A non-invasive near-infrared blood glucose detection device

Abstract

The application belongs to the technical field of blood glucose detection, and discloses a non-invasive near-infrared blood glucose detection device, which comprises a laser light source module and sequentially connected germanium single photon avalanche diode modules, a signal amplification module, a data processing module and a display module; the germanium single photon avalanche diode module comprises a silicon substrate, a distributed Bragg reflector, an N-type silicon electrode layer, an avalanche multiplication layer, a P-type silicon charge regulation layer, an intrinsic germanium absorption layer and a P-type germanium electrode layer which are sequentially stacked. The application can improve the effective absorption rate of the optical signal in the germanium single photon avalanche diode module, improve the responsivity, sensitivity and accuracy of the device, and effectively improve the signal-to-noise ratio.

Description

Technical Field

[0001] This application relates to the field of blood glucose detection technology, and in particular to a non-invasive near-infrared blood glucose detection device. Background Technology

[0002] Currently, non-invasive blood glucose monitoring technologies exhibit extremely weak reception of blood glucose-related optical signals within specific wavelength ranges. Particularly in the 1050 nm range, limitations imposed by tissue scattering, background absorption, and environmental noise, coupled with the low light absorption efficiency of existing silicon PIN detectors at this wavelength, make it difficult to detect blood glucose-related optical signals, thus exacerbating the challenges of non-invasive blood glucose monitoring. Furthermore, the significantly reduced light absorption efficiency of traditional silicon PIN detectors in this band further weakens detection capabilities. While silicon itself is non-toxic and inexpensive, improving its response performance at 1050 nm often requires the introduction of additional structures or special processes, indirectly increasing system costs and limiting its expansion in wearable medical and consumer electronics fields. Therefore, there is an urgent need to explore germanium-based alternatives to improve detection performance in this band and promote the development of non-invasive blood glucose monitoring. Summary of the Invention

[0003] This application provides a non-invasive near-infrared blood glucose detection device. By selecting a germanium single-photon avalanche diode module, the reception capability of blood glucose-related optical signals is enhanced. By designing a multi-cycle stacked avalanche multiplication layer and a distributed Bragg reflector, the effective absorption rate of optical signals in the germanium single-photon avalanche diode module is improved, thereby increasing the device's responsivity, sensitivity, and accuracy, and effectively improving the signal-to-noise ratio. Furthermore, the use of non-toxic materials such as silicon nitride and silicon dioxide facilitates low-cost and safe large-scale production and system integration.

[0004] This application provides a non-invasive near-infrared blood glucose detection device, including a laser light source module and a germanium single-photon avalanche diode module, a signal amplification module, a data processing module and a display module connected in sequence.

[0005] The laser source module is used to emit light signals of a preset wavelength to the germanium single-photon avalanche diode module; the preset wavelength is 1050 nanometers.

[0006] The germanium single-photon avalanche diode module comprises a silicon substrate, a distributed Bragg mirror, an N-type silicon electrode layer, an avalanche multiplication layer, a P-type silicon charge control layer, an intrinsic germanium absorption layer, and a P-type germanium electrode layer stacked sequentially.

[0007] The germanium single-photon avalanche diode module is used to receive and process optical signals, obtain electrical signals, and send them to the signal amplification module.

[0008] The signal amplification module is used to receive and process electrical signals, obtain blood glucose signals, and send them to the data processing module;

[0009] The data processing module is used to receive and process blood glucose signals, obtain blood glucose concentration values, and send them to the display module;

[0010] The display module is used to display blood glucose concentration values.

[0011] Furthermore, it also includes a wireless communication module;

[0012] The data processing module is also used to send blood glucose concentration values ​​to the wireless communication module;

[0013] The wireless communication module is used to receive blood glucose concentration values ​​and upload them to mobile devices or cloud platforms.

[0014] Furthermore, it also includes a power management module;

[0015] The power management module is used to monitor battery status.

[0016] Furthermore, it also includes an optical coupling module;

[0017] The laser source module is also used to transmit optical signals of a preset wavelength to the optical coupling module;

[0018] The optical coupling module is used to receive and process optical signals, obtain coupled optical signals, and send them to the germanium single-photon avalanche diode module;

[0019] The germanium single-photon avalanche diode module is also used to receive and process the coupled optical signal, obtain an electrical signal, and send it to the signal amplification module.

[0020] Furthermore, the avalanche multiplication layer is a multi-period stacked structure composed of silicon and silicon-germanium layers.

[0021] Furthermore, the avalanche multiplication layer is a multi-period stacked structure composed of germanium and silicon-germanium layers.

[0022] Furthermore, the thickness of the avalanche multiplication layer ranges from 200 nanometers to 500 nanometers.

[0023] Furthermore, the distributed Bragg reflector is a periodic structure with a predetermined number of periods; a single period consists of silicon nitride and silicon dioxide layers stacked sequentially.

[0024] Furthermore, the preset number of cycles is greater than or equal to 6 and less than or equal to 10.

[0025] Furthermore, the thickness of the intrinsic germanium absorber layer ranges from 0.8 micrometers to 1.5 micrometers.

[0026] In summary, compared with the prior art, the beneficial effects of the technical solution provided in this application include at least the following:

[0027] This application provides a non-invasive near-infrared blood glucose detection device. By selecting a germanium single-photon avalanche diode module, the device enhances the reception capability of blood glucose-related optical signals. By designing a multi-period stacked avalanche multiplication layer and a distributed Bragg reflector, the effective absorption rate of optical signals in the germanium single-photon avalanche diode module is improved, thereby increasing the device's responsivity, sensitivity, and accuracy, and effectively improving the signal-to-noise ratio. Furthermore, the use of non-toxic materials such as silicon nitride and silicon dioxide facilitates low-cost and safe large-scale production and system integration. Attached Figure Description

[0028] Figure 1 This is a structural diagram of a non-invasive near-infrared blood glucose detection device provided as an exemplary embodiment of this application.

[0029] Figure 2 This is a structural diagram of a non-invasive near-infrared blood glucose detection device, which is provided as another exemplary embodiment of this application. Detailed Implementation

[0030] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0031] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Please see Figure 1 This application provides a non-invasive near-infrared blood glucose detection device, including a laser light source module and a germanium single-photon avalanche diode module, a signal amplification module, a data processing module and a display module connected in sequence.

[0033] In some embodiments, the non-invasive near-infrared blood glucose detection device is first activated to ensure that it is in standby mode and all modules are working properly. Secondly, the detection parameters are set, such as selecting an appropriate light source wavelength (1050nm), adjusting the intensity of the laser beam (i.e., the light signal), the irradiation time, the detection area, etc. Finally, the measurement area is selected, generally a part with thinner skin and more concentrated blood vessels (such as fingers, palms, or earlobes).

[0034] The laser source module is used to emit light signals of a preset wavelength to the germanium single-photon avalanche diode module; the preset wavelength is 1050 nanometers.

[0035] The laser source module emits a near-infrared laser beam (i.e., optical signal) with a wavelength of 1050nm. This wavelength is highly matched with the absorption characteristics of blood glucose molecules, enabling it to effectively penetrate the skin, pass through the skin and blood vessels, and enter the blood flow area. The laser source module provides a stable optical signal, laying a solid foundation for the stable operation of the non-invasive near-infrared blood glucose detection device.

[0036] The germanium single-photon avalanche diode module comprises a silicon substrate, a distributed Bragg mirror, an N-type silicon electrode layer, an avalanche multiplication layer, a P-type silicon charge control layer, an intrinsic germanium absorption layer, and a P-type germanium electrode layer stacked sequentially.

[0037] Among them, the distributed Bragg reflector can increase the photogenerated carrier density and reduce the avalanche triggering threshold; the intrinsic germanium absorption layer operates at a wavelength of 1050nm, enabling a rapid response to low-energy photons; and the avalanche multiplication layer can reduce the bias voltage required for breakdown and optimize the multiplication efficiency at low voltages. The synergistic effect of these three components can enhance photon input, improve ionization efficiency, and ultimately significantly improve the performance of the germanium single-photon avalanche diode module.

[0038] Specifically, the germanium single-photon avalanche diode module operates with an optical power range of 1pW-1μW, significantly lower than the conventional 10nW, enabling detection in low-power scenarios; its detection sensitivity is greater than 10. 5 The counts / pW is two orders of magnitude higher than the equivalent A / W; the signal-to-noise ratio is greater than or equal to 40 dB, further reducing noise; the detection accuracy is tested to be better than 5%, which is better suited for monitoring subtle fluctuations in blood glucose; the light dose is less than 1 μJ / cm². 2 The dosage is significantly lower than the IEC Class 1 standard, reducing it by 3 to 4 orders of magnitude, ensuring user safety. The voltage requirement is reduced to 10V, compared to the 20V of traditional SPADs, greatly reducing user safety risks. The device is smaller and more portable, facilitating on-the-go measurements. It can also perform low-power continuous detection, suitable for various scenarios including home and hospital settings. Its high sensitivity, combined with a statistical mechanism, also makes it suitable for early pancreatic function monitoring. Furthermore, the safe dosage is less than 1 μJ / cm³. 2 Compared to ordinary detectors, it exhibits a significant reduction in values; it also employs the 1050nm band, which can highly match the absorption characteristics of blood glucose; benefiting from the single-photon sensitivity of the germanium single-photon avalanche diode module, this device can also detect minute changes of less than 0.3mmol / L, creating conditions for accurate blood glucose detection.

[0039] Among them, the germanium single-photon avalanche diode module can significantly reduce tissue irritation: it is especially suitable for long-term irradiation of sensitive areas such as the eyes and hands, avoiding discomfort or biological tissue damage caused by photothermal accumulation; it also supports high-frequency, continuous, non-invasive detection, which can meet the needs of dynamic blood glucose level monitoring under different physiological states (such as after meals and after exercise), improving the adaptability of personalized medicine; and it is also suitable for use by special populations, including infants, the elderly, and people with sensitive skin, reducing the risk of side effects during long-term monitoring. The germanium single-photon avalanche diode module of this application has nanosecond / picosecond level time resolution and single-photon event triggering mechanism, which significantly enhances the adaptability and accuracy of early screening while achieving high-sensitivity blood glucose detection, and is suitable for hypoglycemia warning, dynamic blood glucose monitoring in a short period of time after meals, and populations such as children and pregnant women who need to control the irradiation dose. Furthermore, the germanium single-photon avalanche diode module has strong dynamic response capabilities, which can accurately capture the subtle absorption changes caused by slight fluctuations in blood glucose, making it particularly suitable for identifying states such as impaired glucose regulation (IGR) or prediabetes. It also supports photon statistics accumulation: by accumulating subtle signal changes through multiple samplings, it improves the ability to identify subtle trend changes and expands the coverage of the detectable population. It can also provide high-resolution input data for intelligent prediction systems: which helps to integrate with AI models, realize early intervention and personalized treatment strategy optimization, and promote the shift from "post-event management" to "pre-event prediction".

[0040] The germanium single-photon avalanche diode module is used to receive and process optical signals, obtain electrical signals, and send them to the signal amplification module.

[0041] Blood glucose molecules in the human body absorb light signals at a wavelength of 1050nm to some extent. Part of the light signal is absorbed, while the remaining light signal is reflected back by the skin and blood vessels. The germanium single-photon avalanche diode module is responsible for receiving the reflected light signal and converting it into an electrical signal. Due to its high quantum efficiency and low dark count rate, the germanium single-photon avalanche diode module can efficiently capture weak reflected signals and accurately record the intensity of the light signal.

[0042] The germanium single-photon avalanche diode module integrates a distributed Bragg mirror enhancement structure on a silicon substrate, exhibiting a high absorption coefficient for near-infrared light in the 1050nm band and achieving high-gain detection through an avalanche multiplication layer. The distributed Bragg mirror has high reflectivity for the 1050nm band, reflecting light not absorbed by the germanium absorption layer back to the avalanche multiplication layer, thus significantly improving the photon absorption probability. By optimizing the germanium layer doping and electric field distribution of the germanium single-photon avalanche diode module, dark current is effectively suppressed while achieving high-gain detection, achieving a balance between high sensitivity and low noise.

[0043] The signal amplification module is used to receive and process electrical signals, obtain blood glucose signals, and send them to the data processing module.

[0044] The signal amplification module receives the electrical signal from the germanium single-photon avalanche diode module, amplifies it, and performs noise suppression processing to obtain the blood glucose signal and ensure that the blood glucose signal strength is sufficient for subsequent processing modules to analyze.

[0045] The data processing module is used to receive and process blood glucose signals, obtain blood glucose concentration values, and send them to the display module.

[0046] The blood glucose signal enters the digital signal processing stage through the data processing module. The digital signal processor (DSP) in the data processing module performs noise reduction, filtering, and normalization on the signal to remove errors caused by environmental and system noise. Techniques such as time-domain synchronous analysis, spectrum analysis, and wavelength absorption analysis are also employed to extract blood glucose-related features from the signal, particularly focusing on the absorption peak at 1050 nm. By comparing the changes in reference data and characteristic absorption peaks, an estimated blood glucose concentration is obtained. Based on the relationship between the estimated blood glucose concentration and the characteristic absorption peak of the reflected light, regression algorithms or machine learning models (such as linear regression and support vector machines) are used to calculate the real-time blood glucose concentration value from the processed data.

[0047] The display module is used to display blood glucose concentration values.

[0048] The analyzed blood glucose concentration value will be displayed in real time on the display module, such as an LCD or OLED display, in the form of numerical values ​​or trend charts, providing users with a clear report and making it easy for them to view data such as blood glucose concentration.

[0049] The non-invasive near-infrared blood glucose detection device provided in the above embodiments enhances the reception capability of blood glucose-related optical signals by selecting a germanium single-photon avalanche diode module; by designing a multi-period stacked avalanche multiplication layer and a distributed Bragg reflector, the effective absorption rate of optical signals in the germanium single-photon avalanche diode module is improved, thereby increasing the device's responsivity, sensitivity, and accuracy, and effectively improving the signal-to-noise ratio; and by using non-toxic materials such as silicon nitride and silicon dioxide, it is possible to achieve low-cost and safe large-scale production and system integration.

[0050] Please see Figure 2 In some embodiments, a wireless communication module is also included.

[0051] The data processing module is also used to send blood glucose concentration values ​​to the wireless communication module.

[0052] The wireless communication module is used to receive blood glucose concentration values ​​and upload them to mobile devices or cloud platforms.

[0053] The system utilizes a wireless communication module to upload blood glucose levels and other data in real time to the user's mobile device (such as a smartphone) or cloud platform. Users can choose between automatic or manual upload. Users, doctors, or the health management system can view historical blood glucose records and trends through the mobile application or cloud platform, providing relevant health advice. Doctors can also provide personalized health management plans for patients based on the analysis results of blood glucose levels.

[0054] In some embodiments, a power management module is also included.

[0055] The power management module is used to monitor battery status.

[0056] The power management module monitors and manages the device's battery status in real time and displays the battery level, ensuring the device reminds the user to charge when the battery is low. The power management module ensures long-term device use and supports fast charging. It can also perform periodic self-tests to ensure all modules within the device are functioning correctly. Furthermore, users can obtain device health reports through the device's status monitoring interface.

[0057] In some embodiments, an optical coupling module is also included.

[0058] The laser source module is also used to transmit light signals of a preset wavelength to the optical coupling module.

[0059] The optical coupling module is used to receive and process optical signals, obtain coupled optical signals, and send them to the germanium single-photon avalanche diode module.

[0060] The germanium single-photon avalanche diode module is also used to receive and process the coupled optical signal, obtain an electrical signal, and send it to the signal amplification module.

[0061] The optical coupling module collimates and focuses the laser beam to ensure that the laser beam accurately irradiates the skin surface at an appropriate angle and intensity, ensuring a uniform irradiation area and avoiding local over-irradiation or reflection signal errors.

[0062] In some embodiments, if the blood glucose concentration value exceeds the normal range, an audio feedback module is also included; the audio feedback module will issue an alarm to alert the user. The alarm content may include "blood glucose is high" or "blood glucose is low," and may provide further suggestions or reminders.

[0063] In some embodiments, the germanium single-photon avalanche diode module includes a silicon substrate, a distributed Bragg mirror, an N-type silicon electrode layer, an avalanche multiplication layer, a P-type silicon charge modulation layer, an intrinsic germanium absorption layer, and a P-type germanium electrode layer stacked sequentially; its design parameters are listed in Table 1 below:

[0064] Table 1

[0065]

[0066]

[0067] The silicon substrate provides mechanical support, reduces the effects of dark current and capacitance, and is suitable for back-illuminated or back-end processing, ensuring the versatility of the germanium single-photon avalanche diode module. The distributed Bragg reflector creates high reflectivity at 1050nm, improving absorption and single-photon detection efficiency. The N-type silicon electrode layer provides an electron conduction path and forms an ohmic contact with the metal bottom electrode. The avalanche multiplication layer enables impact ionization, enhances gain, and controls the avalanche initiation voltage, thereby improving bandgap engineering capabilities. The P-type silicon charge control layer controls the electric field distribution of the avalanche layer, preventing field distortion and premature breakdown. The intrinsic germanium absorption layer centers the high-absorption band at 1050nm, while requiring a low defect density. The P-type germanium electrode layer provides ohmic contact and collects holes; the transparent window area of ​​the P-type germanium electrode layer must avoid light obstruction.

[0068] In some embodiments, the design parameters of the germanium single-photon avalanche diode module are listed in Table 2 below:

[0069] Table 2

[0070]

[0071]

[0072] SOI substrates are used to construct high reflectivity at 1050nm, improving absorption efficiency and single-photon detection efficiency.

[0073] In some embodiments, although germanium exhibits excellent absorption properties in the near-infrared band (especially 1050 nm), making it an important candidate material for biomedical imaging fields such as non-invasive blood glucose detection, traditional germanium single-photon avalanche diode modules typically require high bias voltages (usually above 20V, or even exceeding 30V) to enter avalanche mode. This high-voltage operating mode brings a series of adverse effects, such as increased power consumption, increased thermal noise, decreased device reliability, increased power system complexity, increased biosafety and usage risks, gain instability, and response drift. Simultaneously, it increases the size and weight of the detection device, reduces ease of use, increases the difficulty of device integration, and decreases patient compliance. The high-sensitivity non-invasive near-infrared blood glucose detection device proposed in this application employs a distributed Bragg reflector (DBR) made of SiNx / SiO2 as the optical enhancement substrate, combined with a Si / SiGe superlattice or quantum well (QW) avalanche layer with quantum control capabilities, significantly reducing the operating voltage of the germanium single-photon avalanche diode module and simultaneously improving the device's photoelectric conversion efficiency and signal-to-noise ratio.

[0074] In some embodiments, the mechanism by which a distributed Bragg mirror reduces the operating voltage of a device is as follows: First, resonant absorption enhancement: The distributed Bragg mirror is formed by alternating stacks of high / low refractive index materials (such as SiNx / SiO2) to create a one-dimensional optical photonic crystal structure. Its designed wavelength center is located at 1050 nm to match the near-infrared absorption peak of blood glucose molecules in subcutaneous tissue. By constructing an optical cavity structure, the distributed Bragg mirror generates strong Bragg reflection and standing wave effects near the target wavelength, significantly enhancing the light field intensity at the absorption layer, thereby increasing the excited photogenerated carrier density per unit volume. Second, secondary absorption enhancement and photon recycling: The distributed Bragg mirror reflects unabsorbed downward light back to the germanium absorption layer, effectively realizing multiple round-trip absorption of photons and improving the external quantum efficiency (EQE). This mechanism reduces the dependence on high-power laser sources, enabling the device to output a sufficient number of initial carriers under low incident power conditions, providing a good precondition for avalanche triggering, thereby reducing the required multiplication bias voltage. Third, the increased incident efficiency corresponds to a decrease in voltage (Photon-to-Electron Conversion Efficiency): The enhanced light field directly reduces the minimum number of incident photons required to trigger an avalanche. Therefore, under the condition of achieving sensitive single-photon detection, the trigger voltage threshold (Vbr) can be effectively reduced, power consumption can be reduced, portability and safety can be improved, and it is particularly suitable for clinical wearable devices.

[0075] In some embodiments, avalanche multiplication layers with Si / SiGe quantum wells or superlattice structures can form a modulated band structure through periodic barrier modulation, enabling carriers to achieve higher directional acceleration efficiency within the avalanche multiplication layer. Band discontinuities guide electrons or holes along specific channels, achieving effective impact ionization under lower applied electric fields, thus significantly reducing breakdown voltage. The SiGe strained material also introduces a bandgap gradient, enhancing the electron ionization coefficient and suppressing hole ionization, which helps construct a unipolar avalanche mechanism, reducing the excess noise factor during multiplication and enhancing detection accuracy and stability under low voltage conditions. Furthermore, the superlattice structure exhibits good lattice matching, reducing interface defect density and suppressing dark current and breakdown fluctuations caused by thermal excitation. The combination of low defect density and low breakdown voltage contributes to achieving low-noise, low-power, and highly consistent photon detection characteristics, meeting the high requirements for stability and accuracy in continuous clinical testing.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A non-invasive near-infrared blood glucose detection device, characterized in that, It includes a laser source module and a germanium single-photon avalanche diode module, a signal amplification module, a data processing module, and a display module connected in sequence; The laser source module is used to emit a light signal of a preset wavelength to the germanium single-photon avalanche diode module; the preset wavelength is 1050 nanometers. The germanium single-photon avalanche diode module comprises a silicon substrate, a distributed Bragg mirror, an N-type silicon electrode layer, an avalanche multiplication layer, a P-type silicon charge control layer, an intrinsic germanium absorption layer, and a P-type germanium electrode layer stacked sequentially. The germanium single-photon avalanche diode module is used to receive and process the optical signal, obtain an electrical signal, and send it to the signal amplification module. The signal amplification module is used to receive and process the electrical signal to obtain the blood glucose signal and send it to the data processing module. The data processing module is used to receive and process the blood glucose signal, obtain the blood glucose concentration value, and send it to the display module. The display module is used to display the blood glucose concentration value.

2. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, It also includes a wireless communication module; The data processing module is also used to send the blood glucose concentration value to the wireless communication module; The wireless communication module is used to receive the blood glucose concentration value and upload it to a mobile device or cloud platform.

3. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, It also includes a power management module; The power management module is used to monitor the battery status.

4. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, It also includes an optical coupling module; The laser source module is also used to emit light signals of a preset wavelength to the optical coupling module; The optical coupling module is used to receive and process the optical signal, obtain the coupled optical signal, and send it to the germanium single-photon avalanche diode module. The germanium single-photon avalanche diode module is also used to receive and process the coupled optical signal to obtain an electrical signal and send it to the signal amplification module.

5. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, The avalanche multiplication layer is a multi-period stacked structure composed of silicon and silicon-germanium layers.

6. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, The avalanche multiplication layer is a multi-period stacked structure composed of germanium and silicon-germanium layers.

7. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, The thickness of the avalanche multiplication layer ranges from 200 nanometers to 500 nanometers.

8. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, The distributed Bragg reflector is a periodic structure with a predetermined number of periods; each period consists of a silicon nitride layer and a silicon dioxide layer stacked sequentially.

9. The non-invasive near-infrared blood glucose detection device according to claim 8, characterized in that, The preset number of cycles is greater than or equal to 6 and less than or equal to 10.

10. The non-invasive near-infrared blood glucose detection device according to claim 1, characterized in that, The thickness of the intrinsic germanium absorber layer ranges from 0.8 micrometers to 1.5 micrometers.

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