JP2018061901A - Subject information acquisition device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique of, in photoacoustic imaging, obtaining a photoacoustic signal at an interval shorter than an arrangement interval of reception elements.SOLUTION: A subject information acquisition device includes: a probe where a plurality of reception elements, which each receive an acoustic wave generated from a subject irradiated with light from a light source and convert the acoustic wave into an electric signal, are arranged in a first direction; moving means for moving the probe in the first direction; control means for controlling the light source and the moving means; and generation means for generating data on an internal image of the subject on the basis of the electric signal. The control means performs control to irradiate the subject with the light each time the probe is moved by a distance that is (n+1)/k times or (n-1)/k times as long as an arrangement interval of the reception elements, where n is an integer equal to or larger than one and k is an integer equal to or larger than two.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a subject information acquisition apparatus and a control method thereof.

  The photoacoustic imaging method is a method of imaging a three-dimensional structure inside a subject by irradiating the subject with light such as a pulse laser and detecting a photoacoustic wave generated by thermal expansion. By changing the wavelength of light, the distribution of substances that particularly absorb light of that wavelength, such as hemoglobin and glucose in blood, can be imaged. Therefore, since neovascularization characteristic of tumor can be detected non-invasively, it has been attracting attention as a means for early detection of breast cancer.

Conventionally, a specific procedure of the photoacoustic imaging method is disclosed, for example, in Patent Document 1 as follows.
(Procedure 1) A probe (two-dimensional probe) in which receiving elements for converting an acoustic wave into an electric signal are two-dimensionally arranged is arranged on the surface of the subject, and the subject is irradiated with a single pulse of electromagnetic energy.
(Procedure 2) Immediately after electromagnetic energy irradiation, the received signal of each receiving element is sampled and stored.

(Procedure 3) The delay time until the acoustic wave reaches the position of each receiving element from the point of interest in the subject is calculated, and the reception signal corresponding to the delay time is added to obtain the intensity of the image data of the point of interest. .
(Procedure 4) Procedure 3 is repeated for each attention point to be imaged.

  Patent Document 2 discloses a method for reconstructing both a photoacoustic image and a normal ultrasonic echo image by using a common probe in which receiving elements are one-dimensionally arranged (one-dimensional probe). . In order to reconstruct a wide range of three-dimensional images using this one-dimensional probe, it is necessary to mechanically move the probe in a direction orthogonal to the arrangement direction of the receiving elements.

JP-T-2001-507952 JP 2005-21380 A

  Here, in order to improve the quality of a three-dimensional reconstructed image using the photoacoustic imaging method, a photoacoustic wave is received at a fine interval, and a three-dimensional image is obtained using a photoacoustic signal based on the photoacoustic wave. Reconstruction is known to be effective.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for acquiring photoacoustic waves at intervals smaller than the arrangement interval of receiving elements in photoacoustic imaging. is there.

The present invention employs the following configuration. That is,
A light source;
A probe in which a plurality of receiving elements that receive an acoustic wave generated from a subject irradiated with light from the light source and convert it into an electrical signal are arranged in a first direction;
Moving means for moving the probe in the first direction;
Control means for controlling the light source and the moving means;
AD conversion means for converting the electrical signal converted by the receiving element into a digital signal;
Storage means for storing the digital signal converted by the AD conversion means;
Generating means for generating image data inside the subject based on the digital signal stored in the storage means;
Have
The control means, when n is an integer greater than or equal to 1 and k is an integer greater than or equal to 2, the probe has a distance of (n + 1 / k) times or (n−1 / k) times the array interval of the receiving elements. The subject information acquiring apparatus is characterized in that control is performed so that light is emitted from the light source each time the light source moves.

The present invention also employs the following configuration. That is,
An ultrasonic transmitter;
A probe having a plurality of receiving elements arranged in a first direction for receiving an echo wave reflected from the subject after being transmitted from the ultrasonic transmitter to the subject and converting it into an electrical signal;
Moving means for moving the probe in the first direction;
Control means for controlling the ultrasonic transmitter and the moving means;
AD conversion means for converting the electrical signal converted by the receiving element into a digital signal;
Storage means for storing the digital signal converted by the AD conversion means;
Generating means for generating image data inside the subject based on the digital signal stored in the storage means;
Have
The control means, when n is an integer greater than or equal to 1 and k is an integer greater than or equal to 2, the probe has a distance of (n + 1 / k) times or (n−1 / k) times the array interval of the receiving elements. The subject information acquiring apparatus is characterized in that control is performed so that an ultrasonic wave is transmitted from the ultrasonic wave transmitter each time it moves.

The present invention also employs the following configuration. That is,
A light source, a probe having a plurality of receiving elements arranged in a first direction, a moving means for moving the probe in the first direction, a control means for controlling the light source and the moving means, and an AD conversion means Storage means, generation means,
A method for controlling a subject information acquisition apparatus comprising:
A first conversion step in which the plurality of receiving elements receive an acoustic wave generated from a subject irradiated with light from the light source and convert it into an electrical signal;
A second conversion step in which the AD conversion means converts the electrical signal converted in the conversion step into a digital signal;
A storage step in which the storage means stores the digital signal converted in the second conversion step;
A generating step for generating image data inside the subject based on the digital signal stored in the storing step;
Have
In the first conversion step, the control means is configured such that when n is an integer of 1 or more and k is an integer of 2 or more, the probe is (n + 1 / k) times the arrangement interval of the receiving elements or (n− A control method for an object information acquiring apparatus, wherein control is performed so that light is emitted from the light source each time a distance of 1 / k) is moved.

  ADVANTAGE OF THE INVENTION According to this invention, the technique for acquiring a photoacoustic wave with a space | interval finer than the arrangement | positioning space | interval of a receiving element can be provided as a result in photoacoustic imaging.

The figure which shows the structure of a photoacoustic imaging apparatus. The figure which shows the procedure which carries out the mechanical scan of a wide area | region. The figure which shows the example of the moving stand position at the time of photoacoustic signal acquisition. Another figure which shows the example of the moving stand position at the time of photoacoustic signal acquisition. Another figure which shows the example of the moving stand position at the time of photoacoustic signal acquisition. Another figure which shows the example of the moving stand position at the time of photoacoustic signal acquisition. The table | surface which shows the number of element arrangement | sequences N and a movement space | interval when inputting an acoustic signal by 4 times density. The figure which shows the movement space | interval at the time of inputting the acoustic signal of various densities. Another figure which shows the movement interval at the time of inputting the acoustic signal of various densities. Another figure which shows the movement interval at the time of inputting the acoustic signal of various densities. The table | surface which shows the movement space | interval when inputting the acoustic signal of various densities by the number of elements 13. The figure which shows the movement space | interval when inputting the photoacoustic signal of the same position twice. The figure which shows the example which scans a probe along the circumference. The figure which shows the structure of the apparatus which irradiates an ultrasonic wave. The figure explaining the calculation procedure of a movement interval.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the detailed calculation formulas, calculation procedures, and the like described below should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions, and the scope of the present invention is limited to the following description. It is not intended.

  The subject information acquisition apparatus of the present invention receives the acoustic wave generated and propagated in the subject by the photoacoustic effect when the subject is irradiated with light (electromagnetic wave), and acquires subject information as image data. It is a device to do. The object information acquiring apparatus can also be regarded as a photoacoustic imaging apparatus that images the inside of the object. The object information acquired at this time is a source distribution of acoustic waves generated by light irradiation, an initial sound pressure distribution in the object, or a light energy absorption density distribution or an absorption coefficient distribution derived from the initial sound pressure distribution, It shows the concentration distribution of the substances that make up the tissue. The substance constituting the tissue is, for example, a blood component such as an oxygen saturation distribution or an oxidized / reduced hemoglobin concentration distribution, or fat, collagen, moisture, and the like.

  The present invention can also be applied to an ultrasonic device that transmits ultrasonic waves to a subject and receives reflected waves (ultrasonic echoes) in the subject to generate image data. The object information in this case indicates a difference in acoustic impedance.

The acoustic wave referred to in the present invention is typically an ultrasonic wave and includes an elastic wave called a sound wave or an acoustic wave. An acoustic wave generated by the photoacoustic effect is called a photoacoustic wave or an optical ultrasonic wave. The apparatus of the present invention receives an acoustic wave generated or reflected in a subject by an acoustic wave detector such as a probe and propagated.
In the following description, an electrical signal derived from such a photoacoustic wave is also referred to as a photoacoustic signal. The photoacoustic signal is a concept including an analog signal converted from a photoacoustic wave by a receiving element of the probe and a digital signal obtained by performing amplification or digital conversion on the analog signal. When it is said that the photoacoustic signal is acquired, it means that the subject is irradiated with light and the generated photoacoustic wave is input as a digital signal to a memory or the like.

(Image quality improvement technique)
As described above, as a method for improving the quality of a three-dimensional reconstructed image by photoacoustic imaging, as a result, a photoacoustic signal is acquired at an interval smaller than the arrangement interval of receiving elements in the two-dimensional probe, and the photoacoustic signal is obtained. A 3D image may be reconstructed using a signal. less than,
Two methods for acquiring signals at intervals of 1/4 of the array interval d will be considered.

The first method is to alternately repeat the first step of acquiring photoacoustic signals at a fine pitch and the second step of moving the probe greatly. In the first step, the photoacoustic signal is acquired once at each position, that is, a total of four times while finely moving the probe by d / 4. In the second step, the probe is moved by the width of the probe.
In this way, a photoacoustic signal can be acquired at a density four times the normal density in an inspection region wider than the width of the probe. However, in this method, since the moving speed of the probe is greatly different between the first step and the second step, the moving speed is frequently switched. Therefore, it is difficult to control the probe, and it is difficult to acquire a signal at high speed.

In the second method, mechanical scanning of the entire inspection area is repeated four times. At this time, the receiving position of the photoacoustic signal is shifted by d / 4 between each mechanical scanning. This can be realized, for example, by shifting the position of the probe at the start of measurement by d / 4. In each mechanical scan, each time the probe moves by the width of the probe, a photoacoustic signal is acquired once.
In this way, signals can be acquired at high speed while moving the probe at a constant speed. However, in this case, the time required for the entire measurement becomes long because the probe needs to be folded back. In addition, since the timing of acquiring the photoacoustic signals at adjacent positions shifted by d / 4 is greatly different, there is a problem that the accuracy of the reconstructed image is deteriorated with respect to a subject that varies with time, such as a living body.

(Configuration and scanning of the probe of the present invention)
In the present invention, probes including receiving elements arranged at equal intervals are continuously moved in the element arrangement direction with respect to the subject. And a probe receives a photoacoustic wave, moving continuously, and acquires a photoacoustic signal. A three-dimensional image inside the subject is generated based on this signal.
In the above-described Patent Document 2, it is assumed that the one-dimensional probe is continuously moved. However, it differs from the present invention in that the moving direction is a direction orthogonal to the arrangement direction of the receiving elements.

When the photoacoustic wave is received while the probe continuously moves, there is a problem that the position of the probe moves during reception. However, photoacoustic waves are received in an extremely short time of about 50 to 100 μs after light irradiation. On the other hand, the repetition cycle of a high-power pulse laser is usually limited to a slow cycle of about 100 ms. Therefore, the receiving element has to move at a low speed in accordance with the slow irradiation period. For this reason, even if the photoacoustic wave is acquired while the probe is continuously moving, there is virtually no difference in position from the case where the probe is stopped and the photoacoustic wave is acquired.
As in the present invention, by receiving the photoacoustic wave while the probe continuously moves, the movement of the probe can be easily controlled, and the time for positioning can be omitted, so that the photoacoustic signal can be acquired at high speed.

<Example 1>
FIG. 1 shows the overall configuration of the photoacoustic imaging apparatus. The photoacoustic imaging apparatus includes a holding plate 2a and 2b, a moving table 3a and 3b, a pulse laser light source 4, a probe 8, a computer 11, a laser light source control circuit 13, a moving table control circuit 14, an AD conversion circuit 15, a storage circuit 16, An image reconstruction circuit 17 and a display device 18 are included. The measurement target is the subject 1 held by the holding plates 2a and 2b. The subject 1 includes a detection target 6 that is a light absorber such as hemoglobin. A pulse laser light source 4 is movably installed on the moving table 3a. Instead of moving the pulse laser light source 4, the emission part from which the light guided by the optical system is emitted may be moved. A probe 8 is movably installed on the moving table 3b.

  When the subject 1 is irradiated with the irradiation light 5 from the pulse laser light source 4 through the holding plate 2a, the detection target 6 absorbs light energy and expands, and an acoustic wave 7 (photoacoustic wave) is generated. A part of the acoustic wave 7 is received by the receiving element of the probe 8 through the holding plate 3b and converted into an electric signal (photoacoustic signal). If there are a plurality of detection objects 6 inside the subject, the acoustic wave resulting from each is superimposed and received by the probe 8.

The signal received by each receiving element of the probe 8 is temporarily stored in the storage circuit. Then, the distribution of the detection target inside the subject is reconstructed as a three-dimensional image based on the stored received signal. Various known methods (for example, phasing addition method) can be used for the reconstruction process.
When the subject is larger than the receiving element array region of the probe, the pulse laser light source 4 and the probe 8 are moved in synchronization by the moving bases 3a and 3b, and a photoacoustic signal is acquired at each position. In this case, a partial three-dimensional image may be reconstructed every time the photoacoustic signal is acquired, or the photoacoustic signal is accumulated in the storage circuit, and the photoacoustic signal is acquired from the entire measurement target and then the image is acquired. It may be reconfigured.

  The computer 11 is a control device for the entire apparatus. The computer 11 starts the laser light source control circuit 13 at the same time as issuing a start command to the moving table control circuit 14. The moving table control circuit 14 and the laser light source control circuit 13 perform control so that the pulse laser light source 4 emits light when the moving tables 3a and 3b reach a predetermined position. Each receiving element inside the probe 8 receives a photoacoustic wave generated from the detection target 6 and converts it into a photoacoustic signal 9. The photoacoustic signal 9 is digitally converted by the AD conversion circuit 15 and then stored in the storage circuit 16. The computer 11 corresponds to the control means of the present invention. The moving table control circuit 14 controls the moving tables 3a and 3b, and includes these and corresponds to the moving means of the present invention. The AD conversion circuit 15 corresponds to AD conversion means of the present invention. The storage circuit 16 corresponds to the storage means of the present invention.

The reception signal stored in the storage circuit 16 is read by the image reconstruction circuit 17 at appropriate time points and reconstructed into a three-dimensional image. The computer 11 reads the three-dimensional image data reconstructed by the image reconstruction circuit 17, transforms it into a form that can be easily seen by the operator of the apparatus, and displays it on the image display device 18. The reconstruction process of the image reconstruction circuit 17 may be executed by a dedicated electronic circuit as shown in the figure, or may be performed by a normal computer software process or a computer 11 software process. The image reconstruction circuit 17 corresponds to the generation unit of the present invention. The image display device 18 corresponds to display means of the present invention.
As will be described later, the feature of the present invention resides in the setting of the moving base position and the moving distance at the time of inputting the photoacoustic signal. With these settings, photoacoustic signals can be acquired at high speed at intervals smaller than the receiving element interval.

  FIG. 2 shows a specific procedure for mechanically scanning an inspection region wider than the size of the receiving element array of the probe 8. In the figure, the inspection area 101 is divided into a plurality of stripe areas 102. The probe 8 acquires a photoacoustic signal while continuously moving for each stripe region 102. Thereby, a three-dimensional image of a wide inspection area can be generated. Each stripe region 102 may overlap in the Y direction. Further, the S / N ratio can be improved by scanning the same stripe region 102 a plurality of times and averaging the reconstructed images of each time by addition averaging or the like.

FIG. 3 specifically shows a setting example of the moving table position at the time of photoacoustic wave acquisition in the present invention. In this figure, the positions of the probe 8 and the laser light source 4 with respect to the subject 1 are shown for each laser emission time point (T = 1, 2, 3,...). The probe 8 in this example includes five receiving elements, and each element is arranged at equal intervals by a distance d.
The probe 8 moves by a distance (1 + 1/4) × d for each laser emission. If the light emission period of the pulse laser is constant, the moving speed of the moving table can be made constant. At this time, in the effective input range shown in the figure, one of the receiving elements can receive the photoacoustic wave at an interval of 1/4 of the arrangement interval d. In other words, although the probe is continuously moved at a constant speed, as a result, photoacoustic signals can be acquired at a fine interval equal to or smaller than the arrangement interval of the receiving elements. Furthermore, if the movement is performed at a constant speed, the control is easy and the mechanical vibration error is reduced, so that a photoacoustic signal having a good S / N ratio can be acquired.

  4A to 4C show a method of acquiring a photoacoustic signal having a density four times that of a normal one using a probe having a different number of receiving elements from that in FIG. In FIG. 4A, a three-element probe is used. In this case, by setting the moving distance for each laser emission to (1-1 / 4) × d, it is possible to obtain a photoacoustic signal having a density four times as high as that of a normal moving at a constant speed. In FIG. 4B, a seven-element probe is used. In this case, the distance traveled for each laser emission is (2-1 / 4) × d. In FIG. 4C, a 9-element probe is used. In this case, the moving distance for each laser emission is (2 + 1/4) × d. Even in these cases, as in the case described above, it is possible to obtain a dense signal using a probe that continuously moves at a constant speed.

  According to the present invention, photoacoustic signals having various densities can be acquired by continuous movement at a constant speed using probes having various numbers of elements. FIG. 5 specifically shows the optimum movement interval in units of element arrangement interval d and the movement distance per light emission period when a photoacoustic signal is acquired at a normal quadruple density using a probe with N arrangement elements. It is shown in. Even when the photoacoustic signal acquisition density is other than four times the normal density, the control speed and interval can be designed in the same way.

<Example 2>
6A to 6C show a method of acquiring photoacoustic signals having various densities using a probe having seven receiving elements. In FIG. 6A, the movement interval for each laser emission is (2-1 / 4) × d. In this case, a normal quadruple density photoacoustic signal can be acquired. In FIG. 6B, a normal three-fold density photoacoustic signal can be acquired by setting the movement interval to (2 + 1/3) × d. In FIG. 6C, a normal double-density photoacoustic signal can be acquired by setting the movement interval to (3 + 1/2) × d.
As described above, when the movement interval is expressed as (n ± 1 / k) × d using an integer n of 1 or more and an integer k of 2 or more, the distance d / k is small with a continuous movement method at a constant speed. Photoacoustic signals can be acquired at intervals. The integer k is determined according to the desired acquisition density, and can also be taken as the number of divisions.

<Example 3>
FIG. 7 specifically shows the division number k, the optimum movement interval, and the movement distance per light emission period when the number of elements N = 13. If the division number k is large, the moving distance per light emission period decreases, but a photoacoustic signal having a density k times higher can be acquired while continuously moving at a constant speed.
In order to implement the present invention, it is important that the optimum movement interval (n ± 1 / k) shown in FIG. 5 and FIG. 7 can be specifically calculated from the number N of receiving elements arranged and the division number parameter k. is there. The optimum movement interval (n ± 1 / k) can be calculated by, for example, a procedure as shown in FIG. In FIG. 11, a function Floor [x] is a function for obtaining a maximum integer not exceeding x.

Assuming that the laser emission cycle is ΔT and the element arrangement interval of the probe is d, the moving speed V of the probe according to the present invention can be expressed by the following equation (1).
V = (optimum movement interval) × d / (ΔT) (1)
Therefore, it can be understood that the moving speed of the moving table may be set to the speed V in the equation (1) in order to input an optical ultrasonic signal having a density of k times using the probe 8 having the number N of array elements.
Conversely, the necessary number N of array elements can be calculated from the division number k and the movement interval (n ± 1 / k) for each laser emission. A specific calculation formula for the number N of elements is expressed by Formula (2).
N = k × (n ± 1 / k) (2)
Therefore, if the movement interval is calculated from the desired movement speed V and the division number k based on the equation (1), the minimum required number N of receiving element arrangements can be easily obtained from the equation (2) based on the movement interval. It is done. That is, a photoacoustic signal can be acquired so as to realize the desired moving speed V and the division number k if the probe has N or more receiving elements calculated by Expression (2).

  This can be paraphrased as follows. In order to set the effective input range, a predetermined number or more of receiving elements are required in the first direction according to the moving distance of the probe. When control is performed such that light is emitted from the light source every time the probe moves a distance (n + 1 / k) times the arrangement interval d, at least (n × k + 1) elements are required. Further, when control is performed such that light is emitted from the light source every time the probe moves a distance (n−1 / k) times the arrangement interval d, at least (n × k−1) receiving elements is necessary. Thereby, it is possible to acquire photoacoustic signals at fine intervals so as not to be lost.

<Example 4>
FIG. 8 shows signal acquisition when the number of receiving elements N = 10. This is twice as many elements as the probe of FIG. By doing so, two photoacoustic signals derived from the photoacoustic waves generated at the same position on the subject are input two by two within the effective input range in the figure, so that the SN ratio can be improved by addition averaging. . Similarly, if the number of receiving elements is increased by M times, M signals can be acquired at the same position, so that the SN ratio can be further improved.

<Example 5>
In the above description, the probe is mechanically scanned linearly in the arrangement direction of the receiving elements. FIG. 9 shows a case where the probe is mechanically scanned along the circumference. FIG. 9A shows a state of scanning along the outside of the cylindrical subject 901. In this case, it is possible to generate a tomographic image such that the cylindrical subject is cut into a circle. FIG. 9B shows a state where the surface of the subject 902 is scanned in a circle. In this case, a cylindrical tomographic image can be generated in the depth direction of the paper surface.

<Modification>
In the above embodiments, a one-dimensional probe in which receiving elements are arranged in the first direction is shown for the sake of simplicity. However, the present invention can also be applied to a two-dimensional probe in which receiving elements are two-dimensionally arranged. In this case, elements are also arranged in a second direction (typically orthogonal) that intersects the first direction. A two-dimensional probe is considered that a plurality of one-dimensional probes are operating in parallel. By using such a two-dimensional probe, a wide area on the subject can be scanned at high speed.
Further, the two-dimensional probe may be moved in the second arrangement direction by (n ± 1 / k) times the receiving element arrangement interval as in the first direction. By such control, photoacoustic signals can be acquired at intervals of 1 / k of the receiving element arrangement interval also in the second direction.
Further, even when the elements are not adjacent to each other as in the sparse probe, there is no problem in applying the present invention with the element interval being d.
Further, the light source is not limited to the above-described pulse laser device, and an electromagnetic wave generator including microwaves, LED light, and the like may be used.

<Example 6>
In each of the above embodiments, the probe is configured to receive a photoacoustic wave. However, an ultrasonic wave (echo wave) that has been transmitted to the subject and then reflected within the subject can be used as a sound source. Even in the case of an ultrasonic sound source, if the ultrasonic sound source is fixed to the subject, the same echo wave is always generated from the detection target 6 regardless of the movement of the probe. Similarly, the present invention can be applied. In this case, the ultrasonic sound source may be single or may be composed of a plurality of sound sources operating in synchronization.
The ultrasonic sound source may be fixed to the moving probe as long as it generates a plane wave parallel to the moving direction of the probe. Even in this case, the present invention can be applied because the acoustic waves received by the receiving elements at the same point are substantially the same regardless of the movement of the probe.

FIG. 10 shows the configuration of the ultrasonic imaging apparatus of the present embodiment. In the figure, reference numeral 201 denotes an ultrasonic transmitter that generates an ultrasonic pulse from a position fixed to the subject. Reference numeral 202 denotes an ultrasonic signal generation circuit that drives the ultrasonic transmitter 201 and irradiates the subject with an ultrasonic pulse from the ultrasonic transmitter 01.
In this way, if the ultrasonic transmitter 201 is a position fixed with respect to the subject position, the same echo wave is always generated from the detection target 6 inside the subject 1, so that the present invention can be applied and described above. Effect.

  3a, 3b: moving table, 4: pulsed laser light source, 5: irradiated light, 7: photoacoustic wave, 8: probe, 9: received electric signal, 11: computer, 13: laser light source control circuit, 14: moving table control Circuit, 15: AD conversion circuit, 16: storage circuit, 17: image reconstruction circuit

Claims (9)

A light source;
A probe in which a plurality of receiving elements that receive an acoustic wave generated from a subject irradiated with light from the light source and convert it into an electrical signal are arranged in a first direction;
Moving means for moving the probe in the first direction;
Control means for controlling the light source and the moving means;
AD conversion means for converting the electrical signal converted by the receiving element into a digital signal;
Storage means for storing the digital signal converted by the AD conversion means;
Generating means for generating image data inside the subject based on the digital signal stored in the storage means;
Have
The control means, when n is an integer greater than or equal to 1 and k is an integer greater than or equal to 2, the probe has a distance of (n + 1 / k) times or (n−1 / k) times the array interval of the receiving elements. A subject information acquisition apparatus that performs control so that light is emitted from the light source each time the light source moves. The object information acquiring apparatus according to claim 1, wherein the moving unit moves the probe at a constant speed. The probe is
When the control means performs control such that light is emitted from the light source every time the probe moves a distance (n + 1 / k) times the arrangement interval of the receiving elements, at least (n × k + 1) Pieces,
When the control means performs control such that light is emitted from the light source every time the probe moves a distance of (n−1 / k) times the arrangement interval of the receiving elements, at least (n × k-1),
The object information acquiring apparatus according to claim 1, wherein the receiving elements are arranged in the first direction. 4. The object information acquiring apparatus according to claim 1, wherein the probe has a receiving element arranged in a second direction intersecting the first direction. 5. . The generating means adds and averages the digital signals derived from the acoustic waves received at the same position on the subject, and generates image data inside the subject based on the added and averaged signal. The object information acquiring apparatus according to claim 1, wherein: The object information acquiring apparatus according to claim 1, wherein the control unit moves the light source and the probe in synchronization. The object information acquiring apparatus according to claim 1, further comprising display means for displaying an image based on the image data generated by the generating means. An ultrasonic transmitter;
A probe having a plurality of receiving elements arranged in a first direction for receiving an echo wave reflected from the subject after being transmitted from the ultrasonic transmitter to the subject and converting it into an electrical signal;
Moving means for moving the probe in the first direction;
Control means for controlling the ultrasonic transmitter and the moving means;
AD conversion means for converting the electrical signal converted by the receiving element into a digital signal;
Storage means for storing the digital signal converted by the AD conversion means;
Generating means for generating image data inside the subject based on the digital signal stored in the storage means;
Have
The control means, when n is an integer greater than or equal to 1 and k is an integer greater than or equal to 2, the probe has a distance of (n + 1 / k) times or (n−1 / k) times the array interval of the receiving elements. A subject information acquisition apparatus that performs control such that an ultrasonic wave is transmitted from the ultrasonic transmitter each time the apparatus moves. A light source, a probe having a plurality of receiving elements arranged in a first direction, a moving means for moving the probe in the first direction, a control means for controlling the light source and the moving means, and an AD conversion means Storage means, generation means,
A method for controlling a subject information acquisition apparatus comprising:
A receiving step in which the plurality of receiving elements receive an acoustic wave generated from a subject irradiated with light from the light source and convert it into an electrical signal;
A digital conversion step in which the AD conversion means converts the electrical signal converted in the conversion step into a digital signal;
A storage step in which the storage means stores the digital signal converted in the digital conversion step;
A generating step for generating image data inside the subject based on the digital signal stored in the storing step;
Have
In the reception step, the control means is configured such that when n is an integer of 1 or more and k is an integer of 2 or more, the probe is (n + 1 / k) times the arrangement interval of the reception elements or (n−1 / k). (2) A control method for an object information acquiring apparatus, wherein control is performed so that light is emitted from the light source each time a double distance is moved.

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