KR102180436B1 - 3D Photoacoustic imaging apparatus - Google Patents

Abstract

According to the present invention, a 3D photoacoustic imaging apparatus capable of generating a 3D photoacoustic image by scanning an ultrasonic collector and capable of variously adjusting the resolution of a 3D photoacoustic image is disclosed.
A 3D photoacoustic imaging apparatus according to an embodiment of the present invention includes a laser irradiation unit for irradiating a laser pulse onto an object; An ultrasonic collection unit for collecting a photoacoustic signal generated by thermoelastic expansion of the object by the laser pulse; A scanning unit that moves the ultrasound collection unit to scan an examination area of the object; And a photoacoustic generating unit generating a 3D photoacoustic image using the photoacoustic signal collected from the ultrasonic collecting unit. The photoacoustic generation unit generates 2D photoacoustic images using photoacoustic signals collected while moving the ultrasound collection unit, and combines the 2D photoacoustic images based on scan positions of the ultrasound collection unit to obtain the 3D Generate photoacoustic images.

Description

3D photoacoustic imaging apparatus

The present invention relates to a 3D photoacoustic imaging apparatus, and more particularly, to a 3D photoacoustic imaging apparatus that generates a 3D photoacoustic image using photoacoustic signals sequentially collected by scanning an inspection area of an object. will be.

Photoacoustic imaging technology is a technology for imaging an object, such as a living body tissue, using a photoacoustic effect. When a non-ionizing laser pulse is radiated to an object, the emitted energy is converted into heat in the object, and among them, a wide band of ultrasonic waves is generated due to thermoelastic expansion. In this way, the photoacoustic imaging technology collects ultrasonic waves generated from an object by a laser pulse using an ultrasonic transducer and constructs an image using the collected ultrasonic information.

Patent Document 1 (Korean Patent Publication 10-2017-0093378, published on August 16, 2017) discloses a blood clot detection system based on photoacoustic imaging. The photoacoustic imaging technology disclosed in Patent Document 1 is limited to the position of an ultrasonic sensor in which an examination area of an object senses photoacoustics. In addition, there is a problem in that it is difficult to accurately identify diseases such as blood clots of an object with a 2D image generated from photoacoustic information collected by an ultrasonic sensor.

KR 10-2017-0093378 A

The present invention is to provide a 3D photoacoustic imaging device capable of generating a 3D photoacoustic image by scanning an ultrasonic collector.

In addition, the present invention is to provide a 3D photoacoustic imaging apparatus capable of variously adjusting the resolution of a 3D photoacoustic image.

A 3D photoacoustic imaging apparatus according to the present invention includes a laser irradiation unit for irradiating a laser pulse onto an object; An ultrasonic collection unit for collecting a photoacoustic signal generated by thermoelastic expansion of the object by the laser pulse; A scanning unit that moves the ultrasound collection unit to scan an examination area of the object; And a photoacoustic generator configured to generate a 3D photoacoustic image by using the photoacoustic signal collected from the ultrasonic collector. The photoacoustic generation unit generates 2D photoacoustic images using photoacoustic signals collected while moving the ultrasound collection unit, and combines the 2D photoacoustic images based on scan positions of the ultrasound collection unit to obtain the 3D Create photoacoustic images.

The 3D photoacoustic imaging apparatus according to an embodiment of the present invention may further include a control unit for controlling the scanning unit by collecting the photoacoustic signals from the ultrasonic collecting unit.

When the photoacoustic signal is collected at a first position from the ultrasonic collecting unit, the controller may control the scanning unit to move the ultrasonic collecting unit to collect the photoacoustic signal at the second position.

The ultrasonic collection unit includes a probe unit that collects the photoacoustic signal, and the probe unit includes a probe support formed in a hemispherical shape recessed toward the opposite side of the object, and a two-dimensional array on the hemispherical surface of the probe support. It may include a plurality of ultrasonic probes.

The laser irradiation unit may include a laser generator that generates the laser pulse and a laser output unit that outputs the laser pulse to the object, and the laser output unit may be provided at the center of the probe unit.

The scan unit may be configured to rotate the probe unit around the object.

The scanning unit may include: a first stage configured to scan an inspection area of the object in the vertical direction by moving the ultrasound collection unit in a vertical direction; And a second stage for rotating the ultrasound collection unit around the object to scan the examination area of the object in a circumferential direction.

The second stage includes a circular rotating plate that is rotatably installed about an axis in an up-down direction; A driving unit that rotates the rotating plate; A support installed downward on one side of the periphery of the rotating plate; And an equilibrium holder installed downward on a periphery of the rotating plate opposite the support. The ultrasound collection unit may be coupled to the support in a direction toward the object.

The second stage may include a step motor that moves the ultrasonic collector at a set interval along the circumferential direction and then stops it.

The laser irradiation unit may irradiate the laser pulse to the object whenever the second stage is stopped after moving at the set interval, and the ultrasonic collector may collect the photoacoustic signal at the set interval.

The laser irradiator may output a trigger signal synchronized with the laser pulse, and the photoacoustic generator may generate the two-dimensional photoacoustic image by synchronizing with the trigger signal to collect the photoacoustic signal from the ultrasonic collector. .

The laser irradiation unit may include a tunable laser capable of varying the wavelength of the laser pulse. The laser irradiator may change the wavelength of the laser pulse in a wavelength range in which an ultrasonic signal is generated from target materials of the object by inducing thermal expansion elasticity in the object. The controller may control the wavelength and repetition rate of the tunable laser.

The 3D photoacoustic imaging apparatus according to an embodiment of the present invention may further include a display unit that displays a 3D photoacoustic image generated by the photoacoustic generating unit.

According to an embodiment of the present invention, there is provided a 3D photoacoustic imaging device capable of generating a 3D photoacoustic image by scanning an ultrasonic collector.

Further, according to an embodiment of the present invention, there is provided a 3D photoacoustic imaging apparatus capable of variously adjusting the resolution of a 3D photoacoustic image.

1 is a side view schematically showing a 3D photoacoustic imaging apparatus according to an embodiment of the present invention.
2 is a bottom view of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention.
3 is a front view of an ultrasonic collector constituting a 3D photoacoustic imaging apparatus according to an embodiment of the present invention.
4 is a block diagram of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention.
5 and 6 are diagrams for explaining the operation of the 3D photoacoustic imaging apparatus according to an embodiment of the present invention.
7 is a flowchart illustrating an operation of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein. In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not necessarily limited to the illustrated bar.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are assigned to the same or similar components throughout the specification.

Although the first, second, and the like are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical idea of the present invention.

The same reference numerals refer to the same components throughout the specification.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and as a person skilled in the art can fully understand, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other. It may be possible to do it together in a related relationship.

On the other hand, the potential effects that can be expected by the technical features of the present invention that are not specifically mentioned in the specification of the present invention are treated as described in the present specification, and this embodiment is intended for those with average knowledge in the art. It is provided to more completely describe the present invention, and the contents shown in the drawings may be exaggerated compared to the actual implementation of the present invention, and a detailed description of the configuration determined to unnecessarily obscure the subject matter of the present invention. Omit or briefly describe.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a side view schematically showing a 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 2 is a bottom view of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 1 and 2, a 3D photoacoustic imaging apparatus 100 according to an embodiment of the present invention includes a laser irradiation unit 110, an ultrasonic collection unit 120, a scanning unit 130, and a photoacoustic generation unit ( 140).

The 3D photoacoustic imaging apparatus 100 irradiates a laser pulse that causes thermoelastic expansion to an object 10 such as a living body due to a photoacoustic effect, and the object ( A 3D photoacoustic molecular image is generated by photoacoustic tomography by collecting photoacoustic signals generated from the object by the thermoelastic expansion of 10).

The laser irradiation unit 110 irradiates a laser pulse onto the object 10. The laser pulse emitted to an object such as a body tissue may be a non-ionizing laser pulse. The laser pulse may have a wavelength for generating an ultrasonic signal from a target material of the object 10 by inducing thermal expansion elasticity in the object 10. In an embodiment, the target material may include a carotid blood clot, but is not limited thereto.

In an embodiment, the laser irradiation unit 110 outputs a laser pulse generated by the laser generating unit 112 and the laser generating unit 120 such as a pulsed laser device that generates a non-ionizing laser pulse. A laser transmission unit (optical fiber) 114 that is transmitted to the unit 116 and a laser output unit 116 that outputs a laser pulse transmitted through the laser transmission unit 114 to the object.

The laser generator 112 may be provided as a tunable laser. The laser generator 112 may generate laser pulses of various wavelengths and irradiate the object. The pulse period of the laser pulse generated by the laser generator 112 may be set in advance or may be controlled according to the position of the ultrasonic collecting unit 120 moved by the scanning unit 130. When generating a photoacoustic image for detecting a carotid blood clot, the wavelength of the laser pulse may be set to include 1210 nm, but is not limited thereto.

The ultrasound collection unit 120 collects photoacoustic signals in an ultrasound band emitted by the object 10 reacting (thermoelastic expansion) by the laser pulse emitted by the laser irradiation unit 110. The ultrasonic collection unit 120 may include a probe unit for collecting photoacoustic signals in an ultrasonic band.

3 is a front view of an ultrasonic collector constituting a 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 1 to 3, the ultrasonic collection unit 120 may be provided as an array ultrasonic probe unit in which a plurality of ultrasonic probes are arranged in a peripheral region of the laser output unit 116. The laser output unit 116 may be disposed in the center of the probe unit.

The ultrasonic collector 120 may include a probe support 122 and a plurality of ultrasonic probes 120a. The ultrasonic collector 120 may be provided with a multi-channel ultrasonic probe 120a such as 128 channels. The probe support 122 may be installed on the lower surface of the rotating plate 136 of the scanning unit 130 and fixed to the lower end of the support 138a extending downward. The ultrasound collection unit 120 may be coupled to the support 138a in a direction toward the object 10.

The probe support part 122 may be formed as a hemispherical surface 124 in which a front portion facing the object 10 is recessed toward the opposite side of the object 10. In the probe support 124, a plurality of ultrasonic probes 120a may be two-dimensionally arranged on the hemispherical surface 124 of the probe support 122. The plurality of ultrasonic probes 120a may be arranged in various forms such as a matrix structure or a concentric structure.

The scan unit 130 may move the ultrasound collection unit 130 to scan an examination area of the object 10. In an embodiment, the scan unit 130 may be configured to rotate the probe support unit 122 and the ultrasound probes 120a of the ultrasound collection unit 120 around the object 10. The scan unit 130 may rotate the ultrasound collection unit 130 by 360° or an angular range corresponding to the inspection area of the object.

In an embodiment, the scan unit 130 may include a first stage 132 and a second stage 134. The first stage 132 may vertically move the second stage 134 and the ultrasonic collector 120 installed therein to scan the inspection area of the object 10 in the vertical direction. The first stage 132 may include a step motor that moves the ultrasonic collector 120 at a predetermined interval along the vertical direction and then stops it.

The second stage 134 may rotate the ultrasound collection unit 120 around the object 10 to scan the inspection area of the object 10 in the circumferential direction. In an embodiment, the second stage 134 includes a circular rotating plate 136 that is rotatably installed around an axis 134a in an up-down direction, a driving unit (not shown) that rotates the rotating plate 136, and a rotating plate It may include a support (138a) installed downward on one side of the periphery of (136) and a counter weight (138b) that is installed downward on the circumference of the opposite side of the support (138a) of the rotating plate 136. The driving unit of the second stage 134 may include a step motor that moves the ultrasonic collector 120 along the circumferential direction at a set interval and then stops it.

When the rotating plate 136 is inclined by the load of the support 138a and the ultrasonic collecting unit 120, the scanning direction is distorted, so that an accurate 3D photoacoustic image cannot be generated. Therefore, in order to maintain the balance of the rotating plate 136, the balance holder 138b is designed to have a weight capable of maintaining the balance of the scan unit 130 in consideration of the load of the support bar 138a and the ultrasonic collector 120. I can.

The photoacoustic generation unit 140 may generate a 3D photoacoustic image by using the photoacoustic signal collected from the ultrasonic collecting unit 120. The photoacoustic generation unit 140 generates 2D photoacoustic images by using the photoacoustic signals collected while moving the ultrasound collection unit 120 by the scanning unit 130, and the 2D photoacoustic images are ultrasonically collected. A 3D photoacoustic image may be generated by combining based on the scan positions of 120.

4 is a block diagram of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 1 to 4, the 3D photoacoustic imaging apparatus 100 may include a control unit 150. The control unit 150 controls the laser generator 112 and the scan unit 130 of the laser irradiation unit 110 by collecting photoacoustic signals from the ultrasonic collection unit 120.

When the photoacoustic signal is collected at the first position from the ultrasonic collecting unit 120, the control unit 150 moves the scanning unit 130 to move the ultrasonic collecting unit 120 to collect the photoacoustic signal at the second position. Can be controlled. In an embodiment, the controller 150 may control the wavelength and repetition rate (pulse period) of the tunable laser. The laser irradiation unit 110 may irradiate a laser pulse to the object 10 whenever the second stage 134 is moved at a set interval and then stopped according to a control signal from the controller 150. The controller 150 controls the scan unit 130 by comparing the current position and the target position of the ultrasound collection unit 120 to determine an operation of the scan unit 130. The ultrasonic collection unit 120 may collect photoacoustic signals at set intervals according to a control signal from the control unit 150.

5 and 6 are views for explaining the operation of the 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 7 is a flowchart illustrating an operation of a 3D photoacoustic imaging apparatus according to an embodiment of the present invention. 5 to 7, first, as shown in FIG. 5, when the laser pulse LS emitted by the laser output unit 116 is irradiated to the object (S10), the laser pulse LS The photoacoustic signal PS of the ultrasonic band generated from the object may be collected by the ultrasonic collector 120 as illustrated in FIG. 6 (S20 ).

The ultrasonic collector 120 may collect the photoacoustic signal at every first interval in the vertical direction and may collect the photoacoustic signal at every second interval in the circumferential direction. The ultrasound collection unit 120 is moved by the scanning unit 130 in the vertical direction and the circumferential (rotation) direction along the inspection area of the object 10, and collects photoacoustic signals at each set position at a first interval and a second interval. Collect sequentially.

According to an exemplary embodiment of the present invention, the photoacoustic signal PS generated from the object may be efficiently collected by the hemispherical surface 124 of the ultrasound collecting unit 120. The photoacoustic signal PS collected by the ultrasonic collecting unit 120 may be transmitted to the photoacoustic generating unit 140 through an optical transmission unit (optical fiber).

In order to collect the photoacoustic signal at an accurate position while scanning the inspection area of the object 10, the laser irradiation unit 110 may output a trigger signal synchronized with the laser pulse. The trigger signal output from the laser irradiation unit 110 may be transmitted to the scanning unit 130 and the photoacoustic generation unit 150 through the control unit 150.

The photoacoustic generator 150 collects the photoacoustic signal PS from the ultrasonic collector 120 in synchronization with the trigger signal, and then generates a 2D photoacoustic image using the collected photoacoustic signal PS. I can. When the photoacoustic signal is collected from the ultrasound collection unit 120 at the first position, the controller 150 moves the ultrasound collection unit 120 to the second position in order to scan the inspection area of the object 10. It is possible to control (130) (S30, S40).

When the ultrasound collection unit 120 is moved to a predetermined scan position by the scanning unit 130, a laser pulse is emitted again by the laser irradiation unit 110, and a photoacoustic signal is collected by the ultrasound collection unit 120. . The photoacoustic generation unit 140 generates a 2D photoacoustic image each time it is moved to the scan position by using the photoacoustic signals sequentially collected by the ultrasound collection unit 120 while scanning the inspection area of the object 10 can do.

When all the photoacoustic signals are collected for a set scan range, the photoacoustic generation unit 140 may generate a 3D photoacoustic image by combining the 2D photoacoustic images based on the scan positions (scan angles) (S50). , S60). In an embodiment, the photoacoustic generation unit 140 rotates the direction of the 2D photoacoustic images according to the collection direction of the ultrasound collecting unit 120 that collects the photoacoustic signals and matches them to a common coordinate system to generate 2D photoacoustic images. By combining, a three-dimensional photoacoustic image can be created. The 3D photoacoustic image generated by the photoacoustic generation unit 140 may be displayed through the display unit 160 (S70).

In the 3D photoacoustic imaging apparatus according to an embodiment of the present invention, the ultrasonic collection unit 120 can be moved (scanned) in the vertical and rotational directions, and the movement (scan) interval of the ultrasonic sensor unit 120 can be adjusted. It is possible to generate a 3D photoacoustic image by photographing a body tissue at a desired resolution.

In addition, according to an embodiment of the present invention, photoacoustic signals are collected while finely adjusting the movement (scan) interval of the ultrasonic collector 120 to generate a high-resolution 3D photoacoustic image based on the collected photoacoustic signals. In addition, the resolution of the photoacoustic image may be variously adjusted by adjusting the movement (scan) interval of the ultrasound collection unit 120 to a desired interval by the user.

In addition, by generating a photoacoustic image by collecting photoacoustic data by synchronizing to the scan position in accordance with the trigger signal synchronized with the laser pulse generated by the laser irradiation unit 110, the accuracy of the photoacoustic signal is improved and the 3D photoacoustic image is The accuracy is improved and a clear 3D photoacoustic image can be obtained.

In addition, the trigger signal of the laser irradiation unit 110 can synchronize and control the photoacoustic signal collection and photoacoustic image generation time, thereby collecting photoacoustic data for generating a 3D photoacoustic image at high speed, It is possible to shorten the time required to generate a photoacoustic image.

The 3D photoacoustic imaging apparatus according to an embodiment of the present invention may be used, for example, to identify the internal structure of an inflammatory blood vessel and to determine properties.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is natural to fall within the scope of

10: object
100: 3D photoacoustic imaging device
110: laser irradiation unit
112: laser generator
114: laser transmission unit
116: laser output unit
120: ultrasonic collector
120a: ultrasonic probe
122: probe support
124: hemisphere
130: scan unit
132: first stage
134: second stage
134a: axis
136: rotating plate
138a: support
138b: counterweight
140: photoacoustic generation unit
150: control unit
160: display unit

Claims (15)

A laser irradiation unit including a laser generator for generating a laser pulse and a laser output unit for irradiating the laser pulse to an object;
An ultrasonic collection unit including a probe unit for collecting a photoacoustic signal generated by thermal elastic expansion of the object by the laser pulse;
A scanning unit that moves the ultrasound collection unit to scan an examination area of the object; And
A photoacoustic generator configured to generate a three-dimensional photoacoustic image using the photoacoustic signal collected from the ultrasonic collector,
The probe unit,
A probe support formed in a hemispherical shape recessed toward the opposite side of the object, and a plurality of ultrasonic probes arranged two-dimensionally on a hemispherical surface of the probe support, and the laser output unit is provided in the center of the hemispherical surface of the Move with multiple ultrasonic probes,
The scanning unit,
A first stage for moving the ultrasound collection unit in a vertical direction to scan an examination area of the object in the vertical direction, and
A circular rotating plate that is rotatably installed about an axis in an up-down direction, a driving part that drives the rotation of the rotating plate, a support installed downward on one side of the peripheral edge of the rotating plate, and a peripheral part of the rotating plate opposite the support, And a balance holder formed with a weight capable of maintaining an equilibrium of the scanning unit in consideration of the load of the support and the ultrasound collection unit, and rotating the ultrasound collection unit around the object to rotate the inspection area of the object in a circumferential direction Including a second stage to scan with, and moving the ultrasound collection unit three-dimensionally around the object,
The photoacoustic generation unit,
Generating 2D photoacoustic images using the photoacoustic signals collected while moving the ultrasonic collection unit, and combining the 2D photoacoustic images based on the scan positions of the ultrasound collecting unit to generate the 3D photoacoustic image 3D photoacoustic imaging device. The method of claim 1,
3D photoacoustic imaging apparatus further comprising a control unit for controlling the scanning unit by collecting the photoacoustic signals from the ultrasonic collecting unit. The method of claim 2,
The control unit, when the photoacoustic signal is collected at a first position from the ultrasonic collecting unit, controls the scanning unit to move the ultrasonic collecting unit to collect the photoacoustic signal at a second position. delete delete delete delete delete The method of claim 1,
The second stage 3D photoacoustic imaging apparatus comprising a step motor for moving the ultrasonic collector at a set interval along the circumferential direction and stopping. The method of claim 9,
The laser irradiation unit irradiates the laser pulse to the object whenever the second stage is stopped after moving at the set interval,
The ultrasonic collecting unit 3D photoacoustic imaging apparatus for collecting the photoacoustic signal at every set interval. The method of claim 1,
The laser irradiation unit outputs a trigger signal synchronized with the laser pulse,
The 3D photoacoustic imaging apparatus generates the 2D photoacoustic image by synchronizing the photoacoustic generator with the trigger signal to collect the photoacoustic signal from the ultrasonic collector. The method of claim 2,
The laser irradiation unit 3D photoacoustic imaging apparatus including a variable-wavelength laser capable of varying the wavelength of the laser pulse. The method of claim 12,
The laser irradiation unit induces thermal expansion elasticity in the object to change the wavelength of the laser pulse in a wavelength range for generating an ultrasonic signal from target materials of the object. The method of claim 12,
The control unit is a 3D photoacoustic imaging apparatus that controls the wavelength and repetition rate of the tunable laser. The method of claim 1,
A 3D photoacoustic imaging apparatus further comprising a display unit for displaying a 3D photoacoustic image generated by the photoacoustic generating unit.

Images