Photoacoustic diagnostic device and method

Abstract

This invention relates to a photoacoustic diagnostic apparatus and method for measuring blood glucose levels by measuring morphological changes in a membrane caused by sound waves. More specifically, it relates to a photoacoustic diagnostic apparatus and method for adjusting the frequency response of the diagnostic apparatus by adjusting the size of the membrane. According to an embodiment of the invention, the photoacoustic diagnostic apparatus includes: a light source for irradiating a test object with light to emit sound; a plurality of pickup units, each equipped with a membrane that undergoes morphological changes due to the sound; and a measuring unit for measuring the morphological changes of the membrane. The membranes of the plurality of pickup units may have different sizes.

Description

Technical Field

[0001] This invention relates to a photoacoustic diagnostic device and method for measuring blood glucose by measuring the morphological changes caused by sound waves on a membrane, and more specifically, to a photoacoustic diagnostic device and method for adjusting the frequency response of the diagnostic device by adjusting the size of the membrane. Background Technology

[0002] Photoacoustic diagnostics is a technique that uses the photoacoustic effect to non-invasively create biological tissue. When a short electromagnetic pulse of laser light is incident on biological tissue for photoacoustic diagnosis, a portion of the energy is absorbed by the tissue and converted into heat, causing instantaneous thermoelastic expansion. As a result, ultrasonic waves with a wide frequency band are emitted. These ultrasonic waves are then detected in multiple directions using a transducer, thereby converting them into images.

[0003] Because photoacoustic diagnostic technology converts electromagnetic waves into ultrasound waves for detection, it has the advantage of combining the characteristics of optical and ultrasound imaging. While pure optical imaging techniques offer significantly higher contrast than ultrasound imaging, the high light scattering in soft tissue limits imaging depth to a specific depth from the surface of the organism. In contrast, ultrasound imaging offers high spatial resolution, suitable for applications such as fetal examinations. Photoacoustic imaging overcomes the limitations of optical imaging, namely low imaging depth, by utilizing the ultrasound wave transformation caused by the photoacoustic effect, thus achieving both high optical contrast and high spatial resolution simultaneously.

[0004] A device for photoacoustic diagnostics generally consists of an optical component that irradiates a laser and a transducer that measures ultrasonic waves. Transducers for measuring ultrasonic waves can be piezoelectric or microelectromechanical systems (MEMS). In the piezoelectric method, the pressure caused by the ultrasonic waves creates a potential within the piezoelectric material; the ultrasonic wave is measured by measuring the potential difference, i.e., the voltage. In the MEMS method, the pressure caused by the ultrasonic waves changes the shape of a membrane; the ultrasonic wave is measured by measuring the change in electrostatic capacitance resulting from this change in shape.

[0005] The aforementioned transducer is composed of a module independent of the optical section. Therefore, photoacoustic diagnostic devices with the aforementioned transducer have the problem of difficulty in reducing their size and reduced ease of use. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a photoacoustic diagnostic device and method that adjusts the resonant frequency of a transducer by adjusting the size of a membrane to match the photoacoustic peak of blood glucose.

[0007] An embodiment of the present invention provides a photoacoustic diagnostic device.

[0008] According to an embodiment of the present invention, a photoacoustic diagnostic apparatus includes: a light source for irradiating light onto a test object to emit sound; a plurality of pickup units, each having a membrane whose shape changes due to the sound; and a measuring unit for measuring the shape change of the membrane, wherein the membranes of the plurality of pickup units may have different sizes.

[0009] In a photoacoustic diagnostic device according to an embodiment of the present invention, the resonant frequencies of the aforementioned pickup units can be matched with the photoacoustic peak of blood glucose.

[0010] An embodiment of the present invention provides a photoacoustic diagnostic method.

[0011] A photoacoustic diagnostic method according to an embodiment of the present invention may include the following steps: a light irradiation step, in which a light source is used to irradiate the test object; a sound pickup step, in which a plurality of sound pickup parts having a membrane are used to pick up the sound emitted from the test object; a measurement step, in which the morphological changes of the membrane are measured; and a blood glucose analysis step, in which the presence and amount of blood glucose contained in the blood are analyzed by analyzing the morphological changes of the membrane.

[0012] The photoacoustic diagnostic method according to an embodiment of the present invention may further include the following steps: adjusting the size of the diaphragm of the pickup section to match the resonant frequencies of the pickup section with the photoacoustic peak of blood glucose.

[0013] According to one embodiment of the present invention, a computer-readable recording medium can be provided, which records a program for implementing the above-described method.

[0014] The photoacoustic diagnostic device according to the present invention adjusts the resonant frequency of the transducer by adjusting the size of the diaphragm, thereby having the advantage of improving the frequency response of the photoacoustic diagnostic device.

[0015] The effects that can be obtained from this disclosure are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art based on the following description. Attached Figure Description

[0016] Figure 1 This is a diagram showing the overall structure of an existing photoacoustic diagnostic device.

[0017] Figure 2 This is a block diagram of a photoacoustic diagnostic device according to an embodiment of the present invention.

[0018] Figure 3 This is an embodiment of the pickup section in the photoacoustic diagnostic device according to the present invention.

[0019] Figure 4The frequency response of the pickup section of a photoacoustic diagnostic device according to an embodiment of the present invention is shown.

[0020] Figure 5 This is a diagram illustrating an example of photoacoustic signals caused by blood glucose.

[0021] Figure 6 This is a flowchart of a photoacoustic diagnostic method according to an embodiment of the present invention. Detailed Implementation

[0022] An embodiment of the present invention provides a photoacoustic diagnostic device.

[0023] According to an embodiment of the present invention, a photoacoustic diagnostic apparatus includes: a light source for irradiating light onto a test object to emit sound; a plurality of pickup units, each having a membrane whose shape changes due to the sound; and a measuring unit for measuring the shape change of the membrane, wherein the membranes of the plurality of pickup units may have different sizes.

[0024] In a photoacoustic diagnostic device according to an embodiment of the present invention, the resonant frequencies of the aforementioned pickup units can be matched with the photoacoustic peak of blood glucose.

[0025] An embodiment of the present invention provides a photoacoustic diagnostic method.

[0026] A photoacoustic diagnostic method according to an embodiment of the present invention may include the following steps: a light irradiation step, irradiating the test object with light using a light source; a sound pickup step, picking up the sound emitted from the test object by means of a plurality of sound pickup parts having a membrane; a measurement step, measuring the morphological changes of the membrane; and a blood glucose analysis step, analyzing the presence and amount of blood glucose contained in the blood by analyzing the morphological changes of the membrane.

[0027] The photoacoustic diagnostic method according to an embodiment of the present invention may further include the following steps: adjusting the size of the diaphragm of the pickup section to match the resonant frequencies of the pickup section with the photoacoustic peak of blood glucose.

[0028] According to one embodiment of the present invention, a computer-readable recording medium can be provided, which records a program for implementing the above-described method.

[0029] In the following description, embodiments of the invention will be given in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement them. However, the invention can be implemented in various different forms and is not limited to the embodiments described herein. Furthermore, for clarity of illustration, parts unrelated to the description have been omitted from the drawings, and similar reference numerals have been assigned to similar parts throughout the specification.

[0030] The terminology used in this specification is described in brief, while the invention is described in detail.

[0031] The terminology used in this invention has been selected as widely used conventional terms as possible while considering the functionality of the invention. However, this may be changed based on the intent or judgment of those skilled in the art, the emergence of new technologies, etc. Furthermore, in certain cases, terms arbitrarily chosen by the applicant may be used; in such cases, their meanings will be described in detail in the corresponding description of the invention. Therefore, the terminology used in this invention is not merely the name of the term, but should be defined based on its meaning and the overall content of this invention.

[0032] Throughout the specification, when it is stated that a part "contains" a certain component, unless specifically stated otherwise, it implies that other components may be included, rather than excluding them. Furthermore, terms such as "part" and "module" used in the specification refer to units that perform at least one function or action, which can be implemented by hardware or software, or a combination of both. Additionally, throughout the specification, when it is stated that a part is "connected" to other parts, this includes not only direct connections but also connections where "other elements are disposed between them."

[0033] The present invention will now be described in detail with reference to the accompanying drawings.

[0034] Figure 1 This is an overall configuration diagram of the photoacoustic diagnostic device according to an embodiment of the present invention. Figure 2 This is a block diagram of a photoacoustic diagnostic device according to an embodiment of the present invention.

[0035] Reference Figure 1 and Figure 2 According to an embodiment of the present invention, a photoacoustic diagnostic device may include: a light source 100 that irradiates light onto a test object to emit sound; a plurality of pickup units 200, each having a membrane whose shape changes due to the sound; and a measuring unit 300 that measures the shape change of the membrane, wherein the membranes of the plurality of pickup units 200 may have different sizes.

[0036] Light source 100 can output laser light, which can be infrared light.

[0037] The laser emitted by the light source 100 irradiates the object under test, causing the molecules contained in the object to vibrate. Due to the vibration of the molecules, ultrasonic waves are emitted.

[0038] The photoacoustic diagnostic device may include multiple pickup units 200. By forming the diaphragm included in each pickup unit 200 into different sizes, the resonance frequency (RF) of each pickup unit 200 can be set in various ways.

[0039] That is, the photoacoustic diagnostic device according to the present invention can have multiple resonant frequencies by including multiple pickup units 200 of different sizes, and the photoacoustic signal caused by blood glucose can be measured using the photoacoustic diagnostic device of the present invention.

[0040] The aforementioned measuring unit 300 can measure the morphological changes of the membrane by measuring the electrostatic capacitance. An optical method can be used to measure the morphological changes of the membrane by irradiating the aforementioned pickup unit 200 with a light source and measuring and analyzing the reflected light.

[0041] Figure 3 This is an embodiment of the pickup section in the photoacoustic diagnostic device according to the present invention.

[0042] Reference Figure 3 The pickup unit 200 also includes a diaphragm for detecting sound and a protective portion for the diaphragm. In the photoacoustic diagnostic apparatus according to the present invention, the sound can be equivalent to ultrasound.

[0043] The membrane can vibrate in the vertical direction Y in response to an applied sound X. The amplitude of the membrane's vertical vibration varies depending on the intensity of the sound X. For example, the greater the intensity of the sound X, the greater the amplitude of the membrane's vertical vibration.

[0044] The membrane can be used to detect the intensity of sound X applied from the outside, and can be configured as a thin film so that it can vibrate with the largest possible amplitude in response to sound X applied from the outside.

[0045] The film can be configured as monocrystalline silicon, polycrystalline silicon, silicon nitride, silicon oxide, aluminum and other metal thin film materials, carbon or carbon-containing compounds, and the stacked forms of the above materials, which are mainly used in MEMS processes.

[0046] The protective layer is preferably formed of a material having a structure that both protects the membrane from external impacts and does not impede the transmission of sound to the membrane. For example, a mesh material with a mesh structure can be used.

[0047] Figure 4 The frequency response of the pickup section of a photoacoustic diagnostic device according to an embodiment of the present invention is shown.

[0048] Reference Figure 4 From this, we can know the frequency response of a single pickup unit 200. Figure 4In the diagram, the horizontal axis represents frequency (Hz), and the vertical axis represents amplitude (dB). The resonant frequency is the frequency with a significantly larger amplitude compared to other frequencies. Figure 4 In this context, A represents the resonant frequency.

[0049] The pickup unit 200 may include a diaphragm, and the diaphragm has a resonant frequency. For example, when the photoacoustic diagnostic device includes 6 pickup units 200, it may include 6 diaphragms with 6 resonant frequencies.

[0050] According to an embodiment of the present invention, the photoacoustic diagnostic device may include six of the above-mentioned pickup units 200, and the resonant frequency of each of the pickup units 200 may be matched with the photoacoustic peak of blood glucose.

[0051] Figure 5 This is a diagram illustrating an example of photoacoustic signals caused by blood glucose.

[0052] exist Figure 5 In the diagram, the horizontal axis represents frequency (Hz), and the vertical axis represents power spectral density (W / Hz).

[0053] Reference Figure 5 The photoacoustic signal can have 6 peaks, and the frequency and shape of the peaks can vary depending on the measurement conditions.

[0054] That is, a desired number of peaks can be selected from the main peaks detected when blood is irradiated with a laser to match the resonant frequency of the pickup. The larger the amplitude of the peaks measured from the matched resonant frequency, the greater the amount of blood glucose.

[0055] The photoacoustic diagnostic device according to the present invention includes a plurality of pickup units 200. By matching the resonant frequency of each pickup unit 200 with the frequency of the peak caused by blood glucose, small signals caused by low concentrations of blood glucose or blood glucose in blood vessels far from the skin can be measured by the pickup unit showing a large amplitude. Thus, the amount of blood glucose can be accurately measured.

[0056] Figure 6 This is a flowchart of a photoacoustic diagnostic method according to an embodiment of the present invention.

[0057] Reference Figure 6 According to an embodiment of the present invention, a photoacoustic diagnostic method for measuring blood glucose using a photoacoustic diagnostic device includes the following steps: a light irradiation step S100, in which light is irradiated onto the test object using a light source 100; a sound pickup step S200, in which sound reflected from the test object is picked up by a plurality of sound pickup parts 200 having a membrane; a measurement step S300, in which the morphological changes of the membrane are measured; and a blood glucose analysis step S400, in which the presence and amount of blood glucose contained in the blood are analyzed by analyzing the measured morphological changes.

[0058] The photoacoustic diagnostic method according to an embodiment of the present invention may further include the following step: step S110, which involves adjusting the size of the diaphragm of the pickup unit 200 to match the resonant frequencies of the pickup unit 200 with the photoacoustic peak of blood glucose.

[0059] The methods described above can be applied to the methods according to an embodiment of the present invention. Therefore, descriptions of the same content as those described above regarding the methods are omitted.

[0060] The foregoing description of the present invention is illustrative, and those skilled in the art will understand that it can be readily modified into other specific forms without altering the technical concept or essential features of the invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. For example, the constituent elements described individually may also be implemented separately, and similarly, the constituent elements described separately may be implemented in combination.

[0061] The scope of this invention is defined by the following claims rather than by the detailed description above, and should be understood to include the meaning and scope of the claims and all modifications or variations derived therefrom.

Claims

1. A photoacoustic diagnostic device, comprising: A light source shines light onto the object being inspected to produce sound; Multiple pickup units, each equipped with a diaphragm whose shape changes in response to the sound; as well as The measuring unit measures the morphological changes of the membrane. The diaphragms of the plurality of pickup units have different sizes from each other. The resonant frequencies of the membrane in the pickup section match the photoacoustic peaks of blood glucose. Specifically, the desired number of peaks are selected from the main peaks detected when the blood is irradiated with laser to match the resonant frequencies of the diaphragm of the pickup unit.

2. A photoacoustic diagnostic method for measuring blood glucose using a photoacoustic diagnostic device, the photoacoustic diagnostic method comprising: Illuminate the object being inspected using a light source; The sound emitted from the object under test is picked up by multiple sound pickup parts equipped with membranes; The morphological changes of the membrane were measured; The presence and amount of blood glucose in the blood can be analyzed by analyzing the morphological changes of the membrane; and the size of the membrane in the pickup unit can be adjusted to match the resonant frequencies of the membrane with the photoacoustic peaks of blood glucose. Specifically, the desired number of peaks are selected from the main peaks detected when the blood is irradiated with laser to match the resonant frequencies of the diaphragm of the pickup unit.

3. A computer-readable recording medium having a program for implementing the method of claim 2.

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