Photoacoustic image input device and control method thereof

Abstract

The present invention provides a high-speed scanning photoacoustic image input device and method that can quickly generate high-resolution two-dimensional or three-dimensional images of an object to be inspected by inputting ultrasonic signals into the object to be inspected while moving an photoacoustic probe at high speed and converting them into two-dimensional or three-dimensional images. [Solution] A high-speed scanning photoacoustic image input device according to one embodiment of the present invention includes a photoacoustic transmitter / receiver (10, 20) that outputs a laser pulse output toward an object under inspection through a laser generator (10) and receives an ultrasound image signal emitted from the object under inspection through an ultrasound receiver (20) in response thereto; an analog-to-digital converter (30) that receives the ultrasound image signal and converts it into a digital image signal; a main controller (40) that receives the digital image signal and generates ultrasound image information related to the object under inspection; and a trigger controller (50) that receives motion information (encoder pulse signal) of the photoacoustic probe and generates a scan trigger signal corresponding to the motion information, receives the laser pulse output information (laser detection signal) and generates a laser trigger signal corresponding to the laser pulse output, and generates an output trigger signal corresponding to the laser trigger signal and outputs it to the analog-to-digital converter (30). The main controller (40) can generate an image of the object under inspection by sequentially synthesizing images corresponding to the ultrasound image signals corresponding to the output trigger signals in units of scan lines.

Description

[Technical Field]

[0001] The present invention relates to a high-speed scanning photoacoustic image input device and a control method thereof, and more particularly to a high-speed scanning photoacoustic image input device and a control method thereof that can generate two-dimensional or three-dimensional images of an object under examination (test subject) while moving an photoacoustic probe at high speed. [Background technology]

[0002] When a target object is irradiated with light with extremely high energy, the object absorbs the light energy and undergoes thermal elastic expansion. In this case, pressure waves are generated by the elastic expansion, and these pressure waves take the form of ultrasound. This phenomenon is known as the "photoacoustic effect," and the ultrasound signal generated by this expansion is called a photoacoustic signal.

[0003] Recently, technologies that utilize the photoacoustic effect to acquire information about the internal state of a target object and generate it as image information have been actively developed. Much research has been conducted on this topic, particularly in the medical field. In the medical field, visual confirmation of the internal state of a living body is sometimes required during the treatment of a disease. Currently, well-known methods for generating image information about the internal state of a living body include X-rays, CT scans, and MRI scans. However, these methods have been reported to have various drawbacks, such as high equipment costs, very low image resolution, a narrow field of view (FOV), long image generation times, and potential harm to the human body due to sustained use. Therefore, methods that utilize the photoacoustic effect to generate image information about the internal state of a living body (photoacoustic image) have been attracting attention as an alternative to this method.

[0004] However, for technology that generates image information of the inside of a living body to be effectively utilized in medical treatment, it is necessary to enable high-speed scanning, reduce the time required to generate an image, and obtain the inside of a living body's status information in real time. To achieve this, it is necessary to generate high-resolution images by ensuring a high signal-to-noise ratio (SNR) and a sufficient field of view (FOV). Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide a high-speed scanning photoacoustic image input device and method that can quickly generate high-resolution two-dimensional or three-dimensional images of an object to be inspected by inputting ultrasonic signals into the object to be inspected while moving an photoacoustic probe at high speed and converting them into two-dimensional or three-dimensional images. [Means for solving the problem]

[0006] A high-speed scanning photoacoustic image input device according to an embodiment of the present invention converts a unidirectional rotational motion of a driving motor into a linear reciprocating motion of a photoacoustic probe connected to the driving motor, and generates an image of the object to be inspected (test subject) by two-dimensionally scanning the object to be inspected using the linear motion of the photoacoustic probe and a vertical motion perpendicular to the linear motion. The high-speed scanning photoacoustic image input device includes a photoacoustic transmitting / receiving unit (10, 20) that outputs a laser pulse output toward the object to be inspected through a laser generating unit (10) and receives an ultrasound image signal emitted from the object to be inspected through an ultrasound receiving unit (20), and an analog-to-digital converter (ADC) that receives the ultrasound image signal and converts it into a digital image signal. The apparatus includes a conversion unit 30, a main control unit 40 that receives the digital image signal and generates ultrasound image information regarding the object to be inspected, and a trigger control unit 50 that receives motion information of the photoacoustic probe and generates a scan trigger signal corresponding to the motion information, receives the laser pulse output information and generates a laser trigger signal corresponding to the laser pulse output, and generates an output trigger signal corresponding to the laser trigger signal and outputs it to the analog-to-digital conversion unit 30, and the main control unit 40 can generate an image of the object to be inspected by sequentially synthesizing images corresponding to the ultrasound image signals corresponding to the output trigger signals in units of scan lines.

[0007] The analog-to-digital converter 30 can convert the ultrasound image signal (A-scan signal) corresponding to the output trigger signal from the ultrasound image signal input from the ultrasound receiver 20 into a digital image signal and transmit it to the main controller 40.

[0008] The main control unit 40 can sequentially synthesize the input digital video signals in units of scan lines to generate a line image (B scan signal), and can synthesize the line images of each scan line to generate a 3D image (C scan signal).

[0009] Each even-numbered line image can be synthesized in reverse order to generate an even-numbered image, which can then be synthesized with the odd-numbered image to generate a 3D image (C-scan signal).

[0010] The unidirectional rotational motion of the drive motor is converted into linear reciprocating motion of the optoacoustic probe by a slider crank mechanism, and the pair of optoacoustic probes are arranged so as to be spaced apart from each other in the same direction as the direction in which the rail extends on the slider, and the pair of optoacoustic probes can be arranged so as to be spaced apart at the same distance from the slider but twice the radius of rotation of the crank shaft.

[0011] The unidirectional rotational motion of the drive motor is converted into linear reciprocating motion of the optoacoustic probe by a slider crank mechanism, and the pair of optoacoustic probes are arranged so as to be spaced apart from each other in the same direction as the direction in which the rail extends on the slider, and the pair of optoacoustic probes can be arranged so as to be spaced apart at the same distance relative to the slider but at a distance less than twice the radius of rotation of the crank shaft.

[0012] The device further includes a beam splitter that splits the laser beam generated by the laser generating unit 10 into a first laser beam and a fourth laser beam, a photodetector (PD) that detects the fourth laser beam and generates a laser detection signal (pulse signal), and a coupling unit that reflects the first laser beam, irradiates the object to be inspected, and passes an ultrasonic signal generated in the object to be inspected, and the ultrasonic receiving unit 20 can receive the ultrasonic image signal that has passed through the coupling unit.

[0013] The ultrasonic wave receiving unit 20 may further include a first beam splitter (VBS1) for splitting the laser beam generated by the laser generating unit 10 into a first laser beam and a second laser beam, a second beam splitter (VBS2) for splitting the second laser beam into a third laser beam and a fourth laser beam, a photodetector (PD) for detecting the fourth laser beam and generating a laser detection signal, a first coupling unit (OAC1) for reflecting the first laser beam to irradiate a part of the object to be inspected and passing an ultrasonic signal generated from the object to be inspected, and a second coupling unit (OAC2) for reflecting the third laser beam to irradiate another part spaced a predetermined distance from the part of the object to be inspected and passing an ultrasonic signal generated from the object to be inspected. The ultrasonic wave receiving unit 20 may receive an ultrasonic image signal that has passed through the coupling units (OAC1, OAC2).

[0014] The coupling portion includes a coupling surface where two prisms are coupled, and the coupling surface is coated with an aluminum material to reflect the irradiated laser beam and pass the ultrasonic image signal.

[0015] The image generation unit of the main control unit can calculate the position of the photoacoustic probe corresponding to the output trigger signal and store the ultrasound image signal at the calculated position in correspondence with each output trigger signal.

[0016] The motion information of the photoacoustic probe is rotational motion information of a rotary encoder that detects the rotational motion of the drive motor, and the rotary encoder can be an incremental rotary encoder that outputs an A-phase signal, a B-phase signal, and a Z-phase signal.

[0017] The scan trigger signal is generated based on rotational position information from an A-phase signal of an incremental rotary encoder that detects the rotational motion of the drive motor, the linear motion position of the photoacoustic probe when generating each output trigger signal is calculated, and the ultrasound image signal at the calculated linear motion position can be stored corresponding to each output trigger signal.

[0018] The scan trigger signal is generated based on the linear motion position of the probe calculated by a linear encoder pulse signal generated by a linear encoder that detects the linear motion of the photoacoustic probe, and the ultrasound image signal at each linear motion position of the probe can be stored corresponding to each output trigger signal.

[0019] The motion information of the optoacoustic probe includes rotational motion information of a rotary encoder that detects the rotational motion of the drive motor and linear motion information of a linear encoder that detects the linear motion of the optoacoustic probe, where the rotary encoder is an incremental rotary encoder that outputs A-phase signals, B-phase signals, and Z-phase signals in pulse form, and the linear encoder can output linear pulse signals at regular pulse intervals depending on the position on the linear motion trajectory of the probe.

[0020] The unidirectional rotation of the drive motor is started, and the trigger control unit generates a first trigger event signal after an A-phase signal of a predetermined number of pulses (Z1) is input after the Z-phase signal of the rotary encoder is generated, and the scan trigger signal can be generated in pulse form up to a predetermined position of the photoacoustic probe using the pulse signal of the linear encoder as a synchronization signal when the first trigger event signal is generated.

[0021] The scan trigger signal may be generated at intervals that are an integer multiple of the pulse signal interval of the linear encoder.

[0022] The trigger control unit generates a second trigger event signal corresponding to a predetermined position of the optoacoustic probe after generation of the scan trigger signal stops, and when the second trigger event signal is generated, the scan trigger signal can be generated in pulse form up to the predetermined position of the optoacoustic probe using the pulse signal of the linear encoder as a synchronization signal.

[0023] The high-speed scanning photoacoustic image input device may further include a target area input unit that inputs an image of a target area including the object to be inspected, and a scan area extraction unit that extracts a scan area from the image of the target area determined by position values ​​corresponding to the start and end points of an area in which a photoacoustic image of the object to be inspected is acquired.

[0024] A method for controlling a high-speed scanning photoacoustic image input device according to an embodiment of the present invention can acquire a photoacoustic image using the high-speed scanning photoacoustic image input device. [Effects of the Invention]

[0025] According to the present invention, by moving an optoacoustic probe at high speed, receiving optoacoustic signals in real time and converting them into two-dimensional or three-dimensional images, high-resolution two-dimensional or three-dimensional image information of the object being examined can be generated at high speed.

[0026] Furthermore, photoacoustic image signals for an object to be inspected are acquired using a slider-crank mechanism, enabling high-speed scanning of the object.

[0027] In addition, the inclusion of a two-channel photoacoustic probe makes it possible to expand the field of view (FOV), enabling high-speed image acquisition of a wide range of inspection areas including the object under inspection.

[0028] Furthermore, when using a slider-crank mechanism, a pulse signal input after a set number of pulse signals have been input following input of an actual reference point pulse signal from the encoder is used as a virtual reference point pulse signal, thereby preventing problems that may occur due to the actual reference point pulse signal not being stably implemented and generating an accurate image of the object to be inspected.

[0029] In other words, there is a time difference between the start of the scanning operation using the actual reference point pulse signal (e.g., a Z-phase pulse signal) and the start of the acquisition of the photoacoustic signal (acquisition of image information) using the virtual reference point pulse signal, so noise and the like can be removed to obtain accurate, high-resolution image information.

[0030] Furthermore, by generating a scan trigger signal at a set encoder pulse signal interval, generating an output trigger signal in response to the scan trigger signal, and converting an input ultrasound image signal in response to the output trigger signal into an image signal for the target object, it is possible to accurately match set position information with image information corresponding to that position information, thereby enabling accurate image information for the target object to be generated at high speed. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a block diagram illustrating a high-speed scanning optical acousto-video input device according to an embodiment of the present invention; [Figure 2] 2 is a diagram illustrating a more specific embodiment of the high-speed scanning acousto-optical image input device of FIG. 1, and is a diagram illustrating a schematic example of a two-channel high-speed scanning acousto-optical image input device. [Figure 3] 3 is a diagram schematically showing a linear reciprocating motion drive unit of a two-channel photoacoustic probe of the high-speed scanning photoacoustic image input device of FIG. 2. FIG. [Figure 4] FIG. 4 is a schematic diagram of a slider-crank mechanism of a linear reciprocating drive of the optoacoustic probe of FIG. 3. [Figure 5] 2 is a timing diagram showing a schematic diagram of how an output trigger signal is generated in the high-speed scanning acousto-optical video input device of FIG. 1. FIG. [Figure 6] 2 is a diagram illustrating a process of scanning an object using a slider-crank mechanism in the high-speed scanning photoacoustic image input device of FIG. 1. FIG. [Figure 7] 10 is a block diagram illustrating a high-speed scanning optical acousto-video input device according to another embodiment of the present invention. [Figure 8]10 is a block diagram illustrating a high-speed scanning optical acousto-video input device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, specific details for carrying out the present invention will be described in detail based on preferred embodiments of the present invention with reference to the accompanying drawings. Hereinafter, components that are disclosed in the drawings of one embodiment and are the same as components disclosed in the drawings of other embodiments will be given the same reference numerals, and the descriptions in the other embodiments may be applied similarly, and detailed descriptions thereof may be omitted. Furthermore, known functions or configurations according to the present invention will be referred to in the prior art, and detailed descriptions thereof will be simplified or omitted.

[0033] Furthermore, the terms used in this specification are generally common terms currently in use, taking into consideration the functions of the present invention, but these may vary depending on the intentions or precedents of engineers in the art, the emergence of new technologies, etc. In addition, in certain cases, terms arbitrarily selected by the inventor may be used, and in such cases, their meanings will be described in detail in the description of the relevant invention. Therefore, the terms used in this specification should be defined based on the meanings of the terms and the overall content of the present invention, rather than simply the names of the terms.

[0034] Throughout this specification, when a part is said to "comprise" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless specifically stated to the contrary. Furthermore, as used herein, the term "module" refers to software components as well as hardware components such as FPGAs or ASICs. However, "module" is not limited to software or hardware. A "module" may be configured to reside on an addressable storage medium or to implement one or more processors. Thus, by way of example, "module" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within components and "modules" may be combined into fewer components and "modules" or further separated into additional components and "modules."

[0035] A method for generating a photoacoustic image of a target object, particularly the inside of a living body, using the photoacoustic effect is as follows: First, an optical beam (e.g., a laser beam) is irradiated onto a specific part of the living body from which a 3D image is to be obtained, and a photoacoustic signal (ultrasound signal) generated in response to thermoelastic expansion of the specific part by the irradiated beam is acquired through an ultrasound probe (ultrasound transducer), and the acquired photoacoustic signal is processed to generate image information of the inside of the living body.

[0036] A high-speed scanning optoacoustic imaging device according to an embodiment of the present invention may include a photoacoustic microscope (PAM). Furthermore, the optoacoustic probe of the PAM may scan a target area including an object to be inspected while moving at high speed using a slider-crank mechanism. The high-speed scanning optoacoustic imaging device may convert unidirectional rotational motion of a driving motor into linear reciprocating motion of an optoacoustic probe connected to the driving motor. Furthermore, the object to be inspected may be scanned two-dimensionally using the linear motion of the optoacoustic probe and a vertical motion perpendicular to the linear motion, thereby generating a three-dimensional image of the object to be inspected.

[0037] The photoacoustic microscope (PAM) of the present invention can use an optical-resolution photoacoustic microscope (OR-PAM) that focuses an optical beam (e.g., a laser beam) to achieve micron-scale spatial resolution. The optical-resolution photoacoustic microscope (OR-PAM) can utilize a high-resolution optical focus.

[0038] On the other hand, photoacoustic microscopy (PAM) can also use acoustic-resolution PAM (AR-PAM), which uses an acoustic focus with a resolution lower than that of optical-resolution photoacoustic microscopy (OR-PAM).

[0039] Optical resolution photoacoustic microscopy (OR-PAM) relies on an optical beam with much higher resolution than an acoustic beam, allowing it to obtain higher resolution images than acoustic resolution photoacoustic microscopy (AR-PAM). Furthermore, it has sufficient optical absorption contrast, making it a powerful imaging tool in many fields, including most medical fields such as biology, dermatology, neurology, oncology, ophthalmology, and pathology.

[0040] Optical resolution photoacoustic microscopy (OR-PAM) can employ confocal and coaxial configurations of optical excitation and acoustic detection beams to maximize the signal-to-noise ratio (SNR) and optimize spatial resolution. Spatial imaging is typically performed by point-by-point raster scanning of the optical and acoustic beams, which can be achieved using a stepper motor scanning stage.

[0041] Due to the scan step interval required for micron-level lateral resolution, the scan speed (and corresponding imaging speed) and scan range of optical resolution photoacoustic microscopy (OR-PAM) can be low (B-scan rate of approximately 1 Hz for a 1 mm scan range). Due to such low imaging speed, it has not been easy to obtain dynamic information on tissues, such as changing drug responses or skin vasculature, using optical resolution photoacoustic microscopy (OR-PAM).

[0042] On the other hand, there are various methods to improve the field of view (FOV), which corresponds to the scan range of an optical-resolution photoacoustic microscope (OR-PAM), increase the scan speed or shorten the scan time, and maintain a high signal-to-noise ratio (SNR). To realize an optical-resolution photoacoustic microscope (OR-PAM), a trade-off between these three characteristics is required. This trade-off can make it difficult to realize an optical-resolution photoacoustic microscope (OR-PAM) that satisfies all three characteristics. This is because the scan time depends on the laser pulse repetition rate and the scanning mechanism, and is limited by the sound speed of the photoacoustic wave (PA wave) in tissue.

[0043] To reduce the scanning time (to increase the scanning speed) in optical resolution photoacoustic microscopy (OR-PAM), various other methods can be used, such as galvanometer scanners, MEMS (microelectromechanical system) scanners, hexagon-mirror scanners, and voice-coil scanners. However, although these techniques have their own advantages, they have limitations such as not providing the maximum or optimal scanning speed.

[0044] A high-speed scanning photoacoustic imaging device according to one embodiment of the present invention can include a high-speed optical resolution photoacoustic microscope (OR-PAM) using a two-channel slider-crank mechanism, where the two channels can be used to double the field of view (FOV).

[0045] FIG. 1 is a block diagram of a high-speed scanning acousto-optical video input device 1 according to one embodiment of the present invention, and FIG. 2 is a more specific illustration of the high-speed scanning acousto-optical video input device 1 of FIG. 1, showing an embodiment of a two-channel high-speed scanning acousto-optical video input device.

[0046] Referring to the drawings, the high-speed scanning photoacoustic image input device 1 can convert the unidirectional rotational motion of the drive motor into linear motion of the photoacoustic probe 15 connected to the drive motor, for example, linear reciprocating motion in the +X and -X directions in FIG. 6, and can perform a two-dimensional scan of the object to be inspected using the linear motion of the photoacoustic probe 15 and motion perpendicular to the linear motion, for example, vertical motion in the Y direction in FIG. 6, to generate a three-dimensional image of the object to be inspected (subject).

[0047] The high-speed scanning photoacoustic video input device 1 can include photoacoustic transmitting and receiving units 10 and 20, an analog-to-digital conversion unit 30, a main control unit 40, and a trigger control unit 50.

[0048] The photoacoustic transmitter / receiver units 10 and 20 can output laser pulses generated by the laser generator unit 10 toward the object to be inspected through the photoacoustic probe 15 and receive ultrasonic image signals emitted from the object to be inspected in response through the ultrasonic probe 20. The photoacoustic transmitter / receiver units 10 and 20 can include the laser generator unit 10 that generates a laser beam and the ultrasonic receiver unit 20 that receives an ultrasonic signal, as well as a laser beam converter unit 11 that splits the laser beam and converts its path, the photoacoustic probe 15, and an ultrasonic probe 21 that inputs the ultrasonic signal. In this case, the ultrasonic receiver unit 20 can include the amplifier (AMP) shown in FIG. 2, or can include the ultrasonic probe unit 21 and the amplifier (AMP) depending on the viewpoint.

[0049] The analog-to-digital converter 30 can receive an ultrasound image signal and convert it into a digital image signal. The main controller 40 can include an image information generator that receives the digital image signal and generates ultrasound scan 3D image information of the object to be examined. The main controller 40 can display the 3D image information on a monitor, communicate with internal and / or external devices to input and / or output various signals, and control various components included in the high-speed scanning photoacoustic image input device 1.

[0050] The trigger control unit 50 can receive motion information (encoder pulse signal) of the photoacoustic probe 15 and generate a scan trigger signal corresponding to the motion information, receive laser pulse output information (laser detection signal) and generate a laser trigger signal corresponding to the laser pulse output, and generate an output trigger signal corresponding to the laser trigger signal and output it to the analog-to-digital conversion unit 30.

[0051] At this time, the main controller 40 can generate an image of the object to be inspected by sequentially synthesizing images corresponding to the ultrasound image signals corresponding to the output trigger signals in units of scan lines.

[0052] That is, the high-speed scanning photoacoustic image input device 1 includes basic photoacoustic transmitting and receiving units 10 and 20, an analog-to-digital converter 30, and a main control unit 40 so that a photoacoustic image can be captured using a laser pulse output and an ultrasound image signal, and may further include a trigger control unit 50 independent of these components. Therefore, with a simple configuration and control, it is possible to obtain an image of the object to be inspected in almost real time by two-dimensionally scanning the area to be inspected, and to generate a three-dimensional ultrasound image at ultra-high speed while ensuring a wide field of view (FOV).

[0053] The analog-to-digital converter 30 can convert the ultrasound image signal (A-scan image) corresponding to the output trigger signal among the ultrasound image signals input from the ultrasound receiver 20 of the photoacoustic transmitter / receiver 10, 20 into a digital image signal and transmit it to the main controller 40. Furthermore, the main controller 40 can sequentially combine the input digital image signals in units of scan lines to generate a line image (B-scan image), and can combine the line images of each scan line to generate a 3D image (C-scan image). Each even-numbered line image can be combined in reverse order to generate an even-numbered image, and can be combined with the odd-numbered images to generate a 3D image (C-scan image).

[0054] At this time, the trigger control unit 50 receives the laser detection signal and the rotary and / or linear encoder pulse signal input from the photoacoustic transceivers 10 and 20, generates a scan trigger signal and a laser trigger signal, respectively, and generates and outputs an output trigger signal synchronized with the laser trigger signal following the scan trigger signal. The analog-to-digital conversion unit 30 receives the output trigger signal from the trigger control unit 50, converts the ultrasound image signal (A-scan signal) corresponding to the output trigger signal among the ultrasound image signals input from the ultrasound receivers 20 of the photoacoustic transceivers 10 and 20 into a digital image signal and transmits it to the image generation unit, which sequentially combines the input digital image signals in units of scan lines to generate a line image (B-scan signal), and combines the line images of each scan line to generate a 3D image (C-scan signal).

[0055] In this case, each even-numbered line image is composited in reverse order to generate an even-numbered image, which is then composited with the odd-numbered image to generate a 3D image (C-scan signal). In this case, one rotation of the drive motor is converted into a linear reciprocating motion of the photoacoustic probe 15, so that one rotation of the motor can cover two scan lines, further increasing the scan speed. In addition, in this case, an accurate 3D image (C-scan signal) can be generated by composited the even-numbered line images and odd-numbered line images in reverse order.

[0056] Therefore, the present invention is capable of high-speed scanning with a wide field of view (FOV) for an object to be inspected using a slider-crank mechanism, and can accurately synthesize high-speed scanned images.

[0057] To this end, the high-speed scanning optoacoustic video input device 1 according to an embodiment of the present invention may further include a beam splitter (VBS), a photodetector (PD), and a combiner (OAC). The beam splitter (VBS) splits the laser beam generated from the laser generator 10 into a first laser beam and a fourth laser beam. In this case, the beam splitter (VBS) may be a variable beam splitter that can adjust the amount and / or size of each split laser beam.

[0058] The photodetector (PD) can detect the fourth laser beam and generate a laser detection signal as a pulse signal. The combiner (OAC) can reflect the first laser beam and irradiate it onto the object to be inspected, and combine the optical signal and the acoustic signal so that the ultrasonic signal generated by the object to be inspected passes through. The ultrasonic receiver (UT) 20 can receive the ultrasonic image signal that has passed through the combiner (OAC).

[0059] This embodiment relates to a one-channel high-speed scanning optoacoustic image input device including one optoacoustic probe 15. Most of the laser beam output from one laser generator 10 can be transmitted to the optoacoustic probe 15 through a beam splitter (VBS), and a relatively small laser beam can be transmitted to a photodetector (PD). In this case, referring to FIGS. 2 and 5, the photodetector (PD) can detect that the laser beam is transmitted to the optoacoustic probe 15 and transmit a laser detection signal to the trigger controller 50. In this case, the trigger controller 50 can generate a scan trigger signal from a rotary and / or linear encoder pulse signal, generate a laser trigger signal corresponding to a laser detection signal following the scan trigger signal, and generate an output trigger signal synchronized with the laser trigger signal and transmit it to the analog-to-digital converter 30.

[0060] Thus, the analog-to-digital converter 30 receives the output trigger signal and the ultrasound image signal, and stores the ultrasound image signal corresponding to the output trigger signal as an ultrasound image signal corresponding to the sequentially designated positions of the rotary and / or linear encoder, thereby synthesizing an accurate image corresponding to the object to be inspected for each scan line, i.e., acquiring ultrasound image signals corresponding to the sequentially designated positions of the rotary and / or linear encoder.

[0061] For this purpose, the image generating unit of the main control unit 40 can calculate the position of the photoacoustic probe 15 corresponding to the output trigger signal and store the ultrasound image signal at the calculated position in correspondence with each output trigger signal.

[0062] 2, the high-speed scanning photoacoustic imaging device 1 may further include a first beam splitter (VBS1), a second beam splitter (VBS2), a photodetector (PD), a first coupling unit (OAC1), and a second coupling unit (OAC2). This embodiment relates to a two-channel high-speed scanning photoacoustic imaging device including two photoacoustic probes 15, and can substantially double the field of view (FOV).

[0063] That is, a laser beam output from one laser generator 10 is split into two main laser beams and one signal laser beam through beam splitters (VBS1, VBS2), and the two main laser beams are mostly formed and transmitted to the photoacoustic probe 15 through the first coupler (OAC1) and the second coupler (OAC2), respectively. Furthermore, a relatively very small signal laser beam can be transmitted to the photodetector (PD).

[0064] The laser generating unit 10 generates a laser beam. The first beam splitter (VBS1) splits the laser beam into a first laser beam and a second laser beam. The second beam splitter (VBS2) splits the second laser beam into a third laser beam and a fourth laser beam. In this case, the beam splitter (VBS) can be a variable beam splitter that can adjust the amount and / or size of each split laser beam.

[0065] The photodetector (PD) can detect the fourth laser beam and generate a laser detection signal as a pulse signal.

[0066] The first combining unit (OAC1) reflects the first laser beam and irradiates it onto the object to be inspected, and combines the optical signal and the acoustic signal so that the ultrasonic signal generated by the object to be inspected can pass through. The second combining unit (OAC2) reflects the third laser beam and irradiates it onto a part of the object to be inspected, and combines the optical signal and the acoustic signal so that the ultrasonic signal generated by the object to be inspected can pass through. In this case, the third laser beam is reflected and irradiated onto another part spaced a certain distance from the part of the object to be inspected, and is irradiated onto an area of ​​the object to be inspected different from the first laser beam, thereby obtaining an image signal of the other area.

[0067] The ultrasonic wave receiving unit (UT) 20 can receive ultrasonic image signals at positions of the object to be inspected that are spaced apart by a predetermined distance and that have passed through the respective coupling units (OAC1, OAC2).

[0068] In this case, the photodetector (PD) can detect that the laser beam is transmitted to the photoacoustic probe 15 and transmit a laser detection signal to the trigger control unit 50. At this time, the trigger control unit 50 can generate a scan trigger signal from the rotary and / or linear encoder pulse signal, generate a laser trigger signal corresponding to the laser detection signal after the scan trigger signal, and generate an output trigger signal synchronized with the laser trigger signal and transmit it to the analog-to-digital conversion unit 30.

[0069] Thus, the analog-to-digital converter 30 receives the output trigger signal and the ultrasound image signal, and stores the ultrasound image signal corresponding to the output trigger signal as an ultrasound image signal corresponding to the sequentially designated positions of the rotary and / or linear encoder, thereby synthesizing an accurate image corresponding to the object of inspection for each scan line, i.e., acquiring ultrasound image signals corresponding to the sequentially designated positions of the rotary and / or linear encoder.

[0070] For this purpose, the image generating unit of the main control unit 40 can calculate the position of the photoacoustic probe 15 corresponding to the output trigger signal and store the ultrasound image signal at the calculated position in correspondence with each output trigger signal.

[0071] In this case, the positions corresponding to the positions of one rotary and / or linear encoder may be two positions at a fixed interval between a pair of photoacoustic probes 15, and a pair of input ultrasound image signals may correspond to each of them.

[0072] The first beam splitter (VBS1) receives a laser beam generated from the laser generator 10 and splits it into a first laser beam and a second laser beam. The laser beam generated from the laser generator 10 can be transmitted to the first beam splitter (VBS1) through a lens or a mirror in free space from the laser generator 10, or through an optical fiber. The generated laser beam is pulsed, and the pulse repetition rate can be adjusted.

[0073] The first laser beam and the third laser beam may be transmitted to the photoacoustic probe 15 and output to the object under test. As a result, ultrasonic signals returned from the object under test may be input to the analog-to-digital converter 30 via the photoacoustic probe 15. The photoacoustic probe 15 may include coupling units (OAC1, OAC2) and an ultrasonic receiver (UT). The coupling units (OAC1, OAC2) combine optical signals of the laser beams output toward the object under test with acoustic signals of the ultrasonic signals returned from the object under test. The coupling units (OAC1, OAC2) combine the optical signals and acoustic signals so that they partially overlap each other through a single member.

[0074] The coupling units (OAC1, OAC2) reflect the laser beam and irradiate it onto the target object. In this case, focusing can be performed using a convex lens, but an aspherical lens can be used for more accurate focusing. The laser beam reflected by the coupling units (OAC1, OAC2) causes the target object to thermally expand elastically, generating an ultrasonic signal that passes through the coupling units (OAC1, OAC2). The ultrasonic receiving unit (UT) receives the ultrasonic signal that has passed through the coupling units (OAC1, OAC2). Meanwhile, the coupling units (OAC1, OAC2) include a coupling surface where two prisms are coupled, and the coupling surface is coated with an aluminum material to reflect the irradiated laser beam and pass the ultrasonic signal.

[0075] In addition, in order to improve the ultrasonic reception performance of the ultrasonic receiver (UT), the ultrasonic signal passing through the coupling parts (OAC1, OAC2) can be received by the ultrasonic receiver (UT) through an acoustic lens, and the ultrasonic receiver (UT) can be provided on an ultrasonic probe that is positioned apart in the vertical direction of the XY plane on which the target object is located and moves in a zigzag pattern in the XY direction.

[0076] Image information about the object can be generated through a scanning process of an inspection area including the object, and the rotational motion of the rotating drive motor can be converted into a linear reciprocating motion of the photoacoustic probe 15 by a slider-crank mechanism.

[0077] FIG. 3 shows a schematic diagram of the linear reciprocating motion drive unit of the two-channel optoacoustic probe of the high-speed scanning optoacoustic video input device 1 of FIG. 2, and FIG. 4 shows a schematic diagram of the slider-crank mechanism of the linear reciprocating motion drive unit of the optoacoustic probe of FIG. 3.

[0078] Referring to the drawings, the high-speed scanning optoacoustic video input device 1 can convert the unidirectional rotational motion of the drive motor into linear translational motion of the optoacoustic probe 160 by a slider-crank mechanism. To this end, the pair of optoacoustic probes 160 are spaced apart from each other on the slider 150 in the same direction as the extension direction of the rail 140, and the pair of optoacoustic probes 160 can be spaced apart by the same distance (R) relative to the slider 150, which is twice the radius of rotation (R) of the crank shaft 120 (2R).

[0079] In this case, by arranging a pair of photoacoustic probes 160 so that they are spaced apart at the same distance (2R) from the slider 150, the maximum field of view (FOV) can be achieved when there are no missing parts in the object to be inspected and there are two or more photoacoustic probes 160.

[0080] In other embodiments, the pair of optoacoustic probes 160 can be spaced apart at the same distance (R) relative to the slider 150 but at a distance less than twice the radius of rotation (R) of the crankshaft 120 (2R).

[0081] In this case, there may be an overlapping portion between the pair of photoacoustic probes 160, which allows the observation field of view (FOV) to be expanded stably without missing any portion of the object to be inspected, which may be particularly useful when the scan trigger signal is generated at intervals that are two or more integer multiples of the linear encoder pulse signal.

[0082] The slider-crank mechanism 100 may include a drive shaft 110, a crank shaft 120, a connecting rod 130, a rail 140, a slider 150, and an optoacoustic probe 160. In this case, the drive shaft 110 may be a rotation shaft of a motor or may extend and be connected to the rotation shaft of a motor. The crank shaft 120 is fixed to the drive shaft and rotates, and one end of the crank shaft 120 may be connected to the connecting rod 130 as a rotary joint.

[0083] In addition, the rail 140 may be fixed to a frame, and the slider 150 may be provided via a linear guide or the like to allow linear movement on the rail 140. In this case, the slider 150 may be connected to an end of the connecting rod 130 opposite to the connection with the crankshaft 120 via a rotary joint. An optoacoustic probe 160 may be provided at the end of the slider 150.

[0084] Therefore, the rotation of the drive shaft 110 generates a rotational motion of the crankshaft 120 , and the rotational motion of the crankshaft 120 can generate a linear translational motion of the optoacoustic probe 160 fixed to the slider 150 .

[0085] Meanwhile, a counterbalance 105 may be connected to the other end of the crankshaft 120. Therefore, the crankshaft 120 may rotate stably, and vibration may be reduced during high-speed translational motion of the photoacoustic probe 160, allowing for stable translational motion.

[0086] In Figure 4, the center point O can be a fixed link, and point B can be a slider link. In the mechanical configuration, the fixed link corresponds to a drive motor that performs rotary motion, and the slider link corresponds to a scanning probe that performs linear reciprocating motion. In Figure 4, OC indicates a crank link, and CB indicates a coupler link. In the mechanical configuration, the crank link can correspond to the crank shaft, and the coupler link can correspond to a connecting rod.

[0087] One end of the crankshaft is fastened to the motor shaft, and the other end is connected to one end of a connecting rod in a manner similar to a hinge connection, with the other end of the connecting rod also connected to the probe in a manner similar to a hinge connection. When the motor rotates, the crankshaft rotates in the same direction as the motor, propelling one end of the connecting rod. This propulsive force is transmitted longitudinally to the other end of the connecting rod, inducing linear reciprocating motion of the probe (movement in the +X and -X directions). This mechanism is similar to the movement mechanism of the crankshaft and pistons used in a four-stroke engine, a type of internal combustion engine. Furthermore, to ensure the stability of the linear reciprocating motion, a linear guide is usually installed on the slider link (probe side).

[0088] Meanwhile, the motor side and the probe side are equipped with encoders that measure physical quantities related to each motion, such as the current position, motion speed, rotation speed, rotation angle, etc. The motor side is equipped with a rotary encoder that easily measures physical quantities related to rotational motion (rotational motion speed, rotation angle, etc.) because the motor rotates, and the probe side is equipped with a linear encoder that easily measures physical quantities related to linear motion (translational motion speed, translational motion distance, probe position, etc.) because the probe moves in a linear translational manner.

[0089] These encoders provide the measured physical quantities in the form of electrical signals to a controller that controls the operation of the motor or probe, and the controller controls the operation based on the provided physical quantities. Here, the expressions "motor side" and "probe side" are used to include cases where an encoder is built into the motor or probe and cases where it is not, and include cases where an encoder is actually built into the motor or probe and cases where an encoder is provided on the exterior of the motor or probe.

[0090] The scanning process for an object using a slider-crank mechanism will be briefly explained with reference to Figure 6. The Nth line (line #N) of the object is scanned in one direction of the probe's translational movement (+X direction). After scanning the Nth line, the probe moves in the Y direction and then scans the N+1th line (line #N+1) in the opposite direction of the translational movement (-X direction). In other words, alternating scanning is performed line by line, resulting in a so-called zigzag two-dimensional scan.

[0091] FIG. 5 shows the signal processing flow in the trigger control unit 50.

[0092] Referring to the drawing, the trigger control unit 50 receives a laser detection signal and a rotary encoder and / or linear encoder pulse signal to generate a scanning trigger signal and a laser trigger signal, and generates an output trigger signal synchronized with the laser trigger signal and transmits it to the analog-to-digital conversion unit 30.

[0093] The scan trigger signal can be generated in synchronization with the rising time of each pulse signal from the rotary encoder. Furthermore, the laser trigger signal can be generated in synchronization with the laser detection signal, which is generated by detecting a laser beam pulse using a photodetector (PD), or with the first rising time after the scan trigger signal is generated. Therefore, the laser trigger signal can be generated in response to the scan trigger signal. When a position on the encoder is specified by the scan trigger signal, the laser trigger signal is generated at the specified position. At this time, an output trigger signal synchronized with the laser trigger signal can be generated and transmitted to the analog-to-digital converter 30.

[0094] In another embodiment, the scan trigger signal may be generated at intervals that are an integral multiple of the pulse signal interval of the rotary encoder. In this case, the interval of the scan trigger signal may be determined according to an externally set resolution. This allows for fewer ultrasound output signals and fewer ultrasound image signals to be output, thereby reducing the load on ultrasound signal generation and processing.

[0095] In another embodiment, the image quality of the image signal generated in real time is evaluated and the interval between scan trigger signals is adaptively adjusted, thereby reducing the load on ultrasound signal generation and processing while still obtaining optimal quality images.

[0096] Encoders are broadly classified as incremental encoders and absolute encoders depending on the method of measuring the physical quantity. Incremental encoders and absolute encoders have different slit shapes. The former have uniform slit shapes, while the latter have unique slit shapes. The difference in slit shapes between the two leads to the need for a reference point (origin) in measuring the physical quantity. The former requires a reference point, while the latter does not. The former has the disadvantage that if a certain problem occurs (such as an unexpected power outage or an unexpected interruption in motion), all information about the physical quantity provided to the motor or probe motion controller is lost (returning to the reference point), and the measurement of the physical quantity must be restarted from the beginning. On the other hand, the latter does not require a reference point, so unlike the former, there is no such concern even if a problem occurs. Unlike the former, the latter has the advantage that, once the problem is resolved, the measurement of the physical quantity can be resumed immediately after the problem occurs. In other words, the continuity of physical quantity measurement can be ensured.

[0097] However, in the latter case, due to the characteristics of the slit shape, it takes a very long time to manufacture it, the design of the related motor operation control mechanism becomes very complicated or difficult, and the realization of the control mechanism also requires a lot of time and effort, which ultimately leads to an increase in the cost required to obtain the final result, such as the production of a product, and furthermore, the cost is much higher than when using the former under the same conditions, so in most industrial fields, the former is used much more despite its disadvantages.

[0098] However, in the case of the former, due to the above drawbacks, it is difficult to utilize in fields requiring precise or continuous control of motor and device (probe) operation. In particular, since it is difficult to ensure the stability (stable realization) of the reference point for several reasons, there is a problem with the reliability of the information generated (information to be obtained) about the target object. In other words, the generated information may be inaccurate. The former reference point generates a so-called Z-phase pulse signal, which is generated every time the motor rotates once. This signal serves as a reference signal (reference point) for measuring the physical quantity. However, as described above, since it is difficult to stably realize the reference point, this may cause imperfections in the control of motor and device (probe) operation, which may result in inaccuracy of the generated information.

[0099] Therefore, in the present invention, when image information related to an object is acquired using a slider-crank mechanism, problems that may occur due to the reference point not being stably realized can be compensated for by predetermined signal processing, thereby ensuring (improving) the accuracy (reliability) of the image information generated related to the object.

[0100] On the other hand, an encoder is required to determine the position on a straight line (X coordinate in Figure 6) of the photoacoustic probe 15 where each signal is input for sequentially input ultrasound image signals to be stored and / or processed, and embodiments using only a rotary encoder, an embodiment using both a rotary encoder and a linear encoder (Figure 8), and an embodiment using only a linear encoder (Figure 7) can be used.

[0101] In an embodiment using only a rotary encoder, the linear position of the optoacoustic probe 15 can be calculated and used from a Z-phase input corresponding to the initial position of the rotary encoder and an A-phase or B-phase input corresponding to the incremental position.

[0102] In an embodiment using both a rotary encoder and a linear encoder (FIG. 8), the linear position of the optoacoustic probe 15 can be calculated and used based on the Z-phase input corresponding to the initial position of the rotary encoder and the incremental position of the linear encoder.

[0103] In an embodiment using only a linear encoder, the linear position of the optoacoustic probe 15 can be calculated and used based on an initial input corresponding to the initial position of the linear encoder and incremental positions of the linear encoder.

[0104] In one embodiment, the motion information of the optoacoustic probe can be rotational motion information of a rotary encoder that detects the rotational motion of the drive motor, and the rotary encoder can be an incremental rotary encoder that outputs an A-phase signal, a B-phase signal, and a Z-phase signal.

[0105] 2 and 5, when the scan trigger signal is generated in the trigger control unit 50 based on rotational position information from the A-phase signal of an incremental rotary encoder that detects the rotational motion of the drive motor, the linear motion position of the photoacoustic probe 15 at the time of generation of each output trigger signal can be calculated, and the ultrasound image signal at the calculated linear motion position can be stored corresponding to each output trigger signal.

[0106] However, when using an incremental encoder, it can be difficult to ensure the stability of the reference point. Specifically, when forming the slit (reference point) from which the Z-phase pulse signal is generated during the manufacturing process of an incremental rotary encoder, the slit may be formed at a location other than the intended one due to process issues. Or, if a rotary encoder already has a slit formed, the position of the slit may become distorted due to storage issues or deformation caused by temperature and humidity. Such a distorted slit position makes it difficult to accurately detect the motor's rotation angle or rotation speed. Specifically, if the position of a slit intended to represent a specific rotation angle becomes distorted, the actual rotation angle indicated by the slit may be different from the desired rotation angle. However, because the rotary encoder recognizes the slit as representing the desired rotation angle, a discrepancy occurs between the actual angle of the slit and the expected angle. This discrepancy can lead to unreliable measurements of the motor's rotation angle or rotation speed. Furthermore, mechanical vibrations that may occur during the movement of the motor and probe can also cause the generation of the Z-phase pulse signal to become unstable.

[0107] This inevitably leads to inaccuracy of image information generated using a slider-crank mechanism, and since the reference point becomes unstable, the reference signal for controlling the operation of the motor and device (probe) becomes unstable, which causes distortion of the generated image information such as distortion and noise of the image signal. As a solution to this problem, the present invention introduces a virtual Z-phase pulse signal (virtual Z) to ensure the accuracy of the generated image information.

[0108] In this case, in an embodiment using both a rotary encoder and a linear encoder (Figure 8), unidirectional rotation of the drive motor is initiated, and the trigger control unit 50 generates a first trigger event signal after a Z-phase signal from the rotary encoder is generated and an A-phase signal with a preset number of pulses is input, and when the first trigger event signal is generated, the scan trigger signal can be generated in pulse form up to a preset position of the photoacoustic probe using the pulse signal from the linear encoder as a synchronization signal.

[0109] Furthermore, the trigger control unit 50 generates a second trigger event signal corresponding to a predetermined position of the photoacoustic probe after generation of the scan trigger signal stops, and when the second trigger event signal is generated, the scan trigger signal can be generated in pulse form up to the predetermined position of the probe using the pulse signal of the linear encoder as a synchronization signal.

[0110] In another embodiment, when only a linear encoder is used (FIG. 7), the unidirectional rotation of the drive motor is initiated, and the trigger control unit 50 can generate a first trigger event signal after a pulse signal of a preset number of pulses is input after the initial reference signal of the linear encoder is generated.

[0111] The scan trigger signal is generated based on the linear motion position of the probe calculated by a linear encoder pulse signal generated by a linear encoder that detects the linear motion of the optoacoustic probe, and the ultrasound signal at each linear motion position of the probe can be stored corresponding to each output trigger signal.

[0112] In another embodiment, in an embodiment where only a rotary encoder is used, the scan trigger signal can be generated in pulses up to a predetermined position of the optoacoustic probe after the first trigger event signal is generated, using the pulse signal of the rotary encoder as a synchronization signal.

[0113] The trigger control unit 50 can generate a reception trigger signal for an ultrasonic signal based on motion information of the photoacoustic probe 15. In this case, the trigger control unit 50 generates a scan trigger signal based on rotational position information from an A-phase signal of an incremental rotary encoder that detects the rotational motion of the drive motor, and can calculate the linear motion position of the photoacoustic probe when each scan trigger signal is generated.

[0114] Meanwhile, the trigger control unit 50 can generate the scan trigger signal based on the linear movement position of the probe calculated from a pulse signal generated by a linear encoder that detects the linear movement of the probe. That is, the scan trigger signal can also be generated based only on the linear movement position of the probe 10 detected from a pulse signal generated by a linear encoder without using a rotary encoder.

[0115] Meanwhile, the trigger control unit 50 can generate a scan trigger signal by simultaneously using rotational motion information from a rotary encoder that detects the rotational motion of the drive motor and linear motion information from a linear encoder that detects the linear motion of the probe. In this case, the rotary encoder is an incremental rotary encoder that outputs A-phase, B-phase, and Z-phase signals in pulse form, and the linear encoder outputs linear pulse signals at regular pulse intervals according to the position on the linear motion trajectory of the probe.

[0116] On the other hand, it is most desirable to always maintain the interval between the generated scan trigger signals equal to the interval between the pulse signals of the linear encoder (because this allows for the acquisition of as much status information of the object as possible contained in the ultrasound signal, thereby enabling the generation of higher-resolution image information). However, this may require excessive processing time for the acquired status information and increase the load on the process of generating a photoacoustic image of the object. This may result in inaccuracies in the generated image information (because the increased load may cause errors in the process of generating image information), thereby diminishing the significance of the present invention. Therefore, the amount of status information required to be acquired must be appropriately determined taking into account various factors such as the type and status of the object, which is determined by the wavelength (output step) of the generated trigger signal. For example, if the interval (resolution) of the pulse signals of the linear encoder is 20 μm, the trigger control unit 50 may generate trigger signals with intervals of 40 μm, 60 μm, 80 μm, etc.

[0117] Meanwhile, after the first trigger event signal is generated and the trigger signal is generated in pulse form using the pulse signal of the linear encoder as a synchronization signal up to the preset position of the probe, the generation of the trigger signal stops (thereby stopping reception of the ultrasound signal and completing acquisition of the state information of the object corresponding to the Nth scan line), and a second trigger event signal is generated corresponding to another preset position of the probe 15 in order to acquire state information of the object corresponding to the N+1th scan line. When the second trigger event signal is generated, the trigger signal is generated in pulse form using the pulse signal of the linear encoder as a synchronization signal up to the preset position of the probe.

[0118] In the above explanation, the first trigger event signal and the second trigger event signal correspond to virtual Z-phase pulse signals (virtual Z), and acquisition of state information is not initiated by the generation of an actual Z-phase pulse signal (physical Z); acquisition of state information is initiated only by the generation of these two event signals. That is, in the present invention, the actual Z-phase pulse signal is assigned only the role of notifying "start of scan operation," and the role of notifying "start of state information acquisition" is assigned to these two event signals; here, "virtual" means that these two event signals function "in accordance with" the actual Z-phase pulse signal, since they perform part of the role that the actual Z-phase pulse signal should play.

[0119] If the "start of scan operation" and the "start of status information acquisition" are performed simultaneously (without time lag) due to the generation of an actual Z-phase pulse signal, the stable realization of the actual Z-phase pulse signal cannot be guaranteed, as described above. In conclusion, the acquisition of status information may become unstable or inaccurate, so these two event signals according to the present invention are significant in compensating for this. The generation of these two event signals results in the acquisition of status information only for a portion of each scan line (the thick line portion in FIG. 2) rather than the entire section.

[0120] Meanwhile, according to the present invention, as described above and shown in FIG. 3, a status information acquisition start event signal (trigger event signal) is generated "for each scan line," which differs from the fact that an actual Z-phase pulse signal occurs only once every two scan lines. This is to ensure the reliability of acquiring status information corresponding to each scan line. That is, due to the nature of the movement of the slider-crank mechanism, the actual Z-phase pulse signal occurs only once every two scan lines. However, as described above, there is a possibility of instability in the actual Z-phase pulse signal, which may make it unclear which scan line the acquired status information corresponds to. Therefore, to prevent this ambiguity, the present invention generates a trigger event signal for "starting status information acquisition" for each scan line.

[0121] 5 shows a timing diagram of a method for generating an output trigger signal in the high-speed scanning photoacoustic image input device 1. Hereinafter, an embodiment in which a scan trigger signal is generated by a linear encoder pulse signal will be mainly described with reference to FIGS.

[0122] The trigger control unit 50 detects the generation of a pulse signal corresponding to the initial position of the linear encoder and starts counting the number of input pulse signals of the linear encoder. When the number of linear encoder pulse signals reaches a preset value (Counting Num: Z1), the trigger control unit 50 generates a first trigger event signal, and generates scanning trigger signals at intervals equal to an integer multiple of the set number of input pulses of the linear encoder after the generation of the first trigger event signal.

[0123] Furthermore, a laser trigger signal is generated in synchronization with the rising edge of the laser detection signal pulse following the scan trigger signal, and an output trigger signal is generated in synchronization with the laser trigger signal and transmitted to the analog-to-digital converter 30.

[0124] At this time, when the number of scan trigger signals reaches a preset number, the generation of the scan trigger signal is stopped. In another embodiment, the scan trigger signal may continue to be generated, but the generation of the laser trigger signal and the output trigger signal may be stopped.

[0125] As a result, in the embodiment shown in Fig. 6, half a rotation of the drive motor is completed, and scanning of the Nth scan line is completed. At this time, before starting scanning of the next (N+1)th scan line, the probe moves a set distance in the Y direction in Fig. 6. For this purpose, the scan module including the photoacoustic probe 15 can be provided on a moving module such as a gantry that is movable in the Y direction.

[0126] The number of input linear encoder pulses is counted and when it reaches a preset value, a second trigger event signal is generated. In another embodiment, the number of pulses of a scanning trigger signal is counted and when it reaches a preset value, a second trigger event signal is generated.

[0127] After generating the second trigger event signal, the scanning trigger signal is generated at intervals that are an integer multiple of the set number of input pulses of the linear encoder. Furthermore, the laser trigger signal is generated in synchronization with the rising edge of the laser detection signal pulse that follows the scanning trigger signal. Furthermore, the output trigger signal is generated in synchronization with the laser trigger signal and transmitted to the analog-to-digital converter 30.

[0128] At this time, the generation of the scanning trigger signal is stopped when the number of scanning trigger signals reaches a preset number. In another embodiment, the generation of the scanning trigger signal may continue, but the generation of the laser trigger signal and the output trigger signal may be stopped.

[0129] This completes 2 / 2 rotation of the drive motor in the embodiment shown in FIG. 6, completing scanning of the N+1th scan line.

[0130] Meanwhile, the control method of the high-speed scanning optoacoustic video input device is for controlling the high-speed scanning optoacoustic video input device of FIGS. 1 to 8, and the control method described for the high-speed scanning optoacoustic video input device of FIGS. 1 to 8 can be applied as is.

[0131] A control method for a high-speed scanning optoacoustic image input device includes the steps of splitting one pulse laser beam output from one laser generator into a first laser beam and a second laser beam, splitting the second laser beam into a third laser beam and a fourth laser beam, generating a laser detection signal pulse from the fourth laser beam, guiding the first laser beam and the third laser beam to different first and second optoacoustic probes, respectively, receiving a first ultrasonic signal from the first optoacoustic probe, receiving a second ultrasonic signal from the second optoacoustic probe, generating an output trigger signal from the laser detection signal pulse and a linear encoder pulse signal which is motion information of the first and second optoacoustic probes, and generating a three-dimensional image of the object to be inspected from the output trigger signal and the first and second ultrasonic signals.

[0132] The first laser beam splitter (VBS1) and the second laser beam splitter (VBS2) are variable beam splitters, and the first and third laser beams have the same size but are much larger than the fourth laser beam. In this case, the fourth laser beam is not used to acquire photoacoustic images but is used to detect that a laser signal is being output, and it is sufficient that the fourth laser beam is at a level that can be detected by a photodetector (PD).

[0133] In one embodiment, the size ratio of the first laser beam, the third laser beam, and the fourth laser beam may be 4:4:2.

[0134] 7 and 8 show high-speed scanning optical acousto-visual input devices 2 and 3 according to other embodiments of the present invention.

[0135] Referring to the drawings, the high-speed scanning photoacoustic image input devices 2 and 3 include a target area input unit 80 and a scan area extraction unit 90, and can receive photoacoustic images only for the necessary part of the target area including the object to be inspected, rather than the entire scan area.

[0136] The target area input unit 80 inputs an image of a target area including an object to be inspected. The scan area extraction unit 90 can extract a scan area from the image of the target area, the scan area being determined by position values ​​corresponding to the start and end points of an area in which a photoacoustic image of the object to be inspected is acquired.

[0137] For this purpose, the target area input unit 80 may include a separate optical camera capable of capturing an image of the target area. The scan area extraction unit 90 may recognize the inspection object from the image of the target area and extract the inspection object. Furthermore, the scan area extraction unit 90 may extract an area that includes the extracted inspection object and the set margin area as a scan area for acquiring a photoacoustic image.

[0138] That is, an input image of the target area is input using a target area input unit 80 such as a separate optical camera, and a scan area extraction unit 90 recognizes the object to be photographed from the input image and extracts only the object to be photographed and sets it as the scan area. In this case, it is possible to set the image to be input in units of each scan line only for the scan area. As a result, laser pulses can be output (and / or ultrasound image signals) at set intervals only in a predetermined area, thereby enabling rapid input of photoacoustic images while minimizing the load on the photoacoustic transceiver, digital converter, and main control unit (image generator).

[0139] For this purpose, the scanning device including the optoacoustic probe 15 can be provided on a moving module such as a gantry movable in the XY direction or the XYZ direction in FIG.

[0140] In another embodiment, the target area input unit 80 and the scan area extraction unit 90 can move the scan module in the entire area to a position determined by an algorithm in which the scan starting point is determined according to the position of the object to be inspected.

[0141] In another embodiment, the target area input unit 80 may include a 3D camera such as a Time of Flight (TOF) camera, and the scan area extraction unit 90 may move the scanning device to a position determined by a preset algorithm, where the scan start point is determined according to the position of the object to be inspected. In this case, the position of the scan start point may be a three-dimensional coordinate value of X, Y, and Z moved by a moving module.

[0142] At this time, the scan of the object is not performed over the entire area (AR) where the scanning device can be positioned, but is performed only over the area (PR) where status information of the object needs to be acquired, thereby preventing the generation of unnecessary data during the status information acquisition process. To this end, in the present invention, after imaging the object as a step prior to scanning the object and acquiring status information, the size of the area (PR) where status information needs to be acquired is determined from the captured image, and status information acquisition (scanning the object) can be performed only over the area (PR) corresponding to this size.

[0143] The laser beam converter 11 includes beam splitters (VBS1, VBS2) and a photodetector (PD), generates a laser detection signal pulse in response to the laser pulse of the fourth laser beam detected by the photodetector (PD), converts the received ultrasound signal into a video signal using the laser detection signal pulse as a trigger, and the video generator receives the converted video signal to generate a photoacoustic image of the object. At this time, since the ultrasound signal contains status information of the object, the status information of the object is ultimately generated as a photoacoustic image.

[0144] The high-speed scanning photoacoustic image input device according to the present invention can be used particularly for medical diagnoses that require visual and immediate confirmation of the inside of a living body, and as an example, can be used for diabetic foot diagnosis.

[0145] Diabetic foot (DM Foot Ulcer) is a general term for neuropathy, structural deformities, calluses, changes in the skin and nail plate, ulcers, infections, and vascular disease that appear in the feet of diabetic patients. As diabetic foot disease progresses, even small wounds do not heal and turn into ulcers, and in severe cases, blood circulation is restricted, causing the feet to turn black and rotten.

[0146] Diagnosing diabetic foot disease requires first capturing images of the inside of a patient's foot. However, conventional methods widely used to generate image information from inside the body, such as X-ray, CT, and MRI, do not easily visualize blood vessels accurately and take a long time to do so, making it difficult to determine whether or not the disease is progressing and to what extent. Therefore, diagnosing diabetic foot disease using these methods is largely based on inference from a doctor's clinical experience, which involves confirming and analyzing the presence or absence of diabetes and the patient's current physical condition, and reliability cannot be guaranteed.

[0147] However, if this invention is used in diagnosing diabetes, a photoacoustic microscope can be combined with a high-speed scanning device to generate high-speed, high-resolution images of the inside of the foot, thereby improving the slow scanning speed of existing photoacoustic microscope systems and enabling early diagnosis of diabetic foot lesions.In addition, because it uses non-invasive ultrasound and light (laser) within a range that is harmless to the human body, the patient and doctor can face each other during the treatment, and the patient's foot blood vessels can be visualized quickly within 60 seconds, allowing for a diagnosis of diabetic foot lesions.

[0148] The technical concept of the present invention has been described above through the disclosure of preferred embodiments of the present invention that ensure the concreteness of the concept. Those skilled in the art will understand that the preferred embodiments can be embodied in modified forms without departing from the technical concept (essential characteristics) of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective, and the scope of the present invention should be interpreted to include not only the matters disclosed in the claims but also all variations within the scope of equivalents thereto.

Claims

1. A photoacoustic probe is moved in a linear direction and in a vertical direction perpendicular to the linear direction to two-dimensionally scan an object to be inspected, thereby generating an image of the object to be inspected (subject), a photoacoustic transmitting / receiving unit (10, 20) that outputs a laser pulse toward the object to be inspected through a laser generating unit (10) and receives an ultrasonic image signal emitted from the object to be inspected in response thereto through an ultrasonic receiving unit; an analog-to-digital converter (30) that receives the ultrasound image signal and converts it into a digital image signal; a main control unit (40) that receives the digital image signal and generates ultrasound image information relating to the object to be examined; an encoder that receives motion information of the photoacoustic probe and generates an encoder pulse signal; a laser detection signal output means for detecting the laser pulse and outputting a laser detection signal; a trigger control unit (50) that generates a scan trigger signal that is adjustably generated at intervals that are an integer multiple of the signal interval of the encoder pulse signal according to the resolution, receives the laser detection signal, generates a laser trigger signal that corresponds to the laser pulse output, generates an output trigger signal that is synchronized with the laser trigger signal that follows the scan trigger signal, and outputs the output trigger signal to the analog-to-digital conversion unit (30); The main control unit (40) calculates the position of the photoacoustic probe corresponding to the output trigger signal, stores the ultrasound image signals at the calculated positions in correspondence with each output trigger signal, and sequentially combines them in scan line units to generate an image of the object to be inspected.

2. The main control unit (40) sequentially synthesizes the input digital video signals on a scan line basis to generate a line image, synthesizes the line images of each scan line to generate a three-dimensional image, The acousto-optical image input device according to claim 1 , wherein each even-numbered line image is synthesized in reverse order to generate an even-numbered image, which is then synthesized with the odd-numbered image to generate a three-dimensional image.

3. a first beam splitter (VBS1) for splitting the laser beam generated by the laser generating unit (10) into a first laser beam and a second laser beam; a second beam splitter (VBS2) that splits the second laser beam into a third laser beam and a fourth laser beam; a photodetector (PD) that detects the fourth laser beam and generates a laser detection signal; a first coupling unit (OAC1) that reflects the first laser beam and irradiates it onto a part of the object to be inspected, and that passes an ultrasonic signal generated from the object to be inspected; a second coupling unit (OAC2) that reflects the third laser beam and irradiates another portion of the object to be inspected at a predetermined distance from the portion of the object to be inspected, and that passes an ultrasonic signal generated from the object to be inspected; 2. The photoacoustic image input device according to claim 1, wherein the ultrasonic wave receiving unit (20) receives the ultrasonic image signal that has passed through the coupling unit (OAC1, OAC2).

4. the trigger control unit generates a second trigger event signal corresponding to a preset position of the photoacoustic probe after generation of the scan trigger signal has stopped; The photoacoustic video input device according to claim 1 , wherein when the second trigger event signal is generated, the scan trigger signal is generated in pulse form up to a predetermined position of the photoacoustic probe using a pulse signal of the linear encoder as a synchronization signal.

5. a target area input unit that inputs an image of a target area including the object to be inspected; The photoacoustic image input device according to claim 1, further comprising: a scan area extraction unit that extracts a scan area determined by position values ​​corresponding to a start point and an end point of an area in which a photoacoustic image of the object to be inspected is acquired from the image of the target area.

6. A method for controlling an acousto-optical image input device for acquiring an acousto-optical image by using the acousto-optical image input device according to claim 1 .

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