abstract

An acoustic probe and the like that can irradiate light more uniformly toward a subject.
An acoustic wave probe includes a plurality of acoustic wave transducers and a plurality of light emitting units arranged in gaps between the plurality of acoustic wave transducers to irradiate light to a subject. Each light emitting unit 103 is surrounded by a plurality of acoustic wave transducers 102 and disposed on a common support member 101. The plurality of acoustic wave transducers and the plurality of light emitting portions can be a common support member.
[Selection] Figure 1-1

Description

  The present invention relates to an acoustic wave probe capable of receiving an acoustic wave such as a photoacoustic wave due to a photoacoustic effect (hereinafter sometimes represented by an ultrasonic wave), an object information acquisition apparatus using the acoustic wave probe, and the like.

  As one of optical imaging technologies, there is a technology called Photoacoustic Imaging (PAI: photoacoustic imaging). Photoacoustic imaging is a technique for receiving acoustic waves (also referred to as “photoacoustic waves”) generated by light irradiation and generating image data from the obtained received signals (see Patent Document 1). This photoacoustic wave is generated when pulsed light from a light source is irradiated on a subject such as a living body and a tissue that absorbs energy of light propagating through the subject expands.

US Patent Application Publication No. 2007/0287912

  In order to image the inside of the subject satisfactorily, it is necessary to irradiate the subject surface with light as uniformly as possible. Furthermore, it is necessary to detect the photoacoustic wave generated in the subject with an acoustic wave transducer without degrading it as much as possible. An object of this invention is to provide the acoustic wave probe etc. which can irradiate light to a subject more efficiently and uniformly.

  The acoustic wave probe of the present invention has the following characteristics. A plurality of light emitting units for irradiating the subject with light; and a plurality of acoustic wave transducers for detecting photoacoustic waves generated in the subject. The light emitting unit is surrounded by the plurality of acoustic wave transducers. Is arranged.

  ADVANTAGE OF THE INVENTION According to this invention, the acoustic wave probe etc. which can irradiate more uniformly the light from light-emitting parts, such as the light source arrange | positioned, to a test object, etc. are realizable.

The figure explaining the acoustic wave probe which concerns on 1st Embodiment. 1 is a schematic cross-sectional view of an acoustic wave probe according to a first embodiment. 1 is a schematic perspective view of an acoustic wave probe according to a first embodiment. 1 is a schematic perspective view of an acoustic wave probe according to a first embodiment. The figure explaining the acoustic wave probe which concerns on 2nd Embodiment. The figure explaining the acoustic wave probe which concerns on 3rd Embodiment. The figure explaining the acoustic wave probe which concerns on 4th Embodiment. The figure explaining the acoustic wave probe which concerns on 5th Embodiment. The figure explaining the acoustic wave probe which concerns on 6th Embodiment. The figure which shows the string-like member for peeling an acoustic wave transducer from a subject. The figure which shows the rod-shaped member for peeling an acoustic wave transducer from a test object. The figure explaining the acoustic wave probe which concerns on 7th Embodiment. The figure explaining operation | movement of the acoustic wave probe which concerns on 7th Embodiment. The figure explaining the acoustic wave probe which concerns on 8th Embodiment. The figure explaining operation | movement of the acoustic wave probe which concerns on 8th Embodiment. The figure explaining the acoustic wave probe which concerns on 9th Embodiment. The figure explaining the acoustic wave probe which concerns on 10th Embodiment. FIG. 10 is a drive detection circuit diagram of an acoustic wave probe according to a tenth embodiment. The figure explaining the subject information acquisition apparatus which concerns on 11th Embodiment. The figure explaining the subject information acquisition apparatus which concerns on 12th Embodiment. The figure which shows the example of arrangement | positioning of the acoustic wave transducer and light-projection part in this invention.

  A feature of one aspect of the acoustic wave probe according to the present invention is that the acoustic wave probe has a plurality of light emitting portions, and each light emitting portion is surrounded by an acoustic wave transducer that receives the photoacoustic waves. It is a point. The arrangement mode of the plurality of light emitting units may be any mode as long as light can be irradiated more uniformly toward the subject. For example, an embodiment in which a pattern in which a plurality of light emitting sections are surrounded by a plurality of acoustic wave transducers is repeated two-dimensionally as shown in FIG. 13 (a), or a light emitting section in a grid pattern as shown in FIG. 13 (b). And an acoustic wave transducer are alternately and repeatedly arranged. However, as shown in FIG. 13C, an aspect in which a plurality of acoustic wave transducers and a plurality of light emitting portions are extremely unevenly distributed may be excluded unless a configuration that can irradiate more uniformly is not possible. is there. The acoustic wave probe of the present invention can constitute an object information acquisition apparatus together with a signal processing unit for converting a signal detected by the acoustic wave probe into a signal representing information on the object. Here, the acoustic wave probe detects a photoacoustic wave from the subject generated by the photoacoustic effect. Furthermore, it is also possible to detect ultrasonic waves from the subject and transmit / receive ultrasonic waves to / from the subject.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

(First embodiment)
In the present embodiment, a plurality of light emitting units that irradiate the subject with light and a plurality of acoustic wave (ultrasound) transducers that detect the generated photoacoustic waves are arranged in a distributed manner. The arrangement is variable according to the surface shape.

  The acoustic wave probe 100 of 1st Embodiment is demonstrated using FIGS. 1-1 to FIGS. 1-4. In the figure, 99 is a subject, 100 is an acoustic wave probe, 103 is a light emitting part (light source), 102 is an acoustic wave transducer, 101 is a support film, 110 is an ultrasonic gel, 121 is emitted light, and 122 is a photoacoustic wave. It is. Fig. 1-1 (a) shows a schematic diagram of the acoustic wave probe of the present embodiment. The acoustic wave probe 100 of the present embodiment has a plurality of light sources 103 and a plurality of acoustic wave transducers, and each is arranged in a two-dimensional array. In a region between the plurality of acoustic wave transducers 102, a plurality of light sources 103 are arranged so as to be nested with respect to the plurality of transducers 102. In the present embodiment, since the light sources 103 are arranged in a distributed manner, the light source 103 is more uniformly over a wide range of the surface of the subject as compared with a configuration in which the light sources are arranged only in one place or a partial region. Light can be irradiated. Here, for example, the plurality of acoustic wave transducers 102 around each light source 103 are arranged at substantially equal distances and / or substantially equal angular intervals around the light sources. In addition, the plurality of acoustic wave transducers and the plurality of light emitting units are arranged on a common support member, and the support member can move the plurality of acoustic wave transducers and the plurality of light emitting units according to the shape of the subject. It is a support film that can be deformed.

  Next, FIG. 1-1 (b) shows a schematic diagram of a cross section of the straight line Z-Z 'of FIG. 1-1 (a). In the acoustic wave probe 100 of the present embodiment, the positions of the plurality of light sources 103 and the plurality of transducers 102 are configured to move along the surface shape of the subject 99. Specifically, this can be easily realized by disposing a plurality of light sources 103 and a plurality of transducers 102 surrounding the light source 103 on a flexible support film 101 that can be bent and stretched.

  The acoustic wave probe of the present embodiment can be used by pressing the acoustic wave probe 100 directly against the subject 99 as shown in FIG. At that time, in order to efficiently transmit the photoacoustic wave 122 generated in the subject 99 to the acoustic wave transducer 102, an ultrasonic gel 110 is disposed between the subject 99 and the acoustic wave probe 100. When a bubble enters between the subject 99 and the acoustic wave transducer 102, reflection or attenuation of the photoacoustic wave (ultrasonic wave) 122 generated in the subject 99 occurs at that portion. The ultrasonic gel 110 is an ultrasonic wave propagation material and has an effect of preventing the bubbles from entering between the subject 99 and the acoustic wave transducer 102. The photoacoustic wave 122 generated in the subject 99 is efficiently converted into an acoustic wave. Can be transmitted to the transducer 102.

  However, when the object 99 is irradiated with the emitted light 121 from the light source 103, the light irradiated on the object 99 may decrease by passing through the ultrasonic gel 110. The magnitude of the photoacoustic wave 122 generated inside the subject 99 is reduced due to a reduction in the amount of light irradiated to the subject 99. Therefore, in order to accurately grasp information on the subject or to obtain information on a deeper part of the subject, it is necessary to make the light irradiated on the subject 99 as large as possible. Since the ultrasonic gel 110 is a translucent substance and does not have high transmittance, the distance between the light source 103 and the subject 99 should be as small as possible, that is, the amount of the ultrasonic gel 110 between the light source 103 and the subject 99. It is important to make as small as possible.

  When the positions of the acoustic wave transducer 102 and the light source 103 are fixed with respect to the subject 99, the subject 99 and the light source are in a region where the surface shape of the subject 99 is greatly deviated from the fixed shape. The distance between 103 becomes large. Therefore, the emitted light from the light source 103 is attenuated by the ultrasonic gel 110, and the amount of light irradiated to the subject 99 is reduced. In addition, since the distance between the light source and the subject is not constant, the amount of light that irradiates the subject 99 changes depending on the measurement settings and conditions, and the accuracy of the obtained subject information varies. Even in a configuration having a plurality of light sources 103, the distance to the subject 99 varies for each light source 103, so the amount of light irradiated to the subject 99 varies depending on the location.

  When the acoustic wave probe 100 according to the present embodiment is used, the position of the light source 103 can be moved in accordance with the surface shape of the subject 99. Therefore, as shown in FIG. Can be placed in close proximity. Therefore, since the thickness of the ultrasonic gel 110 between the light source 103 and the subject 99 can be made thin and substantially uniform, the amount of light irradiated on the subject 99 can be increased and the irradiation light can be made substantially uniform. Furthermore, since the acoustic wave probe 100 of the present embodiment has a plurality of light sources dispersed between the acoustic wave transducers arranged in an array, it can irradiate a wide range of the subject 99 and the irradiation light. Can be irradiated almost uniformly at any place.

  As described above, according to this embodiment, it is possible to realize an acoustic wave probe that can irradiate light from a light emitting unit (light source) toward a subject more efficiently and uniformly.

  As another effect of the present embodiment, the photoacoustic wave 122 can be received efficiently. The reason will be described below. The photoacoustic wave 122 has a characteristic that the sound spreads as it propagates. If the distance from the generation location of the photoacoustic wave to the acoustic wave transducer 102 is long, the photoacoustic wave received by the acoustic wave transducer 102 becomes small. . As described above, since the position of the acoustic wave transducer 102 is movable along the surface shape of the subject 99 by using the acoustic wave probe 100 of the present embodiment, the distance between the acoustic wave transducer 102 and the subject 99. Are also brought close together. Therefore, since the acoustic wave transducer 102 can receive the signal without reducing the size of the photoacoustic wave 122, the photoacoustic wave 122 generated by the subject 99 can be received efficiently. On the other hand, when the position of the acoustic wave transducer 102 and the light source 103 is fixed with respect to the subject 99, the subject 99 is in a region where the surface shape of the subject 99 is greatly deviated from the fixed shape. And the distance between the transducers 102 becomes large. Therefore, the photoacoustic wave 122 that reaches the acoustic wave transducer 102 is reduced, and the efficiency of receiving the photoacoustic wave 122 generated by the subject 99 is lowered.

  As described above, when this embodiment is used, an acoustic wave that can irradiate the light from the light source 103 more uniformly into the subject 99 and efficiently detect the photoacoustic wave 122 generated inside the subject 99. The probe 100 can be realized.

  As another effect, the photoacoustic wave 122 can be received in a state where the influence of reflection between the subject 99 and the acoustic wave transducer 102 is small. This will be described below. A part of the photoacoustic wave 122 generated in the subject 99 may be reflected on the surface of the acoustic wave transducer 102. A part of the reflected wave is reflected again on the surface of the subject 99 due to the difference in acoustic impedance between the subject 99 and the ultrasonic gel 110 and returns to the surface of the acoustic wave transducer 102. If the distance between the subject 99 and the acoustic wave transducer 102 is wide, the time until the reflected wave returns to the acoustic wave transducer 102 becomes long, and is detected as another signal separated from the original received signal. On the other hand, according to the present embodiment, since the distance between the subject 99 and the acoustic wave transducer 102 can be close, the reflected wave can be obtained as a signal integrated with the original received signal. When the reflected wave is detected as another received signal, an artifact (virtual image) is generated when converted into the object information. However, when this embodiment is used, the reflected wave may be difficult to be detected as another received signal. it can.

  As described above, when the present embodiment is used, the light from the light source 103 is more uniformly irradiated into the subject 99, and the photoacoustic wave 122 generated inside the subject 99 can be detected accurately and efficiently. The acoustic wave probe 100 can be provided.

  Any film that can be deformed along the surface shape of the subject 99 is used for the film 101 that is the support film of the present embodiment. In particular, it is desirable to be a flexible film that curves and expands and contracts in accordance with the surface shape of the subject 99, but it is not limited to flexibility (microelasticity) and does not exclude elastic bodies. . Various materials including an elastic body can be used as long as characteristics necessary for bending and expansion / contraction can be obtained. The film 101 can be easily configured by using a resin film, rubber, or the like. Specifically, epoxy resin, vinyl chloride resin, polyester resin, fluorine-based resin, silicone rubber, or the like can be used. The Young's modulus is about 0.01 GPa to 5 GPa, more preferably about 0.01 GPa to 0.1 GPa. Other than this, any pressure can be used as long as it can be expanded and contracted and bent to the same size as the subject with the pressure applied from the subject. In FIG. 1, a film having a uniform thickness is used. However, the present invention is not limited to this, and a support film partially having a pattern having a thickness different from that of the periphery can be used. Thereby, it is possible to optimally adjust the ease of movement of the acoustic wave transducer 102 and the ease of bending of the film 101 by the subject 99.

  The acoustic wave transducer 102 can be used as long as it can receive an acoustic wave generated by irradiating the subject with light. Specifically, PZT, PVDF, CMUT, etc., which have an acoustic wave transducer 102 that is generally used in an ultrasonic diagnostic apparatus, can also be used. In the figure, the acoustic wave transducer 102 is disposed on the surface of the film 101 on the subject 99 side, but the present invention is not limited to this. Even if the acoustic wave transducer 102 is partially embedded in the film 101 or penetrates to the opposite side, it can be used similarly. Furthermore, if the acoustic wave transmission characteristics of the film 101 are not problematic in use, a configuration in which the film 101 is disposed on the reverse surface (back surface) of the subject 99 can also be used.

  The light source 103 can be used as long as an acoustic wave is generated by irradiating the subject with light. In the figure, the light source 103 is disposed on the surface of the film 101 on the subject 99 side, but the present invention is not limited to this, and a configuration that penetrates the film 101 or a configuration that is partially embedded in the film 101 is the same. Can be used. The light source 103 may use a configuration in which light from a light generation source disposed outside the acoustic wave probe 100 is guided to the light emitting unit 103 by an optical fiber or the like. Further, by using an LED, a semiconductor laser, or the like as the light source 103, the light source 103 can be directly arranged on the film 101. As a result, the light source 102 can be reduced in weight, and the film 101 can easily follow the shape of the subject 99. In addition, the mechanism for irradiating the subject with light can be simplified and miniaturized, and the acoustic probe itself can be miniaturized.

  The pressing of the film 101 against the subject 99 can be easily realized by a method in which the film 101 is wound around the subject 99 and both ends of the film are fixed by the fixing means 104 as shown in FIG. it can. Thereby, a photoacoustic wave can be acquired by irradiating light from all directions of the outer periphery of the subject 99. Therefore, subject information can be acquired not only from a specific surface of the subject 99 but also from more directions, and a more detailed subject image can be reproduced by using this probe.

  Moreover, as another form, as shown in FIGS. 1-4, the method of supporting the film 101 with the support frame member 105, and pressing the whole support frame member against the test object 99 can be used. The support frame member 105 has a half-moon-shaped recess (groove) with respect to the subject, and the film 101 is disposed so as to cover the recess of the support frame member 105 and is held by the support frame member 105. . The film 101 is held from the left and right by the support frame member 105, and is in a state where the film 101 itself is tensioned (stretched state). In this state, the support frame member 105 is pressed against the subject 99 to deform the film 101 along the surface shape of the subject 99, and the acoustic wave transducer 102 and the light source 103 on the film 101 are also subject to the subject 99. It is arrange | positioned in the position along the surface shape. In the configuration of FIGS. 1-4, since the support frame member 105 is used, a substantially uniform tension is applied to the film 101. Therefore, only by controlling the force with which the support frame member 105 is pressed against the subject 99, the entire film 101 can be pressed against the subject 99 side in a stable state even with a large area film.

  By using the configurations of FIGS. 1-3 and 1-4, the positions of the acoustic wave transducer 102 and the light source 103 of the acoustic wave probe 100 can be automatically changed along the surface of the subject 99. Therefore, a photoacoustic signal can be acquired from the subject 99 having various surface shapes. The method of pressing the film 101 against the subject 99 is not limited to that shown in FIGS. 1-3 and 1-4. Any other configuration can be used as long as the film 101 is pressed against the subject 99 and the film 101 can follow the shape of the surface of the subject 99.

  In the present embodiment, the ultrasonic gel 110 between the light source 103 and the subject 99 is provided by means for making the distance between the light source 103 and the subject 99 smaller than the distance between the acoustic wave transducer 102 and the subject 99. Can be thinned. For this reason, the amount of light emitted from the light source 103 is attenuated by the ultrasonic gel 110 can be reduced, so that the amount of light applied to the subject can be increased. A specific configuration will be described using the second to fifth embodiments.

  In the second and subsequent embodiments, the ultrasonic transmission characteristic between the acoustic wave transducer and the subject is higher than the ultrasonic transmission characteristic between the light source and the subject, and the light transmission characteristic between the light source and the subject is It has a characteristic control means that is higher than the light transmission characteristic between the objects. The characteristic control means will be specifically described below.

(Second Embodiment)
The second embodiment relates to the positional relationship between the acoustic wave transducer 102 and the light source 103. The rest is the same as the first embodiment. A second embodiment will be described with reference to FIG. FIG. 2 is a schematic diagram of the acoustic wave probe according to the present embodiment. FIG. 2A is a schematic diagram of a cross section of the acoustic wave probe in a state in which the film 101 is flattened, and FIG. 2B is a diagram in which the subject 99 is brought into contact with the subject 99 via an ultrasonic gel to obtain subject information. The schematic diagram of the cross section of the probe at the time of doing is shown.

  The present embodiment is characterized in that when the film 101 is flattened, the surface of the light source 103 on the subject side is arranged closer to the subject 99 than the surface of the acoustic wave transducer 102 on the subject side. When the film 101 is pressed against the subject 99 with a certain force, the ultrasonic gel 110 has a viscosity, so that the thickness between the film 101 and the subject 99 is a certain thickness. Stabilize. As shown in FIG. 2B, the distance between the light source 103 and the surface of the subject 99 is greater than the distance between the acoustic wave transducer 102 and the surface of the subject 99 due to the configuration of the present embodiment. Narrow. Specifically, in the probe 100 of the present embodiment, the height of the light source 103 (the distance protruding from the film surface to the subject side) is higher than the height of the acoustic wave transducer 102. As a result, the ultrasonic gel 110 is pushed away by the light source 103 and the ultrasonic gel 110 escapes to a region where the light source 103 is not present. Therefore, the ultrasonic gel 110 filled between the film 101 and the subject 99 is in front of the light source 103. This is thinner than before the acoustic wave transducer 102. Actually, as shown in FIG. 2B, the film 101 slightly bends downward in the drawing, but if the difference in height is larger than the amount of bending, the ultrasonic gel 110 in front of the light source 103 is moved. It can always be kept thin.

  According to the acoustic wave probe according to the present embodiment, since the surface of the light source 103 can be arranged closer to the subject 99, an acoustic wave probe that can irradiate light from the light source toward the subject more efficiently and uniformly is provided. can do. In FIG. 2B, for the sake of explanation, a cross-sectional view in which the subject 99 is in a planar state is used. However, the present invention is not limited to this. The same applies to an example in which the surface of the subject 99 shown in FIG.

(Third embodiment)
The third embodiment relates to the structure of the light source 103. The rest is the same as in the second embodiment. A third embodiment will be described with reference to FIG. FIG. 3A is a schematic diagram of a cross section of the acoustic wave probe in a state where the film 101 is flattened, and FIG. 3B is a diagram in which object information is obtained by bringing the object 99 into contact with the object 99 via an ultrasonic gel. The schematic diagram of the cross section of the probe at the time of acquisition is shown. FIG. 3 is a schematic diagram of the acoustic wave probe according to the present embodiment. In FIG. 3, 106 is a transparent member.

  The present embodiment is characterized in that a transparent member 106 is provided on the subject 99 side of the light source 103. The transparent member 106 can be used as long as it is a material having high light transmittance at the wavelength of the light source 103. Even if the height of the light source 103 is the same, the presence of the transparent member 106 makes it possible to increase the substantial height and reduce the thickness of the ultrasonic gel 110 in the portion through which the emitted light passes. In the present embodiment, since the transparent member 106 is provided, the same effect as in the second embodiment can be obtained without increasing the height of the light source 103. Therefore, restrictions on the shape and arrangement of the light source 103 can be reduced. Moreover, the cross-sectional shape of the transparent member 106 does not necessarily need to be a square, and the ultrasonic gel 110 can escape more easily by making it a trapezoidal shape or the like.

  According to the present embodiment, the surface of the light source 103 is arranged closer to the subject 99 without increasing the restrictions on the light source 103, and the light from the light source is directed toward the subject more efficiently and uniformly. It is possible to provide an acoustic wave probe capable of

(Fourth embodiment)
The fourth embodiment relates to the structure of the light source 103. The rest is the same as in the second embodiment. A fourth embodiment will be described with reference to FIG. FIG. 4A is a schematic diagram of a cross section of the acoustic wave probe in a state where the film 101 is flattened, and FIG. 4B is a diagram in which object information is obtained by bringing the object 99 into contact with the object 99 via an ultrasonic gel. The schematic diagram of the cross section of the probe at the time of acquisition is shown. FIG. 4 is a schematic diagram of an acoustic wave probe according to the present embodiment. In FIG. 4, 107 is a deformable bag.

  The present embodiment is characterized in that a deformable bag 107 containing gas is provided on the subject 99 side of the light source 103. The deformable bag 107 can be used as long as it has a high light transmission property and deforms in response to an external force. By filling the deformable bag 107 with gas and sealing it, it is possible to have a function of deforming under external force. As shown in FIG. 4B, when the probe 100 is brought into contact with the subject 99 via the ultrasonic gel, the bag 107 is slightly crushed and spreads in the lateral direction of the drawing. Even if the height of the light source 103 is the same, the presence of the deformable bag 107 makes it possible to increase the substantial height and to reduce the thickness of the ultrasonic gel 110 in the portion through which the emitted light passes. In this embodiment, since the deformable bag 107 is provided, the same effect as that of the second embodiment can be obtained without increasing the height of the light source 103. Furthermore, in this embodiment, the deformation amount of the film 101 at the portion that supports the light source 103 can be adjusted by the ease of deformation of the bag 107. Therefore, it becomes easier to more optimally adjust the deformation amount of the film 101 at the portion that supports the light source 103 than the configuration in which the height is set in the second embodiment or the third embodiment.

  According to the present embodiment, it is easy to design a configuration in which the surface of the light source 103 is arranged closer to the subject 99, and an acoustic probe that can irradiate light from the light source toward the subject more efficiently and uniformly is provided. can do.

(Fifth embodiment)
The fifth embodiment relates to a structure for supporting the light source 103 from a film. The rest is the same as in the second embodiment. A fifth embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram of the acoustic wave probe according to the present embodiment. FIG. 5A is a schematic diagram of a cross section of the acoustic wave probe in a state in which the film 101 is flattened, and FIG. 5B is a diagram in which subject information is obtained by bringing the subject 99 into contact with the subject 99 via an ultrasonic gel. The schematic diagram of the cross section of the probe at the time of acquisition is shown. In FIG. 5, 108 is a spring.

  The present embodiment is characterized in that the light source 103 is held on the film 101 via a spring 108. The light source 103 held by the spring 108 has a structure that is displaced in a direction perpendicular to the surface of the film 101 (up and down direction in the drawing) when an external force is applied. As shown in FIG. 4B, when the probe 100 is brought into contact with the subject 99 via the ultrasonic gel, the spring 108 is slightly collapsed, and the light source 103 moves slightly in the opposite direction to the subject 99. . Even if the amount by which the spring 108 contracts and the amount by which the film 101 in the region supporting the light source 103 bends are subtracted, the surface of the light source 103 on the subject 99 side is closer to the subject 99 than the surface of the acoustic wave transducer 102 on the subject 99 side. The design is on the side. Therefore, since the ultrasonic gel 110 is pushed away by the light source 103 and the ultrasonic gel 110 escapes to an area where the light source 103 is not present, the ultrasonic gel 110 filled between the film 101 and the subject 99 is located in front of the light source 103. However, it becomes thinner than before the acoustic wave transducer 102.

  Further, since no member is arranged on the subject side of the light source 103 as compared with the third embodiment and the fourth embodiment, there is no attenuation of light at that portion, and a larger amount of light is given to the subject 99. Can be irradiated. In addition, since the light source 103 is held by the spring 108, there is no restriction on the height of the light source 103, and the degree of freedom in designing the light source 103 can be increased. Further, the distance between the light source 103 and the subject 99 can be easily set by adjusting the hardness of the spring 108.

  The spring material and the method for fixing the spring to the film will be described. The spring can be used as long as it is deformed according to the external force and is restored when the external force is removed. As a material, a resin, rubber, or the like can be used as long as it can be easily configured with various metals and has a similar function. The spring can be fixed to the film as long as the spring is securely fixed to the film. For example, the spring can be easily realized by using an adhesive.

  According to the acoustic wave probe according to the present embodiment, the surface of the light source 103 is arranged closer to the subject 99 without significantly restricting the components, and the light from the light source is directed toward the subject more efficiently. In addition, an acoustic wave probe that can irradiate uniformly can be provided.

In addition, in FIG. 5, although demonstrated using the spring 108, it is not restricted to this structure. By increasing the thickness of the film 101 in the region that supports the light source 103, the film 101 in the region that supports the light source 103 can be configured to have the same function as the spring 108. Thereby, the effect similar to the structure of FIG. 5 is acquired, without increasing a component.

(Sixth embodiment)
The sixth embodiment relates to a member disposed on the surface of an acoustic wave transducer. The rest is the same as any one of the first to sixth embodiments. FIG. 6A is a schematic diagram for explaining the acoustic wave probe according to the present embodiment. In FIG. 6A, reference numeral 111 denotes an adhesive sheet that is an adhesive material.

  The present embodiment is characterized in that an adhesive sheet 111 is provided on the surface of the acoustic wave transducer 102, and the adhesive sheet 111 is not provided on the surface of the light source 103. The adhesive sheet 111 is bonded and fixed to the acoustic wave transducer 102. The pressure-sensitive adhesive sheet 111 has adhesiveness on the surface on the subject 99 side, and is pressed against the subject 99 so that it adheres to the surface of the subject 99 and is temporarily fixed. Since the surface of the subject 99 and the adhesive sheet 111 are in close contact with each other so that there is no gap, the photoacoustic wave 122 generated inside the subject 99 is deteriorated at the interface between the surface of the subject 99 and the adhesive sheet 111. And can be transmitted to the adhesive sheet 111 side.

  The adhesive sheet 111 is made of a material close to the acoustic impedance of the subject 99 and has a characteristic of transmitting a photoacoustic wave. Therefore, the ultrasonic wave 122 that reaches the surface of the adhesive sheet 111 can be transmitted to the acoustic wave transducer 102 with almost no attenuation. Therefore, without using the ultrasonic gel 110 used in the first to fifth embodiments, the photoacoustic wave 122 generated in the subject 99 can reach the acoustic wave transducer 102 with almost no attenuation.

  On the other hand, the main feature of this embodiment is that the adhesive sheet 111 is not disposed on the subject side of the light source 103. As described above, in this embodiment, it is not necessary to place the ultrasonic gel 110 between the acoustic wave transducer 102 and the subject 99. Since the acoustic wave transducer 102 is held with respect to the subject 99 via the adhesive sheet 111, there is a slight gap between the light source 103 and the subject 99. Light is irradiated from the acoustic wave probe 100 into the subject 99 through the gap. In the configuration using the ultrasonic gel, a slight attenuation occurs when light is transmitted. Therefore, compared to the first to fifth embodiments, which use the ultrasonic gel 110, there is almost no attenuation in the air gap of this embodiment, so that light can be irradiated substantially uniformly without further attenuation.

  In the present embodiment, it is possible to realize an acoustic wave probe that can irradiate light from a light source toward a subject more efficiently and uniformly.

  The pressure-sensitive adhesive sheet 111 of the present embodiment is a sheet having a sticky surface and can be used as long as it can be attached to or peeled off from the subject 99. Specifically, a thin resin sheet having an adhesive on the surface or rubber can be used. In addition, an elastomer that is elastic rubber can be used. In this case, since it has elasticity, it is deformed along the surface shape of the subject 99 and is easily adhered to the subject 99. Further, when peeling from the subject 99, the pressure sensitive adhesive sheet 111 can be peeled off while being deformed, so that the subject 99 can be peeled off without applying a large load. Also, as the adhesive, rubber adhesive, acrylic adhesive, silicone adhesive, urethane adhesive, etc. can be used, and an optimal material may be selected depending on the required adhesive strength and peelability. . The physical properties of the pressure-sensitive adhesive sheet 111 are preferably those having high ultrasonic transmission and acoustic impedance close to that of the subject 99, but those having necessary characteristics can be selected according to individual use conditions.

  Since the adhesive sheet 111 is used in the present embodiment, the positional relationship between the subject 99 and the acoustic wave transducer 102 is maintained, and the position is unlikely to shift when receiving a photoacoustic wave. Therefore, it is possible to obtain subject information whose position is accurate with respect to the subject. Similarly, the position of the light source 103 sandwiched between the plurality of acoustic wave transducers 102 is not easily displaced. Therefore, the subject 99 can be irradiated with the light 121 substantially uniformly at the same position, so that the photoacoustic wave 122 can be stably generated.

  It can also be set as the structure which has a peeling assistance means for peeling off the adhesive sheet 111 from the test object 99 easily. Any peeling assisting means may be used as long as it applies a force for pulling the acoustic wave transducer 102 in the direction opposite to the subject 99. Specifically, a string 901 and a rod-shaped member 902 as shown in FIGS. 6-2 and 6-3 can be provided on the opposite side of the acoustic wave transducer 102 from the subject 99 side. When the acoustic wave transducer 102 is peeled from the subject, it can be easily peeled by pulling the string 901 or the rod-shaped member 902 in the direction opposite to the subject 99 (the direction of the arrow in the drawing).

  Since the film 101 holding the acoustic wave transducer 102 is along the subject 99, it has a characteristic that it is relatively easily deformed. In this case, when the acoustic wave transducer 102 is peeled from the subject 99, if the film 101 is pulled and peeled, the film 101 itself is deformed. Therefore, there is a possibility that an excessive force is applied to the film 101 to deteriorate the film 101, or an excessive force is applied to the subject 99 to cause pain in the subject 99. However, by providing the peeling assisting means, each acoustic wave transducer 102 can be easily peeled from the subject 99, and the load on the film 101 and the subject 99 can be reduced.

  In addition, since the adhesive sheet 111 is not disposed between the light source 103 and the subject 99 and is separated by a gap, the photoacoustic wave 122 hardly transmits, and is reflected by the surface of the subject 99 to be reflected. It attenuates in the specimen 99. Since the photoacoustic wave 122 is received by the acoustic wave transducer 102, this does not affect the photoacoustic wave detection characteristics. On the other hand, in the configuration in which the photoacoustic wave 122 reaches the light source 103, the photoacoustic wave 122 reflected by the member on the surface of the light source 103 is further reflected by another portion, received by the acoustic wave transducer 102, and an erroneous subject. It may be recognized as information. In the present embodiment, since the photoacoustic wave hardly reaches the light source 103, it is possible to avoid acquiring the erroneous subject information.

  In the present embodiment, the configuration in which there is a slight gap between the subject 99 and the light source 103 is described, but the configuration is not limited thereto. Any structure in which the adhesive sheet 111 is not provided between the light source 103 and the subject 99 can be used, and the same effect can be obtained even in a structure in which the subject 99 and the light source 103 are in close contact.

(Seventh embodiment)
The seventh embodiment relates to a member connecting the acoustic wave transducer 102 and the light source 103. The rest is the same as any one of the first to sixth embodiments.

  The seventh embodiment will be described with reference to FIGS. 7-1 and 7-2. FIG. 7A is a schematic diagram of the acoustic wave probe according to the present embodiment. Fig. 7-1 (a) shows a schematic diagram of a cross section of the acoustic wave probe in a state where the film 101 is flat, and Fig. 7-1 (b) shows a schematic diagram of the film viewed from the opposite side of the subject. Indicates. FIG. 7-2 is a schematic diagram of a cross section of the probe when the subject information is acquired by contacting the subject 99 via the ultrasonic gel. In the figure, 131 is a first beam part, and 132 is a second beam part. In FIG. 7-1 (b), the acoustic wave transducer 102 and the light source 103 arranged on the subject side of the film 101 represent the position where the film 101 is transmitted through the film 101 when viewed from the opposite side of the subject. It is indicated by a dotted line.

  The present embodiment is characterized in that the light source 103 has a mechanism that faces in a direction perpendicular to the surface formed by the plurality of acoustic wave transducers 102 arranged with the light source 103 interposed therebetween. A configuration for realizing this mechanism will be described. As shown in FIGS. 7A and 7B, each light source 103 has a first beam portion 131 extending in the vertical direction, and each acoustic wave transducer 102 is arranged in the vertical direction. An extended second beam portion 132 is provided. As shown in FIG. 7-1 (b), the first beam portion 131 includes a plurality of members extending along the film surface to the vicinity of the second beam portion 132 included in each acoustic wave transducer 102 around the light source 102. It has branches and has a cross shape. The first beam portion 132 included in the acoustic wave transducer 102 surrounding the light source 103 is connected to the branch portion of the first beam portion 131 included in the enclosed light source 103.

  The connection part between the branch part of the first beam part 131 and the second beam part 132 has a structure of a spherical joint (spherical joint). The tip of the branch portion of the first beam portion 131 has a sphere shape, and the tip of the second beam portion 132 has a structure that wraps around the sphere from the periphery. Accordingly, the second beam portion 132 has a structure that can freely move in a direction of about 360 ° with respect to the first beam portion 131. Therefore, as shown in FIG. 7B, when the film 101 is pressed against the subject 99, the light source 103 is oriented in the perpendicular direction of the plane connecting the centers of the four acoustic wave transducers 102 surrounding the light source 103. Automatically placed. As described above, in the present embodiment, the first beam portion extending from the light emitting portion and the plurality of acoustic wave transducers around the light emitting portion can be extended and rotated with respect to the first beam portion. And a second beam portion connected to the second beam portion.

  With this structure, light can be emitted from the light source 103 to substantially the center of the plurality of acoustic wave transducers surrounding the light source 103. Since the four acoustic wave transducers 102 are arranged so as to spread over a wide area, light can be emitted toward the center of the subject 99. Without this mechanism, if the surface of the subject 99 has small irregularities, the direction of the light source 103 is determined according to the irregularities, so the light source 103 is displaced from the center direction of the subject, In the worst case, light may be irradiated at an angle close to the surface direction. By using this embodiment, as shown in FIG. 8-2 described later (FIG. 8-2 shows the configuration of the eighth embodiment), it is not affected by small irregularities on the surface of the subject 99. Light can be irradiated toward the center of the subject 99.

  The acoustic wave probe according to the present embodiment provides an acoustic wave probe that is less affected by the fine surface shape of the subject 99 and that can irradiate light from the light source toward the subject more efficiently and uniformly. Can do.

  In the present embodiment, the four acoustic wave transducers 102 surrounding the light source 103 are connected by a ball joint, but the present invention is not limited to this. The light source 103 and two or more acoustic wave transducers 102 located adjacent to each other can be used similarly.

(Eighth embodiment)
The eighth embodiment relates to a member connected to the light source 103. The rest is the same as any one of the first to seventh embodiments. FIG. 8A is a schematic diagram for explaining the acoustic wave probe according to the present embodiment. In FIG. 8A, reference numeral 140 denotes a flexible printed board or a flexible board including a metal layer.

  The present embodiment is characterized in that the light source 103 is thermally connected to the flexible printed circuit board 140. The flexible printed circuit board 140 has a thin metal layer 142 on a thin film-like support substrate 141 serving as a base material, and can be deformed in accordance with an external force. The light source 103 is thermally connected to the metal layer 142 on the support substrate 141, and heat generated when the light source 103 emits light is transmitted to the metal layer 142. The heat transferred to the metal layer 142 is transferred in the plane of the metal layer 142 and diffuses. Compared with the size of the light source 103, the metal layer 142 has a large surface area, and heat is radiated from the surface of the metal layer 143 having the large surface area. The probe 100 includes a heat radiating means (not shown), and is thermally connected to the metal layer 142 to radiate heat transmitted to the metal layer 142 in the heat radiating means (air-cooling fins or the like). It can also be.

  Since the acoustic wave probe 100 is used in contact with a subject such as a living body, if the light source 103 generates heat and the temperature rises, the heat is transmitted to the subject and a load is applied to the subject. Therefore, it is desirable that the surface temperature of the probe 100 is kept from room temperature to about the body temperature of the subject. According to the present embodiment, the heat generated by the light source 103 can be released to other parts, and the temperature rise due to heat generated by the light source 103 can be reduced, so that the temperature rise on the surface of the acoustic probe 100 can be reduced.

  The acoustic wave probe according to the present embodiment can provide an acoustic wave probe that can reduce the temperature rise in the portion in contact with the living body and can irradiate light from the light source more efficiently and uniformly toward the subject. .

  The flexible printed circuit board 140 of this embodiment can be used as long as it is flexible and can be deformed without breaking the metal layer 142 due to external stress. Specifically, a structure in which a metal layer 142 is formed on a resin film (base material 141) such as polyimide having a thickness of 10 to 50 micrometers can be used. As the material of the metal layer 142, any material that can conduct heat, such as general copper, aluminum, iron, etc., is used. The thickness of the metal layer 142 can be about 10 micrometers to 100 micrometers, but can be used as long as it satisfies characteristics necessary for transferring heat and necessary flexibility. The configuration in which the light source 103 is connected to a flexible flexible substrate allows the posture of the light source 10 to be approximately at the center of the subject 99 without being affected by small irregularities on the surface of the subject 99, as shown in FIG. The same effect as that of the seventh embodiment can be achieved.

  Further, in FIG. 8A, the configuration other than the region thermally connected to the light source 103 has been described as a planar configuration. However, the present invention is not limited to this, and the surface of the metal layer 142 is made uneven to increase the surface area. Can be configured. Thereby, since the surface area increases, the heat dissipation characteristics of the metal layer 142 can be improved, and the temperature rise at the light source 103 can be further reduced. In FIG. 8A, the flexible printed circuit board 140 has been described in the form of the base material 141 and the metal layer 142. However, the present invention is not limited to this, and only the metal layer 142 can be provided if necessary strength and flexibility can be secured. The flexible substrate comprised by can also be used. In this case, since the flexibility is determined only by the thickness of the metal layer 142, the thickness of the metal layer 142 can be increased, the heat transfer characteristics of the metal layer 142 can be improved, and the temperature rise at the light source 103 can be further increased. Can be reduced.

(Ninth embodiment)
In the probe of the above-described embodiment, the positions of the acoustic wave transducer and the light source change along the surface shape of the subject.Therefore, when the surface shape of the target subject 99 has a large curvature or has many irregularities, This is particularly effective when the target area of the subject is wide. However, the ninth embodiment is configured such that the positions of the acoustic wave transducer and the light source do not change. When the surface shape of the subject is small or uneven, or when the region of the subject is narrow, the deformable support film 101 is not used, and the position between the light source 103 and the acoustic wave transducer 102 does not change (the position is changed). A fixed probe can be used. In the ninth embodiment, a probe in which the position between the light source 103 and the acoustic wave transducer 102 does not change will be described.

  FIG. 9 is a schematic diagram for explaining the acoustic wave probe according to the present embodiment. In FIG. 9, reference numeral 150 denotes a support member that does not deform. A configuration in which the film 101 of the second embodiment is replaced with a support member 150 will be described with reference to FIG. Since the support member 150 is not deformed when pressed against the subject 99, the positional relationship between the light source 103 and the acoustic wave transducer 102 does not change. Similar to the second embodiment, the subject-side surface of the light source 103 is characterized in that it is arranged closer to the subject 99 than the subject-side surface of the acoustic wave transducer 102. In the probe 100 of the present embodiment, the height of the light source 103 (the distance that protrudes from the support member surface to the subject side) is higher than the height of the acoustic wave transducer 102. As a result, the ultrasonic gel 110 is pushed away by the light source 103 and the ultrasonic gel 110 escapes to a region where the light source 103 is not present. Therefore, the ultrasonic gel 110 filled between the support member 150 and the subject 99 is placed in front of the light source 103. Is thinner than that before the acoustic wave transducer 102.

  In the present embodiment, since the supporting member 150 that does not deform is used, it is not necessary to consider the bending of the film 101 that supports the light source 103, and the design of the components becomes easier. Further, by using a configuration in which the acoustic wave transducer 102 and the light source 103 are not movable, an acoustic wave probe having a simpler configuration can be obtained.

  Although FIG. 9A has been described based on the second embodiment, the gist of the present embodiment is also the configuration in which the film 101 of the third to fifth embodiments is replaced with the support member 150. Can be applied in the same manner, and the same effect can be obtained. According to the acoustic wave probe according to the present embodiment, since the surface of the light source 103 can be arranged closer to the subject 99, the light from the light source is directed toward the subject more efficiently and uniformly and has a simple configuration. An acoustic wave probe can be realized.

  A configuration in which the film 101 of the sixth embodiment is replaced with the support member 150 will be described with reference to FIG. Since the support member 150 is not deformed when pressed against the subject 99, the positional relationship between the light source 103 and the acoustic wave transducer 102 does not change. Here, as in the sixth embodiment, the adhesive sheet 111 is provided on the surface of the acoustic wave transducer 102, and the adhesive sheet 111 is not provided on the surface of the light source 103.

  The adhesive sheet 111 is bonded and fixed to the acoustic wave transducer 102. The pressure-sensitive adhesive sheet 111 has adhesiveness on the surface on the subject 99 side, and is pressed against the subject 99 so that it adheres to the surface of the subject 99 and is temporarily fixed. Since the surface of the subject 99 and the adhesive sheet 111 are in close contact with each other without a gap, the photoacoustic wave 122 generated inside the subject 99 is not deteriorated at the interface between the surface of the subject 99 and the adhesive sheet 111. It can be transmitted to the adhesive sheet 111 side. The adhesive sheet 111 is made of a material close to the acoustic impedance of the subject 99 and has a characteristic of transmitting a photoacoustic wave. Therefore, the ultrasonic wave 122 that reaches the surface of the adhesive sheet 111 can be transmitted to the acoustic wave transducer 102 with almost no attenuation. Therefore, without using the ultrasonic gel 110 used in the first to fifth embodiments, the photoacoustic wave 122 generated in the subject 99 can reach the acoustic wave transducer 102 with almost no attenuation.

  On the other hand, the adhesive sheet 111 is not disposed on the subject side of the light source 103. As described above, in this embodiment, it is not necessary to place the ultrasonic gel 110 between the acoustic wave transducer 102 and the subject 99. Since the acoustic wave transducer 102 is held with respect to the subject 99 via the adhesive sheet 111, there is a slight gap between the light source 103 and the subject 99. Light is irradiated from the acoustic wave probe 100 into the subject 99 through the gap. In the configuration using the ultrasonic gel, a slight attenuation occurs when the photoacoustic wave is transmitted. Therefore, in the present embodiment, the attenuation in the air gap is compared with the first to fifth embodiments using the ultrasonic gel. Can hardly irradiate light without further attenuation.

  The embodiment of FIG. 9 (b) also has the effect of being able to have a simple configuration as in the embodiment of FIG. 9 (a).

(Tenth embodiment)
The tenth embodiment relates to a configuration characterized by the form of the acoustic wave transducer 102. The rest is the same as any one of the first to ninth embodiments. FIGS. 10A and 10B are schematic and circuit diagrams for explaining the acoustic wave transducer according to the tenth embodiment. In FIG. 10A, 199 is a chip (substrate), 201 is a vibrating membrane, 202 is a first electrode, 203 is a second electrode, 204 is a support portion, and 205 is a gap (cavity). Further, 301 is a first wiring, 302 is a second wiring, 303 is a third wiring, 401 is a DC voltage generating means, and 402 is a receiving circuit.

  The present embodiment is characterized in that the acoustic wave transducer 102 is a capacitive transducer 200. The capacitance transducer is manufactured on a silicon chip 199 by using a micro electro mechanical systems (MEMS) process to which a semiconductor process is applied. The capacitive acoustic wave transducer has a much better reception frequency characteristic than the piezoelectric acoustic transducer. The vibration film 201 is supported on the chip 199 by the support unit 204 and is configured to vibrate upon receiving an acoustic wave. A first electrode 202 is disposed on the vibration film 201, and a second electrode 203 is disposed at a position on the chip 199 that faces the first electrode 202. A set of the first electrode 202 and the second electrode 203 facing each other with the vibration film 201 and the gap 205 interposed therebetween is called a cell.

  In the present embodiment, the first electrode 202 is drawn out of the chip 199 via the first wiring 301 and is connected to the DC voltage generating means 401. The DC voltage generating means 401 generates a potential difference of several tens to several hundreds of volts between the first electrode 202 and the second electrode 203. The second electrode 203 is drawn out of the chip 199 through the second wiring 302 and connected to the receiving circuit 402. When the vibration film 201 and the first electrode 202 vibrate, the distance between the first electrode 201 and the second electrode 203 changes, and the capacitance between the electrodes changes. Since there is a potential difference between the electrodes, a minute current is generated corresponding to the change in capacitance. The minute current is converted from current to voltage by the receiving circuit 402 connected to the second electrode 203 and is output from the third wiring 303 (see FIG. 10B).

  A plurality of cells are arranged on the chip 199, the first electrodes 202 on the chip 199 are electrically connected to each other, and the second electrodes 203 on the chip 199 are also electrically connected to each other. . The second electrode on the chip 199 is connected to a receiving circuit 402 that is different for each chip 199. In the ultrasonic probe of this embodiment, the same number of receiving circuits 402 as the chips 199 are provided, and independent sound receiving elements (sound receiving elements) are provided for each chip 199 in which a plurality of capacitive transducers 200 are arranged. The unit is called an element). The size of the sound receiving element is several hundred micrometers to several millimeters, and the number of sound receiving elements is one hundred to several thousand. In this embodiment, a plurality of such chips 199 are provided on the film 101 which is a support film or the support member 150 which is not deformed.

  In the present embodiment, since the capacitive transducer 200 is used as the acoustic wave transducer 102, the photoacoustic wave reception frequency region is wide, and a signal including more information can be obtained from the subject. . Therefore, coupled with the ability to efficiently and uniformly irradiate light from the light source toward the subject, it is possible to provide an acoustic wave probe with better reproducibility of the subject information.

  As a more specific form of the present embodiment, a detection circuit of the reception circuit 402 will be described with reference to FIG. This embodiment is characterized in that a transimpedance circuit configuration including an operational amplifier 411 is used for the detection circuit. A resistor 412 and a capacitor 413 are arranged in parallel in the negative feedback section of the operational amplifier 411, and convert the current input in the feedback section into a voltage. Since there is a feedback characteristic of the operational amplifier 411, the influence of the parasitic capacitance in the wiring on the input side on the current-voltage conversion efficiency can be reduced by using a broadband operational amplifier. Therefore, compared with the case where the receiving circuit 402 is disposed in the immediate vicinity of the capacitive transducer 200 (when the parasitic capacitance of the wiring is extremely small), the current-voltage conversion is less deteriorated and excellent ultrasonic reception characteristics can be obtained. Can do.

  According to the present embodiment, since the detection circuit 402 uses a transimpedance circuit configuration using the operational amplifier 411, the detection circuit 402 is hardly affected by the parasitic capacitance at the input terminal of the detection circuit 402. For this reason, when the film 101 is deformed, the position of the wiring 302 connected to the detection circuit 402 changes. In this embodiment, the reception characteristics are affected by the change in the magnitude of the parasitic capacitance of the wiring 302 associated therewith. Hateful. Thus, it is possible to provide an acoustic wave probe with little deterioration in reception characteristics.

  10-2 is characterized in that a drive detection circuit 421 is provided instead of the detection circuit. The drive detection circuit 421 not only detects the photoacoustic wave received by the capacitive transducer (CMUT) 200 as a signal, but also irradiates (transmits) ultrasonic waves from the capacitive transducer 200 toward the subject. It has a function.

  10-2, 421 is a drive detection circuit, 431 is an operational amplifier, 432 is a feedback resistor, 433 is a feedback capacitor, 434 and 435 are high breakdown voltage switches, 436 and 437 are diodes, and 438 is a high breakdown voltage diode. One or more capacitive transducers 200 are arranged on one chip, and the second electrode 203 of the capacitive transducer 200 is connected to the drive detection circuit 421. The drive detection circuit 421 has a function of applying a high voltage pulse used for transmitting ultrasonic waves from the device side to the transducer 200 and outputting a minute current from the transducer 200 to the device side as a detection signal.

  FIG. 10B is a circuit diagram for explaining the drive detection circuit 421. A feedback resistor 432 and a feedback capacitor 433 are arranged in parallel in the negative feedback section of the operational amplifier 431 and have a function of performing current-voltage conversion. High voltage switches 434 and 435 and diodes 436 and 437 are connected to the input and output terminals of the operational amplifier, respectively. The high voltage diode 438 cuts the wiring connection between the terminals when the voltage between the terminals is equal to or lower than a predetermined voltage (less than 1 volt). Further, the high breakdown voltage switches 434 and 435 cut the wiring between the input and output terminals of the switch when a voltage higher than a predetermined voltage (several volts) is applied. When a high voltage pulse for transmission is not applied, there is almost no potential difference between the terminals, so that the wiring at the input / output terminals is disconnected in the high voltage diode 438. On the other hand, since the high voltage switches 434 and 435 are not applied with a high voltage from the outside, the wiring between the switches is connected. Therefore, a minute current from the transducer can be converted into a current voltage by the operational amplifier 431, and a detection signal can be output to an externally connected device (not shown).

  On the other hand, when a high voltage pulse for transmission is applied from the device (not shown) side, the wiring inside the high voltage diode 438 is connected, and the high voltage switches 434 and 435 have a predetermined voltage (about several volts). A higher voltage is applied. Therefore, the high voltage switches 434 and 435 cut the wiring inside the switch. Thus, it is possible to prevent the operational amplifier 431 from being damaged by applying a high voltage to the operational amplifier 431. Since the signal output from the operational amplifier is cut by the high voltage switch 435, the high voltage pulse applied for transmission is not affected. Therefore, a high voltage pulse for transmitting ultrasonic waves can be applied to the second electrode 203 of the transducer.

  According to this embodiment, a capacitive transducer with a wide frequency characteristic can perform transmission in addition to reception of ultrasonic waves. Therefore, in addition to reception of photoacoustic waves, transmission / reception of ultrasonic waves to / from the subject is performed. Object information can be obtained. Therefore, coupled with the ability to efficiently and uniformly irradiate light from the light source toward the subject, it is possible to provide an acoustic probe that can obtain even more detailed subject information.

(Eleventh embodiment)
The probe of any one of the first to tenth embodiments can be used for receiving a photoacoustic wave (ultrasonic wave) using the photoacoustic effect, and can be applied to the object information acquiring apparatus of FIG. . In FIG. 11, the probe is drawn in a simplified manner. Although the film 802, the acoustic wave transducer 803, and the light source 804 are shown, other members are omitted.

  The operation of the subject information acquiring apparatus of this embodiment will be specifically described with reference to FIG. First, the light 702 (pulse light) is generated from the light source 804 (103) based on the light emission instruction signal 701 to irradiate the measurement target (subject) 800 (99) with the light 702. A photoacoustic wave (ultrasonic wave) 703 is generated in the measurement object 800 by irradiation with the light 702, and the ultrasonic wave 703 is a plurality of acoustic wave transducers arranged on the flexible film 802 (101) of the acoustic wave probe. Received at 803. An ultrasonic gel 801 is filled between the flexible film 802 and the subject 800 in order to avoid attenuation of acoustic waves (ultrasonic waves) due to bubbles.

  Information on the size, shape, and time of the received signal is sent as a photoacoustic wave received signal 704 to an image information generating device 805 that is a signal processing unit. On the other hand, the size, shape, and time information (light emission information) of the light 702 generated by the light source 804 is stored in the photoacoustic signal image information generation device 805. The photoacoustic signal image information generation device 805 generates an image signal of the measurement object 800 based on the photoacoustic wave reception signal 704 and the light emission information, and outputs it as reproduced image information 705 based on the photoacoustic signal. The image display 806 displays the measurement object 800 as an image based on the reproduced image information 705 based on the photoacoustic signal. As described above, the present embodiment has a signal processing unit for converting a signal detected by the acoustic wave probe into a signal representing information on the subject, and the signal processing unit is detected by the acoustic wave probe. The signal is converted into an image signal of the subject.

  Since the acoustic wave probe according to the present embodiment can irradiate light from the light source toward the subject more efficiently and uniformly, accurate information from the subject can be obtained, and high-quality images can be obtained. An image can be generated.

(Twelfth embodiment)
The acoustic wave probe according to any one of the first to tenth embodiments transmits ultrasonic waves to a subject and receives reflected ultrasonic waves in addition to receiving photoacoustic waves using a photoacoustic effect. You can also Such a probe can be applied to a subject information acquisition apparatus that acquires subject information based on the acquired signal. Here, the acoustic wave probe of the present invention performs reception of photoacoustic waves generated by the photoacoustic effect in the subject and transmission / reception of ultrasonic waves to the subject to acquire information on the subject.

  FIG. 12 shows a schematic diagram of a subject information acquisition apparatus according to this embodiment. In FIG. 12, 706 is an ultrasonic transmission / reception signal, 707 is a transmitted ultrasonic wave, 708 is a reflected ultrasonic wave, and 709 is reproduced image information by ultrasonic transmission / reception. In FIG. 12, the part corresponding to the support member and the like is omitted, but the probe described in any one of the first to tenth embodiments is used.

  The subject information acquisition apparatus according to the present embodiment performs pulse echo (transmission / reception of ultrasonic waves) in addition to reception of photoacoustic waves to form an image. Since reception of photoacoustic waves is the same as that in the eleventh embodiment, pulse echo (transmission / reception of ultrasonic waves) will be described here. Based on the ultrasonic transmission signal 706, ultrasonic waves 706 are output (transmitted) from the plurality of acoustic wave transducers 803 arranged on the film 802 included in the acoustic wave probe toward the measurement object 800. Inside the measurement object 800, ultrasonic waves are reflected due to the difference in intrinsic acoustic impedance of the underlying object. The reflected ultrasonic wave 708 is received by a plurality of acoustic wave transducers 803, and information on the magnitude, shape, and time of the received signal is sent to the image information generation device 805 as an ultrasonic reception signal 706. Here, an ultrasonic gel 801 is filled between the film 802 and the subject 800 in order to avoid attenuation of acoustic waves (ultrasonic waves) due to bubbles. On the other hand, the size, shape, and time information of the transmitted ultrasound is stored in the image information generation device 805 as ultrasound transmission information. The image information generation device 805 generates an image signal of the measurement object 800 based on the ultrasonic reception signal 706 and the ultrasonic transmission information, and outputs it as reproduced image information 709 for ultrasonic transmission / reception.

  The image display 806 displays the measurement object 800 as an image based on two pieces of information, that is, reproduced image information 705 using a photoacoustic signal and reproduced image information 709 using ultrasonic transmission / reception. The acoustic wave probe according to the present embodiment can irradiate the subject with light more uniformly, can accurately acquire the photoacoustic wave, and can accurately transmit and receive ultrasonic waves with the same probe. Therefore, a high-quality photoacoustic image and ultrasonic image having the same coordinate system can be generated.

  In the above embodiment, the transducer receives at least ultrasonic waves from the subject, and the processing unit can acquire information on the subject using the ultrasonic reception signals from the transducer. Here, the capacitive transducer may transmit ultrasonic waves toward the subject, but other transducers may transmit ultrasonic waves. Moreover, it is also possible to adopt a form in which only ultrasonic reception is performed without receiving photoacoustic waves. As described above, the acoustic wave probe detects the photoacoustic wave and / or ultrasonic wave from the subject, and the signal processing unit detects the object from the photoacoustic wave and / or ultrasonic signal acquired by the acoustic wave probe. A biological tissue image of a specimen can be constructed.

  For this reason, when the acoustic wave probe according to the present embodiment is used, different object information can be acquired, so that the object information can be obtained in more detail, and an object image with a large amount of information can be generated. it can. Furthermore, since it is possible to receive photoacoustic waves and transmit / receive ultrasonic waves using the same acoustic wave transducer, the object information acquired by each can be acquired as information with almost no coordinate deviation. Therefore, an image with little deviation can be displayed when the subject images are superimposed.

  99 .. Subject, 100 .. Acoustic wave probe, 101 .. Support member (support film), 102 .. Acoustic wave (ultrasonic) transducer, 103 .. Light emitting part (light source)

Claims (22)

  A plurality of light emitting units for irradiating the subject with light; and a plurality of acoustic wave transducers for detecting photoacoustic waves generated in the subject, wherein the light emitting unit is surrounded by the plurality of acoustic wave transducers. An acoustic wave probe characterized by being arranged.   The acoustic wave probe according to claim 1, wherein the light emitting unit is a light source that emits light.   The acoustic wave probe according to claim 1, wherein the plurality of acoustic wave transducers and the plurality of light emitting portions are disposed on a common support member.   4. The acoustic film according to claim 3, wherein the supporting member is a supporting film that can be deformed so that the plurality of acoustic wave transducers and the plurality of light emitting portions are movable according to the shape of the subject. Wave probe.   The acoustic wave probe according to claim 4, wherein the support film is a flexible film that can be bent and stretched.   6. The height from the surface of the support member to the surface of the light emitting part is higher than the height from the surface of the support member to the surface of the acoustic wave transducer. The acoustic wave probe according to Item.   An adhesive material is provided on the surface of the acoustic wave transducer, and a height from the surface of the support member to the surface of the adhesive material is higher than a height from the surface of the support member to the surface of the light emitting portion. The acoustic wave probe according to any one of claims 3 to 5.   The acoustic wave probe according to any one of claims 1 to 5, wherein a deformable bag containing gas is provided on the subject side of the light emitting unit.   The acoustic wave probe according to claim 1, wherein the light emitting unit is held via a spring.   The common support member that supports the plurality of acoustic wave transducers and the plurality of light emitting portions is supported by a support frame member having a recess with respect to the subject. The acoustic wave probe according to claim 1.   A first beam portion extending from the light emitting portion and a second beam extending from each of the plurality of acoustic wave transducers around the light emitting portion and rotatably connected to the first beam portion The acoustic wave probe according to claim 1, further comprising a restraining unit including a beam portion.   6. The acoustic wave probe according to claim 4, further comprising means for fixing the support film in a state in which the support film is wound around a subject.   The acoustic wave probe according to any one of claims 1 to 12, wherein the light emitting portion is thermally connected to a metal layer of a flexible substrate.   The plurality of acoustic wave transducers around the light emitting part are arranged at substantially equal distances and / or substantially equiangular intervals with the light emitting part as a center. The acoustic wave probe according to claim 1.   The acoustic wave probe according to any one of claims 1 to 14, wherein the acoustic wave transducer is a capacitive transducer.   16. The acoustic wave according to claim 15, wherein a detection circuit that includes a transimpedance circuit using an operational amplifier and detects a current when the acoustic wave transducer receives an acoustic wave is connected to the acoustic wave transducer. Wave probe.   A drive detection circuit for transmitting and receiving a signal related to an acoustic wave, including a circuit for detecting a current when the acoustic wave transducer receives an acoustic wave, is connected to the acoustic wave transducer. Item 16. The acoustic wave probe according to Item 15.   18. The acoustic wave probe according to claim 1, and a signal processing unit for converting a signal detected by the acoustic wave probe into a signal representing information on a subject. A subject information acquisition apparatus.   The object information acquiring apparatus according to claim 18, wherein the signal processing unit converts a signal detected by the acoustic wave probe into an image signal of the object.   The object information acquiring apparatus according to claim 18, wherein the acoustic wave probe detects a photoacoustic wave from the object generated by a photoacoustic effect.   21. The object information acquiring apparatus according to claim 18, wherein the acoustic wave probe detects ultrasonic waves from the object.   The object information acquiring apparatus according to claim 21, wherein the acoustic wave probe transmits and receives ultrasonic waves.

Images