JP2017006161A - Photoacoustic imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoacoustic imaging apparatus capable of imaging a moving detection object smoothly.SOLUTION: A photoacoustic imaging apparatus 100 includes: a first light source unit 1 for irradiating a light of a first wavelength; a second light source unit 2 for irradiating a light of a second wavelength different from the first wavelength; a control unit 41 for executing control to alternately and repeatedly irradiating the lights of the first wavelength and the second wavelength from the first light source unit 1 and the second light source unit 2 respectively; and a detection unit 31 for detecting photoacoustic waves generated from the detection object Q that has absorbed the lights, respectively. The control unit 41 executes control to irradiate the light of the first wavelength from the first light source unit 1 a plurality of times in a period when a tissue shape in a subject P does not change substantially, and to irradiate the light of the second wavelength from the second light source unit 2 a plurality of times in a period when a tissue shape in the subject P does not change substantially, and creates an image based on the detection signal of the photoacoustic waves AW.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a photoacoustic imaging apparatus, and more particularly to a photoacoustic imaging apparatus that generates an image based on photoacoustic waves.

  Conventionally, a photoacoustic imaging apparatus that generates an image based on a photoacoustic wave is known (see, for example, Patent Document 1).

  Patent Document 1 discloses a photoacoustic imaging apparatus capable of imaging a difference in tissue shape by irradiating a subject with two types of light having different wavelengths. This photoacoustic imaging apparatus is configured to perform detection twice when the tissue shapes are different from each other, and to image the difference in the tissue shape.

JP 2010-46215 A

  However, in the photoacoustic imaging apparatus described in Patent Document 1, detection is performed twice when the tissue states are different from each other. Therefore, after the first detection, the second detection is performed with a relatively long time interval. It is thought that detection has been performed. For this reason, it is considered that there is a problem that a moving detection target cannot be imaged smoothly.

  The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a photoacoustic imaging apparatus capable of smoothly imaging a moving detection object. Is to provide.

  A photoacoustic imaging apparatus according to an aspect of the present invention includes a first light source unit that irradiates a subject with light having a first wavelength, and a second light source that irradiates the subject with light having a second wavelength different from the first wavelength. Irradiated from the light source unit, the first light source unit, and the second light source unit, the control unit that performs control to alternately and repeatedly irradiate light of the first wavelength and the second wavelength, and the first light source unit and the second light source unit, respectively. A detection unit that detects each photoacoustic wave generated from a detection target in the subject that has absorbed the emitted light, and the control unit includes a first light source within a period in which the tissue shape in the subject does not substantially change. At least one of the control of irradiating the light of the first wavelength from the unit multiple times or the control of irradiating the light of the second wavelength from the second light source unit a plurality of times within a period in which the tissue shape in the subject does not substantially change. Based on the photoacoustic wave detection signal detected by the detection unit. Te, and it is configured to generate an image.

  In the photoacoustic imaging apparatus according to one aspect of the present invention, as described above, the control unit emits light of the first wavelength from the first light source unit a plurality of times within a period in which the tissue shape in the subject does not substantially change. Photoacoustic detected by the detection unit by performing at least one of irradiation control or control of irradiating light of the second wavelength from the second light source unit a plurality of times within a period in which the tissue shape in the subject is not substantially changed. An image is generated based on the wave detection signal. Thereby, since the detection is performed a plurality of times within a period in which the tissue shape in the subject is not substantially changed, compared to the case where the detection is performed a plurality of times with a relatively long time interval as in the prior art, A moving detection target can be smoothly imaged. In the present invention, the period during which the tissue shape in the subject does not substantially change means that the tissue shape of the subject is maintained substantially the same so that the contraction (expansion) state of the heart that repeats contraction and expansion is maintained, for example. A relatively short period of time.

  In the photoacoustic imaging apparatus according to the above aspect, preferably, the control unit continuously irradiates light in units of frames from the first light source unit a plurality of times and then continuously irradiates light in units of frames from the second light source unit. It is comprised so that it may perform repeatedly, and it is comprised so that the detection signal for several times irradiated continuously may be added for every 1st light source part and 2nd light source part, respectively. If constituted in this way, since the detection signals for a plurality of times are added, the data of the detection object is accumulated by the addition, and the image becomes clear, but the temporal random noise appearing in the image is not accumulated. Random noise can be relatively reduced. Therefore, a moving detection target can be imaged more smoothly. In general, random light is likely to appear in a light source such as a light-emitting diode element having a small output, so that random noise can be effectively suppressed. Further, in the present invention, the light for each frame is light required for imaging one image of a frame corresponding to an integral multiple of one frame.

  In this case, preferably, for each of the first light source unit and the second light source unit, an addition processing unit that adds the detection signals for a plurality of times of continuous irradiation, and continuous irradiation for each of the first light source unit and the second light source unit. A temporary storage unit that temporarily stores the detection signals for a plurality of times, and adds the detection signals stored in the temporary storage unit in the addition processing unit and erases them after outputting the added detection signals 1 One data processing unit is further provided. If comprised in this way, since light is continuously irradiated from the 1st light source part and the 2nd light source part, a data processing part will continue the detection signal (same kind of detection signal) based on the light from the same light source part. By detecting this, it can be temporarily stored in the temporary storage unit. For this reason, since the same kind of detection signals detected continuously can be added in the addition processing unit, the detection signal addition processing can be performed by one data processing unit. As a result, the circuit scale can be reduced and the circuit configuration can be simplified.

  In the configuration in which the detection signals for a plurality of times continuously irradiated for each of the first light source unit and the second light source unit are added, preferably, the first light source unit has more light in units of frames than the second light source unit. It is configured to continuously irradiate. If comprised in this way, by setting the wavelength which can detect the specific detection object which wants to image more clearly to the 1st wavelength of a 1st light source part, it wants to image more clearly by a 1st light source part It is possible to focus on irradiation with light of a predetermined wavelength toward a specific detection target.

  In the first light source unit and the second light source unit, the detection signals for a plurality of times of continuous irradiation are added. Preferably, the photoacoustic wave detection signal averages the added detection signals. It is configured. If comprised in this way, it can suppress that the highest digit of digital data overflows in the circuit which performs an addition process by the averaging process.

  In the photoacoustic imaging apparatus according to the above aspect, the light source section preferably includes at least one of a light emitting diode element, a semiconductor laser element, and an organic light emitting diode element as a light source. If comprised in this way, since a light emitting diode element, a semiconductor laser element, and an organic light emitting diode element are light sources which can be made to light-emit by a comparatively simple drive mechanism, a 1st light source part and a 2nd light source part are An increase in size can be suppressed. As a result, it is possible to suppress the apparatus from becoming large.

  In the photoacoustic imaging apparatus according to the above aspect, the period during which the tissue shape in the subject does not substantially change is preferably 10 μsec or more and 100 msec or less. According to this configuration, the period during which the tissue shape in the subject is not substantially changed is set to 10 μsec or more, so that the light irradiation period, which is a period that causes the temperature increase of the first light source unit (second light source unit), is performed. On the other hand, it can suppress that the period when light is not irradiated becomes too short. Therefore, the temperature rise of the first light source unit (second light source unit) can be suppressed. Thereby, the fall of the luminous efficiency resulting from the excessive temperature rise of a 1st light source part (2nd light source part), and shortening of a light source lifetime can be suppressed. In addition, by setting the period during which the tissue shape in the subject does not substantially change to 100 milliseconds or less, it is possible to suppress the image display from being delayed to the extent that a human sense of delay is felt. In short, it is possible to prevent the real-time property of imaging from being impaired.

  According to the present invention, as described above, it is possible to provide a photoacoustic imaging apparatus that can smoothly image a moving detection target.

It is the schematic diagram which showed the use condition of the photoacoustic imaging device by 1st-4th embodiment of this invention. It is the block diagram which showed the whole structure of the photoacoustic imaging device by 1st, 3rd and 4th embodiment of this invention. It is a figure for demonstrating the timing of the irradiation of light by the 1st Embodiment of this invention, the detection of a photoacoustic wave, and an addition process. It is the block diagram which showed the reception memory addition part of the photoacoustic imaging device by 1st Embodiment of this invention. It is the block diagram which showed the whole structure of the photoacoustic imaging device by 2nd Embodiment of this invention. It is the block diagram which showed the reception memory addition part of the photoacoustic imaging device by 3rd Embodiment of this invention. It is a figure for demonstrating the timing of the irradiation of light by the 3rd Embodiment of this invention, the detection of a photoacoustic wave, and an addition process. It is a figure for demonstrating the timing of the irradiation of the light by 4th Embodiment of this invention, the detection of a photoacoustic wave, and an addition process.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

[First Embodiment]
(Configuration of photoacoustic imaging device)
With reference to FIGS. 1-4, the structure of the photoacoustic imaging device 100 by 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the photoacoustic imaging apparatus 100 according to the first embodiment of the present invention includes a first light source unit 1, a second light source unit 2, a probe unit 3, and an apparatus main body unit 4. Yes. The apparatus main body 4 is connected to the first light source unit 1 and the second light source unit 2 via a wiring 51 and a wiring 52, respectively. Further, the apparatus main body 4 and the probe unit 3 are connected via a wiring 53. The apparatus main body 4 can output electric power, a control signal, and the like to the first light source unit 1, the second light source unit 2, and the probe unit 3 through these wirings 51, 52 and 53.

  The photoacoustic imaging apparatus 100 emits light from the first light source unit 1 and the second light source unit 2 to the detection target Q of the subject P, and the light generated when the light is absorbed by the detection target Q. The acoustic wave AW is detected by the probe unit 3 (a detection unit 31 described later). The photoacoustic imaging apparatus 100 is configured to generate an image based on a detection signal of the photoacoustic wave AW detected by the probe unit 3 (detection unit 31).

  Each of the first light source unit 1 and the second light source unit 2 is configured to irradiate light for imaging toward a subject P such as a human body. The first light source unit 1 and the second light source unit 2 are configured to irradiate the subject P with light having different wavelengths (referred to as a first wavelength and a second wavelength, respectively). Further, the first light source unit 1 and the second light source unit 2 are light having a first wavelength and a second wavelength, respectively, with respect to the subject P under the control of a control unit 41 (to be described later) of the apparatus main body unit 4. Are alternately and repeatedly irradiated. Details will be described later. Moreover, the 1st light source part 1 and the 2nd light source part 2 are respectively arrange | positioned 1 each on both sides of the probe part 3 so that the probe part 3 may be pinched | interposed. The first light source unit 1 and the second light source unit 2 are fixedly attached to the probe unit 3 by an attachment member (not shown).

  As shown in FIG. 2, the first light source unit 1 includes a first light source substrate 11 and a first light emitting semiconductor element 12 as a light source. Although not shown, a plurality of first light-emitting semiconductor elements 12 are mounted on the first light source substrate 11 in an array on the subject P side. Further, the first light source substrate 11 is configured to cause the first light emitting semiconductor element 12 to emit pulses under the control of the control unit 41. Note that the second light source unit 2 also includes a second light source substrate 21 and a second light emitting semiconductor element 22, similarly to the first light source unit 1. Below, the 1st light source part 1 is mainly demonstrated and the description about the 2nd light source part 2 is abbreviate | omitted.

  The first light emitting semiconductor element 12 is configured to generate light having a measurement wavelength in the infrared region suitable for measurement of the subject P such as a human body (for example, light having a central wavelength of about 700 nm to about 1000 nm). ing. For example, a light emitting diode element, a semiconductor laser element, or an organic light emitting diode element can be used as the first light emitting semiconductor element 12.

  The wavelength of light generated by the first light emitting semiconductor element 12 (first light source unit 1) and the second light emitting semiconductor element 22 (second light source unit 2) is appropriately determined according to the detection target Q. In the present embodiment, it is assumed that the wavelength (first wavelength) of light generated by the first light emitting semiconductor element 12 is 750 nm that is easily absorbed by deoxygenated hemoglobin. That is, the first light emitting semiconductor element 12 emits light capable of imaging the vein. In addition, it is assumed that the wavelength (second wavelength) of light generated by the second light-emitting semiconductor element 22 is 850 nm that is easily absorbed by oxygenated hemoglobin. That is, the second light emitting semiconductor element 22 emits light capable of imaging an artery.

  As described above, the probe unit 3 includes the detection unit 31. The detection unit 31 is configured to detect the photoacoustic wave AW generated from the detection target Q in the subject P that has absorbed the light emitted from the first light source unit 1 (first light source unit 1). .

  Specifically, the detection unit 31 includes an ultrasonic transducer 31a. In the detection unit 31, the ultrasonic transducer 31a is vibrated by the photoacoustic wave AW generated from the detection target Q in the subject P that has absorbed the light emitted from the first light source unit 1 (first light source unit 1). Thus, the photoacoustic wave AW is detected. 128 ultrasonic transducers 31a are provided on the side in contact with the subject P. The ultrasonic transducers 31a are arranged in one row. The detection unit 31 (ultrasonic transducer 31a) is configured to output a detection signal of the detected photoacoustic wave AW to the apparatus main body unit 4 via the wiring 53 (see FIG. 1).

  The apparatus body 4 includes a control unit 41, a reception memory addition unit 42, a frame data generation unit 43, a RAW data output unit 44, an image generation unit 45, and a display unit 46.

  The apparatus main body 4 is configured to generate RAW data based on the detection signal in the reception memory adding unit 42 and the frame data generating unit 43. The apparatus main body 4 is configured to be able to output the generated RAW data to the outside of the apparatus main body 4 via the RAW data output unit 44. The RAW data is so-called raw data before being imaged, and is data including position information and size information of the subject P. With this RAW data, various analyzes on the subject P can be performed. The reception memory adding unit 42 is an example of a “data processing unit” in the claims.

  The control unit 41 outputs a light trigger signal to the first light source unit 1 and the second light source unit 2, thereby causing the first wavelength (750 nm) and the second wavelength from the first light source unit 1 and the second light source unit 2, respectively. It is configured to perform control to alternately and repeatedly irradiate light having a wavelength (850 nm). Specifically, the control unit 41 emits light of the first wavelength (750 nm) from the first light source unit 1 within a predetermined period T1 (time) (see FIG. 3) in which the tissue shape in the subject P does not substantially change. It is configured to perform control to irradiate twice. That is, the control unit 41 is configured to perform control to irradiate the second light after a period t1 (see FIG. 3) that is less than the predetermined period T1 when the first light is emitted from the first light source unit 1. Has been. The predetermined period T1 is preferably set within a range of 10 μs or more and 0.1 seconds (100 milliseconds) or less. More preferably, it is set within a range of 10 μs or more and 0.05 seconds or less. For example, if the light source is a light emitting diode element, the control unit 41 irradiates light about every 0.001 second (1 kHz).

  Further, the control unit 41 performs control to irradiate light of the second wavelength (850 nm) from the second light source unit 2 twice within a predetermined period T1 (time) in which the tissue shape in the subject P does not substantially change. It is configured.

  In addition, the control unit 41 is configured to perform control of irradiating the first light from the second light source unit 2 after a period t1 when the second light is radiated from the first light source unit 1. Similarly, the control unit 41 is configured to perform control to irradiate the first light from the first light source unit 1 after a period t1 when the second light source unit 2 radiates the second light. The control unit 41 is configured to perform control to irradiate light in units of one frame from the first light source unit 1 and the second light source unit 2.

  As described above, the control unit 41 repeatedly performs the control of continuously irradiating light of one frame unit from the second light source unit 2 twice after continuously irradiating light of one frame unit from the first light source unit 1. It is configured.

  The reception memory addition unit 42 acquires the detection signal output from the probe unit 3 (detection unit 31) via an A / D (analog / digital) converter (not shown) in the apparatus main body unit 4 or the like. It is configured. One reception memory addition unit 42 is provided. In addition, as shown in FIG. 4, the reception memory adding unit 42 includes a frame memory unit 42a, a first latch unit 42b, a second latch unit 42c, and an addition processing unit 42d. The first latch unit 42b and the second latch unit 42c are both examples of the “temporary storage unit” in the claims.

  The frame memory unit 42a is configured to store a detection signal based on light emitted from the first light source unit 1 (see FIG. 2) and the second light source unit 2 (see FIG. 2). Further, the frame memory unit 42a sequentially outputs (distributes) detection signals for each irradiation time from the first light source unit 1 (second light source unit 2) to the first latch unit 42b and the second latch unit 42c. ) Is configured as follows. That is, the frame memory unit 42a outputs a detection signal based on the first light irradiation from the first light source unit 1 (second light source unit 2) to the first latch unit 42b, and based on the second light irradiation. The detection signal is output to the second latch unit 42c.

  The first latch unit 42b and the second latch unit 42c are arranged in parallel with each other between the frame memory unit 42a and the addition processing unit 42d. Further, both the first latch unit 42b and the second latch unit 42c are configured to temporarily store detection signals for two times of continuous irradiation for each of the first light source unit 1 and the second light source unit 2. Has been. Specifically, the first latch unit 42b is configured to temporarily store a detection signal based on the first light irradiation from the first light source unit 1 (second light source unit 2). The second latch unit 42c is configured to temporarily store a detection signal based on the second light irradiation from the first light source unit 1 (second light source unit 2). The first latch unit 42b and the second latch unit 42c are configured to be able to temporarily store the same type of detection signal.

  In other words, the detection signal based on the light irradiation from the first light source unit 1 is temporarily stored in the first latch unit 42b, and the second latch unit 42c is based on the light irradiation from the second light source unit 2. A detection signal (a different type of detection signal) cannot be temporarily stored. On the other hand, if the detection signal based on the light irradiation from the first light source unit 1 is temporarily stored in the first latch unit 42b, the second latch unit 42c also receives the signal from the first light source unit 1. It is possible to temporarily store a detection signal based on light irradiation.

  Both the first latch unit 42b and the second latch unit 42c are configured to output the temporarily stored detection signal to the addition processing unit 42d. Further, both the first latch unit 42b and the second latch unit 42c are configured to be erased after outputting the temporarily stored detection signal by outputting the detection signal to the addition processing unit 42d.

  The addition processing unit 42d acquires detection signals from all the latch units when the detection signals are stored in all the latch units (the first latch unit 42b and the second latch unit 42c) connected to the addition processing unit 42d. Is configured to do. And the addition process part 42d is comprised so that the detection signal for 2 times of continuous irradiation may be added for every 1st light source part 1 and 2nd light source part 2, respectively. The addition processing unit 42d is configured to output the added detection signal to the frame data generation unit 43.

  As illustrated in FIG. 2, the frame data generation unit 43 is configured to generate RAW data based on the added detection signal acquired from the addition processing unit 42 d. In addition, the frame data generation unit 43 is configured to output the generated RAW data to the RAW data output unit 44 or the image generation unit 45.

  The RAW data output unit 44 is configured to be able to output the RAW data generated from the apparatus main body unit 4 to an external system (external device) such as the medical database system S.

  The image generation unit 45 performs processing such as phasing and detection for each RAW data generated by the detection signal based on the light from the first light source unit 1 and the second light source unit 2, and each of the predetermined images is displayed. The photoacoustic wave image is generated by generating and subtracting the generated predetermined image. The image generation unit 45 is configured to output a photoacoustic wave image to the display unit 46.

  The display unit 46 has a screen and is configured to display a photoacoustic wave image (an image of an artery or a vein) generated in the apparatus main body unit 4 on the screen. A photoacoustic wave image acquired at a frame rate of 1000 fps (1 kHz) is displayed in real time at the refresh rate of the display unit 46, for example, 120 fps.

(Light irradiation, photoacoustic wave detection and addition processing timing)
Next, the timing of light irradiation, photoacoustic wave AW detection and addition processing will be described with reference to FIG.

  First, under the control of the control unit 41, light having the first wavelength (750 nm) is emitted from the first light source unit 1 twice in succession. Note that the period (time) between the first irradiation and the second irradiation is t1. Then, immediately after each irradiation, detection signals A1 and A2 are detected by the detection unit 31. Immediately after the detection signal A2 is detected, the reception memory addition unit 42 adds the detection signal A1 and the detection signal A2.

  Next, under the control of the control unit 41, the second light source unit 2 emits light of the second wavelength (850 nm) twice in succession. Then, immediately after each irradiation, the detection signals B1 and B2 are detected by the detection unit 31. Immediately after the detection signal B2 is detected, the reception memory addition unit 42 adds the detection signal B1 and the detection signal B2. Thereafter, the above-described process in which the light is continuously irradiated twice from the first light source unit 1 and the second light source unit 2 and the detection signal is added is repeated.

(Effect of 1st Embodiment)
In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the control unit 41 controls the irradiation of the first wavelength light from the first light source unit a plurality of times within a period in which the tissue shape in the subject P does not substantially change, or The detection signal of the photoacoustic wave detected by the detection unit 31 is performed by performing one of the control of irradiating the light of the second wavelength from the second light source unit 2 a plurality of times within a period in which the tissue shape in the subject P is not substantially changed. Based on the above, an image is generated. Thereby, since the detection is performed a plurality of times within a period in which the tissue shape in the subject P is not substantially changed, as compared with the case where the detection is performed a plurality of times with a relatively long time interval as in the prior art. The moving detection object Q can be smoothly imaged. In the present invention, the period in which the tissue shape in the subject P is not substantially changed is, for example, that the tissue shape of the subject P is such that the contraction (expansion) state of the heart that repeats contraction and expansion is maintained. A relatively short period of time maintained.

  In the first embodiment, as described above, the control unit 41 continuously irradiates light from the first light source unit 1 in units of one frame multiple times, and then outputs light from the second light source unit 2 in units of one frame. It is configured to repeatedly perform the continuous irradiation control, and the detection signals for a plurality of continuous irradiations are added for each of the first light source unit 1 and the second light source unit 2. Thereby, since the detection signals for a plurality of times are added, the data of the detection object Q is accumulated by the addition, and the image becomes clear, but the temporal random noise appearing in the image is not accumulated. It can be reduced relatively. Therefore, the moving detection target Q can be imaged more smoothly. In general, random light is likely to appear in a light source such as a light-emitting diode element having a small output, so that random noise can be effectively suppressed. In the present invention, the light for each frame is light required for imaging one image of a frame corresponding to an integral multiple of one frame.

  In the first embodiment, as described above, for each of the first light source unit 1 and the second light source unit 2, an addition processing unit 42d that adds the detection signals for a plurality of times of continuous irradiation, and the first light source unit. Each of the first and second light source units 2 includes a first latch unit 42b and a second latch unit 42c that temporarily store a plurality of consecutively irradiated detection signals, and the first latch unit 42b and the second latch In addition to adding the detection signals stored in the unit 42c in the addition processing unit 42d, there is further provided one reception memory adding unit 42 for deleting after the added detection signals are output. Thereby, since light is continuously emitted from the first light source unit 1 and the second light source unit 2, the reception memory adding unit 41 continuously outputs detection signals (same type detection signals) based on light from the same light source unit. By detecting this, the first latch part 42b and the second latch part 42c can be temporarily stored. For this reason, since the same type of detection signals detected continuously can be added in the addition processing unit 42d, the detection signal addition processing can be performed by one data processing unit. As a result, the circuit scale can be reduced and the circuit configuration can be simplified.

  In the first embodiment, as described above, the first light source unit 1 and the second light source unit 2 are configured by any one of a light emitting diode element, a semiconductor laser element, and an organic light emitting diode element as a light source. As a result, the light-emitting diode element, the semiconductor laser element, and the organic light-emitting diode element are light sources that can emit pulses with a relatively simple driving mechanism, so that the first light source unit 1 and the second light source unit 2 are increased in size. Can be suppressed. As a result, it is possible to suppress the apparatus from becoming large.

  In the first embodiment, as described above, the period T1 in which the tissue shape in the subject P is not substantially changed is set to 10 μsec or more and 100 msec or less. Thereby, by setting the period during which the tissue shape in the subject P is not substantially changed to 10 μsec or more, the light irradiation period, which is the period that causes the temperature rise of the first light source unit 1 (second light source unit 2). Thus, it is possible to prevent the period during which no light is irradiated from becoming too short. Therefore, the temperature rise of the 1st light source part 1 (2nd light source part 2) can be suppressed. Thereby, the fall of the luminous efficiency resulting from the excessive temperature rise of the 1st light source part 1 (2nd light source part 2), and shortening of a light source lifetime can be suppressed. In addition, by setting the period during which the tissue shape in the subject P is not substantially changed to 100 milliseconds or less, it is possible to suppress the image display from being delayed to the extent that a human sense of delay is felt. In short, it is possible to prevent the real-time property of imaging from being impaired.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIGS. 1 and 5. In the second embodiment, an example in which a photoacoustic image is generated at a frame rate different from that of the first embodiment will be described. In addition, about the structure same as the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

(Configuration of photoacoustic imaging device)
As shown in FIG. 5, the photoacoustic imaging apparatus 200 (see FIGS. 1 and 5) according to the second embodiment of the present invention includes a reception memory addition averaging unit 242 in that the photoacoustic image according to the first embodiment is provided. It differs from the imaging device 100. The reception memory addition averaging unit 242 is an example of the “data processing unit” in the claims.

  The reception memory addition averaging unit 242 is configured to average the added detection signals in addition to the addition processing performed by the reception memory addition unit 42 described in the first embodiment. Specifically, the reception memory addition averaging unit 242 is configured to reduce the frame rate of 1 kHz to 62.5 Hz by averaging the frame rate of 1 kHz to 1/16.

(Effect of 2nd Embodiment)
In the second embodiment, the following effects can be obtained.

  In the second embodiment, similarly to the first embodiment, the control unit 41 irradiates light of the first wavelength from the first light source unit 1 a plurality of times within a period in which the tissue shape in the subject P does not substantially change. The photoacoustic detected by the detection unit 31 by performing one of the control of performing the control of irradiating the second wavelength light from the second light source unit a plurality of times within a period in which the tissue shape in the subject P is not substantially changed. An image is generated based on the wave detection signal. Thereby, compared with the case where the detection is performed a plurality of times with a relatively long time interval as in the prior art, the moving detection target Q can be smoothly imaged.

  Moreover, in 2nd Embodiment, as mentioned above, the photoacoustic imaging device 200 is comprised so that the added detection signal may be averaged. As a result, the averaging process can suppress the overflow of the most significant digit of the digital data in the circuit that performs the addition process.

[Third Embodiment]
Next, a third embodiment will be described with reference to FIG. 1, FIG. 2, FIG. 6, and FIG. In the third embodiment, unlike the first embodiment in which light is continuously irradiated twice from the same light source unit (first light source unit 1 and second light source unit 2) under the control of the control unit 41, An example in which light is continuously emitted four times from the same light source unit (the first light source unit 1 and the second light source unit 2) under the control of the control unit 341 will be described. In addition, the same structure as the said 1st Embodiment attaches | subjects and shows the same code | symbol as 1st Embodiment, and abbreviate | omits description.

(Configuration of photoacoustic imaging device)
As shown in FIG. 2, the photoacoustic imaging apparatus 300 (see FIGS. 1 and 2) according to the third embodiment includes a control unit 341. Further, the device main body 4 includes a reception memory adding unit 342. The reception memory adding unit 342 is an example of the “data processing unit” in the claims.

  The control unit 341 is configured to repeatedly perform control of continuously irradiating light of one frame unit from the second light source unit 2 four times after irradiating light of one frame unit from the first light source unit 1 four times. Yes.

  As shown in FIG. 6, the reception memory addition unit 342 includes a frame memory unit 342a, a first latch unit 342b, a second latch unit 342c, and an addition processing unit 342d. The first latch unit 342b and the second latch unit 342c are both examples of the “temporary storage unit” in the claims.

  The first latch unit 342b is configured to acquire a detection signal from the detection unit 31 and temporarily store the detection signal. The first latch unit 342b is configured to output the temporarily stored detection signal to the addition processing unit 342d.

  The second latch unit 342c is configured to acquire the detection signal from the frame memory unit 342a and temporarily store the detection signal. The second latch unit 342c is configured to output the temporarily stored detection signal to the addition processing unit 342d.

  The addition processing unit 342d is configured to add the detection signals acquired from the first latch unit 342b and the second latch unit 342c. The addition processing unit 342d is configured to output the added detection signal to the frame memory unit 342a.

  The frame memory unit 342a is configured to store the acquired detection signal. The frame memory unit 342a adds detection signals based on four times of light irradiation from the same light source unit (the first light source unit 1 (see FIG. 2) or the second light source unit 2 (see FIG. 2)). If not, the stored detection signal is output to the second latch unit 342c. Further, the frame memory unit 342a is configured to output the stored detection signal to the frame data generation unit 43 when the detection signals based on the light irradiation for four times are added.

(About timing of light irradiation, photoacoustic wave detection and addition processing)
Next, the timing of light irradiation, photoacoustic wave detection and addition processing will be described with reference to FIG.

  First, under the control of the control unit 341 (see FIG. 2), the first light source unit 1 (see FIG. 2) emits light of the first wavelength (750 nm) four times in succession. Then, immediately after each irradiation, the detection signals A1 to A4 are detected by the detection unit 31 (see FIG. 2). Immediately after the detection signal A4 is detected, the reception signals adder 342 adds the detection signals A1 to A4.

  Next, under the control of the control unit 341, the second light source unit 2 (see FIG. 2) emits light having the first wavelength (850 nm) four times in succession. And detection signal B1-B4 is each detected in the detection part 31 immediately after irradiation of each irradiation. Immediately after the detection signal B4 is detected, the detection signals B1 to B4 are added in the reception memory addition unit 342. Thereafter, the above process of irradiating light from the first light source unit 1 and the second light source unit 2 is repeated.

(Effect of the third embodiment)
In the third embodiment, the following effects can be obtained.

  In the third embodiment, similarly to the first embodiment, the control unit 341 irradiates light of the first wavelength from the first light source unit 1 a plurality of times within a period in which the tissue shape in the subject P does not substantially change. The photoacoustic detected by the detection unit 31 by performing one of the control of performing the control of irradiating the second wavelength light from the second light source unit a plurality of times within a period in which the tissue shape in the subject P is not substantially changed. An image is generated based on the wave detection signal. Thereby, compared with the case where the detection is performed a plurality of times with a relatively long time interval as in the prior art, the moving detection target Q can be smoothly imaged.

[Fourth Embodiment]
Next, a fourth embodiment will be described with reference to FIGS. 1, 2, and 8. In the fourth embodiment, unlike the first embodiment in which light is continuously emitted from the first light source unit 1 and the second light source unit 2 by the same number of times, the first light source unit 1 and the second light source unit 2 respectively. Therefore, an example in which light is continuously irradiated at different times will be described. In addition, the same structure as the said 1st Embodiment attaches | subjects and shows the same code | symbol as 1st Embodiment, and abbreviate | omits description.

(Configuration of photoacoustic imaging device)
As shown in FIG. 2, the photoacoustic imaging apparatus 400 (see FIGS. 1 and 2) according to the fourth embodiment includes a control unit 441.

  As shown in FIG. 8, the control unit 441 continuously irradiates light in units of one frame from the first light source unit 1 (see FIG. 2) three times, and then in units of one frame from the second light source unit 2 (see FIG. 2). It is configured to repeatedly perform the control of continuously irradiating the light twice.

  In addition, the detection signals A1, A2, and A3 are sequentially detected by continuously irradiating light of one frame unit from the first light source unit 3 three times. Then, the addition processing unit 42d adds the detection signal A1, the detection signal A2, and the detection signal A3 immediately after the detection of the detection signal A3. Thereafter, the second light source unit 2 similarly emits light twice continuously, and the addition processing of the detection signal B1 and the detection signal B2 is performed.

(Effect of 4th Embodiment)
In the fourth embodiment, the following effects can be obtained.

  In the fourth embodiment, similarly to the first embodiment, the control unit 441 emits light of the first wavelength from the first light source unit 1 a plurality of times within a period in which the tissue shape in the subject P is not substantially changed. The photoacoustic detected by the detection unit 31 by performing one of the control of performing the control of irradiating the second wavelength light from the second light source unit a plurality of times within a period in which the tissue shape in the subject P is not substantially changed. An image is generated based on the wave detection signal. Thereby, compared with the case where the detection is performed a plurality of times with a relatively long time interval as in the prior art, the moving detection target Q can be smoothly imaged.

  In the fourth embodiment, as described above, the first light source unit 1 is configured to continuously irradiate light in units of frames more times than the second light source unit 2. Thereby, the wavelength which can detect the specific detection target Q to be imaged more clearly is set to the first wavelength of the first light source unit 1, thereby specifying the image to be imaged more clearly by the first light source unit 1. It is possible to focus on irradiation of light of a predetermined wavelength toward the detection object Q.

(Modification)
In addition, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims, and further includes meanings equivalent to the scope of claims and all modifications (variants) within the scope.

  For example, in the said 1st-4th embodiment, after irradiating the light of a frame unit from the 1st light source part 2-4 times continuously, the light of the frame unit is continuously irradiated 2 times or 4 times from the 2nd light source part. Although an example in which the control is repeated has been shown, the present invention is not limited to this. In the present invention, the control of alternately irradiating light in units of frames from the first light source unit and the second light source unit one by one may be repeated. In this case, it is necessary to provide two reception memory addition units (reception memory addition averaging units).

  Moreover, although the said 1st-4th embodiment showed the example which irradiated the light of the frame unit from the 1st light source part (2nd light source part) 2-4 times continuously, this invention is not limited to this. . In this invention, you may irradiate 5 times or more of light of a frame unit from a 1st light source part (2nd light source part).

  In the first to fourth embodiments, the example in which the detection signal addition processing (addition averaging processing) is performed in the reception memory addition unit (reception memory addition averaging unit) of the apparatus main body has been described. Is not limited to this. In the present invention, detection signal addition processing (addition averaging processing) may be performed in the image generation unit of the apparatus main body.

  Moreover, although the said 1st-4th embodiment provided in the reception memory addition part (reception memory addition average part) in the apparatus main-body part, the example which performed the addition process (addition average process) of the detection signal was shown. The present invention is not limited to this. In the present invention, the reception memory addition is not performed between the device main body, the probe unit, the first light source unit, and the second light source unit without providing the reception memory addition unit (reception memory addition averaging unit) in the device main body. A RAW data generation unit including a unit (reception memory addition averaging unit) may be provided separately from the apparatus main body unit.

  Moreover, although the example which averaged the added detection signal to 1/16 was shown in the said 2nd Embodiment, this invention is not limited to this. In the present invention, the added detection signals may be averaged to a value other than 1/16. For example, the added detection signals may be averaged to 1/32. In this case, the frame rate is a value in the vicinity of 30 fps.

  Moreover, although the said 1st-4th embodiment showed the example which provided the two light source parts and irradiated the light of two wavelengths, this invention is not limited to this. In the present invention, three or more light source units may be provided and irradiated with light having three or more wavelengths.

  Moreover, in the said 1st-4th embodiment, although the example which comprised the probe part, and the 1st light source part and the 2nd light source part separately was shown, this invention is not limited to this. In the present invention, the probe unit, the first light source unit, and the second light source unit may be configured integrally.

DESCRIPTION OF SYMBOLS 1 1st light source part 2 2nd light source part 31 Detection part 41,341,441 Control part 42,342 Reception memory addition part (data processing part)
42b, 342b First latch section (temporary storage section)
42c, 342c Second latch part (temporary storage part)
42d Addition processing unit 100, 200, 300, 400 Photoacoustic imaging apparatus 242 Reception memory addition averaging unit (data processing unit)

Claims (7)

A first light source unit that irradiates the subject with light of a first wavelength;
A second light source unit that irradiates the subject with light having a second wavelength different from the first wavelength;
A control unit that performs control to alternately and repeatedly irradiate light of the first wavelength and the second wavelength from the first light source unit and the second light source unit, respectively;
A detection unit that detects each photoacoustic wave generated from a detection target in the subject that has absorbed light emitted from the first light source unit and the second light source unit;
The control unit controls the irradiation of the light of the first wavelength from the first light source unit a plurality of times within a period in which the tissue shape in the subject is not substantially changed, or the tissue shape in the subject is not substantially changed. Within the period, at least one of the control of irradiating the second wavelength light from the second light source unit a plurality of times is performed,
A photoacoustic imaging apparatus configured to generate an image based on a photoacoustic wave detection signal detected by the detection unit. The control unit is configured to repeatedly perform control to continuously irradiate light in units of frames from the second light source unit a plurality of times after continuously irradiating light in units of frames from the first light source unit,
2. The photoacoustic imaging apparatus according to claim 1, wherein the photoacoustic imaging apparatus is configured to add a plurality of consecutively irradiated detection signals for each of the first light source unit and the second light source unit.   For each of the first light source unit and the second light source unit, an addition processing unit that adds the detection signals for a plurality of times of continuous irradiation, and for each of the first light source unit and the second light source unit, continuous irradiation was performed. A temporary storage unit that temporarily stores a plurality of detection signals, and adds the detection signals stored in the temporary storage unit in the addition processing unit, and erases them after the output of the added detection signals 1 The photoacoustic imaging apparatus according to claim 2, further comprising two data processing units.   4. The photoacoustic imaging apparatus according to claim 2, wherein the first light source unit is configured to continuously irradiate light in units of frames more times than the second light source unit. 5.   The photoacoustic imager according to any one of claims 2 to 4, wherein the photoacoustic imager is configured to average the added detection signals.   6. The device according to claim 1, wherein each of the first light source unit and the second light source unit includes any one of a light emitting diode element, a semiconductor laser element, and an organic light emitting diode element. Photoacoustic imaging device. The photoacoustic imaging apparatus according to any one of claims 1 to 6, wherein a period during which the tissue shape in the subject does not substantially change is 10 µsec or more and 100 ms or less.

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