KR101956446B1

KR101956446B1 - Controlling method of light energy penetration depth using ultrasonic energy and apparatus thereof

Info

Publication number: KR101956446B1
Application number: KR1020170045525A
Authority: KR
Inventors: 장진호; 김혜민
Original assignee: 서강대학교산학협력단
Priority date: 2017-04-07
Filing date: 2017-04-07
Publication date: 2019-03-08
Also published as: WO2018186560A1; KR20180113863A

Abstract

According to an aspect of the present invention, there is provided an apparatus for controlling depth of penetration of light using ultrasound energy, including: a light source for generating light energy; And an ultrasound transducer configured to increase an infiltration depth of the light energy into an illuminated subject by generating an air bubble using ultrasonic waves in a region where the light energy travels, And the intensity of the ultrasonic energy is controlled within a range in which the ultrasonic waves do not damage the tissue at all, whereby air bubbles can be generated and the depth of light penetration can be increased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling the penetration depth of light energy using ultrasound energy,

The present invention relates to a control method and apparatus using ultrasonic energy, and more particularly, to a method and apparatus for controlling the depth of penetration of light energy using ultrasonic energy.

Optical imaging system is a device that irradiates light energy to a target object, detects optical signals reflected, absorbed, and scattered by the target object to perform a high resolution internal structure of the target object and imaging. In addition, photoacoustic signals generated from an absorber absorbing irradiated light energy are received by using an ultrasonic sensor to form a characteristic image, and they are also used for selective treatment with improved light utilization efficiency. Due to these advantages using light energy, the range of use in clinics is greatly expanding.

On the other hand, optical scattering is a major factor limiting the depth of light energy transfer in medical image devices and medical treatment devices using such light energy, which is a great obstacle to enhance utilization of the image in optical image and treatment. That is, light transmission to a deep-lying target region is the greatest challenge in optical imaging and therapy. This difficulty is due to scattering rather than optical absorption in biological media, so light scattering determines the ballistic regime and the transport mean free path length, This is because the length is very low, 1-2 mm. To overcome this difficulty, various optical focusing methods based on a guide star have been proposed. Ultrasound and photoacoustic signals have been used to non-invasively generate a guide star in a non-optical approach.

However, these methods are associated with iterative wavefront shaping for optical focusing using the help of a guide star, which is still a burden for real-time operation in vivo.

In addition, in order to achieve the optimum performance of the guide star system using the ultrasonic wave and the photoacoustic signal, it is preferable that the ultrasonic transducer is arranged perpendicular to the light propagation direction. However, such a configuration has the problem that it may be a hindrance to the implementation of clinical applications such as endoscopic optical imaging and therapy.

On the other hand, ultrasound can cause local temperature rise in the focal area portion of biological tissues, and if local temperature reaches a certain level (i.e., above 60 [deg.] C) do; This method is used for noninvasive cancer treatment called high intensity focused ultrasound (HIFU) surgery. In addition, when energy is used much lower than the ultrasonic energy used in the high-fu operation, that is, when ultrasonic energy is applied to the living tissue at a level not affecting the living tissue, air bubbles are generated in the ultrasonic focusing region, A phenomenon that the generated air bubble disappears is observed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide an apparatus and method for generating air bubbles by controlling the intensity of ultrasonic energy, Improvement method.

It is still another object of the present invention to provide an apparatus for measuring and controlling the penetration depth of light energy by generating air bubbles by adjusting the intensity of ultrasonic energy.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood from the following description.

According to an aspect of the present invention, there is provided an apparatus for controlling depth of penetration of light using ultrasound energy, including: a light source for generating light energy; And an ultrasound transducer configured to increase an infiltration depth of the light energy into an illuminated subject by generating an air bubble using ultrasonic waves in a region where the light energy travels, And adjusting the intensity of the ultrasonic energy within a range in which the ultrasonic waves do not damage the tissue at all to adjust the size of the area of the air bubble to be generated so that the penetration depth of the light energy passing through the area can be increased.

In one embodiment, when there is no air bubble in the region, the light energy is caused by scattering medium to cause Rayleigh scattering in all directions. Further, in the case where the air bubble is present in the region, the depth of penetration into the object to be irradiated increases as the scattering of light occurs in the traveling direction corresponding to the front due to the collision of the light energy with the air bubble. Lt; / RTI >

In one embodiment, the ultrasonic transducer is configured to increase the intensity of the ultrasonic wave to adjust the size of the region of the air bubble to be formed so that the depth of penetration of the light energy into the subject is further increased .

In one embodiment, the ultrasonic transducer has a shape having an inner diameter and an outer diameter, and has a hole, through which the light energy from the light source passes through the hole corresponding to the inner diameter, It can be applied to the survey subject. For example, the ultrasonic transducer may be in the form of a ring having the inner diameter and the outer diameter, but is not limited thereto.

In one embodiment, the control unit controls the intensity of the ultrasonic waves to be increased when the depth of penetration is determined to be not the desired level by measuring or predicting the depth of penetration of the light energy into the subject .

According to another aspect of the present invention, there is provided a method of controlling depth of penetration of light using ultrasound energy, comprising: a light energy generating step of generating light energy using a light source; And an air bubble generating step of generating an air bubble using ultrasonic waves in a region where the light energy travels so that the depth of penetration of the light energy into the subject is increased.

In one embodiment, in the light energy generating step, when there is no air bubble in the region, the light energy may be Rayleigh scattering in all directions by a scattering medium. Further, in the air bubble generating step, when the air bubble is present in the region, the light energy is scattered in the traveling direction corresponding to the forward direction due to the collision with the air bubble, The depth of penetration into the surface is increased.

In one embodiment, the method may further include increasing the intensity of the ultrasonic wave by the ultrasonic transducer so that the depth of penetration of the light energy into the subject is further increased.

In one embodiment, in the air bubble generating step, light energy is applied to the object to be irradiated through the hole of the ultrasonic transducer from the light source, and the ultrasonic transducer has an inner diameter And a hole having an outer diameter, the hole corresponding to the inner diameter. For example, the ultrasonic transducer may be in the form of a ring having the inner diameter and the outer diameter, but is not limited thereto.

In one embodiment, a penetration depth measurement / estimation step of measuring or predicting a depth at which the light energy penetrates the subject; And controlling the intensity of the ultrasonic waves to be increased if it is determined that the penetration depth is not a desired level.

According to another aspect of the present invention, there is provided an apparatus for measuring / controlling the depth of penetration of light energy using ultrasound energy, comprising: a laser source for generating a laser as a light source for generating light energy; An ultrasound transducer disposed between the laser source and a phantom or a chicken breast corresponding to a sample irradiated with the light energy and generating ultrasonic waves; And an ultrasonic controller for controlling the ultrasonic transducer to generate an air bubble in an area between the ultrasonic transducer and the sample through the ultrasonic transducer.

In one embodiment, a CCD camera configured to measure the laser intensity, the CCD camera being spaced apart from and spaced apart from the sample, the CCD camera being disposed behind the CCD camera; And an optical filter disposed between the sample and the CCD camera and configured to filter light of a specific wavelength.

In one embodiment, the phantom is injected with a fluorescent dye, which fluoresces the second wavelength of fluorescence after absorbing the laser of the first wavelength emit), and the optical filter is configured to pass only the fluorescence of the second wavelength.

In one embodiment, the ultrasound controller includes a function generator configured to generate a sinusoidal electric signal; A signal amplifier (RF Amplifier) configured to amplify the sinusoidal electric signal to increase the intensity of the ultrasonic wave; And a matching network that performs impedance matching to excite the transducer at a resonant frequency.

In one embodiment, the laser source is a continuous wave laser of the first wavelength with a Gaussian profile and is configured to be coupled to the laser source to adjust the optical energy by turning the laser source on or off Lt; / RTI > laser power module.

The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to fully inform the owner of the scope of the invention.

According to at least one of the embodiments of the present invention, the intensity of the ultrasonic energy is controlled within a range in which the ultrasonic waves do not damage the tissue at all, thereby generating air bubbles and increasing the depth of penetration of light.

Also, according to at least one embodiment of the present invention, there is an advantage that the light penetration depth can be increased by increasing the amount of forward light energy components generated by the air bubbles generated by adjusting the intensity of the ultrasonic energy.

1 is a block diagram of an apparatus for controlling the depth of penetration of light energy using ultrasound energy according to the present invention.
2 shows a measurement result of a light intensity distribution on a tissue-like phantom of a certain thickness according to an embodiment of the present invention.
FIG. 3 shows the observation result of the light intensity distribution on the ex-vivo chicken breast having a certain thickness according to another embodiment of the present invention.
Figure 4 illustrates the change in fluorescence intensity emitted in a fluorescent die according to another embodiment of the present invention.
FIG. 5 is a flowchart illustrating a method of controlling the depth of penetration of light energy using ultrasonic energy according to the present invention.
FIG. 6 is a block diagram of an optical energy penetration depth measurement / control test apparatus using ultrasound energy according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, numerals (e.g., first, second, etc.) used in the description of the present invention are merely an identifier for distinguishing one component from another.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the context of the present invention, an optical energy penetration depth control apparatus using ultrasonic energy and a method of controlling the penetration depth of light energy using the apparatus will be described. In addition, a description will be given of a device for measuring and controlling the penetration depth of light energy using ultrasound energy.

In this regard, light is an attractive means for high spatial-resolution imaging, high contrast-resolution imaging, high-sensitivity molecular imaging, and target-selective therapy to be. Also, light does not involve risks associated with ionizing radiation. The main limitation of using light in clinical applications is the limitation of superficial imaging and therapeutic depth caused by high light scattering in biomedical media. In the present invention, scattering of incident light and hence defocusing can be alleviated when ultrasonic waves transmitted with incident light generate air bubbles in the path of incident light, . The air bubbles can be made temporarily by ultrasonic waves with a sufficiently low intensity to avoid tissue damage and operate mainly as a Mie scattering medium in the forward direction. When the ultrasonic transmission is cessed, the air bubble generated by the ultrasonic waves disappears and the return is made to the original light scattering characteristic again. The present invention corresponds to pioneering a new route to overcome the limitations of current optical imaging and treatment techniques.

1 is a block diagram of an apparatus for controlling the depth of penetration of light energy using ultrasound energy according to the present invention. On the other hand, according to the configuration diagram of FIG. 1, the principle of increase of light penetration due to ultrasound-induced air bubbles in scattering media can be seen.

In the present invention, it is proposed that light penetration in a biological tissue can be increased by causing air bubbles, which are temporarily induced by ultrasonic energy, to be generated in the light propagation region.

1 (a) shows a case where a light source is incident on a scattering medium without an ultrasonic transducer. At this time, as shown in the figure, the light is spread and the intensity of the light decreases as the light travels through a Rayleigh scattering medium scattered in all directions.

1 (b) and 1 (c) show a case where a light source is incident on a scattering medium in the case of using an ultrasonic (US) transducer. On the other hand, FIG. 1 (c) shows that the intensity of the ultrasonic wave US is increased as compared with FIG. 1 (b). 1 (b) and 1 (c), an ultrasonic wave generates air bubbles in a focal area of the ultrasonic wave, and as the ultrasonic intensity increases, The size increases. Since the incident light undergoes Mie scattering in the bubble entities, scattering of the incident light occurs mainly in the forward direction. As a result of this phenomenon, the light diffusion is reduced and the light penetration depth is increased.

In other words, FIG. 1 (a) shows that light traveling through the Rayleigh scattering medium is scattered in all directions, causing light to diffuse through the medium, resulting in a significant decrease in light intensity. When an ultrasonic wave having a certain level of intensity is transmitted into the medium, an air bubble is generated inside the focus area and operates as a non-scattering medium. Since the light is scattered predominantly in the forward direction in the non-scattering regime, the light propagation through the bubble cloud is less diffused as compared with the case where the light energy alone is irradiated (see (b ) (c). This means that the depth of light penetration is increased if the intensity of the ultrasound transmitted together is high enough to produce air bubbles and low enough to avoid cell damage.

The depth of light penetration is related to optical scattering. On the other hand, depending on the ratio of the radius of the circular particle to the light wavelength, optical scattering is generally categorized as Rayleigh scattering or Mie scattering. Rayleigh scattering occurs in all directions when the particle size is much smaller than the light wavelength. On the other hand, in a non-scattering region corresponding to a case where the particle size is similar to or slightly larger than the light wavelength, the incident light is mainly scattered in the forward direction.

Thus, if all other conditions are the same, the light penetration depth is deeper in the non-scattering medium than in the Rayleigh scattering medium. Biological tissues are characterized by having two types of scattering regimes at the same time, and the degree of Rayleigh scattering and non-scattering varies depending on the biotissue; Rayleigh scattering greatly increases the reduced optical scattering coefficient of biological tissues when the light wavelength is less than 800 nm.

Optical scattering is also influenced by the medium temperature. For example, as the temperature is increased, the scattering coefficients of the epidermis, subcutaneous tissue, and lecithin membrane are decreased while increased in the case of dermis.

The factors affecting optical scattering in relation to the depth of penetration according to the present invention have been described above. Hereinafter, components of the optical energy penetration depth control apparatus 1000 according to the present invention will be described in detail. As shown in FIG. 1, the optical energy penetration depth control apparatus 1000 includes a light source 100 and an ultrasonic transducer 200.

The light source 100 is configured to generate light energy, and may be, for example, a laser generating unit configured to generate a laser.

The ultrasonic transducer 200 is configured to generate an air bubble using ultrasonic waves in a region where the light energy travels. Accordingly, the ultrasonic transducer 200 can be configured such that the depth of penetration of the light energy into an illuminated subject is increased.

On the other hand, as shown in the figure, when there is no air bubble in the region, the light energy is Rayleigh scattering in all directions due to a scattering medium. On the other hand, when the air bubble is present in the region, Mie scattering occurs in the traveling direction corresponding to the front due to the collision of the light energy with the air bubble. Accordingly, the depth to be penetrated into the object to be irradiated can be increased.

In addition, the ultrasonic transducer 200 may be configured to increase the intensity of the ultrasonic waves so that the depth of penetration of the light energy into the subject is further increased.

The ultrasonic transducer may be a ring-shaped ring having an inner diameter and an outer diameter, and may include a hole through which the light energy can be applied to the object to be irradiated have.

On the other hand, although not shown, the control unit measures or predicts the depth at which the light energy penetrates the subject. In addition, the controller 500 controls the intensity of the ultrasonic waves to increase when it is determined that the penetration depth does not reach a desired level. At this time, the control unit may increase the intensity of the ultrasonic wave, but may set a threshold value that does not cause tissue damage.

In order to verify this concept, a change in penetration depth of light energy irradiated on a tissue-mimicking phantom having a constant thickness, divided into cases in which the light energy was irradiated singly and light and ultrasonic energy were simultaneously irradiated Were experimentally verified. In this regard, Fig. 2 shows the measurement results of the light intensity distribution on a tissue-like phantom of a certain thickness according to an embodiment of the present invention. At this time, the predetermined thickness value may be 8 mm, but is not limited to these values. 2 (a) shows a light intensity distribution observed at an end portion of a phantom by a CCD (charge-coupled device) camera when only laser irradiation is transmitted. Meanwhile, FIG. 2 (b) shows the light intensity distribution along the horizontal axis and the corresponding smoothing spline fitting curve. 2 (c) and 2 (d) show the light intensity distribution when the laser and the ultrasonic wave having the intensity of 200 W / cm- ² are simultaneously transmitted to the medium. 2 (e) and 2 (f) show the light intensity distribution when the laser and the ultrasonic wave having the intensity of 268 W / cm- ² are simultaneously transmitted to the medium. 2 (g) and 2 (h) show the light intensity distribution when the laser and the ultrasonic wave having the intensity of 310 W / cm < ² & gt ^; are simultaneously transmitted to the medium.

Three different ultrasound intensities of 200, 268, and 310 W / cm-2 were used, as described above: They caused an increase in the local temperature of the ultrasound focus region: 1, 3, and 5 ° C respectively. This small temperature rise does not result in coagulation in the focus area. Also, in case of chick breast tissue, if the tissue coagulation is induced in the light propagation path, the light penetration depth is decreased considerably because it causes an increase of optical scattering by 25 times or more.

When a laser with a Gaussian beam profile and a full-width at half-maximum (FWHM) of 4 mm was delivered into the medium, the laser was significantly scattered and defocused after advancing into the phantom (a)); It can be seen that the light intensity varies strongly along the horizontal axis, and the initial beam profile disappears (FIG. 2 (b)).

The FWHM of the average normalized intensity was measured to be 0.626. On the other hand, the effect of scattering and defocusing was reduced when ultrasonic waves were transmitted simultaneously with the laser (Fig. 2 (c) to (h)).

The extent of this improvement depends on the ultrasound intensity. As the ultrasonic intensity increases, the variations in the light intensity become weaker and the light intensity distribution becomes closer to the Gaussian form. As the ultrasound intensity increased to 200, 268, and 310 W / cm-2, the optical energy magnitude enhancement was 14.6, 19.0, and 25.2%, which means that the average normalization intensities were increased to 0.718, 0.745, and 0.784, respectively . Also, in the case of 310W cm-2, the light intensity distribution shows a Gaussian form, and the FWHM in this case was measured as 4.88 mm. The reason that the intensity of light increases with increasing ultrasonic intensity can be clarified through inspection of air bubbles induced by incident ultrasound; It was observed that as the intensity of the ultrasonic waves increased, the bubble objects generated around the focus region of the transmitted ultrasonic waves grew. It can be seen that the growth of these bubble entities is much greater along the depth direction along the horizontal direction. This result indicates that the defocusing of the incident laser beam is smaller because it means that the non-scattering region is increased depending on the depth when the intensity of the ultrasonic waves is increased.

Meanwhile, FIG. 3 shows a result of observation of light intensity distribution on an ex vivo chicken breast having a certain thickness according to another embodiment of the present invention. At this time, the predetermined thickness may be 7 mm, but is not limited thereto. 3 (a) is a light intensity distribution observed at the end of a chicken breast by a CCD camera when only laser emission is transmitted. On the other hand, FIG. 3 (b) shows a case in which ultrasonic waves having a laser intensity of 310 W / cm.sup.- ² are all transmitted to the medium. 3 (c) shows the ratio of the average light intensity at each ultrasonic intensity to the intensity increase relative to the intensity measured when only the laser is transmitted.

Meanwhile, FIG. 3 shows the observation result of the light intensity distribution on the ex-vivo chicken breast having a certain thickness according to another embodiment of the present invention. At this time, the predetermined thickness may be 7 mm, but is not limited thereto. 3 (a) is a light intensity distribution observed at the end of a chicken breast by a CCD camera when only laser emission is transmitted. On the other hand, FIG. 3 (b) shows a case in which ultrasonic waves having a laser intensity of 310 W / cm.sup.- ² are all transmitted to the medium. Also, Fig. 3 (c) shows the ratio of the average light intensity at each ultrasonic intensity to the intensity measured when only the laser is transmitted.

On the other hand, the same phenomenon was observed in ex vivo chicken breasts with a thickness of 7 mm. On the other hand, if the average normalized to increase in FIG. Referring to (c) of 3, and the average normalized intensity in the case where only the laser passing was 0.56, the strength of the ultrasonic wave to be transmitted with each 200, 268, and 310 W / cm ^-2 The intensity increased to 13.2, 19.5, and 23.7%. Also, it can be seen that as the intensity of ultrasound increases, the amount of defocused decreases through examination of the light intensity distribution, which is consistent with the results of the phantom experiment. These results suggest that local temperature rise due to incident ultrasound does not play a role in reducing light scattering, because light scattering increases in tissue composed mainly of proteins, such as chicken breasts, as the medium temperature increases. It also means that it performs less of a role.

Meanwhile, FIG. 4 illustrates a change in fluorescence intensity emitted from a fluorescent dye according to another embodiment of the present invention. 4, when a laser and ultrasound with an intensity of 310 W / cm <" ² & gt ^; are delivered together into a chicken breast containing a fluorescent die at a thickness of 7 mm, Fluorescence emission is increased.

As shown in FIG. 4, when fluorescence emitted from a fluorescent dye injected into the trunk chicken breast is detected at a depth of 7 mm, the advantage of transmitting ultrasonic waves and light together as described above will become more apparent. Fluorescent radiation totally induced by the incident laser exhibits a peak normalized intensity of 0.71, while this value is increased when ultrasound with an intensity of 310 W / cm-2 is delivered together; The rate of increase in time slots 1 and 2 was 21.1%. Upon interruption of the ultrasound transmission, this fluorescence intensity recovered to 0.72, which was similar to the initial value (see time slot 3 in FIG. 4).

When ultrasound and laser were delivered again, the fluorescence intensity increased to 0.88 and 0.85 (corresponding to 24% and 20% increments) in time slots 4 and 5, respectively, at the initial value; These values are similar to the values for time slots 1 and 2. This result implies that the transmitted ultrasound transiently changes the light scattering characteristics of the tissue in the laser path to a non-scattering without permanently changing the tissue damage or tissue properties. Otherwise, light intensity regression and re-augmentation can not be controlled by ultrasonic waves.

In the above, the optical energy penetration depth control apparatus using ultrasonic energy was examined. In the following, a method of controlling the penetration depth of light energy using ultrasonic energy will be described. In this regard, FIG. 5 shows a flow chart of a method of controlling the depth of penetration of light energy using ultrasonic energy according to the present invention. It is needless to say that the content of the optical energy penetration depth control device described above can also be utilized in the optical energy penetration depth control method.

5, the light energy penetration depth control method may further include a light energy generating step S510, an air bubble generating step S520, a penetration depth measuring / anticipating step S530, and an ultrasonic intensity increasing step S540 . Meanwhile, the above-described steps are not limited to the listed order, but can be freely modified depending on the application. For example, the light energy generating step (S510) and the air bubble generating step (S520) may be performed at the same time or may generate light energy after air bubbles are generated.

In the light energy generating step S510, light energy is generated using a light source. The air bubble generating step S520 generates an air bubble using ultrasonic waves in a region where the light energy travels so that the depth of penetration of the light energy into the subject is increased.

At this time, in the light energy generating step S510, when there is no air bubble in the region, the light energy generates Rayleigh scattering in all directions by a scattering medium, In the air bubble generation step (S520), when the air bubble is present in the region, the light energy is scattered in the forward direction corresponding to the forward direction due to the collision with the air bubble, Lt; / RTI > increases. Further, in the air bubble generating step (S520), the light energy is applied to the object to be irradiated through the hole of the ultrasonic transducer from the light source. In this case, the ultrasonic transducer may have an inner diameter and an outer diameter, and may include holes corresponding to the inner diameter. For example, the ultrasonic transducer may be in the form of a ring having the inner diameter and the outer diameter, but is not limited thereto.

On the other hand, the penetration depth measurement / prediction step S530 measures or predicts the depth at which the light energy penetrates the subject. At this time, if it is determined that the penetration depth does not become a desired level, an ultrasonic intensity increasing step (S540) may be performed to control the intensity of the ultrasonic waves to be increased. At this time, increasing the ultrasonic intensity can be performed within a range that does not cause tissue damage.

It is also possible to perform the ultrasound intensity increasing step S540 without performing the penetration depth measuring / anticipating step S530. At this time, the step of increasing the ultrasonic intensity (S540) increases the intensity of the ultrasonic wave by the ultrasonic transducer so that the depth of penetration of the light energy into the subject is further increased.

On the other hand, if it is determined that the penetration depth is a desired level, the low penetration depth adjustment determination step S550 may be performed. That is, if it is necessary to adjust the penetration depth to a lower position in the low level penetration depth adjustment step S550, the ultrasonic inspection can be performed while reducing the ultrasonic intensity. At this time, the decreasing ultrasonic intensity may be an ultrasonic intensity value that decreases stepwise in accordance with the increased ultrasonic intensity. Alternatively, the decreasing ultrasonic intensity may be a reduced ultrasonic intensity value corresponding to a lower position that needs to be adjusted, or a value considering a certain margin in the reduced ultrasonic intensity value.

On the other hand, if it is not necessary to adjust the penetration depth to a lower position in the low level penetration depth adjustment step S550, ultrasound transmission may be performed with the previously determined ultrasonic intensity. Here, the previously determined ultrasonic intensity may be the ultrasonic intensity most recently determined in the ultrasonic intensity increasing step (S540).

In the foregoing, the apparatus and control method of the penetration depth of light energy using ultrasonic energy have been described. Next, the optical energy penetration depth measurement / control test apparatus using ultrasonic energy will be described. It should be understood that the details of the apparatus and control method of the penetration depth of light energy using ultrasonic energy can be utilized in combination with the apparatus for measuring and controlling the penetration depth of light energy.

In this regard, FIG. 6 shows a configuration diagram of an apparatus for measuring and controlling the penetration depth of light energy using ultrasound energy according to the present invention. 6, the penetration depth measurement / control apparatus 1000 'includes a laser source 100', an ultrasonic transducer 200 ', a CCD camera 300', an optical filter 400 ' And an ultrasonic wave controller 500 '.

The laser source 100 'generates a laser as a light source for generating light energy. The ultrasonic transducer 200 'is disposed between the laser source 100' and a phantom or chicken breast corresponding to the sample to which the light energy is irradiated, thereby generating ultrasonic waves. Meanwhile, the laser source 100 'may be a continuous wave laser of the first wavelength having a Gaussian profile. On the other hand, it is not limited to the CW laser, but may be a pulsed wave (PW). The laser source 100 'may further include a laser power module 110 configured to be connected (100') to the laser source to adjust the optical energy by turning the laser source on or off.

The CCD camera 300 'is spaced apart from the sample by a predetermined distance, and is disposed behind and is configured to measure the intensity of the ultrasonic wave. An optical filter 400 'is disposed between the sample and the CCD camera 300' and is configured to filter light of a specific wavelength.

The ultrasonic control unit 500 'controls the air bubble to be generated in the region between the ultrasonic transducer 200' and the sample through the ultrasonic transducer 200 '.

On the other hand, when a fluorescent dye is inserted into the phantom in the penetration depth measurement / control apparatus 1000 ', the following operation can be performed. That is, a fluorescent dye is injected into the phantom, and the fluorescent dye emits a fluorescence of a second wavelength after absorbing the laser of the first wavelength . In this case, the optical filter 400 'is configured to pass only the fluorescence of the second wavelength.

The ultrasound controller 500 'may include a function generator 510, a signal amplifier (RF amplifier) 520, and a matching network 530. The function generator 510 is configured to generate a sinusoidal electric signal. The signal amplifier 520 is configured to amplify the sinusoidal electrical signal to increase the intensity of the ultrasonic wave. In addition, the matching network 530 performs impedance matching to effectively oscillate the transducer 200 '.

As discussed above, in the field of optical imaging and therapy, an increase in ultrasound-assisted light penetration is useful. In theory, there is no limitation on the position and size of the ultrasonic focusing region. Therefore, the foregoing can be used with a wide uniform beam for photodynamic therapy and a tightly focused light beam, which is desirable for optical imaging.

For a deeply-placed target, an ultrasonic transducer designed specifically to have a long focal depth may be used to create an air bubble along the optical path. In addition, if the ultrasonic waves are capable of producing bubble entities within the region of interest, any configurations of the angles of incidence of ultrasound and light are possible, which is particularly useful for real-time endoscopic applications.

Meanwhile, according to the software implementation in the ultrasonic energy induced optical imaging and treatment apparatus and the ultrasonic energy induced optical imaging and treatment apparatus according to the present invention, not only the procedures and functions described in the present specification but also respective components are separately Lt; RTI ID = 0.0 > software module. Each of the software modules may perform one or more of the functions and operations described herein. Software code can be implemented in a software application written in a suitable programming language. The software code is stored in a memory and can be executed by a controller or a processor.

1000: Optical energy penetration depth control device
1000 ': Optical energy penetration depth measurement / control test device
100: light source 100 ': laser source
110: laser power module
200, 200 ': Ultrasonic transducer
300, 300 ': CCD camera 400, 400': Optical filter
500: controller 500: ultrasonic controller
510: function generator 520: signal amplifier
530: matching network

Claims

An optical energy penetration depth control apparatus using ultrasonic energy,
A light source for generating light energy; And
An ultrasound transducer configured to generate an air bubble using an ultrasonic wave in a region where the light energy travels to increase the depth at which the light energy penetrates an illuminated subject, Incorporating depth control device for optical energy penetration using ultrasonic energy.

The method according to claim 1,
When there is no air bubble in the region, the light energy is Rayleigh scattering in all directions due to the scattering medium,
When the air bubble is present in the region, the depth of penetration into the object to be irradiated increases due to the occurrence of Mie scattering in the traveling direction corresponding to the forward direction due to the collision of the light energy with the air bubble , A device for controlling the penetration depth of light energy using ultrasonic energy.

The method according to claim 1,
Wherein the ultrasonic transducer is configured to increase an intensity of an ultrasonic wave to adjust a size of an area of the air bubble to be generated so that the depth of penetration of the light energy into the subject is further increased, The penetration depth control device using optical energy.

The method according to claim 1,
Wherein the ultrasonic transducer has an inner diameter and an outer diameter and has a hole corresponding to the inner diameter, wherein light energy is applied from the light source to the irradiation object through the hole , A device for controlling the penetration depth of light energy using ultrasonic energy.

The method of claim 3,
Further comprising a control unit for measuring or predicting the depth of penetration of the light energy into the subject and controlling the intensity of the ultrasonic wave to increase when it is determined that the depth of penetration does not become a desired level, A device for controlling the penetration depth of light energy using energy.

A method for controlling the penetration depth of light energy using ultrasound energy in a device for controlling depth of penetration of light,
A light energy generating step of generating light energy in a light source; And
And an air bubble generating step of generating an air bubble using ultrasonic waves generated by the ultrasonic transducer in a region where the light energy travels so that the depth of penetration of the light energy into the subject is increased , Depth Control Method of Optical Energy Penetration using Ultrasonic Energy.

The method according to claim 6,
In the light energy generating step,
When there is no air bubble in the region, the light energy is Rayleigh scattering in all directions due to the scattering medium,
In the air bubble generating step,
When the air bubble is present in the region, the depth of penetration into the object to be irradiated increases due to the occurrence of Mie scattering in the traveling direction corresponding to the forward direction due to the collision of the light energy with the air bubble A method of controlling penetration depth of light energy using ultrasonic energy.

The method according to claim 6,
The intensity of the ultrasonic wave is increased in the ultrasonic transducer so that the depth of penetration of the light energy into the subject is further increased by adjusting the size of the region of the air bubble to be generated, Further comprising the step of controlling the penetration depth of light energy using ultrasonic energy.

The method according to claim 6,
In the air bubble generating step,
Wherein the ultrasonic transducer has an inner diameter and an outer diameter and has a hole corresponding to the inner diameter,
Wherein the ultrasonic transducer applies the light energy to the object to be irradiated through the hole from the light source.

9. The method of claim 8,
A penetration depth measuring / predicting step in which a control unit measures or predicts a depth at which the light energy penetrates the subject; And
Further comprising an ultrasonic intensity increasing step of controlling the intensity of the ultrasonic wave to increase when the controller determines that the penetration depth does not become a desired level.

A device for measuring and controlling the penetration depth of light energy using ultrasound energy,
A laser source for generating a laser as a light source for generating light energy;
An ultrasound transducer disposed between the laser source and the sample to be irradiated with the light energy to generate ultrasonic waves; And
And an ultrasonic wave controller for controlling the ultrasonic transducer to generate air bubbles in the area between the ultrasonic transducer and the sample through the ultrasonic transducer.

12. The method of claim 11,
A CCD camera configured to be spaced apart from the sample and spaced apart from the sample and configured to measure the light energy intensity; And
Further comprising an optical filter disposed between the sample and the CCD camera and configured to filter light of a specific wavelength.

13. The method of claim 12,
The sample is injected with a fluorescent dye,
The fluorescent die emits fluorescence of a second wavelength after absorbing the laser of the first wavelength,
Wherein the optical filter is configured to pass only the fluorescence of the second wavelength.

12. The method of claim 11,
The ultrasonic wave controller may include:
A function generator configured to generate a sinusoidal electric signal;
A signal amplifier (RF Amplifier) configured to amplify the sinusoidal electric signal to increase the intensity of the ultrasonic wave; And
And a matching network that performs impedance matching to excite the transducer with a resonant frequency. &Lt; Desc / Clms Page number 20 >

14. The method of claim 13,
Wherein the laser source is a continuous wave laser of the first wavelength having a Gaussian profile,
Further comprising a laser power module coupled to the laser source and configured to adjust the optical energy by turning the laser source on or off, wherein the laser power module is configured to measure the optical energy penetration depth using the ultrasonic energy.