JP6100322B2 - Acoustic wave measuring apparatus and acoustic wave measuring method - Google Patents

Description

  The present invention relates to an acoustic wave measuring device and an acoustic wave measuring method. In particular, the present invention relates to an acoustic wave measuring apparatus and an acoustic wave measuring method for receiving an acoustic wave generated in a subject by irradiating light.

  One of in-vivo imaging techniques using near-infrared light is photoacoustic tomography (PAT). In PAT, by irradiating a subject such as a living body with pulsed light generated from a light source, the light propagated and diffused in the subject is absorbed by a light absorber, and an acoustic wave (typically, an ultrasonic wave) is generated. To do. This mechanism of acoustic wave generation is called the photoacoustic effect. The tumor absorbs more light than the surrounding tissue because of its high absorption rate of near-infrared light energy relative to the surrounding tissue. Generate acoustic waves. The photoacoustic imaging device, which is an acoustic wave measuring device, receives this acoustic wave with an acoustic wave detection element, and analyzes the received signal to analyze the spatial initial sound pressure distribution of the acoustic wave generated in the subject. It is a device that calculates and images information. Since the distribution of the generated sound pressure is related to the light absorption coefficient, it has been studied to diagnose a subject using the distribution related to the light absorption coefficient.

An acoustic wave measuring apparatus that measures a living body using a photoacoustic effect uses a high-power short pulse (up to several tens of nanoseconds) light source having a near infrared wavelength. A near-infrared wavelength band in which light absorption by a living body is low is called a living body window, and light can reach a deep part of the living body.
In an acoustic wave measuring apparatus using PAT, it is necessary to prevent the measurer from being irradiated with light.
In particular, it is necessary to prevent the eye from being irradiated with light.
Therefore, in the apparatus shown in Non-Patent Document 1, the subject and the person to be measured are separated by a dark screen.

Srirang Manohar, Sanne E .; Vaartjes, Johan C.I. G. van Hespen, Joost M .; Klasse, Frank M. et al. van den Engh, Andy K. et al. H. The, Wiendel Steenbergen, and Ton G. van Leeuwen, “Region-of-interest breast studies using the Twenty Photoistic Mammoscope (PAM)”, Proc. of SPIE Vol 6437 643702

  In the acoustic wave measuring device, in order to efficiently receive the acoustic wave, it is desirable to detect the acoustic wave by moving the acoustic wave probe as the acoustic wave detecting means to a predetermined measurement position of the subject. Furthermore, in order to generate an acoustic wave efficiently, it is desirable that the irradiation means for irradiating light is also moved to a predetermined measurement position for irradiation. Therefore, the measurer confirms the measurement position on the subject and moves the acoustic wave probe and the irradiation means there. However, the apparatus described in Non-Patent Document 1 cannot visually check the subject because the subject and the measurer are separated from each other by the dark curtain, and it is difficult to move the irradiation unit to the measurement position with high accuracy. It has a problem. Another possible method is to open the dark curtain without irradiating light and visually move the irradiation means to the measurement position, then close the dark curtain and perform the measurement. Since it is performed every time, it is easy to forget to close the dark curtain and to generate a gap.

An acoustic wave measuring apparatus according to the present invention includes an irradiating unit that irradiates a subject with light, and an acoustic wave that receives an acoustic wave generated by irradiating the subject with light from the irradiating unit and outputs a signal. a receiving unit, a holding means for holding the object, imaging means for imaging the object held by the previous SL holding means, and moving means for moving the acoustic wave receiving means, the driving of said moving means Control means for controlling, the control means of the moving means to move the acoustic wave receiving means to a position corresponding to the measurement position specified on the image acquired by the imaging means Control the drive.
Further, an acoustic wave measuring apparatus according to another aspect of the invention receives an acoustic wave generated by irradiating the subject with light from the irradiating unit for irradiating the subject with light, and receiving a signal An acoustic wave receiving means for outputting the object, a holding means for holding the subject, an imaging means for imaging the subject held by the holding means, and a moving means for moving an irradiation region of light from the irradiation means And control means for controlling the driving of the moving means, the control means moving the irradiation region to a position corresponding to a measurement position designated on the image acquired by the imaging means. In addition, the driving of the moving means is controlled.
Further, an acoustic wave measuring apparatus according to another aspect of the invention receives an acoustic wave generated by irradiating the subject with light from the irradiating unit for irradiating the subject with light, and receiving a signal An acoustic wave receiving means for outputting the image, a holding means for holding the object, an imaging means for imaging the object held by the holding means, an irradiation area of light from the irradiation means, and the acoustic wave reception Moving means for moving the means, and control means for controlling the driving of the moving means, the control means at the position corresponding to the measurement position specified on the image acquired by the imaging means The driving of the moving means is controlled so as to move the irradiation area and the acoustic wave receiving means.

Display method of the present invention includes receiving and displaying a subject Karadaga image, and setting a measurement position of said object image, an acoustic wave generated by light irradiation to the subject And a step of displaying a photoacoustic image corresponding to the measurement position based on the signal obtained by.
The display method according to another aspect of the present invention is a display method for displaying a photoacoustic image using a signal obtained by receiving a photoacoustic wave generated due to light irradiation on a subject. A step of displaying a subject image captured using a camera which is an imaging means different from an acoustic wave probe for receiving an acoustic wave, and specifying the displayed subject image Displaying the photoacoustic image corresponding to the set position.

  According to the present invention, in an acoustic wave measuring apparatus, it is possible to designate a measurement position with high accuracy and acquire an acoustic wave at a desired position.

It is a schematic diagram which shows the outline | summary of the acoustic wave measuring apparatus of 1st embodiment. It is a schematic diagram when it sees from the camera 103 side. It is the figure which showed the flow of the measurement in 1st embodiment. It is the schematic diagram which showed the relationship between a measurement position pixel coordinate and a coordinate on a movable holding plate. It is the schematic diagram which looked at the fixed holding plate 105, the movable holding plate 104, and the camera 103 from the apparatus upper surface in 1st embodiment. It is a schematic diagram which shows the outline | summary of the acoustic wave measuring apparatus of 2nd embodiment. It is the figure which showed the flow of the measurement in 2nd embodiment. It is the schematic diagram which looked at the fixed holding | maintenance board 105, the movable holding board 104, and the camera 103 from the apparatus upper surface in 2nd embodiment.

  In the present invention, the acoustic wave includes what is called a sound wave, an ultrasonic wave, and a photoacoustic wave, and indicates an elastic wave generated by irradiating a subject with light (electromagnetic wave) such as near infrared rays.

(First embodiment)
The acoustic wave measuring apparatus according to the first embodiment includes a camera that is an imaging apparatus for imaging a breast in an apparatus configuration in which a breast is a subject and the breast is held from both sides to hold the breast. Then, the measurement position is indicated on the image obtained by the camera, and at least one of the irradiation means and the acoustic wave detection means is moved to the corresponding position on the subject.

(Device configuration)
FIG. 1 is a side view showing an outline of an acoustic wave measuring apparatus according to the first embodiment of the present invention. FIG. 1A shows a state where the irradiation unit 101 is moving outside the imaging range of the camera 103, and FIG. 1B shows a state where the irradiation unit 101 moves within the imaging range of the camera 103 and irradiates the measurement position with light. It is a schematic diagram which shows a state.

  The acoustic wave measuring apparatus to which the present invention can be applied generates light (pulse light) from a light source and irradiates the subject 111 with light through the irradiation unit 101. In the present embodiment, the housing 100 prevents light emitted to the subject 111 from leaking to the outside. A light absorber (detection target such as a tumor) in the subject 111 absorbs light energy and generates an acoustic wave. The generated acoustic wave propagates through the subject and reaches the acoustic wave probe 102 as the acoustic wave detection means via the fixed holding plate 105 as the holding means. The acoustic wave probe 102 receives an acoustic wave, converts it into an electrical signal, and outputs it to the photoacoustic arithmetic unit 110 which is a signal processing means. The photoacoustic calculation unit 110 generates (accommodates) photoacoustic image data using the input signal. Further, the camera 103 that is an imaging unit captures an image of a subject via a movable holding plate 104 that is a holding unit, and obtains image information. The measurement position designating unit 107 is used by the measurer to designate the measurement position based on the image information sent from the camera 103. The measurement position on the designated image is coordinate-converted as pixel coordinates. Is output to the unit 108. The coordinate conversion unit 108 converts the pixel coordinates output from the measurement position designating unit 107 into coordinates on the movable holding plate 104 (coordinates on the holding unit). At this time, coordinate conversion is performed using the distance between the fixed holding plate 105 and the movable holding plate 104 measured by the distance measuring device 106. The converted coordinates are output to the position control unit 109. The position control unit 109 moves at least one of the acoustic wave probe 102 and the irradiation unit 101 by controlling at least one of the acoustic wave probe driving mechanism 113 and the irradiation unit driving mechanism 112 which are moving means.

  The light source of the present invention includes at least one coherent or incoherent pulsed light source. In order to generate the photoacoustic effect, the pulse width is preferably several hundred nanoseconds or less, more preferably 5 nanoseconds to 50 nanoseconds. Moreover, when measuring breast cancer etc., the light of the specific wavelength absorbed by a specific component (for example, hemoglobin) among the components which comprise a living body is generated. A laser capable of obtaining a large output is preferable as the light source, but a light emitting diode or the like can be used instead of the laser. As the laser, various lasers such as a solid laser, a gas laser, a dye laser, and a semiconductor laser can be used.

  The irradiation unit 101 serving as an irradiation unit irradiates a subject with light from a light source by a method suitable for measurement. In this embodiment, light is irradiated from the opposite side to the acoustic wave probe 102, but the present invention is not limited to this. For example, light may be irradiated from the same side as the acoustic wave probe 102, or light may be irradiated from both sides of the subject. Since the sound pressure of the acoustic wave is proportional to the intensity of light, it is preferable to irradiate light from a plurality of surfaces as well as from a part of the subject because the signal-to-noise ratio of the signal increases. Specifically, the irradiation unit 101 is an optical component including a mirror, a lens that collects or enlarges light, or changes its shape, a prism that disperses, refracts, or reflects light, or an optical fiber. In addition to the above-described optical component, any optical component may be used as long as it can irradiate the subject with a desired method (irradiation direction, shape, etc.). In addition, it is preferable that the region where the light is irradiated on the subject is movable on the subject because the light can be irradiated over a wider range. Specifically, the irradiation unit 101 itself may be moved with respect to the subject. Further, it is more preferable that the region where the object is irradiated with light moves in synchronization with the acoustic wave probe 102. Further, when the light source is small, the light source may also be used as an irradiation unit, and the light source itself may be mechanically moved.

  The acoustic wave probe 102 which is an acoustic wave detecting means converts the acoustic wave into a reception signal which is an electric signal. The acoustic wave probe is any element that can receive an acoustic wave and convert it into an electric signal, such as a conversion element using a piezoelectric phenomenon, a conversion element using optical resonance, or a conversion element using a change in capacitance. Such a conversion element may be used. Further, it is preferable to use an element array in which a plurality of conversion elements are arranged because an acoustic wave can be received in a wide range. The acoustic wave is received by the acoustic wave probe 102, and the received signal is input to the photoacoustic calculation unit 110. Although the acoustic wave probe 102 is provided on the fixed holding plate 105 side in FIG. 1, it may be provided on the movable holding plate 104 side.

  The photoacoustic operation unit 110 that is a signal processing unit may be a program installed in a computer or an electronic circuit. The photoacoustic calculation unit 110 generates (acoustic image reconstruction) photoacoustic image data using back projection or the like in the time domain or Fourier domain normally used in tomography technology. The photoacoustic image data in the present invention indicates data indicating information inside the subject (biological information such as an initial sound pressure distribution and a light absorption coefficient distribution in the living body) regardless of two-dimensional or three-dimensional. The photoacoustic image data is configured by arranging a plurality of pixel data in the case of two dimensions, and is configured by arranging a plurality of voxel data in the case of three dimensions.

  The fixed holding plate 105 and the movable holding plate 104 which are holding means are holding means for holding the subject and keeping at least a part of the shape of the subject constant. As shown in FIG. 1, when the subject is sandwiched from both sides, the subject is fixed in position during measurement, so that a position error due to body movement or the like can be reduced. In addition, by pressing the subject, light can efficiently reach the deep part of the subject. As the holding means (movable holding plate 104 in FIG. 1) on the side where the irradiation unit 101 is provided, a member having a high light transmittance is preferably used. The holding means (fixed holding plate 105 in FIG. 1) on the side where the acoustic wave probe 102 is provided is a member having high acoustic matching (close acoustic impedance) to the subject 111 and the acoustic wave probe 102. It is preferable to use it. For the purpose of enhancing acoustic matching, an acoustic matching material such as a gel may be interposed between the holding unit and the subject 111 or between the holding unit and the acoustic wave probe 102. Further, the holding means is not limited to the above configuration, and both holding plates may be movable. Furthermore, the configuration may be such that the subject is held from below by a bowl-shaped member, instead of being clamped from both sides.

  The casing 100 has a function of preventing light irradiated to the subject 111 from leaking outside by surrounding the periphery of the irradiation unit 101, the acoustic wave probe 102, and the like. This prevents light from being irradiated to the measurer. Moreover, the housing | casing 100 of this embodiment also has the function to mount a test subject.

  A camera 103 serving as an imaging unit is installed inside the housing 100 and acquires image information of the subject 111. As the camera 103, a CCD camera, a CMOS camera, or the like can be used. The camera 103 of this embodiment is fixed to the housing 100. When the camera 103 images the subject, the irradiation unit 101 is preferably moved outside the imaging region so as not to overlap the subject. In FIG. 1, the camera 103 is provided on the movable holding plate 104 side, but may be provided on the fixed holding plate 105 side.

  The irradiation unit drive mechanism 112 that is a moving unit can move the irradiation unit 101 to an arbitrary position within the imaging region of the camera 103 or move the irradiation unit 101 outside the imaging region of the camera 103.

FIG. 2 is a schematic diagram when the apparatus is viewed from the camera 103 side. 2A is a schematic diagram illustrating a case where the irradiation unit 101 is moved outside the imaging region of the camera 103, and FIG. 2B is a schematic diagram illustrating a case where the irradiation unit 101 is moved within the imaging region of the camera 103. is there. The irradiation unit driving mechanism 112 has a mechanism for driving the irradiation unit 101 independently in the horizontal direction and the vertical direction. A motor and a rack and pinion, a motor and a belt, a linear motor, etc. can be used for the mechanism to drive.
The irradiation unit driving mechanism 112 has an origin sensor 201. The position of the origin sensor 201 is designed so that the position of the irradiation unit 101 defined by the origin sensor 201 is outside the imaging area of the camera 103. As the origin sensor, a contact sensor, an optical sensor, an origin encoder of an absolute encoder, or the like can be used. The irradiation unit driving mechanism 112 is controlled by the position control unit 109. In order to move the irradiation unit 101 outside the imaging region of the camera 103, a command for moving the irradiation unit 101 to the origin position is sent from the position control unit 109 to the irradiation unit drive mechanism 112. As a result, the state shown in FIG. 1A is realized by moving the irradiation unit 101 outside the imaging region of the camera 103 as shown in FIG. In order to move the irradiation unit 101 into the imaging region of the camera 103, a command for moving the irradiation unit 101 to a position in the imaging region is sent from the position control unit 109 to the irradiation unit drive mechanism 112. Thus, the state shown in FIG. 1B is realized by moving the irradiation unit 101 into the imaging region of the camera 103 as shown in FIG.

  The acoustic probe driving mechanism 113 that is a moving means may move the acoustic probe 102 to a position facing the irradiation unit 101 with the subject interposed therebetween. The acoustic probe driving mechanism 113 is controlled by the position control unit 109. When the camera 103 is provided on the acoustic wave probe 102 side, the same movement as the irradiation unit 101 described above may be performed so that the subject and the acoustic wave probe 102 do not overlap during imaging.

  A distance measuring device 106 serving as a distance measuring unit measures the distance between the fixed holding plate 105 and the movable holding plate 104. The distance here is a distance in the optical axis direction of the camera 103. One end of the distance measuring device 106 is fixed to the fixed holding plate 105, and the other end is fixed to the movable holding plate 104. A distance that differs depending on the characteristics (size, etc.) of each subject 111 is output to the coordinate conversion unit 108.

  The measurement position specifying unit 107 is used by the measurer to specify the measurement position on the image acquired by the camera 103. Specifically, an image is displayed on a display unit such as a monitor using image information from a camera, and a measurement position on the displayed image is designated with a mouse, or measurement on a screen having a contact type position detection sensor. Specify the position with your finger. Alternatively, the coordinates of the measurement position on the image may be input and specified using a keyboard or the like. The designated measurement position is output to the coordinate conversion unit 108 as pixel coordinates on the image.

  The coordinate conversion unit 108 converts the pixel coordinates output from the measurement position designating unit 107 into coordinates at a position corresponding to the pixel coordinates on the holding unit (on the movable holding plate 104 in the present embodiment). At this time, conversion is performed using the distance between the fixed holding plate and the movable holding plate measured by the distance measuring device 106. The converted coordinates are output to the position control unit 109.

  The position control unit 109 controls the acoustic wave probe driving mechanism 113 and the irradiation unit driving mechanism 112 to move at least one of the acoustic wave probe 102 and the irradiation unit 101. For example, the irradiation unit 101 can be moved to the position of the coordinates output from the coordinate conversion unit 108 or can be moved to the origin position defined by the origin sensor 201.

(Measurement flow)
The measurement flow of this embodiment is shown in FIG. Each step of the measurement flow will be described in detail with reference to FIGS. In the following description, as shown in FIG. 1, it has a holding means composed of a fixed holding means and a movable holding means, an acoustic probe 102 is provided on the fixed holding means side, and an irradiation unit 101 is provided on the movable holding means side. An example of providing the above will be described. However, as described above, the present invention is not limited to such a form.

  First, when measurement is started (step 301), the subject is inserted between the fixed holding plate 105 and the movable holding plate 104, and in step 302, the measurer moves the movable holding plate 104 to hold the subject 111. At this time, it is desirable to keep the subject 111 as thin as possible in terms of the SN ratio of the received signal and the measurement depth. When the holding is completed, the distance measuring device 106 measures the distance between the fixed holding plate 105 and the movable holding plate 104.

  In step 303, the irradiation unit 101 is moved to the origin position. The irradiation unit driving mechanism 112 is driven by the position control unit 109, and the irradiation unit 101 moves to the origin position.

In step 304 (imaging step), the subject 111 is imaged by the camera 103.
In step 303, the irradiation unit 101 has moved to the origin position outside the imaging area of the camera 103, so that the entire subject 111 including the measurement position can be imaged.

  In step 305, based on the image information of the subject 111 obtained in step 304, the measurer designates the measurement position on the image with pixel coordinates, and the measurement position pixel coordinates are obtained.

  The process in step 306 (coordinate conversion step) will be described with reference to FIGS. FIG. 4 is a schematic diagram showing the relationship between the pixel coordinates on the image and the coordinates on the movable holding plate. The coordinate conversion unit 108 converts the pixel coordinates (Xm, Ym) of the measurement position designated by the measurer in Step 305 into the measurement position coordinates (xm, ym) on the movable holding plate. The measurement position coordinates on the movable holding plate are indicated by values in units of millimeters or micrometers, for example. Next, the conversion formula will be described. FIG. 5 is a schematic view of the fixed holding plate 105, the movable holding plate 104, and the camera 103 as viewed from the top of the apparatus. The movable holding plate 104 can take an arbitrary distance L. Reference numerals 501 and 502 denote the positions of the movable holding plate when L = L1 and L = L2, respectively. The imaging width of the camera 103 at a certain distance L is represented by W (L). As can be seen from FIG. 5, the imaging width W varies depending on the position of the movable holding plate. The distance between the movable holding plate and the camera 103 when L = L1 is represented by Dis. Dis is expressed by the following equation (1) from the relation of an isosceles triangle having the angle of view in FIG. 5 as the apex angle.

図４で示される座標関係から、測定位置ピクセル座標を可動保持板上測定位置座標に変換する変換式は、式（１）のＤｉｓを用いて、

From the coordinate relationship shown in FIG. 4, the conversion formula for converting the measurement position pixel coordinate to the measurement position coordinate on the movable holding plate is expressed by using Dis of the formula (1)

で表される。式（２）によりピクセル座標Ｘｍがｘｍに変換されることを以下に説明する。図４において、Ｘは水平ピクセル座標軸、Ｙは垂直ピクセル座標軸、Ｘｍは測定位置水平ピクセル座標、Ｙｍは測定位置垂直ピクセル座標、Ｘｗは撮像領域端水平ピクセル座標、Ｙｗは撮像領域端垂直ピクセル座標である。また、ｘは可動保持板上水平座標軸、ｙは可動保持板上垂直座標軸、ｘｍは測定位置水平座標、ｙｍは測定位置垂直座標、ｘｃは撮像領域中心の水平座標、ｙｃは撮像領域中心の垂直座標である。

It is represented by It will be described below that the pixel coordinates Xm are converted to xm by Expression (2). In FIG. 4, X is a horizontal pixel coordinate axis, Y is a vertical pixel coordinate axis, Xm is a measurement position horizontal pixel coordinate, Ym is a measurement position vertical pixel coordinate, Xw is an imaging region end horizontal pixel coordinate, and Yw is an imaging region end vertical pixel coordinate. is there. Also, x is a horizontal coordinate axis on the movable holding plate, y is a vertical coordinate axis on the movable holding plate, xm is a horizontal coordinate at the measurement position, ym is a vertical coordinate at the measurement position, xc is a horizontal coordinate at the center of the imaging region, and yc is a vertical coordinate at the center of the imaging region. Coordinates.

  In formula (2),

は、カメラ１０３と測定位置との距離により決定される変換係数である。式（３）は、任意のＬにおける撮像幅Ｗ（Ｌ）を示す。式（３）で示される撮像幅Ｗ（Ｌ）を図４の撮像領域端水平ピクセル座標ＸＷで割ることにより、１ピクセルあたりの可動保持板上座標量である

Is a conversion coefficient determined by the distance between the camera 103 and the measurement position. Expression (3) represents an imaging width W (L) at an arbitrary L. By dividing the imaging width W (L) represented by the expression (3) by the horizontal pixel coordinate XW of the imaging region end in FIG. 4, the coordinate amount on the movable holding plate per pixel is obtained.

が得られる。式（４）を、式（２）中の画像中心からＸｍまでのピクセル量である

Is obtained. Expression (4) is the pixel amount from the image center in Expression (2) to Xm.

にかけることにより、可動保持板上座標量である

Is the coordinate amount on the movable holding plate

を得る。式（６）のｘｃを左辺に移項することで式（２）のｘｍを得る。以上は水平方向について説明したが、垂直方向、すなわちＹｍからｙｍへの変換も同じ原理である。

Get. Xm in Expression (2) is obtained by moving xc in Expression (6) to the left side. The horizontal direction has been described above, but the vertical direction, that is, the conversion from Ym to ym is based on the same principle.

  L1, L2, W (L1), and W (L2) are known values that are measured in advance, and xc, xc, Xw, and Yw are obtained in advance as specifications of the apparatus. The distance between the fixed holding plate 105 and the movable holding plate 104 measured in step 302 is substituted into L in equation (2), and the measurement position pixel coordinates obtained in step 305 are (Xm, Ym) in equation (2). By substituting into, the measurement position coordinates (xm, ym) on the movable holding plate can be obtained. Even if the distance between the movable holding plate 104 and the camera 103 changes, the relationship between the pixel coordinates and the measurement position coordinates on the movable holding plate is correctly corrected by performing Step 306.

  In step 307 (position control step), the irradiation unit 101 is moved to the measurement position coordinates on the movable holding plate obtained in step 306 by the position control unit 109. In step 306, the conversion is performed in consideration of the distance between the fixed holding plate 105 and the movable holding plate 104, so that the movement can be performed with high accuracy. In this step, it is preferable to move not only the irradiation unit 101 but also the acoustic wave probe 102 to the coordinates (xm, ym) of the measurement position on the fixed holding plate. Here, the measurement position is a position on the subject to be measured in detail, or a start position when measurement is performed while moving the acoustic wave probe 102 or the irradiation unit 101.

  In step 308, the object is irradiated with light from the irradiation unit 101, and the generated acoustic wave is detected by the acoustic probe 102 to obtain a reception signal. In step 309, photoacoustic image data is generated by the photoacoustic calculation unit 110 using the reception signal obtained in step 308. The photoacoustic image data is presented to the measurer by being displayed on a display unit (not shown) as numerical information or an image, for example, and the measurement is terminated (step 309).

  As described above, even in an acoustic wave measuring device in which it is difficult to visually specify a measurement position, the measurement position can be specified by providing the camera 103. Furthermore, by providing the irradiation unit drive mechanism 112 that moves the irradiation unit 101 outside the imaging region of the camera 103 and the distance measuring device 106, it is possible to specify the measurement position with high accuracy.

(Second embodiment)
In the second embodiment, a case will be described in which a mechanism for maintaining a constant distance between an imaging unit that images a subject and a movable holding unit is provided. Other configurations are the same as those in the first embodiment.

(Device configuration)
FIG. 6 is a schematic diagram showing an outline of an acoustic wave measuring apparatus according to the second embodiment of the present invention. In the present embodiment, the processing content in the coordinate conversion unit is different from that in the first embodiment, but the other components are the same as those in the first embodiment, and therefore the description of the same terms is omitted.

A fixing tool 801 serving as a distance fixing unit fixes the movable holding plate 104 and the camera 103.
The fixture 801 is designed to fix the distance between the movable holding plate 104 and the camera 103 to a certain value. For this reason, even if the movable holding plate 104 moves, the distance from the camera 103 is kept constant. The fixture 801 is preferably arranged so as not to enter the imaging region of the camera 103. The coordinate conversion unit 108 converts the pixel coordinates output from the measurement position specifying unit 107 into coordinates on the movable holding plate 104. At this time, the conversion is performed using a distance determined by the fixture 801. The converted coordinates are output to the position control unit 109.

(Measurement flow)
The measurement flow of this embodiment is shown in FIG. The coordinate conversion step (step 906) of this embodiment is different from step 306 of the first embodiment, but the other steps are the same as in FIG.

  The process in step 906 will be described with reference to FIG. FIG. 8 is a schematic view of the fixed holding plate 105, the movable holding plate 104, and the camera 103 as viewed from the top of the apparatus. Reference numerals 1001 and 1002 denote positions of the camera 103 when the distance between the fixed holding plate 105 and the movable holding plate 104 is L1 and L2, respectively. Since the distance Dis0 between the movable holding plate 104 and the camera 103 is constant by the fixture 801, the imaging width W of the camera 103 is a value determined by Dis0 in both the distances L1 and L2. 4 and 8, the conversion formula for converting the measurement position pixel coordinates into the measurement position coordinates on the movable holding plate is expressed by the following formula (3).

式（７）中のＷ（Ｄｉｓ０）は撮像手段と測定位置との距離により決定される変換係数である。Ｄｉｓ０は固定具８０１により決定される装置の緒元値なので、変換係数Ｗ（Ｄｉｓ０）は予め得られている。ステップ３０５で得られた測定位置ピクセル座標を式（３）の（Ｘｍ、Ｙｍ）に代入することで、可動保持板上測定位置座標（ｘｍ、ｙｍ）を得る事ができる。

W (Dis0) in equation (7) is a conversion coefficient determined by the distance between the imaging means and the measurement position. Since Dis0 is a specification value of the apparatus determined by the fixture 801, the conversion coefficient W (Dis0) is obtained in advance. The measurement position coordinate (xm, ym) on the movable holding plate can be obtained by substituting the measurement position pixel coordinate obtained in step 305 into (Xm, Ym) of Expression (3).

  As described above, the measurement position can be specified by providing the camera 103 even in the acoustic wave measurement apparatus in which it is difficult to specify the measurement position visually. Further, by providing the fixture 801, the distance between the movable holding plate 104 and the camera 103 does not change even if the thickness of the object to be clamped changes, so that the processing in the coordinate conversion step is simplified.

DESCRIPTION OF SYMBOLS 100 Case 101 Irradiation part 102 Acoustic wave probe 103 Camera 104 Movable holding plate 105 Fixed holding plate 106 Distance measuring device 107 Measurement position designation part 108 Coordinate conversion part 109 Position control part 112 Irradiation part drive mechanism 113 Acoustic wave probe Drive mechanism

Claims (58)

Irradiating means for irradiating the subject with light;
An acoustic wave receiving means for receiving an acoustic wave generated by irradiating the subject with light from the irradiating means and outputting a signal;
Imaging means for imaging the holding means, the subject held by the previous SL holding means for holding the object,
Moving means for moving the acoustic wave receiving means;
Control means for controlling the driving of the moving means;
Have
The control means controls the drive of the moving means so as to move the acoustic wave receiving means to a position corresponding to a measurement position designated on an image acquired by the imaging means. Wave measuring device. Irradiating means for irradiating the subject with light;
An acoustic wave receiving means for receiving an acoustic wave generated by irradiating the subject with light from the irradiating means and outputting a signal;
Imaging means for imaging the holding means, the subject held by the previous SL holding means for holding the object,
Moving means for moving an irradiation area of light from the irradiation means ;
Control means for controlling the driving of the moving means;
Have
The control means controls the drive of the moving means so as to move the irradiation region to a position corresponding to a measurement position designated on an image acquired by the imaging means. apparatus. Irradiating means for irradiating the subject with light;
An acoustic wave receiving means for receiving an acoustic wave generated by irradiating the subject with light from the irradiating means and outputting a signal;
Imaging means for imaging the holding means, the subject held by the previous SL holding means for holding the object,
A moving means for moving an irradiation region of the light from the irradiation means and the acoustic wave receiving means;
Control means for controlling the driving of the moving means;
Have
The control means controls driving of the moving means so as to move the irradiation area and the acoustic wave receiving means to a position corresponding to a measurement position designated on the image acquired by the imaging means. A characteristic acoustic wave measuring device. The acoustic wave measuring apparatus according to claim 2, wherein the moving unit moves the irradiation region by moving the irradiation unit. 5. The apparatus according to claim 1, further comprising a position specifying unit configured to allow a measurer to specify the measurement position on the image acquired by the imaging unit. The acoustic wave measuring apparatus as described. The acoustic wave measuring device according to claim 5, wherein the position specifying means is at least one of a mouse, a keyboard, and a contact-type position detection sensor. With a housing,
The irradiation means is disposed inside the housing,
The casing prevents light irradiated by the irradiation means from leaking outside the casing.
Acoustic wave measuring apparatus according to any one of claims 1, wherein the this 6. The acoustic wave measuring device according to claim 7 , wherein the casing surrounds at least the periphery of the irradiation unit. The imaging means is disposed inside the housing.
The acoustic wave measuring device according to claim 7 or 8, characterized in that. The casing is configured so that the subject can be placed inside the casing.
The acoustic wave measuring apparatus according to any one of claims 7 to 9, wherein The housing includes an opening configured to be able to insert the subject.
The acoustic wave measuring apparatus according to any one of claims 7 to 10, wherein The imaging means is an acoustic wave measuring apparatus according to any one of claims 1 to 11, characterized in that imaging the illumination means and the said subject as the subject does not overlap. The imaging means is an acoustic wave measuring apparatus according to any one of claims 1 to 12, characterized in that the said acoustic wave receiving means and the object for imaging the object so as not to overlap. It said moving means, said as the imaging means do not overlap with the irradiation unit and the subject to the subject can be imaged, either of claims 1 to 13, characterized in that for moving the irradiation unit The acoustic wave measuring apparatus of Claim 1. The said moving means moves the said acoustic wave receiving means so that the said imaging means can image the said test object so that the said acoustic wave receiving means and the said test object do not overlap. The acoustic wave measuring device according to any one of 1 to 14 . It said moving means, acoustic wave measuring apparatus according to any one of claims 1 to 15, characterized in that moving the acoustic wave receiving means in two dimensions. It said moving means, acoustic wave measuring apparatus according to any one of claims 1 to 16, characterized in that for moving the irradiation unit in two dimensions. The acoustic wave measuring apparatus according to any one of claims 1 to 17 , wherein the moving unit moves the irradiation unit and the acoustic wave receiving unit in synchronization. The acoustic wave measuring apparatus according to any one of claims 1 to 18 , wherein the imaging unit includes a camera that images an outer shape of a subject. The acoustic imaging apparatus according to any one of claims 1 to 19 , wherein the imaging unit includes a CCD camera or a CMOS camera. The acoustic wave measuring apparatus according to any one of claims 1 to 20 , wherein the irradiating unit irradiates the subject with light from the same side as the acoustic wave receiving unit. The acoustic wave measuring device according to any one of claims 1 to 21 , wherein the irradiation unit includes an optical fiber. The acoustic wave measuring device according to any one of claims 1 to 22 , wherein the acoustic wave receiving unit includes a conversion element using a change in capacitance. The acoustic wave measuring apparatus according to any one of claims 1 to 23 , wherein the holding unit holds the subject from below. The acoustic wave measuring device according to any one of claims 1 to 24 , wherein the holding means is a bowl-shaped member. The acoustic wave measuring device according to any one of claims 1 to 23 , wherein the holding unit is two holding units configured to sandwich the subject. The acoustic wave measuring device according to claim 26 , wherein the two holding parts are configured by a fixed holding part and a movable holding part. The acoustic wave measuring device according to any one of claims 1 to 27, further comprising arithmetic means for generating photoacoustic image data using a signal output from the acoustic wave receiving means. The acoustic wave measuring device according to claim 28 , wherein the arithmetic means generates the photoacoustic image data by reconstructing an image using the signal. The acoustic wave measuring device according to claim 28 or 29 , further comprising display means for displaying information based on the photoacoustic image data. The acoustic wave measuring device according to any one of claims 28 to 30 , wherein the calculation unit generates the two-dimensional or three-dimensional photoacoustic image data. The acoustic wave measurement apparatus according to any one of claims 1 to 31 , wherein the irradiation unit includes a laser that emits light irradiated to the subject . The acoustic wave measuring device according to any one of claims 1 to 32 , wherein the irradiation unit includes a light emitting diode that emits light irradiated to the subject . It said illumination means, an acoustic wave measuring apparatus according to any one of claims 1 to 33, characterized in that irradiating the object with pulse light as the light. And displaying the test Karadaga image,
Setting a measurement position in the subject image;
Displaying a photoacoustic image corresponding to the measurement position based on a signal obtained by receiving an acoustic wave generated by irradiating the subject with light; and
A display method characterized by comprising: Wherein in the step of displaying the test Karadaga image, and displays the subject Karadaga image obtained by imaging the subject held by the hold means,
In the step of displaying a photoacoustic image corresponding to the measurement position, based on the signal obtained by receiving the acoustic wave light to the subject held is generated by being irradiated by said holding means, The display method according to claim 35 , wherein the photoacoustic image corresponding to the measurement position is displayed. It said subject Karadaga image display method according to claim 35 or 36, characterized in that said an image representing the outline of the subject. The subject image is an image captured using a camera which is an imaging means different from an acoustic wave probe for receiving an acoustic wave.
The display method according to any one of claims 35 to 37, wherein: The subject image is an image captured using a CCD camera or a CMOS camera.
The display method according to any one of claims 35 to 38, wherein: In the step of displaying a photoacoustic image corresponding to the measurement position, it corresponds to the measurement position based on a signal obtained by receiving an acoustic wave generated by irradiating the position corresponding to the measurement position with light. To display the photoacoustic image
40. A display method according to any one of claims 35 to 39, wherein: In the step of displaying a photoacoustic image corresponding to the measurement position, based on a signal obtained by receiving an acoustic wave generated by irradiating the subject with light at a position corresponding to the measurement position, A photoacoustic image corresponding to the measurement position is displayed.
The display method according to any one of claims 35 to 40, wherein: The step of displaying the photoacoustic image is a step of generating photoacoustic image data by reconstructing an image using a signal obtained by receiving an acoustic wave generated by irradiating the subject with light. And displaying the photoacoustic image corresponding to the measurement position based on the photoacoustic image data
The display method according to any one of claims 35 to 41, wherein: In the step of generating the photoacoustic image data, the two-dimensional or three-dimensional photoacoustic image data is generated.
The display method according to claim 42, wherein: In the step of setting the measurement position, the measurement position designated for the displayed subject image is set.
44. The display method according to any one of claims 35 to 43, wherein: In the step of setting the measurement position, the measurement position is set based on designation of a measurer using at least one of a mouse, a keyboard, and a contact-type position detection sensor for the displayed subject image. Ru
45. The display method according to claim 44. A display method for displaying a photoacoustic image using a signal obtained by receiving a photoacoustic wave generated due to light irradiation on a subject,
Displaying a subject image imaged using a camera that is an imaging means different from an acoustic wave probe for receiving an acoustic wave;
Displaying the photoacoustic image corresponding to a specified position with respect to the displayed subject image;
Have
A display method characterized by that. The subject image is an image representing an outer shape of the subject.
The display method according to claim 46, wherein: The subject image is an image captured using a CCD camera or a CMOS camera.
48. The display method according to claim 46 or 47, wherein: In the step of displaying the photoacoustic image, the position corresponding to the designated position is based on a signal obtained by receiving an acoustic wave generated by irradiating light to a position corresponding to the designated position. Display the photoacoustic image
49. A display method according to any one of claims 46 to 48, wherein: In the step of displaying the photoacoustic image, the acoustic wave generated when the subject is irradiated with light is designated based on a signal obtained by receiving the acoustic wave at a position corresponding to the designated position. Display the photoacoustic image corresponding to the position
The display method according to any one of claims 46 to 49, wherein: The step of displaying the photoacoustic image is a step of generating photoacoustic image data by reconstructing an image using a signal obtained by receiving an acoustic wave generated by irradiating the subject with light. The photoacoustic image corresponding to the designated position is displayed based on the photoacoustic image data
52. The display method according to any one of claims 46 to 51, wherein: In the step of generating the photoacoustic image data, the two-dimensional or three-dimensional photoacoustic image data is generated.
52. The display method according to claim 51, wherein: In the step of displaying the photoacoustic image, the photoacoustic corresponding to the position designated by using at least one of a mouse, a keyboard, and a contact-type position detection sensor for the displayed subject image. Display images
53. A display method according to any one of claims 46 to 52, wherein: In the step of displaying the subject image, the subject image obtained by imaging the subject held by a holding unit is displayed.
In the step of displaying the photoacoustic image, based on a signal obtained by receiving an acoustic wave generated by irradiating light onto the subject held by the holding unit, the photoacoustic image is displayed at the designated position. Display the corresponding photoacoustic image
54. The display method according to any one of claims 46 to 53, wherein: The holding means holds the subject from below.
55. A display method according to claim 36 or 54. The holding means is a bowl-shaped member.
55. A display method according to claim 36 or 54. The holding means is two holding units configured to sandwich the subject.
55. A display method according to claim 36 or 54. The two holding parts are composed of a fixed holding part and a movable holding part.
58. A display method according to claim 57.

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