KR20180136664A - Imaging device for multi-exposure laser speckle image - Google Patents

Abstract

Disclosed is a multi-exposure laser speckle image acquisition device. The present invention can have the same amount of light for each exposure time during multi-exposure laser speckle image acquisition and performs a speckle contrast operation through a graphics processor. According to the present invention, blood flow image information for a blood flow diagnosis in vivo can be obtained more efficiently and accurately, and accurate blood flow image information can be obtained. Therefore, the present invention can be applied to various fields including skin image diagnosis, image monitoring of a surgical procedure, laser treatment and therapeutic effect monitoring, and accurate diagnosis and analysis of diseases associated with blood flow such as diabetes and the like. By performing a high-speed operation for statistical analysis and non-linear optimization of a plurality of speckle images through the graphics processor and acquiring blood flow information from the plurality of speckle images, blood flow image information for the blood flow diagnosis in vivo can be obtained more quickly.

Description

[0001] The present invention relates to a multi-exposure laser speckle image acquisition device,

The present invention relates to a multi-exposure laser speckle image collecting apparatus, and more particularly, to a multi-exposure laser speckle image collecting apparatus, To the device.

Laser speckle refers to a pattern with an irregular distribution of grains formed by a random interference phenomenon of scattered light when a laser, which is a light source with high coherence, is irradiated to a scattering material. Based on this phenomenon, imaging through the multi-exposure imaging technique can image the flow of blood within the object without an external contrast agent such as a fluorescent material.

However, the conventional multi-exposure imaging technique only acquires a plurality of images with different exposure times, so that there is a problem that the brightnesses of the respective images are different from each other, so that a correct flow of blood flow can not be confirmed.

In addition, the conventional multi-exposure imaging technique uses a light source modulation device such as an acoustic-optic modulator (AOM), which is bulky and requires high-voltage operation, which is difficult to miniaturize and difficult to apply to a medical field limited in space there is a problem.

In addition, there is a problem that it is difficult to acquire blood flow information quickly due to the limitation of the operation speed for performing the nonlinear optimization method for obtaining the blood flow.

Patent Document 1 is directed to a quantitative image having a multi-exposure speckle image, and Patent Document 1 discloses a laser light source Discloses a multi-exposure laser speckle contrast imaging system and method that includes a light modulator and a camera, a magnification objective lens and a microprocessor / data acquisition unit and a detector for measurement of the reflected light. Korean Patent Laid-Open Publication No. 2017-0009085 (Samsung Electronics Co., Ltd.), Jan. 201, 2017 Patent Document 2 discloses a laser spec-to-coarse imaging system and method. In Patent Document 2, An image pickup section for picking up a speckle image by photographing the speckle formed by scattering the irradiated laser light from the object with an image sensor and a speckle image obtained by the image pickup section, And a signal processing unit for acquiring a compensated speckle contrast image by compensating for a change due to the motion of the object.

Disclosure of Invention Technical Problem [8] The present invention provides a multi-exposure laser speckle image acquisition system for acquiring multi-exposure laser speckle images having the same amount of light for each exposure time and performing a speckle contrast operation through a graphics processor. Device.

According to an aspect of the present invention, there is provided a multi-exposure laser speckle image collecting apparatus including: a light source unit for irradiating laser light; A light amount adjusting unit having a polarizer and rotating the polarizer to adjust a light amount of laser light irradiated through the light source unit; An image capturing unit for capturing a plurality of speckle images formed by scattering laser light irradiated through a light source from a target object at different exposure times and acquiring a plurality of speckle images having different exposure times; And a light amount controller for controlling the light amount controller so that the light amount of the laser light irradiated through the light source unit is different for each exposure time when the image is taken a plurality of times with different exposure times through the image capturing unit.

The light amount adjusting unit includes: a motor having a rotation shaft and transmitting a rotational force through the rotation shaft; A first gear coupled to a rotational shaft of the motor and transmitting rotational force; A second gear coupled to the first gear and having a second polarizer at the center, the second gear rotatable by a rotational force transmitted from the first gear; A second body coupled to the second gear and having a tubular configuration and being rotatable by a rotational force transmitted from the first gear; A first body coaxial with the second body and having a tube-like structure and having a first polarizer at the center; And a motor control unit for driving the motor to adjust the relative rotation angle of the first polarizer and the second polarizer in accordance with the control signal of the light amount control unit, wherein the first polarizer is disposed between the first polarizer of the first body and the second polarizer of the second gear A path through which laser light is transmitted can be formed.

The light amount control unit controls the relative rotation angle of the first polarizer and the second polarizer by driving the motor according to the rotation angle value based on the control signal of the light amount control unit so that the light amount corresponding to the rotation angle value based on the control signal of the light amount control unit .

The motor may be a servo motor whose rotational angle is determined according to a voltage applied from the outside.

The motor may be a stepping motor whose rotational angle is determined according to the number of input pulses.

The light amount control unit may control the light amount adjusting unit such that the light amount of the laser light irradiated through the light source unit is different for each exposure time so that a plurality of speckle images having different exposure times have the same brightness value.

The light amount control unit determines the common brightness value based on the light amount value-brightness value information according to the previously obtained exposure time, and determines the light amount based on the light amount value-brightness value information according to the previously obtained exposure time and the determined common brightness value It is possible to control the light amount adjusting unit such that the light amount of the laser light irradiated through the exposure unit becomes different according to the exposure time.

The light amount value may be one of a rotation angle value of the light amount control unit, a voltage value corresponding to the rotation angle value, and an input pulse number corresponding to the rotation angle value.

The apparatus may further include an image analyzing unit having a graphics processor and analyzing a plurality of speckle images by performing a speckle contrast operation through a graphics processor on a plurality of speckle images obtained through the image taking unit have.

According to the multi-exposure laser speckle image acquiring apparatus of the present invention, by obtaining the same amount of light for each exposure time in the multi-exposure laser speckle image acquisition, blood flow image information for in vivo blood flow diagnosis can be acquired more efficiently and accurately .

In addition, accurate blood flow image information can be obtained, and it can be applied to various fields such as skin imaging, image monitoring of a surgical procedure, laser treatment and monitoring of therapeutic effect, accurate diagnosis and analysis of diseases associated with blood flow such as diabetes .

In addition, by performing a high-speed operation for statistical analysis and non-linear optimization of a plurality of speckle images through a graphics processor and acquiring blood flow information from a plurality of speckle images, blood flow image information for in vivo blood flow diagnosis is obtained You can get it quickly.

1 is a block diagram illustrating a multi-exposure laser speckle image acquisition apparatus according to a preferred embodiment of the present invention.
FIG. 2 is a block diagram for explaining the image collecting apparatus shown in FIG. 1 in more detail.
FIG. 3 is a diagram for explaining an example of the image capturing apparatus shown in FIG. 2. FIG.
FIG. 4 is a block diagram for explaining the light amount adjusting unit shown in FIG. 2 in more detail.
5 is a diagram for explaining an example of the light amount adjusting unit shown in Fig.
6 is a graph for explaining an example of light amount-brightness value information according to the exposure time according to a preferred embodiment of the present invention.

Hereinafter, a preferred embodiment of a multi-exposure laser speckle image collecting apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First, a multi-exposure laser speckle image collecting apparatus according to a preferred embodiment of the present invention will be described with reference to FIG.

1 is a block diagram illustrating a multi-exposure laser speckle image acquisition apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 1, a multi-exposure laser speckle image collecting apparatus 100 according to a preferred embodiment of the present invention irradiates a laser beam to a target object 200.

The image collecting apparatus 100 photographs the speckle formed by scattering the irradiated laser light from the object 200 a plurality of times at different exposure times and acquires a plurality of speckle images having different exposure times .

At this time, the image capturing apparatus 100 adjusts the light amount of the laser light so that the light amount of the irradiated laser light differs according to the exposure time, when taking a plurality of photographs at different exposure times. In other words, the image capturing apparatus 100 is configured to minimize the influence of the external factors due to the change of the external optical factors with the non-contact method and the high accuracy, and to acquire the more accurate blood flow image information, The light amount of the laser light is corrected by interlocking with the exposure time so as to have the same and constant brightness value at the time of image acquisition. Thus, it is possible to acquire blood flow image information for in vivo blood flow diagnosis more efficiently and accurately.

In addition, the image capturing apparatus 100 can analyze a plurality of speckle images using a graphics processor. That is, the image capturing apparatus 100 can acquire blood flow information from a plurality of speckle images by performing a high-speed operation for statistical analysis and nonlinear optimization of a plurality of speckle images through a graphic processor. Thus, blood flow image information for diagnosis of blood flow in vivo can be acquired more quickly.

The target object 200 may be a body tissue or the like. In particular, the target object 200 may be a biotissue that has been exposed due to skin tissue of the hands and feet, surgical techniques, or other factors.

The multi-exposure laser speckle image collecting apparatus according to the preferred embodiment of the present invention will now be described in more detail with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a block diagram for explaining the image collecting apparatus shown in FIG. 1 in more detail, and FIG. 3 is a view for explaining an example of the image collecting apparatus shown in FIG.

2 and 3, the image capturing apparatus 100 includes a light source 110, a light source controller 120, a light amount controller 130, an image analyzer 140, an image capturing unit 150, A light source 160, and a light amount controller 170.

The light source unit 110 irradiates laser light. At this time, the light source unit 110 can use a laser light source of a visible light and a near-infrared light region having high coherence as laser light. Here, the laser light source may be a laser light source having a center wavelength in the vicinity of 632 nm, 780 nm, and 808 nm.

The light source control unit 120 supplies power to the light source unit 110 and controls the operation of the light source unit 110.

The light amount control unit 130 includes a polarizer 131 and controls the light amount of the laser light irradiated through the light source unit 110 by rotating the polarizer 131. In particular, the light amount controller 130 may control the light amount of the laser light to be irradiated so as to have a light amount corresponding to the control signal of the light amount controller 170 by rotating the polarizer 131 according to the control signal of the light amount controller 170.

The image capturing unit 150 includes a lens 151, a bandpass filter 153 and an image sensor (not shown). The laser light emitted through the light source unit 110 is scattered from the target object 200 The speckle is photographed multiple times with different exposure times. Here, the lens 151 allows the speckle formed by scattering from the target object 200 to be formed on the image sensor. A bandpass filter 153 selectively transmits only light having the same wavelength as that of the laser beam emitted from the light source 110 to remove the influence of unnecessary external light. The image sensor is an image sensor having high quantum efficiency in the visible light and near infrared region, and may be a CCD image sensor, a CMOS image sensor, or the like.

The image capturing unit 150 acquires a plurality of speckle images having different exposure times.

The image capturing control unit 160 supplies power to the image capturing unit 150 and controls the operation of the image capturing unit 150. [

The image analysis unit 140 includes a graphics processor (not shown), performs a speckle contrast operation on a plurality of speckle images acquired through the image capturing unit 150 through a graphics processor , And analyzes a plurality of speckle images.

The light amount control unit 170 controls the light amount control unit 130 so that the light amount of the laser light irradiated through the light source unit 110 is different for each exposure time, do.

That is, the light amount control unit 170 adjusts the amount of light so that the light amount of the laser light irradiated through the light source unit 110 differs according to the exposure time, so that a plurality of speckle images having different exposure times have the same brightness value, The controller 130 may control the light amount controller 130 by providing a control signal to the controller 130.

More specifically, the light amount controller 170 may determine the common brightness value based on the light amount value-brightness value information according to the previously obtained exposure time. Here, the light amount value may be a rotation angle value of the light amount controller 130, a voltage value corresponding to the rotation angle value of the light amount controller 130, an input pulse number corresponding to the rotation angle value, and the like.

That is, the light amount controller 170 obtains a brightness value range from the minimum brightness value to the maximum brightness value according to the exposure time based on the light amount value-brightness value information according to the previously obtained exposure time, It is possible to determine the common brightness value within the brightness value range.

At this time, the light amount controller 170 may determine the maximum brightness value as a common brightness value within a range of overlapping brightness values among the brightness value ranges per exposure time.

The light amount control unit 170 controls the light amount control unit 170 so that the light amount of the laser light irradiated through the light source unit 110 is different according to the exposure time based on the light amount value- (130).

That is, the light amount controller 170 can obtain the light amount value for each exposure time in the light amount value-brightness value information according to the previously obtained exposure time based on the common brightness value. The light amount control unit 170 provides a control signal to the light amount control unit 130 so that the light amount of the laser light irradiated through the light source unit 110 becomes different according to the exposure time based on the light amount value obtained for each exposure time, 130). Here, the control signal may include a light amount value or the like obtained for each exposure time.

Hereinafter, the light amount control unit according to the preferred embodiment of the present invention will be described in more detail with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a block diagram for explaining the light amount adjusting unit shown in FIG. 2 in more detail, and FIG. 5 is a view for explaining an example of the light amount adjusting unit shown in FIG.

4 and 5, the light amount control unit 130 includes a motor 132, a first gear 133, a second gear 134, a first body 135, a second body 136, And a control unit 137 as shown in FIG.

The motor 132 has a rotation axis RA and transmits rotational force to the first gear 133 via the rotation axis RA.

Here, the motor 132 may be a servo motor whose rotational angle is determined according to a voltage applied from the outside. The motor 132 may be a stepping motor whose rotational angle is determined according to the number of input pulses.

The first gear 133 is fixedly coupled to the rotation axis RA of the motor 132 and transmits rotational force to the second gear 134.

The second gear 134 is coupled to the first gear 133 and has a second polarizer 131b at the center thereof and is rotatable by a rotational force transmitted from the first gear 133.

The first body 135 is coaxial with the second body 136 and has a fixed tube shape and a first polarizer 131a at the center.

The second body 136 is fixedly coupled to the second gear 134 and has a tubular structure and is rotatable by a rotational force transmitted from the first gear 133.

The motor control unit 137 drives the motor 132 to adjust the relative rotation angle of the first polarizer 131a and the second polarizer 131b in accordance with the control signal of the light amount control unit 170. [

A path through which the laser beam is transmitted between the first polarizer 131a of the first body 135 and the second polarizer 131b of the second gear 134 is formed.

That is, the light amount control unit 130 controls the relative rotation angle of the first polarizer 131a and the second polarizer 131b by driving the motor 132 according to the rotation angle value based on the control signal of the light amount controller 170 So that the amount of light corresponding to the rotation angle value based on the control signal of the light amount control unit 170 can be adjusted.

6, the correction operation of the multi-exposure laser speckle image collecting apparatus according to the preferred embodiment of the present invention will be described in more detail.

6 is a graph for explaining an example of light amount-brightness value information according to the exposure time according to a preferred embodiment of the present invention.

As shown in FIG. 6, the light amount controller 170 may first obtain the light amount-brightness value information according to the exposure time.

That is, the light amount controller 170 initializes the light amount controller 130. For example, the light amount controller 130 may drive the motor 132 in accordance with the initialization signal of the light amount controller 170 to set the polarizer 131 at a rotation angle, that is, an initial position where the light amount of the laser light is minimized.

Then, the light amount controller 170 increases the light amount of the laser light with respect to each of the exposure times t1, t2, t3, ..., tn (that is, increases the rotation angle of the polarizer or increases the voltage corresponding to the rotation angle And the brightness value is obtained while acquiring the brightness value. Thus, the brightness value-brightness value information according to the exposure time can be obtained. Here, the brightness value may be an average value or a middle value of the brightness values of the pixels of the image sensor of the image capturing unit 150. And, the exposure time may have a value between 0.01 ms and 1,000 ms.

For example, as shown in FIG. 6, the light amount controller 170 increases the light amount of the laser light for each of the exposure times t1, t2, t3, and t4 to obtain a brightness value, Can be obtained.

Then, the light amount controller 170 can determine the common brightness value based on the light amount value-brightness value information according to the obtained exposure time.

That is, the light amount controller 170 obtains the brightness value range from the minimum brightness value to the maximum brightness value according to the exposure time based on the light amount value-brightness value information according to the obtained exposure time, A common brightness value can be determined within a brightness value range.

For example, referring to FIG. 6, the exposure time t1 has a brightness value range of about 5 to about 130, the exposure time t2 has a brightness value range of about 10 to about 220, and the exposure time t3 is about 20 to about 250 The exposure time t4 has a brightness value range of about 50 to about 250. [ The light amount controller 170 may determine the common brightness value within a range of about 50 to about 130 which is a brightness value range overlapping among the brightness value ranges for each exposure time.

At this time, the light amount controller 170 may determine the maximum brightness value as a common brightness value within a range of overlapping brightness values among the brightness value ranges per exposure time.

For example, referring to FIG. 6, the light amount controller 170 may determine the maximum brightness value 130 as a common brightness value within a range of about 50 to about 130, which is a brightness value range overlapping with the exposure time.

Then, the light amount control unit 170 controls the light amount control unit 170 so that the light amount of the laser light irradiated through the light source unit 110 is different according to the exposure time, based on the light amount value-brightness value information according to the obtained exposure time and the determined common brightness value. (130).

For example, when the common brightness value CE is determined as the maximum brightness value 130 within about 50 to about 130 brightness values overlapping with each other in the brightness value range for each exposure time as shown in FIG. 6, the light amount controller 170 (T1_A) determined based on the light amount value-brightness value information and the common brightness value CE at the exposure time t1 when the image capturing unit 150 captures the speckle at the exposure time t1, i.e., the light amount value It is possible to control the light amount adjusting unit 130 such that the light amount of the incident light is irradiated. When the image capturing unit 150 photographs the speckle at the exposure time t2, the light amount control unit 170 controls the light amount control unit 170 to calculate the rotation angle value t2_A (brightness) based on the light amount value-brightness value information and the common brightness value CE at the exposure time t2 ), That is, the quantity of light having the light quantity value is irradiated. When the image capturing unit 150 captures the speckle at the exposure time t3, the light amount control unit 170 controls the light amount control unit 170 such that the light amount value-brightness value information and the rotation angle value t3_A determined based on the common brightness value CE at the exposure time t3 ), That is, the quantity of light having the light quantity value is irradiated. When the image capturing unit 150 captures the speckle at the exposure time t4, the light amount control unit 170 controls the light amount control unit 170 to calculate the rotation angle value t4_A (t4) based on the light amount value-brightness value information and the common brightness value CE at the exposure time t4 ), That is, the quantity of light having the light quantity value is irradiated.

In this way, by controlling the light amount adjusting unit 130 so that the light amount of the laser light irradiated through the light source unit 110 differs according to the exposure time, the plurality of speckle images having different exposure times The same brightness value can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the appended claims.

100: Multi-exposure laser speckle image acquisition device,
110; A light source unit 120, a light source control unit,
130: light amount control unit, 131: polarizer,
131a: a first polarizer, 131b: a second polarizer,
132: motor, 133: first gear,
134: second gear, 135: first body,
136: second body, 137: motor control section,
140: Image analysis unit, 150: Image shooting unit,
151: Lens, 153: Band-pass filter,
160: photographing control unit, 170: light amount control unit,
200: target object

Claims (9)

A light source unit for irradiating laser light;
A light amount adjusting unit having a polarizer and rotating the polarizer to adjust a light amount of laser light irradiated through the light source unit;
An image capturing unit that captures a plurality of speckle images formed by scattering laser light emitted through the light source from a target object at different exposure times and acquiring a plurality of speckle images having different exposure times; And
A light amount control unit for controlling the light amount adjusting unit such that a light amount of the laser light irradiated through the light source unit differs according to an exposure time during a plurality of photographing operations with different exposure times through the image taking unit;
Wherein the multi-exposure laser speckle image acquisition device comprises: The method of claim 1,
The light-
A motor having a rotating shaft and transmitting rotational force through the rotating shaft;
A first gear coupled to the rotation shaft of the motor and transmitting a rotational force;
A second gear coupled to the first gear and having a second polarizer at the center, the second gear being rotatable by a rotational force transmitted from the first gear;
A second body coupled to the second gear and having a tubular structure and rotatable by a rotational force transmitted from the first gear;
A first body that is coaxial with the second body and has a tube-like structure and includes a first polarizer at the center; And
A motor controller for driving the motor to adjust a relative rotation angle of the first polarizer and the second polarizer according to a control signal of the light amount controller;
/ RTI >
Wherein a path through which laser light is transmitted is formed between the first polarizer of the first body and the second polarizer of the second gear. 3. The method of claim 2,
The light amount control unit controls the relative rotation angle of the first polarizer and the second polarizer by driving the motor according to the rotation angle value based on the control signal of the light amount control unit, Value of the laser speckle image is adjusted to be a light quantity corresponding to the value of the laser beam. 3. The method of claim 2,
Wherein the motor is a servomotor whose rotational angle is determined according to a voltage applied from the outside. 3. The method of claim 2,
Wherein the motor is a stepping motor whose rotation angle is determined according to the number of input pulses. The method of claim 1,
Wherein the light amount control unit controls the light amount adjusting unit such that a plurality of speckle images having different exposure times have the same brightness value, the light amount of the laser light irradiated through the light source unit being different according to the exposure time, Exposure Laser Speckle Image Acquisition System. The method of claim 6,
The light amount control unit may determine a common brightness value based on the light amount value-brightness value information according to the previously obtained exposure time, and calculate the light amount value-brightness value information according to the previously obtained exposure time and the determined common brightness value And controls the light amount adjusting unit so that the light amount of the laser light irradiated through the light source unit is different according to the exposure time. 8. The method of claim 7,
Wherein the light amount value is one of a rotation angle value of the light amount control unit, a voltage value corresponding to the rotation angle value, and an input pulse number corresponding to the rotation angle value. The method of claim 1,
An image analysis unit having a graphics processor and performing a speckle contrast operation on the plurality of speckle images acquired through the image capturing unit through the graphic processor and analyzing the plurality of speckle images Further comprising a multi-exposure laser speckle image acquisition device.

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