Laser Doppler heterodyne non-invasive blood glucose concentration measuring device and method

Abstract

The invention discloses a laser Doppler heterodyne noninvasive blood glucose concentration measuring device and method, and belongs to the technical field of medical detection. Comprising a laser generating module which comprises a laser, and a first 1 / 2 wave plate and a polarization splitting prism which are sequentially connected with the laser; and the interference light path module is connected to the two sides of the polarization splitting prism respectively and comprises a first optical fiber coupler connected with the polarization splitting prism, and a second 1 / 2 wave plate and a second optical fiber coupler which are sequentially connected with the other side of the polarization splitting prism. The device has the advantages that noninvasive detection can be achieved, blood sampling wounds are avoided, and the comfort level of a patient is improved; the measurement precision is high, and the blood glucose value can be quickly and accurately obtained by using heterodyne interference and frequency shift technologies.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical detection, and in particular relates to a laser Doppler heterodyne non-invasive blood glucose concentration measuring device and method. Background Art

[0002] Traditional blood glucose monitoring relies on blood sampling, which carries the risk of pain, infection, and high long-term consumable costs. Existing non-invasive technologies (such as near-infrared spectroscopy and impedance analysis) struggle to meet clinical needs due to issues such as insufficient accuracy, susceptibility to motion interference, and excessively large equipment size.

[0003] Therefore, we designed a laser Doppler heterodyne noninvasive blood glucose concentration measurement device and method. By combining laser heterodyne interferometry technology with Doppler frequency shift theory and multi-channel signal processing algorithm, we can achieve high-precision noninvasive blood glucose measurement in a dynamic blood flow environment. Summary of the Invention

[0004] Purpose of the invention: To provide a laser Doppler heterodyne non-invasive blood glucose concentration measurement device and method to solve the above-mentioned problems existing in the prior art.

[0005] Technical solution: A laser Doppler heterodyne non-invasive blood glucose concentration measuring device comprises a laser generating module, comprising a laser, a first 1 / 2 wave plate and a polarization beam splitter prism connected in sequence to the laser; an interference optical path module, wherein the interference optical path modules are respectively connected to both sides of the polarization beam splitter prism, comprising a first optical fiber coupler connected to the polarization beam splitter prism, and a second 1 / 2 wave plate and a second optical fiber coupler connected in sequence to the other side of the polarization beam splitter prism; and a signal processing module, wherein the signal processing module is arranged between the first optical fiber coupler and the second optical fiber coupler, comprising an optical fiber combiner connected between the first optical fiber coupler and the second optical fiber coupler, and a photoelectric detector and a signal processor connected to the optical fiber combiner.

[0006] Preferably, the initial laser light generated by the laser passes through the first 1 / 2 wave plate and the polarization beam splitter prism in sequence, and is then split into two beams of signal light and local oscillator light at 90° angles.

[0007] Preferably, after the signal light passes through the human blood vessels, it generates signal light loaded with blood sugar information and then enters the first optical fiber coupler.

[0008] Preferably, the local oscillation light passes through the second 1 / 2 wave plate and the second optical fiber coupler in sequence.

[0009] Preferably, the initial laser wavelength generated by the laser is 1.55 microns.

[0010] Preferably, the first fiber coupler and the fiber combiner are connected via optical fibers.

[0011] Preferably, the second fiber coupler and the fiber combiner are connected via optical fibers.

[0012] The method for non-invasive measurement of blood glucose concentration by laser Doppler heterodyne is characterized by comprising the following steps: S1, a laser generates an initial laser, the initial laser passes through a first 1 / 2 wave plate, the initial laser is rotated by a certain angle, and is separated into signal light and local oscillation light by a polarization splitter prism; S2, the signal light passes through human blood vessels to generate signal light carrying blood glucose information, the signal light is introduced into the optical fiber via a first optical fiber coupler, and the signal light carrying blood glucose information enters the optical fiber combiner via the optical fiber; S3, the local oscillation light passes through a second 1 / 2 wave plate, the polarization direction is rotated 90°, and the signal light is introduced into the optical fiber via a second optical fiber coupler, and the local oscillation light enters the optical fiber combiner via the optical fiber; S4, the signal light and the local oscillation light perform heterodyne interference in the optical fiber combiner, and then the optical signal is converted into an electrical signal by a photodetector, and the electrical signal is transmitted to a signal processor, which is processed to obtain a heterodyne frequency or phase difference value of the blood glucose concentration, and then the blood glucose value is obtained after algorithm inversion.

[0013] Preferably, the signal light in S1 passes through human blood vessels and generates a frequency shift due to the blood flow velocity. The frequency shift is calculated as follows: Δf = λ2vcosθ; wherein Δf represents the frequency shift caused by the blood flow velocity when the signal light passes through human blood vessels, λ is the wavelength of the initial laser, which is 1.55 microns, v is the blood flow velocity, and cosθ is the irradiation angle of the signal light.

[0014] The beneficial effects of this invention are as follows: Initial laser light is emitted by a laser and split into signal light and local oscillator light by a polarization beam splitter prism. After passing through human blood vessels, the signal light undergoes a frequency shift due to blood flow velocity and carries blood glucose information, entering a fiber optic combiner. The local oscillator light is then guided into the combiner via optical fibers. After heterodyne interference between the two, the signal light is converted into an electrical signal by a photodetector and processed by a signal processor to obtain the blood glucose concentration. This invention enables non-invasive testing, avoids the trauma of blood sampling, and improves patient comfort. It also boasts high measurement accuracy, utilizing heterodyne interference and frequency shift technology to quickly and accurately obtain blood glucose values. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention;

[0016] Figure 2 This is a diagram showing the direction of the laser in the present invention.

[0017] The reference numerals in the figure are: 1. laser light source module; 2. interference optical path module; 3. signal processing module; 11. laser; 12. first 1 / 2 wave plate; 13. polarization beam splitter; 21. first fiber coupler; 22. second 1 / 2 wave plate; 23. second fiber coupler; 31. fiber combiner; 32. photodetector; 33. signal processor. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Specific embodiment 1:

[0020] As attached Figure 1-2 As shown, in this embodiment, the laser Doppler heterodyne non-invasive blood glucose concentration measuring device includes a laser generating module 1, including a laser 11, a first 1 / 2 wave plate 12 and a polarization beam splitter prism 13 connected to the laser 11 in sequence;

[0021] The laser generation module 1 is used to generate laser for heterodyne interference. The laser 11 generates initial laser, which is a linearly polarized laser. The initial laser passes through the first 1 / 2 wave plate 12 to adjust the polarization direction of the initial laser, and then passes through the polarization splitter prism 13 to be divided into two mutually perpendicular beams of light, namely signal light and local oscillator light.

[0022] Interference optical path module 2, which is connected to both sides of the polarization beam splitter prism 13, and includes a first fiber coupler 21 connected to the polarization beam splitter prism 13, and a second 1 / 2 wave plate 22 and a second fiber coupler 23 connected in sequence to the other side of the polarization beam splitter prism 13;

[0023] The interference optical path module 2 is used to guide and process the signal light and the local oscillator light to ensure that they can correctly enter the fiber combiner for heterodyne interference. After the signal light passes through the human blood vessels, it generates a signal light loaded with blood sugar information. The signal light is efficiently coupled into the optical fiber through the first optical fiber coupler 21, and the transmission loss of the optical signal in the optical fiber is minimized. The signal light is then transmitted to the optical fiber combiner 31 through the optical fiber. The local oscillator light is processed by the second 1 / 2 wave plate 22 to adjust the polarization direction of the local oscillator light. After rotating the polarization direction of the local oscillator light by 90 degrees, it is coupled into the optical fiber through the second optical fiber coupler 23; the local oscillator light is then transmitted to the optical fiber combiner 31 through the optical fiber.

[0024] The signal processing module 3 is arranged between the first fiber optic coupler 21 and the second fiber optic coupler 23, and includes a fiber optic combiner 31 connected between the first fiber optic coupler 21 and the second fiber optic coupler 23, and a photodetector 32 and a signal processor 33 connected to the fiber optic combiner 31.

[0025] The signal processing module 3 is used to convert the optical signal from the interference optical path module into an electrical signal, and further process it to extract the blood glucose concentration information. The optical fiber combiner 31 is used to combine the signal light and the local oscillator light into one beam to ensure that they perform heterodyne interference on the same path. The optical signal generated by heterodyne interference contains the frequency difference information between the signal light and the local oscillator light, which is related to the blood glucose concentration. The light pad detector 32 converts the received optical signal into an electrical signal, and the output electrical signal contains the frequency and phase information of the heterodyne interference signal, which is then transmitted to the signal processor 33 to calculate the blood glucose concentration. The signal processor includes a filter, an amplifier and a digital signal processing unit. The filter is used to remove noise, the amplifier is used to enhance the signal strength, and the digital signal processing unit analyzes the signal through an algorithm to extract the blood glucose concentration information. The signal processor converts the extracted frequency or phase difference value into a blood glucose concentration value through algorithm inversion and displays it on the user interface.

[0026] The initial laser light generated by the laser 11 passes through the first half-wave plate 12 and the polarization beam splitter prism 13 in sequence, and is then split into two beams of signal light and local oscillation light at 90° angles.

[0027] The polarization directions of the signal light and the local oscillator light are perpendicular to each other, forming a 90° angle, ensuring that they can produce a clear interference signal during heterodyne interference.

[0028] The initial laser wavelength generated by the laser 11 is 1.55 microns. After the signal light passes through the human blood vessels, it generates a signal light carrying blood sugar information and then enters the first optical fiber coupler 21.

[0029] Laser 11 emits an initial laser beam with a wavelength of 1.55 microns. This wavelength is less scattered in biological tissue and has moderate absorption by water (a major component of blood). This wavelength effectively penetrates human blood vessels and carries blood sugar information back, or directly enters first fiber coupler 21.

[0030] The local oscillation light passes through the second half-wave plate 22 and the second fiber coupler 23 in sequence.

[0031] The initial laser light is split into two perpendicular beams of light, signal light and local oscillation light, by a polarization beam splitter prism 13. The local oscillation light then passes through a second half-wave plate (22) to change the polarization direction of the light and rotate it 90 degrees, so that the polarization directions of the local oscillation light and the signal light are the same, ensuring that the two beams of light can achieve heterodyne interference.

[0032] The first fiber coupler 21 and the fiber combiner 31 are connected via optical fibers.

[0033] The second fiber coupler 23 and the fiber combiner 31 are connected via optical fibers.

[0034] The first fiber coupler 21 and the second fiber coupler 23 can couple the signal light and the local oscillator light into the optical fiber, thereby achieving efficient optical signal transmission.

[0035] The method for non-invasively measuring blood glucose concentration using laser Doppler heterodyne is characterized by comprising the following steps:

[0036] S1, laser 11 generates initial laser light, which is rotated by a certain angle by the first half-wave plate 12 and then separated into signal light and local oscillator light by the polarization beam splitter prism 13;

[0037] S2: The signal light passes through the human blood vessels to generate a signal light carrying the blood glucose information, which is then introduced into the optical fiber via the first optical fiber coupler 21. The signal light carrying the blood glucose information enters the optical fiber combiner 31 via the optical fiber.

[0038] S3, the local oscillation light passes through the second half-wave plate 22, and after the polarization direction is rotated 90 degrees, it is introduced into the optical fiber through the second optical fiber coupler 23, and then enters the optical fiber combiner 31 through the optical fiber;

[0039] S4, the signal light and the local oscillator light perform heterodyne interference in the optical fiber combiner 31, and then the optical signal is converted into an electrical signal through the photodetector 32, and the electrical signal is transmitted to the signal processor 33, which processes the heterodyne frequency or phase difference value of the blood glucose concentration, and then obtains the blood glucose value after algorithm inversion.

[0040] The signal light in S1 passes through human blood vessels and generates frequency shift due to the blood flow rate. The frequency shift is calculated as follows:

[0041] Δf=λ2vcosθ

[0042] Here, Δf represents the frequency shift of the signal light due to the blood flow velocity when it passes through human blood vessels, λ is the wavelength of the initial laser, which is 1.55 μm, v is the blood flow velocity, and cosθ is the angle of the signal light.

[0043] When signal light passes through human blood vessels, its frequency changes due to blood flow, a phenomenon known as Doppler shift. The magnitude of the Doppler shift is related to blood flow velocity, the wavelength of the signal light, and the angle between the signal light and the blood flow direction. By calculating the Doppler shift, blood flow velocity can be indirectly measured, thereby assisting in the measurement of blood glucose concentration. is the angle of incidence of the signal light. In this invention, the signal light passes directly through human blood vessels, so the angle of incidence of the signal light is 0, and the value of is 1.

[0044] Working principle: During operation, the laser 11 generates an initial laser beam. The initial laser beam passes through the first half-wave plate 12 to adjust its polarization direction. It then passes through the polarization beam splitter prism 13 to split into two mutually perpendicular beams: the signal beam and the local oscillator beam. The signal beam then passes through human blood vessels to generate signal beams carrying blood glucose information. This signal beam is efficiently coupled into an optical fiber via the first fiber coupler 21 and efficiently transmitted through the fiber to the fiber combiner 31. The local oscillator beam is then processed by the second half-wave plate 22, adjusting its polarization direction so that it aligns with the signal beam. It is then coupled into the optical fiber via the second fiber coupler 23 and transmitted through the fiber to the fiber combiner 31. The fiber combiner 31 couples the signal beam and the local oscillator beam into a single beam, which is then transmitted to the photodetector 32. The photodetector 32 converts the received optical signal into an electrical signal and transmits the electrical signal to the signal processor 33. The signal processor 33 processes and analyzes the received electrical signal to extract key parameters related to blood glucose concentration, such as heterodyne frequency or phase difference. The signal processor 33 then converts the extracted frequency or phase difference value into a blood glucose concentration value through algorithm inversion and displays it on the user interface.

[0045] The present invention has been shown and described in detail in its preferred embodiments, but they are not to be construed as limiting the invention itself. Various changes in form and details may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. Laser Doppler heterodyne non-invasive blood glucose concentration measurement device, characterized by: include A laser generating module (1) comprises a laser (11), a first half-wave plate (12) and a polarization beam splitter prism (13) connected to the laser (11) in sequence; An interference optical path module (2), the interference optical path module (2) being connected to both sides of a polarization beam splitter prism (13), comprising a first optical fiber coupler (21) connected to the polarization beam splitter prism (13), and a second 1 / 2 wave plate (22) and a second optical fiber coupler (23) connected in sequence to the other side of the polarization beam splitter prism (13); and, A signal processing module (3) is provided between a first optical fiber coupler (21) and a second optical fiber coupler (23), and comprises an optical fiber combiner (31) connected between the first optical fiber coupler (21) and the second optical fiber coupler (23), and a photodetector (32) and a signal processor (33) connected to the optical fiber combiner (31).

2. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 1, characterized in that: The initial laser light generated by the laser (11) passes through the first 1 / 2 wave plate (12) and the polarization beam splitter (13) in sequence, and is then split into two beams of signal light and local oscillation light at 90 degrees.

3. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 2, characterized in that: After the signal light passes through the human blood vessels, it generates signal light loaded with blood sugar information and then enters the first optical fiber coupler (21).

4. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 3, characterized in that: The local oscillation light passes through the second 1 / 2 wave plate (22) and the second optical fiber coupler (23) in sequence.

5. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 4, characterized in that: The initial laser wavelength generated by the laser (11) is 1.55 microns.

6. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 5, characterized in that: The first optical fiber coupler (21) and the optical fiber combiner (31) are connected via optical fibers.

7. The laser Doppler heterodyne non-invasive blood glucose concentration measuring device according to claim 6, characterized in that: The second optical fiber coupler (23) and the optical fiber combiner (31) are connected via optical fibers.

8. A method for non-invasive measurement of blood glucose concentration using laser Doppler heterodyne, characterized in that: The steps include: S1, a laser (11) generates an initial laser, which is rotated by a certain angle by a first half-wave plate (12) and then separated into a signal light and a local oscillator light by a polarization beam splitter prism (13); S2, the signal light passes through the human blood vessels to generate signal light carrying blood sugar information, which is introduced into the optical fiber via the first optical fiber coupler (21), and the signal light carrying blood sugar information enters the optical fiber combiner (31) via the optical fiber; S3, the local oscillation light passes through the second half-wave plate (22), and after the polarization direction is rotated by 90 degrees, it is introduced into the optical fiber via the second optical fiber coupler (23), and the local oscillation light enters the optical fiber combiner (31) via the optical fiber; S4, the signal light and the local oscillator light perform heterodyne interference in the optical fiber combiner (31), and then the optical signal is converted into an electrical signal through the photodetector (32), and the electrical signal is transmitted to the signal processor (33), and the heterodyne frequency or phase difference value of the blood glucose concentration is obtained by processing, and then the blood glucose value is obtained after algorithm inversion.

9. The method for non-invasive blood glucose concentration measurement using laser Doppler heterodyne according to claim 8, characterized in that: The signal light in S1 passes through human blood vessels and generates frequency shift due to the blood flow rate. The frequency shift is calculated as follows: Δf=λ2vcosθ Here, Δf represents the frequency shift of the signal light due to the blood flow velocity when it passes through human blood vessels, λ is the wavelength of the initial laser, which is 1.55 μm, v is the blood flow velocity, and cosθ is the angle of the signal light.

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