KR102273928B1 - Light radiation device that secures light transmission depth by focused ultrasonic wave guidance and method of controlling light output by feedback control of ultrasonic wave - Google Patents

Abstract

Provided is a photodynamic therapy device capable of increasing the effect of photodynamic therapy by forming an open channel to secure a photosensitive agent delivery and light penetration depth in a biological barrier covering a target biological tissue.
The photodynamic therapy device includes a light source module for emitting light; an ultrasound module for outputting ultrasound; a detecting module for detecting a result by the output of ultrasound; and an electronic control module for feedback-controlling the output of the ultrasound module according to the detection result of the detecting module.

Description

LIGHT RADIATION DEVICE THAT SECURES LIGHT TRANSMISSION DEPTH BY FOCUSED ULTRASONIC WAVE GUIDANCE AND METHOD OF CONTROLLING LIGHT OUTPUT BY FEEDBACK CONTROL OF ULTRASONIC WAVE}

The present invention relates to a photodynamic therapy device for securing a light penetration depth by induction of focused ultrasound, and a method for irradiating light by feedback-controlling the output of ultrasound.

Photodynamic therapy (PDT) is a single method by generating a chemical reaction between a photosensitizer and a photosensitizer applied to a target biological tissue by light and oxygen. It is a treatment that selectively destroys tumors and cancer cells without any pain to the patient by using single oxygen and free radicals induced by it.

With the recent development of drug delivery technology and the development of light sources, photodynamic therapy, which stands out as a local treatment method centered on a target biological tissue, is a new technology for brain disease treatment.

On the other hand, for effective photodynamic therapy, it is necessary to deliver a sufficient amount of the photosensitizer to the target biological tissue and at the same time secure a certain light penetration depth to the target biological tissue, thereby securing sufficient amount and light amount of the photosensitizer for treatment. There is this.

However, in general, since the target biological tissue is covered by various biological barriers (soft tissue, mucous membrane, blood vessel barrier), there is a problem in that it is not possible to secure an open channel for the light-sensitive agent and light transmission by these biological barriers.

For example, when irradiating light to a target region of brain tissue to treat a brain tumor, etc., there is a problem that the photosensitizer and the light are not effectively transmitted due to the brain blood barrier (BBB). There is a need for a solution.

Korean Patent Publication No. 10-2018-0095587, published on August 27, 2018

The problem to be solved by the present invention is to form an open channel to secure a light-sensitive agent delivery and light penetration depth in a biological barrier (for example, a brain blood barrier (BBB)) covering a target biological tissue, thereby providing photodynamics. An object of the present invention is to provide a photodynamic therapy device capable of increasing the effect of treatment.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A photodynamic therapy apparatus according to an aspect of the present invention for solving the above-described problems includes: a light source module for emitting light; an ultrasound module for outputting ultrasound; a detecting module for detecting a result by the output of ultrasound; and an electronic control module configured to feedback-control an output of the ultrasound module according to a detection result of the detecting module.

The detecting module may sense vibration caused by cavitation of a living tissue generated by ultrasound.

The electronic control module may determine whether stable cavitation or inertial cavitation occurs according to a detection result of the detecting module, and may turn off the ultrasound module or decrease an output value of the ultrasound module when inertial cavitation occurs.

Ultrasound may be focused on the biological barrier between the light source module and the target biological tissue, and light transmittance of the biological barrier may be increased by focusing the ultrasound.

The target biological tissue may be brain tissue, and the biological barrier may be a blood-brain barrier.

The light source module includes a light source for emitting light, an optical fiber unit providing an optical path of the light emitted from the light source, and a diffuser unit disposed at an end of the optical fiber unit to diffuse the light emitted from the light source, and at least a part of the diffuser unit. A spherical surface may be formed to diffuse the light emitted from the light source.

The ultrasound module may include an oscillator for outputting ultrasound and a hollow transducer for focusing the ultrasound output from the oscillation unit.

The optical fiber unit may be movably disposed inside the transducer.

The optical fiber part is slidable, the distance between the divisor part and the target biological tissue is shortened by sliding movement of one side of the optical fiber part, and the distance between the divisor part and the target biological tissue is lengthened by the sliding movement of the other side of the optical fiber part. .

The optical fiber unit may include a first optical fiber that forms a channel through which the light emitted from the light source moves to a target biological tissue, and a second optical fiber that forms a channel through which the emitted light from the light source returns through the target biological tissue. .

According to an aspect of the present invention for solving the above-described problems, a method for irradiating light by feedback control of the output of ultrasonic waves includes: outputting ultrasonic waves to focus ultrasonic waves on a biological barrier with an ultrasonic module; irradiating light to a target biological tissue located inside the biological barrier with a light source module; detecting a result by ultrasonic output with a detecting module; and feedback-controlling the output of the ultrasound module according to the detection result of the detecting module with an electronic control module.

The detecting module may irradiate light by feedback-controlling the output of the ultrasonic wave for sensing the vibration frequency due to cavitation of the living tissue generated by the ultrasonic wave.

The electronic control module determines whether stable cavitation or inertial cavitation occurs according to the detection result of the detecting module, and turns off the ultrasound module or lowers the output value of the ultrasound module when inertial cavitation occurs. can be irradiated with light by feedback control.

The target biological tissue is brain tissue, and the biological barrier may irradiate light by feedback-controlling the output of ultrasound, which is the blood-brain barrier.

The present invention provides a photodynamic therapy device capable of securing an open channel by lowering the binding force of a tissue of a biological barrier by an ultrasound module, thereby securing a light-sensitive agent administration and a light penetration depth.

In addition, in the present invention, by detecting inertial cavitation by a passive cavitation detector (PCD) and feedback-controlling the ultrasound module according to the detection result, microbubbles in the biological barrier grow into bubbles so that ultrasound is generated It is possible to prevent damage to the biological barrier during the application process.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a conceptual diagram illustrating that the photodynamic therapy device of the present invention secures the light penetration depth by opening the biological barrier under ultrasound guidance.
Figure 2 is an operation state diagram showing the operation of the light source module and the ultrasonic module of the present invention.
3 is a perspective view showing an optical fiber unit and a diffuser unit of the light source module of the present invention.
4 is a schematic diagram showing the photodynamic therapy device of the present invention.
5 is a flowchart illustrating a method of irradiating light by feedback-controlling the output of ultrasonic waves according to the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully understand the scope of the present invention to those skilled in the art, and the present invention is only defined by the scope of the claims.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components. Like reference numerals refer to like elements throughout, and "and/or" includes each and every combination of one or more of the recited elements. Although "first", "second", etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein will have the meaning commonly understood by those of ordinary skill in the art to which this invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless specifically defined explicitly.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between a component and other components. A spatially relative term should be understood as a term that includes different directions of components during use or operation in addition to the directions shown in the drawings. For example, when a component shown in the drawing is turned over, a component described as “beneath” or “beneath” of another component may be placed “above” of the other component. can Accordingly, the exemplary term “below” may include both directions below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Hereinafter, the photodynamic therapy apparatus 1000 of the present invention will be described with reference to the drawings. 1 is a conceptual diagram illustrating that the photodynamic therapy device of the present invention secures the light penetration depth by opening the biological barrier under ultrasound guidance, and FIG. 2 is an operational state diagram showing the operation of the light source module and the ultrasound module of the present invention. , Figure 3 is a perspective view showing the optical fiber portion and the diffuser portion of the light source module of the present invention, Figure 4 is a schematic diagram showing the photodynamic therapy device of the present invention.

The photodynamic therapy apparatus 1000 of the present invention may be used to treat various diseases in which the photodynamic therapy effect appears or may appear.

For example, the photodynamic therapy apparatus 1000 of the present invention may be used to treat various cancers (pancreatic cancer, biliary tract cancer, etc.) and tumor diseases, and in particular, it may be used to treat brain diseases such as brain tumors. . In this case, the target biological tissue T may be a brain tissue, and is covered by a brain blood barrier (BBB), which is a problem because it is difficult to administer a light sensitive agent and secure a light penetration depth.

The photodynamic therapy apparatus 1000 of the present invention may include a light source module 100 , an ultrasound module 200 , a detecting module 300 , and an electronic control module 400 .

The light source module 100 may be a module emitting light. In this case, the light may be a concept including not only light for photodynamic treatment, but also light for monitoring for securing a surgical field of view.

The light source module 100 of the present invention may be provided in various forms. The light source module 100 of the present invention may irradiate light from the outside of the target biological tissue T to the target biological tissue T. The light source module 100 of the present invention may irradiate light from the outside of the ultrasound module 200 to the target biological tissue T, but is not limited thereto.

As an example, various optical elements may be added to the light source module 100 of the present invention in addition to the light source 110 , and accordingly, light may be irradiated to the target biological tissue T having various positions and arrangements.

To this end, the light source module 100 includes a light source 110 emitting light, an optical fiber unit 120 providing an optical path of the light emitted from the light source 110, and disposed at the end of the optical fiber unit 120 to provide a light source ( 100) may include a diffuser unit 130 that diffuses the emitted light.

The light source 110 may emit light of various wavelength bands for photodynamic therapy and monitoring. The type of light emitted from the light source 110 may vary depending on the type of disease and the monitoring image. For example, a laser didoe (LD), a vertical-cavity surface0 emitting laser (VCSEL), etc. may be used as the light source 110 to irradiate laser light (excitation light) of various wavelength bands, but is not limited thereto.

The optical fiber unit 120 may be disposed between the light source 110 and the target biological tissue T, and may provide an optical path for guiding the emitted light of the light source 110 to the target biological tissue T.

The optical fiber unit 120 may be movably disposed inside the transducer 220 of the ultrasound module 200 . For example, the optical fiber unit 120 may be slidably movable, and the distance between the diffuser unit 130 and the target biological tissue T may be shortened by sliding movement of one side of the optical fiber unit 120 , and the optical fiber unit may be slidably moved. The distance between the diffuser unit 130 and the target biological tissue T may be increased by the sliding movement of the other side of the 120 .

Accordingly, the medical staff slides and moves the optical fiber unit 120 to determine the light penetration depth of the light emitted from the light source 110 (the position of the main light emitted from the light source) according to the depth (position) of the target biological tissue T. can be controlled

Meanwhile, the optical fiber unit 120 may form a bidirectional channel. For example, the optical fiber unit 120 includes a first optical fiber unit 121 that forms a channel through which the light emitted from the light source 110 moves to the target biological tissue T, and the light emitted from the light source 110 is transmitted to the target biological tissue T. It may include a second optical fiber unit 122 that forms a channel that recurs through (T). In this case, the first optical fiber unit 121 may be located at the center, and the second optical fiber unit 122 may be located at the edge, and the second optical fiber unit 122 may be disposed along the circumference of the first optical fiber unit 121 . have.

The light emitted from the light source 110 (light used for photodynamic therapy and/or monitoring) through the first optical fiber unit 121 may be irradiated to the target biological tissue T. Light passing through the target biological tissue T through the second optical fiber unit 122 may return to the outside to provide a source for a monitoring image. In this case, the light passing through the target biological tissue T may be emitted light by a fluorescent material pretreated on the target biological tissue T, and the monitoring image may be provided as a fluorescence image of various wavelength bands according to the selection of the medical staff. may, but is not limited thereto. For example, the monitoring image may be a brightfield image visualized by light of a white wavelength band.

The diffuser unit 130 may be an optical element that diffuses the light transmitted through the optical fiber unit 120 . The light emitted from the light source 110 by the diffuser unit 130 may be widely irradiated in the form of a surface light source in front of the target biological tissue T.

On the other hand, in the photodynamic therapy apparatus 1000 of the present invention, a spherical surface is formed in at least a portion of the diffuser unit 130 so that the light emitted from the light source 110 is diffused so that the light diffusion efficiency by the diffuser unit 130 can be increased. can be For example, the light diffusion end of the diffuser unit 130 may be provided in a hemisphere type.

Meanwhile, the light source module 100 may further include a first optical element 111 , a second optical element 112 , and a third optical element 113 for forming an optical system in addition to the above-described components. In this case, the first optical element 111 , the second optical element 112 , and the third optical element 113 may be sequentially disposed on the optical path between the light source 110 and the optical fiber unit 120 .

The first optical element 111 may be combined as a "total reflection mirror" and a "half mirror", and a portion of the light emitted from the light source 110 is used for the detecting module 300 and the remaining portion is used for the second optical element 112 . can be guided by The second optical element 112 may attenuate the amplitude of the emitted light as an attenuator. The third optical element 113 may be combined with a "total reflection mirror" and a "half mirror", and a portion of the light passing through the second optical element 112 is used for the detecting module 300 and the remaining portion is transferred to the optical fiber unit 120 . ), or the light returning through the target tissue T may be guided to the detecting module 300 .

The ultrasound module 200 may be a module that outputs ultrasound (eg, HIFU focused ultrasound (FUS)). To this end, the ultrasound module 200 may include an oscillator 210 that outputs ultrasound and a transducer 220 that converts the ultrasound output from the oscillator 210 and focuses it on the target biological tissue T.

Ultrasound may be focused on the biological barrier B between the light source module 100 and the target biological tissue T. Through this, the ultrasound provided from the ultrasound module 200 serves to increase the light transmittance of the biological barrier B by focusing. In more detail, the biological barrier (B) has a biological characteristic (Biological characteristic) is changed by the non-thermal effect of ultrasound, the light transmittance of the biological barrier (B) can be increased.

In addition, when the ultrasound provided from the ultrasound module 200 is applied to the blood-brain barrier, which is one of the biological barriers, when the photodynamic treatment apparatus 1000 is used for the purpose of treating a brain disease, the binding force of the blood-brain barrier is lowered. It serves to enable passage. Specifically, the blood-brain barrier blocks the passage of drugs to protect the brain, and when the binding force is lowered as ultrasound is applied, the drug temporarily passes. Through this, when performing brain disease treatment through drugs, the ultrasound module 200 provides an ultrasound to the blood-brain barrier region so that an effective drug for brain disease treatment is delivered from the blood vessel into the brain.

That is, when ultrasound is provided through the ultrasound module 200 while performing photodynamic therapy, the ultrasound provided to a tissue (eg, brain during brain disease treatment) causes the drug reacting with the photosensitizer to break through the biological barrier. While allowing passage, it increases the depth of penetration of the light source into the tissue. Specifically, the binding force of the biological barrier (B; for example, the blood-brain barrier; BBB; brain blood barier) is lowered by ultrasound, and accordingly, the light-sensitive agent and the light emitted from the light source 110 are applied to the biological barrier (B). An open channel (O) that can be efficiently transmitted is formed to secure the light-sensitive agent delivery and light penetration depth, thereby increasing the effect of photodynamic therapy. As a result, in the photodynamic therapy device 1000 of the present invention, through the open channel O of the biological barrier B, it is possible to secure the administration of the light-sensitive agent and the light penetration depth of a certain level or more to the target biological tissue T. Therefore, the photodynamic treatment effect is maximized.

In another embodiment of the present invention, the photodynamic therapy apparatus further includes a detecting module (300).

In one embodiment, the detecting module 300 may be a module for detecting a result by the output of ultrasound. As an example, the detecting module 300 may detect an output frequency, amplitude, etc. of ultrasonic waves, but is not limited thereto.

In addition, in one embodiment, the detecting module 300 serves to detect the generation of bubbles that may affect the biological barrier (B) by aggregation of air bubbles generated by ultrasound applied to the tissue. Specifically, when excessive ultrasound focusing occurs in the biological barrier (B), microbubbles (for example, microbubbles in blood) in the biological barrier (B) are aggregated to generate bubbles, and accordingly, in the process of applying the ultrasound to the living body Since the barrier B may be damaged, the detecting module 300 detects a bubble aggregation situation during photodynamic treatment using the light source module and the ultrasonic module.

In particular, in the detecting module 300 according to an aspect of the present invention, it is possible to detect vibrations caused by cavitation of biological tissues (phenomena caused by microbubbles, bubbles, etc.) generated by ultrasonic waves. To this end, the detecting module 300 may include a passive cavitation detector (PCD) 310 . In addition, the detection module 300 includes an amplifier 311 that amplifies the vibration signal sensed by the PCD 310 and an oscilloscope 312 that receives the amplified signal from the amplifier 311 and converts it into a waveform signal (frequency signal); Oscilloscope) may be further included. The detection result of the detecting module 300 may be transmitted to the electronic control module 400, and the photodynamic therapy device 1000 of the present invention is a source ( source) can be used.

On the other hand, in a modified example of the present invention, the detecting module 300 may detect light, and may also perform light output feedback control. To this end, the detecting module 300 includes a first sensing unit 313 that detects the light irradiated through the first optical element 111 of the light source module 100 and a third optical element ( A second sensing unit 314 for sensing the light irradiated through the 113 may be further included.

Various light sensing devices may be used for the first sensing unit 313 and the second sensing unit 314 . For example, the first sensing unit 313 may be a photoelectric sensor (PD) and the second sensing unit ( 314) may be an optical output power meter, but is not limited thereto.

In addition, in another embodiment, the photodynamic therapy apparatus 1000 of the present invention further includes an electronic control module (400). The electric control module 400 may be a module that feedback-controls the output of the ultrasound module 200 according to the detection result of the detecting module 300 . That is, the electronic control module 400 may be a module that controls the output of the ultrasound 200 in a dangerous situation according to the detection result of the ultrasound output in order to prevent damage to the biological barrier B due to excessive ultrasound focusing.

As a specific example, the electronic control module 400 feedback-controls the ultrasound output based on the bubble aggregation state measured by the detecting module 300 . Specifically, the photodynamic therapy apparatus 1000 provides ultrasound to open the biological barrier (B) and performs treatment while increasing the light penetration depth. When it is determined that a bubble that may cause damage to the barrier B is formed, the ultrasound output of the ultrasound module 200 is limited through the electronic control module 400 .

As an example, the electronic control module 400 determines whether "stability cavitation" or "inertial cavitation" is determined according to the detection result of the detecting module 300 (waveform signal due to cavitation of the living tissue). “You can decide whether

Stable cavitation may mean a phenomenon in which a stable and predictable vibration waveform appears before a large number of microbubbles in the biological barrier (B) grow into bubbles, and there may be little or slight damage to the biological barrier (B). have.

On the other hand, inertial cavitation may be a phenomenon in which a large number of microbubbles of the biological barrier (B) grow into bubbles, resulting in unstable and unpredictable vibration waveforms, and may be a phenomenon in which damage to the biological barrier (B) may occur. have.

The electronic control module 400 of the present invention provides feedback control for turning off the ultrasound module 200 or lowering the output value of the ultrasound module when there is a risk of damage to the biological barrier B due to inertial cavitation. can be performed.

Meanwhile, the electronic control module 400 of the modified example of the present invention may perform optical feedback control together with the ultrasonic feedback control described above.

Hereinafter, a method of irradiating light by feedback-controlling the output of ultrasound using the photodynamic therapy apparatus 1000 of the present invention will be described with reference to FIG. 5 .

In the method of irradiating light of the present invention, the ultrasonic module 200 is used to focus the ultrasonic waves on the biological barrier (B), and the ultrasonic wave is output (10) and the light source module 100 is positioned inside the biological barrier (B). It may include the step of irradiating light to the target biological tissue (T) (20).

In this case, in order to prevent the biological barrier B from being damaged by the ultrasound, the detecting module 300 detects the result of the ultrasound output ( 30 ) and the electronic control module 40 uses the detecting module ( The method may further include a step 40 of feedback-controlling the output of the ultrasound module 200 according to the detection result of 300 .

In this case, the step of outputting the ultrasound (10) and the step of feedback-controlling the output of the ultrasound module 200 (30, 40) based on the output result of the ultrasound may be performed prior to the step of irradiating light (20). Also, the step 20 of irradiating light may be performed in the process.

On the other hand, as described above, in a preferred embodiment of the present invention, it can be used as a photodynamic treatment method for the treatment of brain diseases. In this case, the target biological tissue (T) is the brain tissue, and the biological barrier (B) may be a blood-brain barrier.

In addition, the detecting module 300 may detect a vibration frequency due to cavitation of a living tissue (biological barrier) generated by ultrasound, and the electronic control module 400 responds to the detection result of the detecting module 300 . Accordingly, it is determined whether stable cavitation or inertial cavitation occurs, and when inertial cavitation occurs, the ultrasound module 100 may be turned off or an output value of the ultrasound module 100 may be lowered.

As mentioned above, although embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can realize that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (14)

An apparatus for irradiating light by feedback-controlling the output of ultrasonic waves,
a light source module emitting light;
an ultrasound module for outputting the ultrasound;
a detecting module for detecting a result of the output of the ultrasonic wave; and
An electronic control module for feedback-controlling the output of the ultrasound module according to the detection result of the detecting module,
The light source module includes a light source for emitting the light, an optical fiber unit providing an optical path of the light emitted from the light source, and a diffuser unit disposed at an end of the optical fiber unit to diffuse the light emitted from the light source,
A spherical surface is formed in at least a part of the diffuser part so that the light emitted from the light source is diffused,
The ultrasound module includes an oscillation unit for outputting the ultrasound and a hollow transducer for focusing the ultrasound output from the oscillation unit,
The optical fiber unit is arranged to be movable inside the transducer. According to claim 1,
The detecting module is
An apparatus for detecting a vibration frequency caused by cavitation of a living tissue generated by ultrasound. 3. The method of claim 2,
The electronic control module,
Determine whether stable cavitation or inertial cavitation according to the detection result of the detecting module,
Turning off the ultrasound module or lowering an output value of the ultrasound module when the inertial cavitation occurs. According to claim 1,
The ultrasound is focused on the biological barrier between the light source module and the target biological tissue,
The apparatus of claim 1, wherein the light transmittance of the biological barrier is increased by focusing the ultrasound. 5. The method of claim 4,
The target biological tissue is a brain tissue,
The biological barrier is a blood-brain barrier, the device. delete delete delete According to claim 1,
The optical fiber unit,
The sliding movement is possible, and the distance between the diffuser part and the target biological tissue is shortened by sliding movement of one side of the optical fiber part,
The distance between the diffuser part and the target biological tissue increases by sliding movement of the other side of the optical fiber part. According to claim 1,
The optical fiber unit,
A device comprising: a first optical fiber forming a channel through which the light emitted from the light source moves to a target biological tissue; and a second optical fiber forming a channel through which the light emitted from the light source returns through the target biological tissue. In the method of irradiating light by feedback-controlling the output of ultrasonic waves,
outputting the ultrasound to focus the ultrasound on the biological barrier with the ultrasound module;
irradiating light to a target biological tissue located inside the biological barrier with a light source module;
detecting a result by the output of the ultrasonic wave with a detecting module; and
Feedback controlling the output of the ultrasound module according to the detection result of the detecting module by an electronic control module;
The light source module includes a light source for emitting the light, an optical fiber unit providing an optical path of the light emitted from the light source, and a diffuser unit disposed at an end of the optical fiber unit to diffuse the light emitted from the light source,
A spherical surface is formed in at least a part of the diffuser part so that the light emitted from the light source is diffused,
The ultrasound module includes an oscillation unit for outputting the ultrasound and a hollow transducer for focusing the ultrasound output from the oscillation unit,
The optical fiber unit, characterized in that it is arranged to be movable inside the transducer, the method. 12. The method of claim 11,
The detecting module is configured to detect a vibration frequency due to cavitation of a living tissue generated by the ultrasound. 13. The method of claim 12,
The electronic control module,
Determine whether stable cavitation or inertial cavitation according to the detection result of the detecting module,
Turning off the ultrasound module or lowering an output value of the ultrasound module when the inertial cavitation occurs. 12. The method of claim 11,
The target biological tissue is a brain tissue,
The biological barrier is a blood-brain barrier, the method.

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