JP5864904B2 - Biological information acquisition device - Google Patents

Description

  The present invention relates to a biological information acquisition apparatus that irradiates a subject with illumination light and images ultrasonic waves emitted from the subject.

  As a method for specifically imaging angiogenesis caused by cancer, photoacoustic tomography (hereinafter referred to as PAT) is drawing attention. PAT is a technique that illuminates a subject with illumination light (near infrared rays), receives a photoacoustic wave emitted from the inside of the subject with an ultrasonic probe, and forms an image. A schematic diagram of the photoacoustic apparatus described in Non-Patent Document 1 is shown in FIG. In FIG. 9, a photoacoustic probe 101 includes a probe 102 composed of 128 elements (vibrators) that receive photoacoustic waves emitted from a subject, and an illumination optical system for irradiating the subject with illumination light. 105. The ultrasonic apparatus 100 is a reception 32-channel system, and the processing apparatus 106 images the photoacoustic signal received by the probe 102. At that time, illumination light is emitted from the laser light source 104 based on a trigger signal from the function generator, and a photoacoustic signal is acquired by the probe 102 in synchronization with the illumination light.

S. Park et al. , Beamforming for photoacoustic imaging using linear array transducer, 2007 IEEE Ultrasonics Symposium, 2007.

  However, the conventional techniques have the following problems.

  In Non-Patent Document 1, a PAT image and an ultrasonic image are acquired using a reception 32-channel ultrasonic device 100 and a 128-element linear probe (probe 102). That is, information is obtained from 32 elements at a time, and an image is acquired based on this information. As described above, when acquiring the PAT image, the number of channels that can be received at one time is smaller than the number of elements of the probe 102, and thus the aperture of the acquired image of the PAT is narrowed. If it does so, when it image-forms, the width | variety of the acquired image will become narrow. On the other hand, increasing the number of channels (number of elements) that can be received at one time in order to widen the aperture of the acquired image of the PAT increases the circuit scale of the processing device 106.

  In addition, although the number of elements that can be received at one time is 32 channels (32 elements), the illumination light is irradiated to the width corresponding to the total number of elements adjacent to the probe 102 (128 elements), so it does not contribute to reception. Illumination light with a width of 96 elements is wasted. The initial sound pressure p of photoacoustics can be expressed by p = Γμaφ (Γ: Gruneisen coefficient, μa: absorption coefficient, φ: light quantity). Therefore, with the same illumination light dose, the initial sound pressure of photoacoustic when the entire width (128 elements) adjacent to the probe 102 is irradiated and the photoacoustic when irradiated to the opening width of 32 elements are irradiated. There is a fourfold difference from the initial sound pressure. This is because, in the former case, the amount of light φ to the tissue (absorber) inside the subject is approximately ¼, and the initial sound pressure p emitted from that portion is approximately ¼. To do. Therefore, the signal intensity that can be received by the probe 102 decreases. On the other hand, it is possible to improve the initial sound pressure of the photoacoustic signal even when the light source 104 having a large total amount of emitted light (total light amount) is applied. Difficulties arise.

  The present invention has been invented in view of such problems of the background art.

  An object of the present invention is to increase the intensity of a photoacoustic signal without increasing the circuit scale for performing photoacoustic signal reception processing and without increasing the output of a light source, thereby improving the SNR (signal noise ratio). It is to improve.

The present invention for solving the above-mentioned problems is a light irradiation means comprising a light source and an emission end that emits light emitted from the light source toward the subject;
An irradiation control means for controlling the irradiation of the light emitted from the emission end of the light irradiation means to the subject; and
A probe comprising a plurality of transducers for receiving an acoustic wave generated by the subject in response to light irradiation from the light irradiation means and outputting an electrical signal;
Receiving means for receiving the electrical signal from some of the plurality of transducers included in the probe;
A biological information acquisition apparatus having probe control means for switching a part of the transducers that output electrical signals received by the reception unit to another part of the transducers;
The irradiation control means maintains the total light amount of the light emitted from the light source by the light emitted from the irradiation end, and the size of the irradiation region of the light on the subject is larger than the size of the probe. The position of the emission end relative to the subject is controlled so that the irradiation area corresponds to the position of the partial transducer.

  According to the present invention, the SNR is improved without increasing the scale of the receiving means and without increasing the output of the light source.

It is a figure explaining the apparatus structure of Example 1 of this invention. It is a figure explaining the switching method of Example 1 of this invention. It is a figure explaining the structure of the switching apparatus of Example 1 of this invention. It is a figure explaining the other structure of the switching apparatus of Example 1 of this invention. It is a figure explaining the apparatus structure of Example 2 of this invention. It is a figure explaining the switching method and structure of Example 2 of this invention. It is a figure explaining the other structure of the switching apparatus of Example 2 of this invention. It is a figure explaining the apparatus structure of Example 3 of this invention. It is a figure explaining background art.

  This embodiment will be described with reference to the drawings. FIG. 1 schematically shows a photoacoustic apparatus 100 which is a handheld biological information acquisition apparatus. The photoacoustic apparatus 100, which is a biological information acquisition apparatus, includes a light irradiation unit, an irradiation control unit that controls light emitted from the light irradiation unit, and a plurality of acoustic waves that are emitted from the subject upon receiving the light irradiation. A combination of a probe including a transducer, a receiving unit that receives an electrical signal generated by the transducer included in the probe, and a transducer that outputs an electrical signal among a plurality of transducers included in the probe is switched. Probe control means. Each will be described in detail below.

  The light irradiation means includes a light source 4 that emits illumination light, and an emission end 3a that is an emission end that emits light emitted from the light source 4 toward a subject (not shown). In the present embodiment shown in FIG. 1, the emission end portion is the end portion 3 a of the bundle fiber 3. In FIG. 1, as a preferred embodiment, an illumination optical system 5 is interposed between the light source 4 and the exit end 3a which is the exit end.

  The irradiation control means controls the irradiation of the light emitted from the emission end of the light irradiation means to the subject. In the present embodiment shown in FIG. 1, the irradiation control means controls the switching device 8. It is comprised with the control apparatus 6a. The switching device 8 is provided between the light source 4 and the illumination optical system 5, and switches the light emitted from the light source 4 from entering the illumination optical system 5. The operation of the switching device 8 is performed based on the switching information from the control device 6a.

  The probe 2 includes a plurality of vibrators 2a (see FIG. 2A described later), and the vibrator 2a is irradiated with light from the emission end 3a which is the emission end of the light irradiation means. And receiving an acoustic wave emitted from the subject and outputting an electronic signal. In the present invention, the relationship between the probe 2 or the vibrator 2a included in the probe 2 and the emission end 3a which is the emission end described above is one of the features. The probe 2 and the emitting end 3a may be collectively referred to as the photoacoustic probe 1 in some cases.

  The processing device 6 which is a receiving means receives an electrical signal from a part of the transducers 2a among the plurality of transducers 2a provided in the probe 2. In the present embodiment, as a more preferable form, the processing device 6 serving as a receiving unit amplifies, digitally converts, or regenerates an electrical signal based on an acoustic wave received by the transducer 2a included in the probe 2. Various processes such as a configuration process are performed, and image information is displayed on the monitor 7.

  The probe control means switches a part of the vibrator that outputs an electric signal received by the receiving means to another part of the vibrator. In the present embodiment shown in FIG. 6a. That is, in the present embodiment shown in FIG. 1, the control device 6a serves as both a part of the irradiation control means and the probe control means.

  In the present embodiment, the switching device 8 that is the irradiation control means and the control device 6a that controls the switching device 8 are such that the light emitted from the emission end 3a that is the irradiation end is the total amount of light emitted by the light source 4. In this manner, the size of the region irradiated with light on the subject (not shown) is controlled to be smaller than the size of the probe 2. Further, the position of the emission end 3a, which is the emission end, with respect to the subject is controlled so that the irradiation region corresponds to the position of a part of the transducers that output the electrical signal received by the receiving means. Here, the irradiation region of light on the subject is equivalent to the area of the emission end 3a.

  As described above, in the present embodiment, the receiving means receives an electrical signal from a part of the vibrators 2a of the plurality of vibrators 2a provided in the probe 2, so that the receiving means Biological information can be acquired without increasing the circuit scale.

  Further, the probe control means switches some of the transducers 2a that output the electrical signals received by the receiving means to other partial transducers 2a. Further, the irradiation control means maintains the total amount of light emitted from the light source 4 by the light emitted from the irradiation end. Further, the irradiation control means corresponds to a position of a part of the transducer that outputs an electrical signal received by the receiving means, and the size of the light irradiation area to the subject is smaller than the size of the probe 2. In addition, the position of the emission end relative to the subject is controlled. As a result, the sound pressure of the photoacoustic wave can be increased without increasing the output of the light source 4, and as a result, the SNR can be improved. Then, it is possible to acquire an acoustic wave that fully utilizes the size of the probe 2.

  Hereinafter, the present invention will be described in detail with reference to examples.

  In Example 1, a handheld photoacoustic apparatus will be described with reference to FIG. The photoacoustic probe 1 includes a probe 2 that receives a photoacoustic wave emitted from a subject, and an irradiation end that irradiates the subject with illumination light including near infrared rays. As an example, the probe 2 is a linear probe, and a plurality of bundle fibers 3 are provided up to the irradiation end. The probe 2 includes a plurality of transducers 2a that receive photoacoustic waves and output electrical signals (see FIG. 2A). Although FIG. 1 does not show the illumination optical system from the exit end 3a of the bundle fiber to the subject, the subject may be irradiated directly from the exit end 3a of the bundle fiber, or an arbitrary optical system such as a diffusion plate may be used. It may be provided. Further, the illumination light is routed to the subject without using the bundle fiber 3 and is effective in the air propagation by a combination of mirrors provided in the light shielding cylinder. Furthermore, although the output end 3a of the bundle fiber is illustrated only on one side of the probe 2, the present invention is not limited to this, and the bundle fiber may be provided so as to be sandwiched symmetrically by the probe 2.

  Near-infrared light is generated by the light source 4, beam-formed by the illumination optical system 5, and incident on the bundle fiber 3. The light source 1 uses a pulsed laser such as an Nd: YAG laser or an Alexandrite laser. In addition, a Ti: sa laser or an OPO laser using Nd: YAG laser light as excitation light may be used.

  A plurality of emission ends 3 a are provided according to the number of bundle fibers on the photoacoustic probe 1 side. The plurality of emission ends 3 a are provided adjacent to the probe 2. And the substantial total light quantity of the illumination light emitted from the light source 4 is propagated to the emission end 3a of any one bundle fiber. In other words, the total amount of light emitted from the light source 4 is maintained and propagated to the emission end 3a. Note that the substantial total light amount from the light source 4 described here means that one point is not obtained at one time of photoacoustic data acquisition without branching by a half mirror or the like to irradiate illumination light to a plurality of irradiation positions. This means that the total amount of light that can be irradiated only to the irradiation position is irradiated. Therefore, even if there is a decrease in the total light amount due to attenuation or reflection of light during propagation or branching for light amount measurement or trigger acquisition, it is ignored. Furthermore, even when the total light amount from the light source 4 is irradiated from one irradiation position and the illumination light is irradiated from the other irradiation positions with a small amount of light, it is understood as the substantial total light amount from the light source 4.

  The area of the emission end 3a of the bundle fiber (the size of the irradiation region on the subject) is determined by the product of the reception aperture width (number of aperture elements) of the probe 2 and the depth in the direction perpendicular thereto. In the following description, the opening width, the opening (reception opening), and the like may be used. However, the opening refers to a part of an electrical signal that is received by an acoustic wave and is output to the processing device 6 that is a receiving unit. It is an element (a part of the probe 2). In other words, this is a part of the vibrator 2a that outputs an electric signal received by the processing device 6 as a receiving means. The depth of the emission end 3a is reduced according to the substantial total light amount from the light source 4 so that the light amount becomes as large as possible below the maximum permissible exposure amount (MPE) of the skin. By doing so, the photoacoustic wave with respect to irradiation of illumination light per time becomes large. It should be noted that the light irradiation area on the subject is equivalent to the area of the emission end 3a. Further, in FIG. 1, the aperture width (the number of aperture elements, which means a part of a plurality of transducers included in the probe) that can acquire photoacoustic waves at a time is 1/4 of the total width. This case is illustrated. Therefore, four exit ends 3a of the bundle fiber are provided, and the width of each exit end is matched with the opening width. Note that the division of the illumination position on the subject (number of bundle fiber emission ends 3a) is not limited to four divisions. If the receivable aperture width that can be acquired at one time is half of the whole, it can be determined in accordance with the acquired reception aperture width (number of aperture elements) of the photoacoustic wave, for example, by dividing into two. And the processing apparatus 6 acquires the electrical signal which the element which consists of transducers outputs using the element which consists of transducers of the probe 2 adjacent to the irradiation position of the switched illumination light. The element of the probe 2 means an acoustic wave receiving element composed of a vibrator provided in the probe 2, and this element is usually composed of a plurality of vibrators. A plurality of elements (acoustic wave receiving elements) composed of a plurality of vibrators are provided. Since the probe 2 outputs electric signals from some elements to the processing device 6, as a result, the processing device 6 receives from some transducers of a plurality of transducers included in the probe 2. The electrical signal is received. However, in FIG. 2A below, in order to facilitate understanding of the invention, the configuration and illustration are simplified, and one element is shown corresponding to one vibrator 2a.

  Even if the number of elements of the probe 2 is 128 and the number of channels (number of elements) that can be acquired by the processing device 6 is 32 channels (32 elements), the opening width is smaller than this (for example, 16 elements). This embodiment may be applied by dividing (for example, dividing into eight). This is suitable when the output of the light source 4 is low.

  An output from a photodiode (not shown) measured by branching a part of the illumination light is used as a trigger signal, and when the processing device 6 receives the trigger signal, the probe 2 acquires a photoacoustic wave, Based on this, an electric signal (hereinafter sometimes referred to as an acoustic wave signal) is output. Then, the electrical signal is amplified, digitally converted, image reconstructed, etc., and image information is generated and displayed on the monitor 7. The trigger signal is not limited to the photodiode, and a method of synchronizing the light emission of the light source 4 and the input trigger to the processing device 6 by a signal generator (function generator) is also effective.

  The switching device 8 which is a part of the irradiation control means is provided for changing the irradiation position of the illumination light. In FIG. 1, a switching device 8 is provided between the light source 4 and the illumination optical system 5, and the illumination optical system 5 is transferred to the illumination optical system 5 based on switching information from the control device 6 a that is part of the irradiation control means in the processing device 6. Is switched. Therefore, the substantial total amount of light from the light source 4 irradiated from the output end 3a of each bundle fiber is maintained and constant by switching. The control device 6a selects the bundle fiber emission end 3a adjacent to the reception opening of the probe 2 from the plurality of emission ends 3a, and sends the light source 4 to the illumination optical system 5 corresponding to the bundle fiber emission end 3a. The switching device 8 is operated so that the illumination light from is incident. The order of the switching device 8 and the illumination optical system 5 shown in FIG. 1 is arbitrary, and even if the order is reversed, it is effective.

  Next, the control device 6a for switching the irradiation position will be described with reference to FIG. FIG. 2A shows a front view of the photoacoustic probe 1, and the probe 2 is a linear probe including a plurality of transducers 2a. Note that the type of the probe 2 is not limited to a linear probe, and can be applied to a convex probe.

  In FIG. 2A, the number of receiving elements of the probe 2 is 128 channels, and the number of channels that can be acquired by the processing device 6 at a time is 32 channels. That is, it is divided into channel numbers 0-31ch (reception opening A), 32-63ch (reception opening B), 64-95ch (reception opening C), and 96-128ch (reception opening D). To the reception opening D in order, the electrical signal (photoacoustic signal) based on the photoacoustic wave is received.

  Next, description will be made with reference to the timing chart of FIG. When the laser emission of the light source 4 is 10 Hz, the light emission interval is 100 ms. First, in order to receive a photoacoustic signal (electrical signal) by the element of the receiving aperture A, the control device 6a drives the switching means 8, and emits illumination light from the emission end 3a of the bundle fiber adjacent to the element of the receiving aperture A. Irradiate. Then, using the element of the reception aperture A in synchronization with the irradiation, the processing device 6 acquires a photoacoustic signal (electric signal) (30 μs in FIG. 2B). The emission end 3a of the bundle fiber adjacent to the element of the reception aperture B is irradiated with illumination light between the light emission of the light source and the next laser emission (50 μs after emission in FIG. 2B). The control device 6a drives the switching means 8. Then, the processing device 6 acquires a photoacoustic signal (electric signal) using the element of the reception aperture B in synchronization with the irradiation. Similarly, the control device 6a drives the switching means 8 so that the emission end 3a of the bundle fiber adjacent to the element of the reception aperture C emits illumination light until the next laser emission, and synchronizes with the irradiation. Then, the processing device 6 acquires a photoacoustic signal (electric signal) from the element of the receiving opening C. Further, the control device 6a drives the switching means 8 so that the emission end 3a of the bundle fiber adjacent to the element of the reception aperture D emits illumination light until the next laser emission, and synchronizes with the irradiation. Then, the processing device 6 acquires a photoacoustic signal (electric signal) from the element of the reception opening D. Thus, photoacoustic signals from the openings for all the elements of the probe 2 can be acquired. When acquiring the photoacoustic signal a plurality of times, the control device 6a switches the switching means so that the emission end 3a of the bundle fiber adjacent to the element of the reception aperture A irradiates illumination light until the next laser emission again. 8 is driven and the processing device 6 acquires a photoacoustic signal (electric signal) from the element of the reception aperture A in synchronization with the irradiation, and repeats this.

  Note that the switching of the output end 3a of the bundle fiber described here and the order from the reception openings A to D are not limited to this, and it is not necessary to continuously output from the output end 3a of the same bundle fiber. For example, a photoacoustic signal (electrical signal) may be acquired first at the reception aperture C and may be continued with the reception aperture A, the reception aperture D, and the reception aperture B. Furthermore, the number of elements of the probe 2, the number of channels of the processing device 6, the delay time of the synchronization timing, the reception time, and the like can be changed.

  Further, an ultrasonic image may be acquired after the photoacoustic signal is acquired until the next laser emission.

  Next, the switching device 8 will be described with reference to FIGS. 3A to 3C and FIGS. 4A and 4B. 3 (a), 3 (b), 4 (a), and 4 (b) show the receiving aperture with respect to the entire element width of the probe 2 in order to simplify the description of the switching device 8. Although the width is shown to be divided into two, naturally, the present invention can also be applied to the case where the reception aperture is divided into four as shown in FIG. 1 and FIG. All illumination optical systems 5 are not shown.

  The switching device 8 in FIG. 3A uses a mirror 8d, and the mirror 8d for switching the optical path can be moved by an actuator 8c. In order to make illumination light enter the incident end 3b of the bundle fiber on the A side, the mirror 8d provided on the actuator 8c is driven so as to reflect the light. Further, as shown in FIG. 3B, in order to make the illumination light incident on the incident end 3b of the B-side bundle fiber, the mirror 8d provided on the actuator 8c is driven so as not to hit the light. In any drive, the actuator 8c is driven and controlled by the control device 6a based on the illumination position information on the A side / B side. 3 (a) and 3 (b) are illustrated on the premise of two divisions. However, when the number of divisions is further increased, for example, in the case of four divisions, a mirror on the actuator 8c as shown in FIG. 3 (c). By positioning 8d, a configuration in which the D side is selected and switched from the A side may be employed.

  Further, the switching device 8 in FIG. 4A uses a polygon mirror 8a instead of the total reflection type mirror 8d. The polygon mirror 8a rotates in synchronization with the light emission frequency of the light source 4 and is adjusted so as to enter the incident end 3b of the A side and B side bundle fibers. When more switching is required using the polygon mirror 8a, it is only necessary to increase the incident end 3b of the bundle fiber and reduce the rotation speed of the polygon mirror 8a. In order to simplify the control, it is preferable that the rotation speed of the polygon mirror 8a is constant, and the incident end 3b of the bundle fiber is provided so that the angles are equidistant about the rotation axis of the polygon mirror 8a.

  In FIGS. 3A to 3C and 4A, the method of driving the mirror 8d by the actuator 8c and the method of using the polygon mirror 8a for switching the optical path have been described. However, it is not limited to these. The switching device 8 can be an optical element such as a galvanometer mirror or an acousto-optic deflection element (AOD).

  As shown in FIG. 4B, the switching device 8 is also effective in a method of switching the irradiation position by using a plurality of light sources, adjusting the light emission operation timing based on the illumination position information from the control device 6a (not shown). is there. In this case, an operation timing control means may be provided separately, or the function may be provided to the control device 6a. In the case of the configuration shown in FIG. 4B, since the light source 4 having a relatively low total light amount can be used, the photoacoustic apparatus can be downsized.

  The switching device 8 may combine the configurations described with reference to FIGS. 3A, 3 </ b> C, 4 </ b> A, and 4 </ b> B. For example, when switching to four divisions, two light sources 4 are provided as shown in FIG. 4 (b), and each of them can be divided into two as shown in FIGS. 3 (a) and 3 (b). It may be divided.

  As described above, according to the configuration described in the first embodiment, the substantial total light amount from the light source 4 without increasing the circuit scale of the processing device 6 as the receiving unit and without increasing the output of the light source 4. , The SNR is improved by increasing the intensity of the photoacoustic signal. Therefore, the amount of light contributing to reception is increased by the amount of division compared to the case where the irradiation end is provided with a width substantially the same as the width of the elements of the probe 2 in the arrangement direction. The generated photoacoustic wave is quadrupled. When a photoacoustic signal that is an electrical signal based on a photoacoustic wave is imaged, contrast resolution is improved, and visibility and clinical diagnostic ability are improved.

  In the first embodiment, the method of providing the emission ends 3a of a plurality of bundle fibers adjacent to the reception aperture and switching the emission position of the illumination light by the reception aperture has been described. The second embodiment will be described with reference to FIG. 5 with respect to a method of scanning the bundle fiber according to the reception aperture with a single exit end 3a of the bundle fiber. The description of the same reference numerals as those in the first embodiment is omitted.

  The exit end 3 a of the bundle fiber is adjacent to the probe 2. The probe 2 is a linear probe, but is not limited to this, and can be applied to a convex probe. Then, as in the first embodiment, the substantial total light amount emitted from the light source 4 is maintained and propagated to the emission end of the bundle fiber 3a. The area of the exit end 3a of the bundle fiber (irradiation area on the subject) is determined by the product of the receiving aperture width and the depth in the direction perpendicular thereto. The depth is narrowed so that the amount of light is as large as possible in the range below the MPE, depending on the substantial total amount of light from the light source 4. By doing so, the photoacoustic wave with respect to one irradiation of illumination light is maximized. And the width | variety of the output end 3a was made to correspond with the receiving aperture width.

  Also, assuming that the number of elements of the probe 2 is 128 and the number of channels that can be acquired by the processing device 6 is 32, the aperture width (for example, 16 elements) smaller than this is divided (for example, divided into eight). Embodiments may be applied. This is suitable when the output of the light source 4 is low.

  And the switching apparatus 8 which is a part of irradiation control means is provided in order to change the irradiation position of illumination light. FIG. 5 illustrates the switching device 8 that scans the exit end 3a of the bundle fiber. Based on the switching information from the control device 6a (a part of the irradiation control means) in the processing device 6, the emission end 3a of the bundle fiber is scanned by the switching device 8. The control device 6a operates the switching device 8 so that the emission end 3a is positioned at a position adjacent to the reception opening (a part of the transducers) of the probe 2.

  Next, a control method of the control device 6a will be described with reference to FIG. FIG. 6A is a front view of the photoacoustic probe, schematically showing changes in the light irradiation position (that is, the position of the emission end) and the position of the reception aperture. This operation control is shown in FIG.

  As shown in FIG. 6B, when the nth photoacoustic signal (electrical signal output based on the photoacoustic wave) is acquired, the reception aperture of the probe 2 is illuminated so that the reception position is obtained. The photoacoustic signal is acquired by making (corresponding) the irradiation position of the light. Then, the reception aperture of the probe 2 and the irradiation position of the illumination light are scanned over the n + 1-th photoacoustic signal acquisition region. This timing is switched 50 μsec after laser emission in FIG. 6B, but may be performed between the nth laser emission and the (n + 1) th laser emission.

  In the second embodiment, the switching device 8 is scanned. However, the present invention is not limited to this. For example, as shown in FIG. 7, a method of scanning illumination position of illumination light with a reflective element such as a polygon mirror 8a using illumination light emitted from a bundle fiber (not shown) is also effective. In this case, the reflection end of the polygon mirror 8a becomes the emission end. More preferably, a beam shaping optical system 8b composed of a concave lens, an Fθ lens, or the like is provided.

  As described above, according to the configuration described in the second embodiment, it is possible to continuously scan the opening position and the light irradiation end portion of the subject. Therefore, it is possible to receive at an arbitrary opening.

  In the first and second embodiments, the photoacoustic apparatus in the case where the probe 2 is a linear probe or a convex probe has been described. In the third embodiment, a configuration and a method of a photoacoustic apparatus capable of acquiring a three-dimensional image in which a linear probe is mechanically scanned in the elevation direction will be described. The overall configuration of the apparatus is the same as that shown in FIG. 1, and the features of the photoacoustic probe 1 are shown in FIG.

  FIG. 8 is a front view of the photoacoustic probe 1 capable of acquiring a three-dimensional image by performing a mechanical sector scan in the elevation direction while electronically scanning the linear probe in the probe 2. Based on the processing device 6, the control device 6 a performs sector scanning of the linear probe in the probe 2 in the elevation direction. In accordance with the direction of the sector scan, that is, the direction of the reception aperture, illumination light is irradiated from the corresponding bundle fiber exit end 3a in the order from the left side (A side) to the right side (B side). This may be applied when the two-dimensional array type probe 2 performs electronic sector scanning. For the switching at this time, the configuration and method described in the first embodiment with reference to FIGS. 3A to 3C, FIG. 4A, and FIG. 4B may be applied.

  As described above, the method of controlling the emission position of the illumination light according to the photoacoustic wave reception direction can irradiate the illumination light from the position according to the sector scanning direction (reception aperture direction). Therefore, the improvement in SNR by increasing the reception sound pressure to the maximum can be applied to the probe 2 capable of acquiring a three-dimensional image.

DESCRIPTION OF SYMBOLS 1 Photoacoustic probe 2 Probe 3 Bundle fiber 3a Outlet end 3b Inlet end 4 Light source 5 Illumination optical system 6 Processing apparatus 6a Control apparatus 7 Monitor 8 Switching apparatus

Claims (2)

A light irradiating means comprising a light source and a plurality of emitting end portions that emit light emitted from the light source toward the subject;
Light is emitted from a part of the plurality of emission ends of the light irradiation means, and a part of the emission end that emits the light is switched to change a light irradiation region to the subject. Irradiation control means for controlling,
A probe comprising a plurality of transducers for receiving an acoustic wave generated by the subject in response to light irradiation from the light irradiation means and outputting an electrical signal;
Receiving means for receiving the electrical signal from some of the plurality of transducers included in the probe;
Probe control means for switching some of the transducers that output electrical signals received by the receiving means to other partial transducers;
Sector scanning means for sector scanning the vibrator;
I have a,
The plurality of emission end portions are positioned with the probe interposed therebetween,
The irradiation control means, while maintaining the total amount of light the emitted light that will be emitted from the hurt portion the light source is emitted, the irradiation area of the light to a subject magnitude of said probe smaller than the size, the irradiation area corresponding to the position of the transducer of said portion, and based on the operation of the sector scanning means, an exit end for emitting the light of the plurality of emission end portion It switched, before Symbol biological information acquisition apparatus characterized by changing the irradiation region of light to the subject. The light irradiation means has a plurality of light sources,
The measuring apparatus according to claim 1, further comprising a timing control means for controlling the operation timing of the plurality of light sources.

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