Photoacoustic array probe capable of enhancing virtual detection point by means of driving actuator

Abstract

The present invention relates to a photoacoustic array probe comprising: a transducer array in which a plurality of transducer elements for detecting photoacoustic waves generated by light irradiated at a subject are arranged; an acoustic reflector arranged to face the transducer array so as to form a plurality of virtual detection points having a function of detecting the photoacoustic waves by reflecting ultrasonic waves generated from the plurality of transducer elements; and a driver for driving rotational motion of the acoustic reflector and / or linear motion of the transducer array and the acoustic reflector, wherein the formation range of the virtual detection points increases according to driving of the driver.

Description

Photoacoustic array probe capable of augmenting virtual detection points by driving a driver

[0001] This invention relates to photoacoustic imaging, which is attracting attention as a next-generation medical imaging technology.

[0002] Conventional array ultrasonic transducer-based photoacoustic imaging devices (Prior Art 1) had a vast number of piezoelectric elements in the transducer array, such as 512 channels, applied to increase the numerical aperture (NA) to improve spatial resolution, and consequently, there was a problem of incurring significant costs in implementing the related invention.

[0003] As such, transducer arrays with vast channels have acted as a major obstacle to commercialization by driving up not only the cost of acquiring the transducers themselves but also the cost of the data acquisition (DAQ) devices that must be linked with them. This is because typically, the same number of DAQ channels as the number of channels in the transducer array is required.

[0004] In addition, conventional technology had many shortcomings in terms of spatial resolution because the center frequency of the transducer array was mostly low at 10 MHz or less (although this was not a major issue in terms of image speed and image depth), and the space occupied by the system was also excessively large, making it very difficult to implement it in a scaled-down form such as an endoscope or handheld probe.

[0005] The present invention was developed to solve the aforementioned problems, and the objective of the present invention is to provide a photoacoustic array probe capable of securing a virtual acoustic aperture sufficient for forming a high-resolution photoacoustic image and having excellent image resolution, even while minimizing the number of transducer elements.

[0006] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0007] A photoacoustic array probe according to one embodiment of the present invention comprises: a transducer array in which a plurality of transducer elements are arranged to detect a photoacoustic wave generated by light irradiated onto a subject; an acoustic reflector disposed facing the transducer array and forming a plurality of virtual detection points having the function of detecting the photoacoustic wave by reflecting ultrasound generated from the plurality of transducer elements; and an actuator configured to drive at least one of the rotational movement of the acoustic reflector and the linear movement of the transducer array and the acoustic reflector, and may be configured such that the formation range of the virtual detection points increases according to the driving of the actuator.

[0008] In addition, the acoustic reflector may include a wedge-shaped acoustic reflector having a wedge-shaped cross-sectional shape.

[0009] In addition, the acoustic reflector may include a tiltable acoustic reflector capable of adjusting the angle of inclination relative to the transducer array.

[0010] Additionally, the actuator may include a rotary motor shaft to which the acoustic reflector is coupled; and a rotary motor that rotates the rotary motor shaft so that the acoustic reflector rotates.

[0011] Additionally, the actuator may include a table portion to which the transducer array and the acoustic reflector are coupled; a rail portion to which the table portion is linearly movable; and a driving motor for linearly moving the table portion.

[0012] Additionally, it may further include a rotating plate on which the rail portion is mounted; and a motorized rotating stage to which the rotating plate is coupled so as to be rotatable relative to it.

[0013] In addition, a plurality of the above transducer elements can be arranged in a row or in a matrix.

[0014] In addition, the transducer array may include 4 to 16 transducer elements.

[0015] In addition, multiple transducer elements can be arranged along a curved shape with the center inwardly curved.

[0016] In addition, the acoustic reflector may be positioned at an angle inclined with respect to the transducer array.

[0017] Other specific details of the present invention are included in the detailed description and drawings.

[0018] A photoacoustic array probe according to one embodiment of the present invention has the effect of being able to secure a virtual acoustic aperture sufficient for forming a high-resolution photoacoustic image and having excellent image resolution, even when the number of transducer elements is minimized.

[0019] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0020] FIGS. 1a and 1b are schematic diagrams for explaining the principles that form the basis of the present invention, based on the principles of sound wave reflection already known in acoustics.

[0021] FIG. 2 is a schematic diagram illustrating the core device concept underlying the device provided by the present invention.

[0022] FIG. 3 is a schematic diagram showing the structure of a photoacoustic array probe according to one embodiment of the present invention.

[0023] FIG. 4 is a schematic diagram showing a rotary motor equipped with a wedge-shaped acoustic reflector having a variable inclination angle of the sound wave reflection surface in a photoacoustic array probe according to one embodiment of the present invention.

[0024] FIG. 5 is a schematic diagram showing a structure in which an LD (laser diode) or LED (light emitting diode) array is applied as a laser light source to a photoacoustic array probe according to one embodiment of the present invention.

[0025] FIG. 6 is a schematic diagram showing an embodiment in which a photoacoustic array probe provided by the present invention is mounted on the base of a conventional endoscope.

[0026] The present invention is capable of various modifications and may have various embodiments; therefore, specific embodiments are illustrated in the drawings and described in detail. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0028] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0029] In the following embodiments, singular expressions include plural expressions unless the context clearly indicates otherwise. In the embodiments below, terms such as "include" or "have" mean that the features or components described in the specification exist, and do not preclude the possibility that one or more other features or components may be added. In the embodiments below, when a component is said to be "connected" to another component, this includes not only being directly connected to that other component, but also being indirectly connected by another component.

[0030] As previously mentioned, the present invention provides an advanced imaging device capable of solving the problem of high system costs that has arisen in conventional transducer array-based photoacoustic imaging devices by simply increasing the numerical aperture (NA) to increase spatial resolution by applying a transducer array having a vast number of piezoelectric elements (e.g., the 2D matrix transducer of Prior Art 1).

[0031] First, before presenting the detailed features of the device provided by the present invention, with reference to FIGS. 1a and 1b, the physical effect that occurs when an acoustic reflector (20) is placed obliquely in front of a transducer array (10) is explained based on the principle of sound wave reflection already known in basic acoustics applied to the present invention.

[0032] FIGS. 1a and 1b are schematic diagrams for explaining the principles underlying the present invention based on the principles of sound wave reflection already known in acoustics, and FIG. 2 is a schematic diagram for explaining the core device concept underlying the device provided by the present invention.

[0033] Of course, throughout this specification, unless otherwise noted, all mentioned transducer arrays (10) and acoustic reflectors (20) are assumed to be basically submerged in a liquid fluid such as water, oil, etc., and the acoustic reflectors (20) involved in the invention are assumed to be made of a material having very high acoustic impedance, such as glass or metal.

[0034] In this way, when a transducer array (10) and an acoustic reflector (20) are arranged in the configuration shown, if the transducer array (10) emits ultrasound in the -Y axis direction, it is reflected almost 100% by the acoustic reflector (20) and propagates downward (i.e., in the -Z direction) according to the principle of reflection of sound waves already well known in acoustics. This means that, according to the principle of time reversal inherent in the acoustic wave equation, acoustic wave propagation is possible in the reverse direction of the direction in which the aforementioned ultrasound propagated.

[0035] In this way, the sound wave reflection phenomenon caused by the acoustic reflector (20) having the above arrangement provides an effect equivalent to the transducer array (10) being placed on the transducer array (10'), regardless of which direction the sound wave travels mentioned above. That is, it means that a virtual transducer array (10') corresponding to the original transducer array (10) is placed at the mirror image position formed by the acoustic reflector (20). Of course, a two-dimensional transducer array (10) was assumed in the above discussion, but this effect is the same even if a single or one-dimensional transducer array is applied.

[0036] The simple principle of sound wave reflection and the resulting physical effect are shown in FIG. 2, which illustrates the core device concept underlying the device provided by the present invention. Even if the tilted angle of the acoustic reflector (20) is changed to "position R2" or "position R3" instead of the initially assumed 45° (i.e., position R1), it provides the effect of moving the position of the transducer array (10) to "position T1," "position T2," and "position T3" in correspondence with the respective changing positions of the aforementioned acoustic reflector (20). That is, a simple angle manipulation of the acoustic reflector (20) provides an effect equivalent to changing the angle of view of the virtual target "o" shown in FIG. 2, which, assuming that a photoacoustic wave is generated at the virtual target "o", provides an effect in which the composite numerical aperture of the transducer array (10) detecting the generated sound wave is much more enhanced than the range in which the corresponding transducer elements (10e) were originally distributed (span) on the transducer array (10).

[0037] Of course, this increase in the number of sound wave detection apertures is not achieved indirectly by changing the angle of the acoustic reflector (20) as described above, but can also be achieved by removing the acoustic reflector (20) and tilting the body of the transducer array (10) while the transducer array (10) is directly facing a virtual target “o”. However, the reason for applying such a method (like looking indirectly at an object through a mirror in everyday life) is that the body length of the transducer array (10) generally applied in related photoacoustic imaging systems is long, and the wires connected to it are usually rigid, making it difficult in reality to achieve smooth tilting of the transducer body.

[0038] FIG. 3 is a schematic diagram showing the structure of a photoacoustic array probe according to one embodiment of the present invention.

[0039] Now, referring to FIG. 3, the structure of a photoacoustic array probe applying the principle described in FIG. 2 according to one embodiment of the present invention will be explained in detail.

[0040] First, the scan drive unit, which is the most core part of the photoacoustic array probe provided by the present invention and has actual physical movement through a predetermined sequence of movements like an industrial robot, is largely composed of a two-dimensional matrix transducer array (10) facing in the -Y direction, a wedge-shaped acoustic reflector (21) that rotates in one direction while facing it at an oblique angle, a rotary motor (30) that provides rotational force to the wedge-shaped acoustic reflector (21) through a rotary motor shaft (31), a motor support frame (32) that supports the rotary motor (30), a linear stage (40) that provides additional linear movement to the rotary motor (30) equipped with the wedge-shaped acoustic reflector (21) through the aforementioned transducer array (10) and motor support frame (32), and a motorized rotary stage (50) that is equipped to rotate the assembly of all the aforementioned components.

[0041] Additionally, the transducer array (10) is configured to detect photoacoustic waves generated by light irradiated onto a test subject, and a plurality of transducer elements (10e) are arranged to individually receive these photoacoustic signals. Accordingly, a plurality of virtual detection points corresponding to mirror images of the transducer array (10) are formed by the reflection action of the wedge-shaped acoustic reflector (21), which can provide an acoustic detection function corresponding to the actual transducer elements (10e). Here, a motor for a rotating plate may be installed in the motorized rotating stage (50) to rotate the rotating plate relative to it.

[0042] In this way, the actuator may be configured to drive at least one of the rotational motion of the wedge-shaped acoustic reflector (21) and the linear motion of the transducer array (10) and the wedge-shaped acoustic reflector (21). The actuator may include a rotary motor (30) and a linear stage (40).

[0043] That is, the motor support frame (32) and the transducer array support frame (12) that supports the transducer array (10) are mounted on the table portion (40-1) of the linear stage (40), so that linear movement is performed with respect to the rail portion (40-2) by a driving motor (not shown) included in the linear stage (40), and in addition to this movement, the rail portion (40-2) of the linear stage (40) is mounted on the rotating plate of the motorized rotating stage (50), so that all elements mounted on the linear stage (40) can rotate around the Y-axis.

[0044] Here, the reason the wedge-shaped acoustic reflector (21) is rotated by the rotary motor (30) to have a wedge-shaped cross-section when cut along the YZ plane is to increase the total solid angle, that is, the synthetic aperture number, of looking at an acoustic point source according to the principle described in FIG. 2 above, thereby creating a virtual detection point that is much more than the actual number of transducer elements (10e) distributed on the surface of the applied transducer array (10), and the reason for adding linear and rotational motion to the wedge-shaped acoustic reflector (21) and the transducer array (10) that are rotated by the rotary motor (30) is to perform a three-dimensional spatial scan.

[0045] In this regard, the motorized rotating stage (50) does not necessarily have to be continuously rotated in one direction, but rather a method of reciprocating scanning, similar to how a person turns their head back and forth, can be applied. If one wishes to scan in all 360° directions by continuously rotating the motorized rotating stage (50) in one direction, it would be desirable to apply a hollow motorized rotating stage (50). In this case, the transducer array cable (11) is connected to the probe body (90) via an empty space on the central axis of the hollow motorized rotating stage (50). In other words, the probe body (90) is provided with an internal space formed in the direction of the central axis so that the transducer array cable (11) can pass through, thereby preventing the cable (11) from being twisted or damaged by tension despite the rotational movement of the hollow motorized rotating stage (50).

[0046] Of course, in the example of FIG. 2, the acoustic reflector (20) rotates only about the X-axis, so the number of apertures in the YZ plane increases, but in the embodiment of FIG. 3, since the wedge-shaped acoustic reflector (21) rotates by the rotation motor (30), the reflective surface of the reflector also rotates about the Y-axis, so the resulting composite number of apertures increases in the XZ plane as well. That is, the spatial angle of looking at an acoustic point source increases not only along the Y-axis direction but also along the X-axis direction.

[0047] Of course, when actually drawing the relevant diagram, it is easy to see that when a wedge-shaped acoustic reflector (21) having a specific angle of inclination simply rotates by a rotary motor (30), the spatial angle increasing along the Y-axis direction and the spatial angle increasing along the X-axis direction are different. However, the problem of anisotropic increase in numerical aperture in these two directions can be corrected by setting the number of transducer elements (10e) of the transducer array (10) differently for the X-axis and Z-axis directions or by adjusting the distribution range (i.e., span range). For reference, FIG. 3 shows a transducer array (10) in which 4x4 piezoelectric elements are arranged at a uniform pitch for the X-axis and Z-axis directions, and the number of piezoelectric elements and the pitch for the two directions do not necessarily have to be the same. However, of course, for the purpose of the present invention, having the minimum number of elements applied to reach the desired image resolution will add to the significance of the present invention.

[0048] Accordingly, when rotational movement of the wedge-shaped acoustic reflector (21) or linear movement of the transducer array (10) and the wedge-shaped acoustic reflector (21) is performed, the position of the virtual transducer array (10) changes continuously, thereby increasing the formation range of the corresponding virtual detection point.

[0049] As the present invention ultimately aims to provide a photoacoustic array probe, the relevant optical illumination unit will be described with reference to FIG. 3.

[0050] Here, the optical illumination unit refers to optical elements that irradiate a laser beam necessary to induce ultrasound, also known as photoacoustic waves, by irradiating a very short laser pulse to a subject according to the already well-known photoacoustic effect, and various forms are possible considering the imaging performance that is particularly of interest. However, in FIG. 3, since the main motivation of the present invention was to pursue deep imaging (i.e., deep imaging) while ultimately implementing it in the form of a miniaturized probe such as an endoscope or a handheld probe, the laser beam necessary to induce photoacoustic waves is guided from a base (not shown) through two strands of optical fibers (70) arranged on the left and right sides of a linear stage (40) with respect to the Y-axis, and the illumination is performed by applying an illumination optical system (60) that irradiates the laser beam irradiated to the subject in a somewhat wide spread rather than concentrating it.

[0051] For this reason, the illumination optical system (60) according to the present invention does not necessarily need to move physically in conjunction with the aforementioned elements, and can be implemented in a form that can extensively illuminate the entire area or even a wider range of the area where a three-dimensional image is to be obtained. For example, the illumination optical system (60) can be implemented so that illumination light is emitted along the entire 360° direction of the scanning head case (80). Meanwhile, the scanning head case (80) may include a transducer array (10), a transducer element (10e), a transducer array cable (11), a transducer array support frame (12), an acoustic reflector (20), a rotary motor (30), a rotary motor shaft (31), a motor support frame (32), a linear stage (40), a table section (40-1), a rail section (40-2), a motorized rotary stage (50), an illumination optical system (60), an LD or LED array (61), and an optical fiber (70).

[0052] Of course, if you want to make the lighting optical system (60) physically move together with the aforementioned elements, you can add a collimator (not shown) to the end of the optical fiber (70) and make it move by shooting it at the lighting optical system (60).

[0053] Above, the scan driving unit, which is the core of the present invention, and the illumination optical system (60) that irradiates a laser beam onto the subject have been described.

[0054] Due to these configurational features, if we assume that a user of the device provided by the present invention detects a photoacoustic wave by firing a single laser pulse, the laser pulse typically applied to the photoacoustic has a nanosecond pulse length, so the mirror image of the transducer elements (10e) by the wedge-shaped acoustic reflector (21) points in a specific direction at a specific location, and thus only a photoacoustic A-line data set having exactly the same number as the applied transducer elements (10e) can be detected, which propagates along that location and direction. However, if this process is repeated whenever the wedge-shaped acoustic reflector (21) rotates by a certain angle, the virtual transducer elements (10e) generated by the wedge-shaped acoustic reflector (21), that is, the photoacoustic waves approaching from the virtual detection position and direction that change with each rotation angle, can be detected, thereby collecting a set of photoacoustic signals that is much more than the number of actual mounted transducer elements (10e), and thus, the image performance of conventional similar systems can be achieved with a much smaller number of transducer elements (10e) than before.

[0055] The general principle of the device provided by the present invention has been explained above through FIG. 3. However, FIG. 3 is merely an example presented to aid in understanding the core concept of the present invention, and it is obvious that the transducer array support frame (12) and the motor support frame (32) are not essential elements for establishing the core principle. In addition, FIG. 3 illustrates a transducer array (10) in which transducer elements (10e) are distributed in a planar form, but this is not strictly necessary, and they may be distributed in a curved form with the center slightly inward or outward.

[0056] Meanwhile, FIG. 3 presents a photoacoustic probe structure with a wedge-shaped acoustic reflector (21) having a fixed inclination of the reflective surface. However, according to another embodiment of the present invention, the inclination of the reflective surface of the wedge-shaped acoustic reflector can be variably moved.

[0057] FIG. 4 is a schematic diagram showing a rotary motor equipped with a wedge-shaped acoustic reflector having a variable inclination angle of the sound wave reflection surface in a photoacoustic array probe according to one embodiment of the present invention.

[0058] Referring to FIG. 4, the tiltable acoustic reflector (20T) rotated by the rotary motor (30) can have its tilt angle adjusted over a predetermined range. The tilt angle can change moment by moment during the process of rotation by the rotary motor (30) according to a preset algorithm, and unlike the fixed detection space angle formed by the wedge-shaped acoustic reflector (21) shown in FIG. 3, it can be freely adjusted, thereby allowing the composite aperture value to be changed to a desired level.

[0059] The above presents the core device concept that the present invention aims to provide. However, since the purpose of the present invention is to reduce the economic costs required to implement the related device, it is also possible to implement a photoacoustic probe structure in which the laser light source, which has been known to account for the highest cost proportion in the field of photoacoustic imaging technology, is replaced with an economical light source such as an LD or LED.

[0060] FIG. 5 is a schematic diagram showing a structure in which an LD or LED array is applied as a laser light source to a photoacoustic array probe according to one embodiment of the present invention, and FIG. 6 is a schematic diagram showing one embodiment in which the photoacoustic array probe provided by the present invention is mounted on the base of a conventional endoscope.

[0061] That is, in FIG. 3, a structure was adopted in which laser light is induced from the outside using an optical fiber (70) and then an appropriate light irradiation area and working distance are formed using an illumination optical system (60) to irradiate the tissue to be examined. However, in this embodiment, these two elements are omitted, and an LD or LED array (61) is placed at the location where the illumination optical system (60) was located. As a result, the pulsed laser light source, which has accounted for a high proportion of the cost in conventional systems, is eliminated and replaced with a more economical light source. Consequently, the implementer of the present invention and the subject can obtain cost savings on the light source in addition to the cost savings in the transducer array part described above, thereby achieving a double economic benefit. Since the remaining elements shown in FIG. 5 are the same as those in FIG. 4, a detailed description of the roles and functions of each element is omitted.

[0062] In addition to the purpose of reducing system costs as explained in the background section of the invention, the purpose of the present invention is to make it easier to implement the related system in a miniaturized form, such as an endoscope probe or a handheld probe, through the unique probe structure provided by the present invention. In this regard, through FIG. 6, it is intended to emphasize that the photoacoustic array probe (2) provided by the present invention can be mounted on the base of an existing endoscope device (1).

[0063] The core device concept of the present invention has been described above. Although this specification presents the implementation of only photoacoustic imaging functions based on the probe structure provided by the present invention, it will be self-evident to those skilled in the art that conventional ultrasound imaging functions can also be added.

[0064] To summarize the core concept of the present invention, with reference to FIG. 2, the principle of increasing the acoustic aperture when looking at a target (sound source) was explained, and this principle was achieved by providing and applying a wedge-shaped acoustic reflector (21) that rotates by a rotary motor (30) in an embodiment presented in FIG. 3. Furthermore, in a situation where these core elements are operating, the part that needs to be scanned over a certain range to obtain a three-dimensional image from the tissue under examination can be achieved by rotating and translating the corresponding part using a linear stage (40) and a motorized rotary stage (50) according to a pre-set operation algorithm.

[0065] Of course, there have been many instances of applying acoustic reflectors in this field. However, acoustic reflectors applied in conventional technologies were primarily intended for performing spatial scanning, and there have been no cases where they were applied for the purpose of increasing the signal detection aperture for a single sound source, as in the present invention.

[0066] To reiterate, for transducer array-based photoacoustic endoscopes to contribute to actual clinical diagnosis, the center frequency of the applied array element must be high, exceeding 20 MHz, as the technology possesses the distinctive advantage of being able to present vascular images. However, implementing a vast number of channels at this center frequency, as in conventional systems, was not even contemplated due to the enormous cost.

[0067] A photoacoustic array probe according to one embodiment of the present invention comprises a transducer array (10) in which a plurality of transducer elements (10e) are arranged to detect photoacoustic waves generated by light irradiated onto a subject, an acoustic reflector (20) arranged to face the transducer array (10) and forming a plurality of virtual detection points that have the function of detecting the photoacoustic waves by reflecting ultrasonic waves generated from the plurality of transducer elements (10e), and a driver configured to drive at least one of the rotational movement of the acoustic reflector (20) and the linear movement of the transducer array (10) and the acoustic reflector (20), and may be configured such that the formation range of the virtual detection points increases according to the driving of the driver.

[0068] Additionally, the acoustic reflector (20) may include a wedge-shaped acoustic reflector (21) having a wedge-shaped cross-sectional shape.

[0069] Additionally, the acoustic reflector (20) may include a tiltable acoustic reflector (20T) capable of adjusting the angle of inclination relative to the transducer array (10).

[0070] Additionally, the actuator may include a rotary motor shaft (31) to which the acoustic reflectors (20, 21) are coupled, and a rotary motor (30) that rotates the rotary motor shaft (31).

[0071] The above actuator may include a table section (40-1) to which the transducer array (10) and the acoustic reflector (20, 21) are coupled, a rail section (40-2) to which the table section (40-1) is linearly movable, and a driving motor that linearly moves the table section (40-1). Here, the table section (40-1) and the rail section (40-2) may be sub-components of a linear stage (40).

[0072] Additionally, it may further include a rotating plate on which the rail portion (40-2) is mounted and a motorized rotating stage (50) to which the rotating plate is coupled so as to be rotatable relative to each other.

[0073] Additionally, a plurality of the above transducer elements (10e) can be arranged in a row or in a matrix.

[0074] Additionally, the transducer array (10) may include 4 to 16 transducer elements (10e).

[0075] Additionally, the plurality of transducer elements (10e) may be arranged along a curved shape with the center recessed inward. In other words, among the plurality of transducer elements (10e), the one placed in the center may be positioned inwardly compared to the one placed at the edge.

[0076] Additionally, the acoustic reflectors (20, 21) may be positioned at an angle inclined with respect to the transducer array (10).

[0077] A photoacoustic array probe according to one embodiment of the present invention has the effect of being able to secure a virtual acoustic aperture sufficient for forming a high-resolution photoacoustic image and having excellent image resolution, even when the number of transducer elements is minimized.

[0078] In this regard, the present invention reduces the enormous costs previously incurred in securing transducer arrays, which are a core element of related systems, and creates an opportunity to apply transducer arrays with a high center frequency of, for example, 50 MHz or higher, thereby significantly improving the image resolution performance ultimately provided by the related device as well as the diagnostic benefits to patients when applied in actual clinical settings.

Claims

1. A transducer array comprising a plurality of transducer elements arranged to detect photoacoustic waves generated by light irradiated onto a subject; Acoustic reflectors arranged to face the transducer array and forming a plurality of virtual detection points having the function of detecting the photoacoustic waves by reflecting ultrasonic waves generated from a plurality of transducer elements; and It includes a driver configured to drive at least one of the rotational movement of the acoustic reflector and the linear movement of the transducer array and the acoustic reflector, and A photoacoustic array probe configured such that the formation range of the virtual detection point is increased according to the driving of the above actuator.

2. In Paragraph 1, The above acoustic reflector is, A photoacoustic array probe comprising a wedge-shaped acoustic reflector having a wedge-shaped cross-sectional shape.

3. In Paragraph 1, The above acoustic reflector is, A photoacoustic array probe comprising a tiltable acoustic reflector capable of adjusting the relative tilt angle with respect to the transducer array.

4. In Paragraph 1, The above actuator is, A rotary motor shaft to which the above acoustic reflector is coupled; and A photoacoustic array probe comprising a rotary motor that rotates the rotary motor shaft so that the acoustic reflector rotates.

5. In Paragraph 1, The above actuator is, A table portion in which the above transducer array and the above acoustic reflector are combined; A rail portion to which the above table portion is linearly movably coupled; and A photoacoustic array probe comprising a drive motor that linearly moves the above table portion.

6. In Paragraph 5, A rotating plate on which the above rail portion is mounted; and A photoacoustic array probe further comprising a motorized rotating stage to which the above-mentioned rotating plate is coupled so as to be rotatable relative to it.

7. In Paragraph 1, A plurality of the above-mentioned transducer elements are arranged in a row or matrix, forming a photoacoustic array probe.

8. In Paragraph 1, The above transducer array is a photoacoustic array probe comprising 4 to 16 transducer elements.

9. In Paragraph 1, A photoacoustic array probe in which multiple transducer elements are arranged along a curved shape with an inward center.

10. In Paragraph 1, The above acoustic reflector is a photoacoustic array probe positioned at an angle inclined with respect to the transducer array.

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