A photoacoustic non-invasive blood glucose detection system

Abstract

The application provides a full-automatic variable-cavity photoacoustic cell and a photoacoustic noninvasive blood glucose detection system, relates to the field of noninvasive blood glucose detection, and is used for solving the defects of traditional photoacoustic cells which are only suitable for a single fixed modulation frequency and solving the problems of low precision and poor continuity of photoacoustic noninvasive blood glucose detection technology. The full-automatic variable-cavity photoacoustic cell is composed of an incident window, an emission window, a photoacoustic resonant cavity, a piezoelectric sensor, a movable extension pipe, a single-chip microcomputer, an electronic valve and the like. The photoacoustic noninvasive blood glucose detection system is established based on the full-automatic variable-cavity photoacoustic cell and is composed of multiple components, including a light signal emission module, a light signal modulation module, a full-automatic variable-cavity photoacoustic cell, an ultrasonic detector, a lock-in amplifier, a filter, a computer system and the like. In the system, the light signal emission module emits a mid-infrared laser pulse of a specific frequency, the light signal is modulated by the light signal modulation module and is irradiated to a detection site, and photoacoustic signals are generated around the site. By measuring the photoacoustic signals generated by the photoacoustic effect, the glucose concentration can be indirectly measured, so that photoacoustic noninvasive blood glucose detection is realized. The device and system provided by the application can effectively improve the accuracy and continuity of noninvasive blood glucose detection and make up for the defects and deficiencies of traditional photoacoustic cells.

Description

Technical Field

[0001] This invention relates to the field of non-invasive blood glucose detection, specifically to a photoacoustic non-invasive blood glucose detection system. Background Technology

[0002] Diabetes is one of the most serious non-communicable diseases posing a significant threat to human health worldwide, second only to cancer and cardiovascular diseases. Despite significant breakthroughs in modern medical technology, there is still no cure for diabetes. Currently, the most widely used treatment for diabetes is insulin injection. Blood glucose monitoring is an essential part of diabetes management. For diabetic patients, continuous blood glucose monitoring can effectively reduce the risk of diabetic complications and help improve their quality of life.

[0003] Photoacoustic non-invasive blood glucose monitoring (PUV) technology, as a novel non-invasive blood glucose detection technology, has broad prospects. However, due to factors such as experimental conditions, equipment, and individual differences, current PUV technology suffers from drawbacks such as low detection accuracy and poor continuity. The photoacoustic cell, as a crucial component of the PUV system, significantly impacts detection accuracy; therefore, optimizing and designing its structure is a current hot topic in PUV technology. Different detection subjects have different requirements for the photoacoustic cell, but traditional photoacoustic cells are only suitable for a single fixed modulation frequency, greatly affecting the continuity and accuracy of PUV technology. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a photoacoustic non-invasive blood glucose detection system that overcomes the shortcomings of traditional photoacoustic cells which are only applicable to a single fixed modulation frequency, as well as the problems of low accuracy and poor continuity of current photoacoustic non-invasive blood glucose detection technology.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a photoacoustic non-invasive blood glucose detection system, characterized in that the fully automatic variable cavity photoacoustic cell is composed of an incident window, a photoacoustic resonant cavity, a piezoelectric sensor, a microcontroller, a movable extension tube, an electronic valve, and an exit window;

[0006] The incident window is located at the upper end of the photoacoustic cell and is used to receive modulated laser pulses transmitted from the upper-level system;

[0007] The photoacoustic resonant cavity is a resonant cavity with variable dimensions, used for energy conversion and transfer between light and sound waves;

[0008] The piezoelectric sensor is used to detect the weak photoacoustic signal generated in the photoacoustic resonant cavity and convert the photoacoustic signal into an electrical signal, which is then transmitted to the microcontroller for logical judgment.

[0009] The piezoelectric sensor is used to detect the photoacoustic signal generated in the resonant cavity and to achieve analog-to-electric conversion;

[0010] The microcontroller is used to perform logical judgments and control the up and down movement of the movable extension tube to change the size of the photoacoustic resonant cavity and realize the fully automatic cavity changing function.

[0011] The emission window contacts the detection area, maximizing the impact of the emitted laser pulse on the detection area.

[0012] Furthermore, the photoacoustic non-invasive blood glucose detection system is a detection system based on a fully automated variable cavity photoacoustic cell. The system includes a light signal transmission module, a light signal modulation module, a fully automated variable cavity photoacoustic cell, an ultrasound detector, a lock-in amplifier, a filter, and a computer system.

[0013] Furthermore, the piezoelectric sensor is implemented using polarized piezoelectric ceramic.

[0014] Furthermore, both the incident window and the exit window are made of transparent and easily processed materials.

[0015] Furthermore, a sealing ring is installed between the movable extension tube and the photoacoustic resonant cavity.

[0016] Furthermore, the optical signal transmitting module operates in the mid-infrared band and is used to transmit ultra-short wave mid-infrared laser pulses of different wavelengths.

[0017] Furthermore, the optical signal modulation module is used to perform amplitude modulation and phase modulation on the laser pulse.

[0018] Furthermore, the ultra-short wave mid-infrared laser pulse is a wavelength-separated mid-infrared laser pulse, one beam being the detection light at the wavelength of the characteristic absorption peak of glucose in the mid-infrared region, and the other beam being the reference light at a wavelength in the wavelength range that is not specifically absorbed by glucose.

[0019] Compared with existing technologies, the advantages of this invention are as follows: This photoacoustic non-invasive blood glucose detection system overcomes the drawback of traditional photoacoustic cell systems that are only applicable to a single fixed modulation frequency, thus improving the accuracy and continuity of photoacoustic non-invasive blood glucose detection technology; clinically, this fully automatic variable cavity photoacoustic cell eliminates the need for manual cavity adjustment by medical staff, greatly improving their work efficiency and reducing their workload. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1This is a fully automatic variable cavity photoacoustic cell; in the figure: 1-incident window, 2-photoacoustic resonant cavity, 3-piezoelectric sensor, 4-microcontroller, 5-movable extension tube, 6-electronic valve, 7-outcrystal window;

[0022] Figure 2 This is a photoacoustic non-invasive blood glucose detection system based on a fully automated variable cavity photoacoustic cell; in the figure: 9-light signal transmitting module, 10-light signal modulation module, 11-fully automated variable cavity photoacoustic cell, 12-ultrasound detector, 13-lock-in amplifier, 14-filter, 15-computer system. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments listed below are not intended to limit the scope of the present invention.

[0024] like Figure 1 As shown, the present invention provides a fully automatic variable cavity photoacoustic cell, which includes an incident window, a photoacoustic resonant cavity, a piezoelectric sensor, a microcontroller, a movable extension tube, an electronic valve, and an exit window;

[0025] The main principle of the fully automatic variable cavity photoacoustic cell is to use a microcontroller to determine the difference between the frequency of the photoacoustic signal and the natural frequency of the photoacoustic resonant cavity, and then control the up and down movement of the movable extension tube to change the size of the photoacoustic resonant cavity, thereby changing the natural frequency of the photoacoustic resonant cavity until the natural frequency of the photoacoustic resonant cavity is equal to the frequency of the photoacoustic signal, thereby generating a resonance phenomenon and achieving the purpose of enhancing the photoacoustic signal.

[0026] like Figure 1 As shown, the specific working steps of the fully automatic variable cavity photoacoustic cell are as follows:

[0027] Step 1: The laser pulse modulated by the upper system enters the photoacoustic cell through the incident window and shines on the detection area through the exit window. The laser pulse reacts with glucose molecules to generate a photoacoustic signal.

[0028] Step 2: The photoacoustic signal in the photoacoustic resonant cavity is detected by the piezoelectric sensor and converted into an electrical signal. The electrical signal is transmitted to the microcontroller and compared with the set natural frequency of the photoacoustic resonant cavity. If the two frequencies are not the same, the microcontroller controls the movable extension tube to move up and down until the natural frequency of the photoacoustic resonant cavity is the same as the frequency of the photoacoustic signal, and the movable extension tube stops moving.

[0029] Step 3: The electronic valve senses that the movable extension tube has stopped moving, opens the valve, and the resonant and enhanced photoacoustic signal is received by the ultrasonic detector behind the electronic valve, thus ending the operation of the fully automatic variable cavity photoacoustic cell.

[0030] like Figure 2 As shown, this is a photoacoustic non-invasive blood glucose detection system based on a fully automated variable cavity photoacoustic cell. The system consists of a light signal transmission module, a light signal modulation module, a fully automated variable cavity photoacoustic cell, an ultrasound detector, a lock-in amplifier, a filter, and a computer system.

[0031] The main principle used in the system is the photoacoustic effect. When a laser beam irradiates a tissue or substance, the light energy is absorbed by the tissue, causing a momentary rise in local temperature. Due to the photothermal effect, the volume of the tissue expands rapidly, forming a momentary sound source. The sound waves generated by this momentary sound source will propagate within the tissue through conduction or scattering, and eventually reach the surface of the tissue or the surrounding detector. This sound source signal is the photoacoustic signal.

[0032] like Figure 2 As shown, the specific testing steps are as follows:

[0033] Step 1: The optical signal transmitting module emits two ultra-short wave mid-infrared laser pulses in succession. One beam is the detection light with the characteristic absorption peak wavelength of the mid-infrared in glucose molecules, and the other beam is the reference light with wavelengths in the wavelength range that are not specifically absorbed by glucose. After emission, the laser pulses enter the optical signal modulation module for frequency modulation and phase modulation. The modulated laser pulses then begin to enter the fully automatic variable cavity photoacoustic cell.

[0034] Step 2: The modulated laser pulse enters the photoacoustic cell through the incident window and irradiates the detection site through the exit window. Glucose molecules in the tissue at the detection site absorb the mid-infrared light wave and generate a photoacoustic signal. The photoacoustic signal propagates from the inside of the tissue to the photoacoustic resonant cavity of the photoacoustic cell. The microcontroller performs logic judgment and controls the movement of the movable extension tube to realize the resonant amplification of the photoacoustic signal. The amplified signal is received by the ultrasonic detector.

[0035] Step 3: The ultrasonic detector receives the initially amplified photoacoustic signal and converts it into an electrical signal. The signal is then sent to a lock-in amplifier for further amplification and noise suppression. The amplified electrical signal carrying blood glucose concentration information enters a filter to remove other interference signals that carry blood glucose concentration information. Finally, the electrical signal containing only blood glucose concentration information is sent to the computer system for analysis and calculation.

[0036] Step 4: The computer system extracts the blood glucose concentration by comparing the differences between the photoacoustic signals generated by the detection light and the reference light, thus completing the photoacoustic non-invasive blood glucose detection.

[0037] This invention provides a photoacoustic non-invasive blood glucose detection system that can be used simultaneously for clinical blood glucose testing and home blood glucose monitoring. This invention solves the problem that traditional photoacoustic cells are only suitable for a single fixed modulation frequency, effectively improving the continuity and accuracy of photoacoustic non-invasive blood glucose detection technology, and meeting the requirements for non-invasive blood glucose detection.

[0038] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all within the protection scope of the present invention.

Claims

1. A photoacoustic non-invasive blood glucose detection system, the system comprising a fully automated variable cavity photoacoustic cell, characterized in that: The fully automatic variable cavity photoacoustic cell consists of an entrance window, a photoacoustic resonant cavity, a piezoelectric sensor, a microcontroller, a movable extension tube, an electronic valve, and an exit window. The incident window is located at the upper end of the photoacoustic cell and is used to receive modulated laser pulses transmitted from the upper-level system; The photoacoustic resonant cavity is a resonant cavity with variable dimensions, used for energy conversion and transfer between light and sound waves; The piezoelectric sensor is used to detect the weak photoacoustic signal generated in the photoacoustic resonant cavity and convert the photoacoustic signal into an electrical signal, which is then transmitted to the microcontroller for logical judgment. The microcontroller is used for logical judgment, comparing the difference between the frequency of the photoacoustic signal and the natural frequency of the photoacoustic resonant cavity, and controlling the movable extension tube to move up and down, thereby adjusting the size of the photoacoustic resonant cavity and changing the natural frequency of the cavity; when the natural frequency of the resonant cavity is the same as the frequency of the photoacoustic signal, resonance is generated, realizing the enhancement of the photoacoustic signal and completing the fully automatic cavity changing function of the photoacoustic cell. The electronic valve opens when it detects that the movable extension tube has stopped moving, so that the photoacoustic signal after resonance enhancement can be transmitted to the ultrasonic detector located behind the electronic valve. The emission window contacts the detection area, maximizing the impact of the emitted laser pulse on the detection area.

2. The photoacoustic non-invasive blood glucose detection system according to claim 1, characterized in that: The photoacoustic non-invasive blood glucose detection system is a detection system based on a fully automated variable cavity photoacoustic cell. The system includes a light signal transmission module, a light signal modulation module, a fully automated variable cavity photoacoustic cell, an ultrasound detector, a lock-in amplifier, a filter, and a computer system.

3. The photoacoustic non-invasive blood glucose detection system according to claim 1, characterized in that: The piezoelectric sensor is implemented using polarized piezoelectric ceramic.

4. The photoacoustic non-invasive blood glucose detection system according to claim 1, characterized in that: Both the entrance window and the exit window are made of transparent and easily processed materials.

5. The photoacoustic non-invasive blood glucose detection system according to claim 1, characterized in that: A sealing ring is installed between the movable extension tube and the photoacoustic resonant cavity.

6. The photoacoustic non-invasive blood glucose detection system according to claim 2, characterized in that: The optical signal transmitting module operates in the mid-infrared band and is used to transmit ultra-short wave mid-infrared laser pulses of different wavelengths.

7. The photoacoustic non-invasive blood glucose detection system according to claim 2, characterized in that: The optical signal modulation module is used to perform amplitude modulation and phase modulation on the laser pulse.

8. The photoacoustic non-invasive blood glucose detection system according to claim 6, characterized in that: The ultra-short wave mid-infrared laser pulse is a wavelength-separated mid-infrared laser pulse, one beam being the detection light at the wavelength of the characteristic mid-infrared absorption peak of glucose, and the other beam being the reference light at a wavelength in the wavelength range not specifically absorbed by glucose.

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