Complementary split ring type antenna sensor for noninvasive blood glucose multi-frequency detection

Abstract

The invention discloses a complementary split ring type antenna sensor for noninvasive blood glucose multi-frequency detection. The complementary split ring type antenna sensor comprises a metal radiation layer, a dielectric layer and a microstrip transmission line, the invention provides a detection method based on a microwave detection (MDT) principle, and the detection method comprises the following steps of: firstly, carrying out a microwave detection (MDT) on the basis of the microwave detection (MDT) principle; the device has the advantages of noninvasive property, high penetrating power, real-time continuous monitoring and the like. According to the present invention, by using a complementary split ring (CSRR) structure, the size design of the antenna sensor is significantly reduced, and a plurality of different resonance modes are successfully excited. A multi-frequency detection mode is adopted, and the robustness and sensitivity of blood glucose concentration detection are improved. The antenna sensor is compact in structure, simple in manufacturing process and low in cost, and has high application value in the field of medical detection. The antenna sensor provided by the invention can monitor the blood glucose concentration in real time, and has the capability of resisting environmental interference (pressure deformation).

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical medical equipment, and in particular to a complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection. Background Art

[0002] Diabetes and its complications are among the leading diseases currently endangering human health. According to the Diabetes Alliance, the global prevalence of diabetes is projected to reach 700 million people by 2045. Blood glucose levels are a key indicator of diabetic status, and frequent blood glucose testing has become a top priority in diabetes management. Currently, there is no safe, reliable, non-invasive blood glucose testing method. Commonly used blood glucose testing methods require drawing blood from a finger, which can be painful and uncomfortable for patients. Near-infrared spectroscopy (NIRS) transmits near-infrared radiation through vascular regions, but is affected by low glucose absorption and interference from tissue background. Bioelectrical impedance (BEI) is based on the principle that human body impedance changes with blood glucose, but in practice, measurements are easily affected by other tissue layers, reducing accuracy. Electrochemical detection methods are currently widely used. These methods primarily involve puncturing the surface skin with a microneedle, allowing blood to flow into the interstitial fluid. This improves sensitivity, but sweat and interstitial fluid lag behind changes in blood glucose.

[0003] Biosensors based on microwave detection technology (MDT) have gradually developed into a new type of sensor due to their advantages of being non-invasive, contactless, and having a high penetration depth. Existing sensors mainly include resonators and filters. Among them, microwave resonators interact with the object to be measured through the surface electromagnetic field, causing changes in S parameters and center frequency, and have been intensively studied in non-invasive blood glucose testing. However, these resonators require a high-intensity localized electric field and need to be precisely aligned with the target to be measured during detection. In addition, surface contact easily introduces environmental interference such as pressure. Summary of the Invention

[0004] The purpose of the present invention is to provide a complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, comprising: a metal radiation layer, a dielectric layer, and a microstrip transmission line.

[0005] The metal radiation layer includes m concentric metal rings, a metal inner circle and m rectangular metal strips, wherein m is a positive integer.

[0006] A layer of m concentric metal rings surrounds the metal inner circle.

[0007] The first layer of concentric metal rings is connected to the metal inner circle through the first rectangular metal strip, and the i-th layer of concentric metal rings is connected to the i-1-th layer of concentric metal rings through the i-th rectangular metal strip, where i = 2, 3, ..., m.

[0008] The m rectangular metal bars are located on the same axis, and the two rectangular metal bars connecting the same concentric metal ring are respectively located on both sides of the axis of the concentric metal ring.

[0009] The dielectric layer is a circular structure, and a metal through hole is provided at the center of the circle.

[0010] The microstrip transmission line is a T-shaped transmission line, and the head of the T-shaped structure serves as an excitation port to feed an excitation signal.

[0011] The metal radiation layer is arranged above the dielectric layer, and the metal inner circle of the metal radiation layer completely covers the metal through hole.

[0012] The mth layer of concentric metal rings is connected to the outer diameter of the dielectric layer and serves as the metal equivalent grounding layer.

[0013] The microstrip transmission line is arranged below the dielectric layer, and the bottom of the T-shaped structure of the microstrip transmission line is connected to the metal inner circle of the metal radiation layer through a metal through-hole.

[0014] The microstrip transmission line transmits the excitation signal to the metal inner circle of the metal radiation layer, thereby exciting the concentric metal rings at different levels, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

[0015] Furthermore, the dielectric layer is made of epoxy resin.

[0016] Furthermore, the metal radiation layer is made of materials including aluminum, iron, gold, and copper.

[0017] Furthermore, the microstrip transmission line is fed with an excitation signal through an SMA connector.

[0018] Furthermore, the inner core of the SMA connector is connected to a microstrip transmission line.

[0019] Furthermore, the outer core of the SMA connector is connected to the mth layer of concentric metal rings serving as a metal equivalent ground layer.

[0020] Furthermore, the axial direction of the microstrip transmission line is perpendicular to the axis of the rectangular metal strip of the metal radiation layer.

[0021] Furthermore, the sizes of the m concentric metal rings are adjusted according to the antenna frequency.

[0022] Furthermore, the number of the concentric metal rings is positively correlated with the number of resonance modes.

[0023] In different resonance modes, the antenna sensor generates electromagnetic wave energy at different resonance frequencies.

[0024] Furthermore, the antenna sensor is applied to non-invasive multi-frequency detection of blood glucose.

[0025] The technical benefits of this invention are undeniable. The present invention proposes a detection method based on the principles of microwave detection technology (MDT). Microwave detection technology focuses on the coupling effect of electromagnetic waves with the surface and internal tissues of living organisms. The amplitude offset of the detection signal is related to the conductivity and dielectric constant of blood glucose concentration. This technology offers the advantages of being non-invasive, highly penetrating, and enabling real-time continuous monitoring.

[0026] The present invention significantly reduces the size design of the antenna sensor by utilizing a complementary split ring resonator (CSRR) structure and successfully excites a variety of different resonance modes.

[0027] The present invention adopts a multi-frequency detection method to improve the robustness and sensitivity of blood sugar concentration detection.

[0028] The antenna sensor of the present invention has a compact structure, a simple manufacturing process, and low cost, and has great application value in the field of medical detection.

[0029] The antenna sensor provided by the present invention can realize blood sugar concentration detection at three frequencies (1.06 GHz, 1.82 GHz, and 2.36 GHz).

[0030] The antenna sensor provided by the present invention can monitor blood sugar concentration in real time and has the ability to resist environmental interference (pressure deformation). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a simulation model diagram of a complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection;

[0032] Figure 2 This is a schematic diagram of the dimensions of the antenna sensor of the present invention. Figure 2 (a) is a front view of the antenna sensor; Figure 2 (b) is a side view of the antenna sensor; Figure 2 (c) is the rear view of the antenna sensor;

[0033] Figure 3 Graph showing return loss and resonant frequency of the antenna sensor of the present invention;

[0034] Figure 4 is the 3D radiation pattern of the antenna sensor of the present invention;

[0035] Figure 5 is the 2D directional pattern of the antenna sensor of the present invention;

[0036] Figure 6 Schematic diagram of the current distribution in the radiation layer of the antenna sensor of the present invention at different resonant frequencies; Figure 6 (a) Schematic diagram of the current distribution in the radiation layer at a frequency of 1.08 GHz; Figure 6 (b) is a schematic diagram of the current distribution in the radiation layer at a frequency of 1.81 GHz; Figure 6 (c) is a schematic diagram of the radiation layer current distribution at a frequency of 2.39 GHz;

[0037] Figure 7 The equivalent circuit and simulation result diagram of the antenna sensor of the present invention; Figure 7 (a) is a schematic diagram of the full-wave simulation and equivalent circuit simulation results of the antenna sensor of the present invention; Figure 7 (b) is a schematic diagram of an equivalent circuit model of the antenna sensor of the present invention;

[0038] Figure 8 This is a schematic diagram of non-invasive blood glucose detection using an antenna sensor loaded with an arm tissue layer model according to the present invention;

[0039] Figure 9 Schematic diagram of electromagnetic field energy distribution at different frequencies when the antenna sensor of the present invention is unloaded and loaded with an arm model; Figure 9 (a) is a schematic diagram of the electric field energy distribution at frequency f1 when no load; Figure 9 (b) is a schematic diagram of the electric field energy distribution at frequency f2 when no load; Figure 9 (c) is a schematic diagram of the electric field energy distribution at frequency f3 when no load; Figure 9 (d) Schematic diagram of electric field energy distribution at frequency f1 when the arm model is loaded; Figure 9 (e) Schematic diagram of electric field energy distribution at frequency f2 when the arm model is loaded; Figure 9 (f) is a schematic diagram of the electric field energy distribution at frequency f3 when the arm model is loaded; Figure 9 (g) is a schematic diagram of the magnetic field energy distribution at the frequency f1 when no load; Figure 9 (h) is a schematic diagram of the magnetic field energy distribution at frequency f2 when no load; Figure 9 (i) is a schematic diagram of the magnetic field energy distribution at frequency f3 when no load; Figure 9 (j) is a schematic diagram of the magnetic field energy distribution at frequency f1 when the arm model is loaded; Figure 9 (k) is a schematic diagram of the magnetic field energy distribution at frequency f2 when the arm model is loaded; Figure 9 (l) is a schematic diagram of the magnetic field energy distribution at frequency f3 when the arm model is loaded;

[0040] Figure 10 This is a diagram showing the measurement results of the antenna sensor of the present invention in simulation software;

[0041] In the figure, there are metal through-hole 100, metal radiation layer 200, metal equivalent ground layer 300, dielectric layer 400, and microstrip transmission line 500. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the following examples, but it should not be understood that the scope of the present invention is limited to the following examples. Without departing from the above technical ideas of the present invention, various substitutions and modifications can be made according to common technical knowledge and customary means in the art, and all should be included in the scope of protection of the present invention.

[0043] Example 1:

[0044] See also Figures 1 to 10 A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection includes: a metal radiation layer 200, a dielectric layer 400, and a microstrip transmission line 500.

[0045] The metal radiation layer 200 includes m concentric metal rings, a metal inner circle and m rectangular metal strips, where m is a positive integer.

[0046] A layer of m concentric metal rings surrounds the metal inner circle.

[0047] The first layer of concentric metal rings is connected to the metal inner circle through the first rectangular metal strip, and the i-th layer of concentric metal rings is connected to the i-1-th layer of concentric metal rings through the i-th rectangular metal strip, where i = 2, 3, ..., m.

[0048] The m rectangular metal bars are located on the same axis, and the two rectangular metal bars connecting the same concentric metal ring are respectively located on both sides of the axis of the concentric metal ring.

[0049] The dielectric layer 400 is a circular structure, and a metal through hole 100 is provided at the center of the circle.

[0050] The microstrip transmission line 500 is a T-shaped transmission line, and the head of the T-shaped structure serves as an excitation port to feed an excitation signal.

[0051] The metal radiation layer 200 is disposed above the dielectric layer 400 , and the metal inner circle of the metal radiation layer 200 completely covers the metal through hole 100 .

[0052] The m-th concentric metal ring layer is connected to the outer diameter of the dielectric layer 400 and serves as the metal equivalent grounding layer 300 .

[0053] The microstrip transmission line 500 is disposed below the dielectric layer 400 , and the bottom of the T-shaped structure of the microstrip transmission line 500 is connected to the metal inner circle of the metal radiation layer 200 through the metal through-hole 100 .

[0054] The microstrip transmission line 500 transmits the excitation signal to the metal inner circle of the metal radiation layer 200 , thereby exciting the concentric metal rings at different levels, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

[0055] Example 2:

[0056] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection. The main technical content is shown in Example 1. Furthermore, the material for making the dielectric layer 400 includes epoxy resin.

[0057] Example 3:

[0058] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 2. Furthermore, the metal radiation layer 200 is made of materials including aluminum, iron, gold, and copper.

[0059] Example 4:

[0060] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 3. Furthermore, the microstrip transmission line 500 is fed with an excitation signal through an SMA connector.

[0061] Example 5:

[0062] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 4. Furthermore, the inner core of the SMA connector is connected to the microstrip transmission line 500.

[0063] Example 6:

[0064] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 5. Furthermore, the outer core of the SMA connector is connected to the mth layer of concentric metal rings serving as the metal equivalent ground layer 300.

[0065] Example 7:

[0066] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 6. Furthermore, the axial direction of the microstrip transmission line 500 is perpendicular to the axis of the rectangular metal strip of the metal radiation layer 200.

[0067] Example 8:

[0068] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 7. Furthermore, the sizes of the m concentric metal rings are adjusted according to the antenna frequency.

[0069] Example 9:

[0070] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 1 to 8. Furthermore, the number of the concentric metal rings is positively correlated with the number of resonant modes.

[0071] In different resonance modes, the antenna sensor generates electromagnetic wave energy at different resonance frequencies.

[0072] Example 10:

[0073] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection. The main technical content is shown in any one of Examples 1 to 9. Furthermore, the antenna sensor is applied to non-invasive multi-frequency blood glucose detection.

[0074] Example 11:

[0075] See also Figures 1 to 10 A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection includes: a metal radiation layer 200, a dielectric layer 400, and a microstrip transmission line 500.

[0076] The metal radiation layer 200 includes four concentric metal rings, a metal inner circle and four rectangular metal strips.

[0077] The structure of the metal radiation layer 200 is composed of four metal rings, a metal inner circle, and four rectangular metal strips connecting the inner circle and the rings, which are combined to form a four-ring CSRR structure.

[0078] Four concentric metal ring levels surround the metal inner circle.

[0079] The first layer of concentric metal rings is connected to the metal inner circle through the first rectangular metal strip, and the i-th layer of concentric metal rings is connected to the i-1-th layer of concentric metal rings through the i-th rectangular metal strip, where i=2, 3, 4.

[0080] The four rectangular metal strips are located on the same axis, and the two rectangular metal strips connecting the same concentric metal ring are respectively located on both sides of the axis of the concentric metal ring.

[0081] The rectangular metal strips of the metal radiation layer 200 are located at the symmetrical center of the four-ring CSRR structure and are spaced apart relative to the metal inner circle.

[0082] The dielectric layer 400 is a circular structure, and a metal through hole 100 is provided at the center of the circle.

[0083] The microstrip transmission line 500 is a T-shaped transmission line, and the head of the T-shaped structure serves as an excitation port to feed an excitation signal.

[0084] The metal radiation layer 200 is disposed above the dielectric layer 400 , and the metal inner circle of the metal radiation layer 200 completely covers the metal through hole 100 .

[0085] The fourth concentric metal ring is connected to the outer diameter of the dielectric layer 400 and serves as the metal equivalent grounding layer 300 .

[0086] The microstrip transmission line 500 is disposed below the dielectric layer 400 , and the bottom of the T-shaped structure of the microstrip transmission line 500 is connected to the metal inner circle of the metal radiation layer 200 through the metal through-hole 100 .

[0087] The microstrip transmission line 500 transmits the excitation signal to the metal inner circle of the metal radiation layer 200 , thereby exciting the concentric metal rings at different levels, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

[0088] The overall dimensions of the antenna sensor are 40mm*40mm*2.73mm, with the metal radiation layer measuring 40mm*40mm*0.365mm, the dielectric layer measuring 40mm*40mm*2mm, and the microstrip transmission line measuring 19.5mm*2mm*0.365mm. This allows the antenna sensor to operate at frequencies of 1.075GHz, 1.79GHz, and 2.36GHz, meeting the penetration requirements for various arm structures.

[0089] Example 12:

[0090] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection. The main technical content is shown in Example 11. Furthermore, the material for making the dielectric layer 400 includes epoxy resin (FR4).

[0091] Example 13:

[0092] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 12. Furthermore, the metal radiation layer 200 is made of materials including aluminum, iron, gold, and copper.

[0093] Example 14:

[0094] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 13. Furthermore, the microstrip transmission line 500 is fed with an excitation signal through an SMA connector.

[0095] Example 15:

[0096] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 14. Furthermore, the inner core of the SMA connector is connected to the microstrip transmission line 500.

[0097] Example 16:

[0098] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 15. Furthermore, the outer core of the SMA connector is connected to the fourth layer of concentric metal rings serving as the metal equivalent ground layer 300.

[0099] Example 17:

[0100] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 16. Furthermore, the axial direction of the microstrip transmission line 500 is orthogonally arranged with the rectangular metal strips of the metal radiation layer 200.

[0101] The axial direction of the microstrip transmission line 500 is perpendicular to the axis of the rectangular metal strips of the metal radiation layer 200 .

[0102] Example 18:

[0103] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 17. Furthermore, the size of the four concentric metal rings is adjusted according to the antenna frequency.

[0104] Example 19:

[0105] A complementary split-ring antenna sensor for non-invasive multi-frequency blood glucose detection, the main technical content of which is shown in any one of Examples 11 to 18. Furthermore, the number of the concentric metal rings is positively correlated with the number of resonant modes.

[0106] In different resonance modes, the antenna sensor generates electromagnetic wave energy at different resonance frequencies.

[0107] Example 20:

[0108] A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection. The main technical content is shown in any one of Examples 11 to 19. Furthermore, the antenna sensor is applied to non-invasive multi-frequency blood glucose detection.

[0109] Example 21:

[0110] See also Figures 1 to 10A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection includes a metal radiation layer 200, a dielectric layer 400, a metal equivalent ground layer 300, a microstrip transmission line 500, and a short-circuit metal hole 100.

[0111] The structure of the metal radiation layer 200 is composed of four metal rings, a metal inner circle, and four rectangular metal strips connecting the inner circle and the rings, which are combined to form a four-ring CSRR structure.

[0112] The inner center of the metal radiation layer 200 is connected to the short-circuit metal hole.

[0113] The rectangular metal strips of the metal radiation layer 200 are located at the symmetrical center of the four-ring CSRR structure and are spaced apart relative to the metal inner circle.

[0114] The outermost ring of the metal radiation layer 200 is equivalent to the metal grounding layer 300 of the antenna sensor and is on the same plane as the metal radiation layer 200 .

[0115] The microstrip transmission line 500 is located below the dielectric layer 400 and serves as an excitation port for signal feeding.

[0116] The head end of the microstrip transmission line 500 is connected to a rectangular metal strip and arranged in a T-shape.

[0117] The end of the microstrip transmission line 500 is connected to the metal through hole 100 , and its axial direction is orthogonal to the rectangular metal strip unit of the metal radiation layer 200 .

[0118] The metal through hole 100 passes through the dielectric layer 400 , the metal radiation layer 200 , and the microstrip transmission line 500 .

[0119] The metal through hole 100 is located at the center of the inner circle of the metal radiation layer 200 .

[0120] The metal through hole 100 connects the inner center of the metal radiation layer 200 and the end of the microstrip transmission line

[0121] The microstrip transmission line 500 provides an excitation signal through the feeding port, transitions to the metal radiation layer 200 through the metal through-hole 100, and then excites metal rings of different sizes to achieve resonance effects of multiple resonant modes, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

[0122] The dielectric layer 400 includes epoxy resin (FR4).

[0123] The metal radiation layer 200 is made of materials including aluminum, iron, gold, and copper.

[0124] The metal equivalent grounding layer 300 is made of materials including aluminum, iron, gold, and copper.

[0125] The metal via 100 is made of materials including aluminum, iron, gold, and copper.

[0126] The microstrip transmission line 500 is fed via an SMA connector.

[0127] The inner core of the SMA connector is connected to the microstrip transmission line 500 , and the outer core is connected to the metal equivalent ground layer 300 .

[0128] The antenna sensor is applied to non-invasive multi-frequency detection of blood glucose.

[0129] Example 22:

[0130] See also Figures 1 to 10 A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection includes a metal radiation layer 200, a dielectric layer 400, a metal equivalent ground layer 300, a microstrip transmission line 500, and a short-circuit metal hole 100.

[0131] The structure of the metal radiation layer 200 is composed of four metal rings, a metal inner circle, and four rectangular metal strips connecting the inner circle and the rings, which are combined to form a four-ring CSRR structure.

[0132] The inner center of the metal radiation layer 200 is connected to the short-circuit metal hole.

[0133] The rectangular metal strips of the metal radiation layer 200 are located at the symmetrical center of the four-ring CSRR structure and are spaced apart relative to the metal inner circle.

[0134] The outermost ring of the metal radiation layer 200 is equivalent to the metal grounding layer 300 of the antenna sensor and is on the same plane as the metal radiation layer 200 .

[0135] The overall dimensions of the antenna sensor are 40mm*40mm*2.73mm, with the metal radiation layer measuring 40mm*40mm*0.365mm, the dielectric layer measuring 40mm*40mm*2mm, and the microstrip transmission line measuring 19.5mm*2mm*0.365mm. This allows the antenna sensor to operate at frequencies of 1.075GHz, 1.79GHz, and 2.36GHz, meeting the penetration requirements for various arm structures.

[0136] The microstrip transmission line 500 is located below the dielectric layer 400 and serves as an excitation port for signal feeding.

[0137] The head end of the microstrip transmission line 500 is connected to a rectangular metal strip and arranged in a T-shape.

[0138] The end of the microstrip transmission line 500 is connected to the metal through hole 100 , and its axial direction is orthogonal to the rectangular metal strip unit of the metal radiation layer 200 .

[0139] The metal through hole 100 passes through the dielectric layer 400 , the metal radiation layer 200 , and the microstrip transmission line 500 .

[0140] The metal through hole 100 is located at the center of the inner circle of the metal radiation layer 200 .

[0141] The metal through hole 100 connects the inner center of the metal radiation layer 200 and the end of the microstrip transmission line.

[0142] The microstrip transmission line 500 provides an excitation signal through the feeding port, transitions to the metal radiation layer 200 through the metal through-hole 100, and then excites metal rings of different sizes to achieve resonance effects of multiple resonant modes, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

[0143] The dielectric layer 400 includes epoxy resin (FR4).

[0144] The metal radiation layer 200 is made of materials including aluminum, iron, gold, and copper.

[0145] The metal equivalent grounding layer 300 is made of materials including aluminum, iron, gold, and copper.

[0146] The metal via 100 is made of materials including aluminum, iron, gold, and copper.

[0147] The microstrip transmission line 500 is fed via an SMA connector.

[0148] The inner core of the SMA connector is connected to the microstrip transmission line 500 , and the outer core is connected to the metal equivalent ground layer 300 .

[0149] The antenna sensor is applied to non-invasive multi-frequency detection of blood glucose.

[0150] The antenna sensor is placed 2.8mm-3mm from the side of the arm model for measurement.

[0151] Example 23:

[0152] See also Figures 1 to 10 , a complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose monitoring, the main contents of which are as follows:

[0153] Figure 1 This is a schematic diagram of the structure of a complementary split ring antenna sensor for non-invasive multi-frequency blood glucose detection according to the present invention. Figure 1As shown, the antenna sensor comprises, from top to bottom, a metal radiating layer 200, a metal equivalent grounding layer 300, a dielectric layer 400, a metal via 100, and a microstrip transmission line 500. The outer ring of the metal radiating layer 200 forms the metal grounding layer 300, and together they form a four-ring CSRR structure. A metal via 100 is located at the center of the inner circle of the metal radiating layer 200, connecting the metal radiating layer 200 to the end of the microstrip transmission line. The microstrip transmission line 500 provides an excitation signal through a feed port, which transitions to the metal radiating layer 200 through the metal via 100. This excitation signal then excites the metal rings of varying sizes, creating resonance effects in multiple resonant modes. This allows the antenna sensor to generate electromagnetic wave energy at multiple resonant frequencies.

[0154] Figure 2 The following diagram illustrates the dimensions of the antenna of the present invention in the front, side, and rear directions. The sizes of the different metal rings in the radiating layer can be adjusted according to the antenna frequency. In this embodiment, the metal radiating layer measures 40mm*40mm*0.365mm. From the outside to the inside, the metal rings measure 1.5mm, 1.5mm, 1mm, 1.5mm, and 3mm, respectively. By adopting these dimensional parameters, the antenna sensor operates at frequencies of 1.075GHz, 1.79GHz, and 2.36GHz, meeting the penetration frequencies of common arm tissue.

[0155] Figure 3 This graph shows the return loss of the antenna sensor calculated using finite element electromagnetic simulation software. The return loss amplitude of the antenna sensor S11 at 1.075 GHz, 1.79 GHz, and 2.36 GHz is less than -10 dB, indicating good impedance matching.

[0156] Figure 4-Figure 5 The figure shows the radiation pattern of this antenna. As can be seen from the figure, the antenna sensor radiates primarily from the top and bottom, forming an "8" shape. This is similar to the radiation principle of a patch antenna and meets the basic requirements for antenna sensor radiation.

[0157] Figure 6 The following is a diagram of the current distribution in the radiation layer of the antenna of the present invention at different frequencies. From the current distribution on the ring, it can be seen that at 2.39 GHz, the current direction of the two inner rings of the antenna is the same as that of the two inner rings at 1.81 GHz, while the current direction of the two outer rings is opposite, and the current of the inner ring is greater than that of the outer ring. Therefore, the operating mode at this frequency is mainly dominated by the traditional CSRR structure composed of the two inner rings. Increasing the number of rings will introduce more high-order resonant modes, and the antenna will thus produce a corresponding weak resonance point at 1.07 GHz. Therefore, the antenna sensor of the present invention can successfully excite electromagnetic wave energy at multiple frequencies.

[0158] Figure 7The figure is a schematic diagram of the full-wave simulation and equivalent circuit simulation results of the antenna sensor of the present invention. As can be seen from the figure, the full-wave electromagnetic simulation and circuit simulation results are similar. The distributed inductance on the microstrip line is equivalent to the inductance L1, the gap between the transmission line and the CSRR ring is equivalent to the capacitance C0, the metal via connecting the transmission line and the CSRR ring is equivalent to the inductance L2, the gap between the inner and outer rings of the CSRR is equivalent to the capacitance C1, and the inner and outer rings are equivalent to the inductance L3, the loss of the current flowing through the ring is equivalent to the resistance R1, and the feeding port is equivalent to the 50Ω resistance R0. Due to the expansion of the traditional CSRR structure, the outer two-ring self-inductance L4 and the RLC parallel resonant circuit (R2, L5, C4) and the outer one-ring self-inductance L6 and the RLC parallel resonant circuit (R3, L7, C5) are newly added.

[0159] Figure 8 This is a schematic diagram of a simulated blood glucose test using an antenna sensor mounted on the side of an arm tissue model. The antenna sensor is placed 2.8mm-3mm from the side of the model for measurement.

[0160] Figure 9 The diagram below shows the electromagnetic field energy distribution at different frequencies when the antenna sensor of the present invention is unloaded and loaded on the arm model. As can be seen from the figure, both the electric and magnetic field energies can reach the target blood layer on the cross section of the model.

[0161] Figure 10 This figure shows the measurement results of the antenna sensor of the present invention in simulation software. As can be seen from the figure, the return loss amplitude and resonant frequency of the antenna sensor at different frequencies change with increasing blood glucose concentration. The changes at different frequencies remain consistent.

Claims

1. A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection, characterized in that: include: A metal radiation layer (200), a dielectric layer (400), and a microstrip transmission line (500); The metal radiation layer (200) comprises m concentric metal rings, a metal inner circle and m rectangular metal strips, wherein m is a positive integer; m concentric metal rings are arranged in layers around the metal inner circle; The first layer of concentric metal rings is connected to the metal inner circle through the first rectangular metal strip, and the i-th layer of concentric metal rings is connected to the i-1-th layer of concentric metal rings through the i-th rectangular metal strip, where i = 2, 3, ..., m; The m rectangular metal bars are located on the same axis, and the two rectangular metal bars connecting the same concentric metal ring are respectively located on both sides of the axis of the concentric metal ring. The dielectric layer (400) is a circular structure, and a metal through hole (100) is provided at the center of the circle. The microstrip transmission line (500) is a T-shaped transmission line, and the head of the T-shaped structure serves as an excitation port to feed an excitation signal; The metal radiation layer (200) is arranged above the dielectric layer (400), and the metal inner circle of the metal radiation layer (200) completely covers the metal through hole (100); The mth layer of concentric metal rings is connected to the outer diameter of the dielectric layer (400) and serves as a metal equivalent grounding layer (300); The microstrip transmission line (500) is arranged below the dielectric layer (400), and the bottom of the T-shaped structure of the microstrip transmission line (500) is connected to the metal inner circle of the metal radiation layer (200) through a metal through hole (100); The microstrip transmission line (500) transmits an excitation signal to the metal inner circle of the metal radiation layer (200), thereby exciting concentric metal rings at different levels, so that the antenna sensor generates electromagnetic wave energy at multiple resonant frequencies.

2. A complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The dielectric layer (400) is made of epoxy resin.

3. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The metal radiation layer (200) is made of materials including aluminum, iron, gold, and copper.

4. The complementary split-loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The microstrip transmission line (500) is fed with an excitation signal via an SMA connector.

5. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 4, characterized in that: The inner core of the SMA connector is connected to the microstrip transmission line (500).

6. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 4, characterized in that: The outer core of the SMA connector is connected to the mth layer of concentric metal rings serving as a metal equivalent grounding layer (300).

7. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The axial direction of the microstrip transmission line (500) is perpendicular to the axis of the rectangular metal strip of the metal radiation layer (200).

8. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The sizes of the m concentric metal rings are adjusted according to the antenna frequency.

9. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The number of the concentric metal rings is positively correlated with the number of resonance modes; In different resonance modes, the antenna sensor generates electromagnetic wave energy at different resonance frequencies.

10. The complementary split loop antenna sensor for non-invasive multi-frequency blood glucose detection according to claim 1, characterized in that: The antenna sensor is applied to non-invasive multi-frequency detection of blood glucose.

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