Microwave nondestructive testing blood glucose sensor based on MP-CSRR structure

Abstract

The invention relates to a novel MP-CSRR-based microwave nondestructive testing blood glucose sensor, which is prepared by the following steps: optimizing the structure of an MP-CSRR sensor through simulation software to obtain structural parameters with excellent performance; parameters such as dielectric constants and conductivity of glucose solutions with different concentrations are measured; setting a simulation model based on the measured solution parameters, loading the simulation model on the sensor for simulation, and verifying the feasibility of the monitoring theory; an MP-CSRR sensor is manufactured, SMA interfaces are welded to the two ends of a microstrip line to configure glucose solutions with different concentration gradients, and a solution container matched with the sensor is subjected to 3D printing; calibrating and setting a vector network analyzer; respectively adding the same volume of solutions with different concentrations into the container, and measuring the S21 parameter of the sensor through the vector network analyzer; by summarizing data, resonance point frequencies are fitted to obtain a change relationship between the S21 resonance frequency and the concentration of the glucose solution, so that the blood glucose of the human body is monitored.

Description

Technical Field

[0001] The invention belongs to the field of biomedical detection and microwave non-destructive detection, and relates to a novel microwave non-destructive blood glucose detection sensor based on multi parallel complementary split resonant ring (MP-CSRR). Background Art

[0002] According to survey data released by the International Diabetes Federation (IDF) in 2021, the global prevalence of diabetes is on the rise and is expected to reach 783.2 million by 2045. Diabetic patients need to continuously monitor their blood sugar levels to meet certain blood sugar targets and control blood sugar through remedial measures to avoid any serious health complications such as heart disease, stroke, coma, kidney failure, blindness, etc. However, the current common method of blood sugar monitoring is still to draw blood from the fingertips, that is, to use a disposable blood collection needle to lightly prick the fingertips and then use a test strip to measure the blood sugar value. Long-term use of this monitoring method will cause certain harm to the patient's body. If the measurement is too frequent and hygiene is not paid attention to, it will also cause wound infection due to multiple punctures in the same position. In order to reduce the pain of testing for diabetic patients and effectively control blood sugar dependence on drugs, some solutions for continuous blood sugar monitoring have been proposed one after another. However, although these commercial solutions can continuously monitor blood sugar levels, they are expensive due to complex processes or harsh testing conditions, and the monitoring time can generally only last about two weeks. Ordinary families can hardly afford such high testing costs. Therefore, a non-invasive blood glucose monitoring technology is needed, which has the characteristics of high reliability and low cost while ensuring that it can continuously and conveniently monitor blood glucose. The detection principle of microwave-based non-invasive blood glucose detection technology is that when the glucose concentration in human blood changes, the dielectric properties of blood will also change accordingly. After the sensor is coupled with blood with different dielectric properties, the resonant frequency obtained will be different. Therefore, a new sensor based on MP-CSRR structure is proposed for non-invasive blood glucose detection. This structure is based on microwave sensing. While avoiding the harm of fingertip blood sampling, it can also provide a relatively deep penetration depth, a larger detection area and a higher detection sensitivity, and has a good application prospect for non-invasive detection. Summary of the invention

[0003] The present invention provides a method for microwave nondestructive detection of blood sugar concentration in human body. The method is simple and fast, and can detect the blood sugar concentration of human body by microwave nondestructive detection. 21The resonant frequency obtained from the parameters is used to judge the blood glucose concentration, avoiding the use of blood glucose detection methods that are harmful to the human body, such as puncture blood tests, and can achieve non-invasive blood glucose detection with higher sensitivity. The experimental process uses a glucose solution to simulate human blood, and the concentration of the glucose solution is changed to represent the different blood glucose levels of the human body. The sensor is loaded with glucose solutions of different concentrations for detection to verify the correctness of the sensor detection and the feasibility of its application in human body detection. The technical solution of the present invention is as follows: A microwave non-destructive blood glucose detection sensor based on MP-CSRR structure realizes non-invasive blood glucose detection, comprising the following steps: (1) Optimize the MP-CSRR sensor structure through simulation software to obtain structural parameters with excellent performance; (2) Measure the dielectric constant, conductivity and other parameters of glucose solutions with different concentrations; (3) Set up a simulation model based on the measured solution parameters, load it on the sensor for simulation, and verify the feasibility of the monitoring theory; (4) Make an MP-CSRR sensor and solder SMA interfaces at both ends of the microstrip line; (5) Prepare glucose solutions with different concentration gradients and 3D print solution containers suitable for sensors; (6) Calibrate and set up the vector network analyzer (VNA); (7) Add the same volume of solutions with different concentrations into the container and measure the S of the sensor using a vector network analyzer. 21 parameter; (8) By summarizing the data, the resonant point frequency is fitted to obtain its S 21 The relationship between the resonant frequency and the concentration of glucose solution; (9) Monitor human blood sugar. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 MP-CSRR sensor structure diagram Figure 2 Experimental testing environment and equipment connection diagram Figure 3 S at different blood glucose concentrations 21 image Figure 4 Relationship between sensor resonant frequency and blood glucose concentration Implementation

[0005] The purpose of the present invention is to avoid the frequent fingertip blood sampling for diabetics to detect their own blood sugar level, and to propose a non-invasive microwave method for detecting blood sugar concentration. When the glucose solution or finger to be tested is placed on one side of the sensor resonant ring, the S21 The parameters will change with the change of the dielectric constant (i.e., glucose concentration) of the object to be tested. The change in glucose concentration can be determined based on the offset of its resonant frequency, thereby achieving non-invasive blood glucose testing.

[0006] The present invention is described below with reference to the accompanying drawings and examples.

[0007] (1) Changes in blood glucose concentration in the human body will cause changes in the dielectric constant of the blood. Therefore, microwave signals can be used to characterize the blood glucose concentration in the human body. Place the finger or the solution to be tested at the corresponding position of the CSRR unit on the sensor, and by imaging different blood glucose concentrations, non-invasive detection of human blood glucose can be achieved. The structure diagram of the MP-CSRR sensor is shown in the figure. Figure 1 shown.

[0008] (2) Connect the sensor to the vector network analyzer, such as Figure 2 As shown, the vector network analyzer is then calibrated and the required working frequency band is set.

[0009] (3) Glucose solutions of different concentrations were prepared and injected into the 3D printed containers in equal amounts, and the S 21 parameter.

[0010] (4) S measured by vector network analyzer 21 Processing summary, the summarized S 21 Test results such as Figure 3 shown.

[0011] (5) Yes Figure 3 The resonance frequencies in the solution are summarized and fitted, and the obtained resonance frequencies vary with the concentration of glucose solution as shown in Figure 4 Experiments have shown that its resonant frequency decreases with the increase of glucose concentration.

[0012] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0013] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A microwave non-destructive blood glucose sensor based on MP-CSRR structure realizes non-invasive blood glucose detection, comprising the following steps: (1) Optimize the MP-CSRR sensor structure through simulation software to obtain structural parameters with excellent performance; (2) Measure the dielectric constant, conductivity and other parameters of glucose solutions with different concentrations; (3) Set up a simulation model based on the measured solution parameters, load it on the sensor for simulation, and verify the feasibility of the monitoring theory; (4) Make an MP-CSRR sensor and solder SMA interfaces at both ends of the microstrip line; (5) Prepare glucose solutions with different concentration gradients and 3D print solution containers suitable for sensors; (6) Calibrate and set up the vector network analyzer; (7) Add the same volume of solutions with different concentrations into the container and measure the S of the sensor using a vector network analyzer. 21 parameter; (8) By summarizing the data, the resonant point frequency is fitted to obtain its S 21 The relationship between the resonant frequency and the concentration of glucose solution; (9) Monitor human blood sugar.

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