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Research area 05 - FUNDAMENTAL RESEARCH IN MEDICINE, 05-310 - Personalized medicine

KeywordsMagnetoelectric effect, magnetocardiograph, magnetocardiography, low magnetic fields, cardiovascular system

Annotation
The project is aimed at solving the fundamental problem of early diagnosis of cardiovascular diseases. The project involves the development of a magnetoelectric (ME) magnetocardiograph based on magnetostrictive-piezoelectric structures. The proposed device relates to the field of personalized medicine, namely to functional diagnostics, cardiology, cardiac surgery and can be used to record changes in time in the magnetic component of the electromotive force of the heart to obtain new, expanded clinical information of human cardiac activity. To achieve the named technical result, it is proposed to implement a magnetoelectric magnetocardiograph with the required sensitivity of the order of 5 pT, capable of detecting weak magnetic signals from the human heart. The principle of operation of a magnetoelectric magnetocardiograph consists in detecting the signal of the magnetic component of the heart with a highly sensitive magnetoelectric element based on a magnetostrictive-piezoelectric structure, which is then transmitted to a low-noise amplifier to amplify a weak magnetic signal, with further signal transmission via wireless communication using a transmitting antenna powered by a magnetoelectric harvester. to the digital signal processing unit, which includes a receiving antenna, a low-pass filter, an analog-to-digital converter, etc., with further image acquisition in the LabView interface. Scientific novelty consists in the developed magnetoelectric sensing element consisting of a piezoelectric phase, a piezoelectric plate (aluminum nitride, lithium niobate) and a magnetostrictive phase made of metglass, an amorphous soft magnetic alloy based on iron. Due to the fact that mortality from diseases of the circulatory system in Russia in 2020 amounted to about 47% of total mortality, which is 6.6% higher than in the same period in 2019 and 54% of total mortality in the Novgorod region, which is the main cause of mortality and an urgent problem, the proposed solution in the form of a magnetoelectric magnetocardiograph can partially solve this problem, since this device will provide regular diagnostics of human cardiac activity.

Expected results
In the course of the project, complex theoretical and experimental studies of the properties of composite structures will be carried out, aimed at increasing the sensitivity of the magnetic field and developing a new magnetoelectric (ME) magnetocardiograph. The following results will be obtained: 1) the sensitivity of the magnetic field of magnetostrictive-piezoelectric structures will be investigated by theoretical calculations, modeling and experimental research; 2) the analysis of structures, manufacturing technologies of modern ME magnetic field sensors will be carried out; 3) the physical principles of creating a ME sensor for magnetocardiography will be developed; 4) a comprehensive study of the sensitivity of the ME sensor for magnetocardiography will be carried out; 5) the physical principles of creating a ME magnetocardiograph will be developed. The expected results will make it possible to move on to the next stage in the development of a new scientific subject - to applied research with the goal of creating a highly sensitive magnetoelectric sensor with a sensitivity of about 5 pT, with specific parameters based on optimal magnetostrictive piezoelectric semiconductor structures. In the future, the creation of a magnetoelectric magnetocardiograph capable of detecting the magnetic component of the human heart with further signal processing, obtaining a magnetocardiogram for further analysis and prevention.

Annotation of the results obtained in 2023
1) By carrying out complex theoretical studies, expressions for ME stress coefficients in quasi-static and electromechanical resonance (EMR) modes were obtained for direct ME effects in symmetric and asymmetric magnetostrictive-piezoelectric structures in longitudinal and bending, as well as longitudinal-shear and torsional modes. Additionally, for the EMR mode, approximate formulas for the main resonant frequencies were obtained and their accuracy was investigated. Within the framework of a unified approach, the main relationships for ME voltage coefficients were obtained for all modes of the low-frequency direct ME effect, which makes it possible to select the optimal parameters of magnetostrictive-piezoelectric structures for ME sensors used in biomedicine, in particular, in magnetocardiographs. The results were published in Bichurin M.I., Sokolov O.V., Ivanov S.V., Ivasheva E.E., Leontiev V.S., Lobekin V.N. and Semenov G.A. "Modeling the Magnetoelectric Composites in a Wide Frequency Range" Materials, 2023. 2) Methods for increasing the magnetoelectric effect in magnetostrictive-piezoelectric structures have been studied. The method of adhesive technology and the heat treatment method are considered. The highest values of the ME coefficient are observed at processing temperatures of the amorphous magnetostrictive material (AMAG 225), 350 and 450°C. From the data obtained it follows that the maximum value of the ME coefficient α is 29.52 V cm^–1 E^–1 at a temperature of 350°C and a longitudinal resonance frequency fres = 53.4 kHz. Without heat treatment of AMAG 225, the maximum value of the ME coefficient reaches 14.44 V cm^–1 Oe^–1 at a frequency of 54 kHz. Heat treatment of the magnetostrictive component makes it possible to increase the ME voltage coefficient by more than 40%. The results are presented in: 1. Ivasheva E. E., Leontiev V. S., Bichurin M. I. & Koledov V. V. “Application of Heat Treatment to Optimize the Magnetostrictive Component of a Magnetoelectric Composite,” Journal of Communications Technology and Electronics, 2023; 2. Ivasheva E. E., Leontyev V. S., Kovalenko D. V., Bichurin M. I. “Methods for increasing the magnetoelectric effect in composite structures: a review,” BULLETIN OF NOVGOROD STATE UNIVERSITY, 2023 and 3. Ivasheva E. E. . “Thermomagnetic processing of an amorphous alloy for magnetoelectric applications”, PROCEEDINGS OF THE VNKSF-27 CONFERENCE AND ABSTRACTS, 2023. 3) The design of the ME sensor for magnetocardiography has been improved, a low-noise amplifier has been added, for which an equivalent, structural and functional diagrams. Due to additional comprehensive theoretical and experimental studies of the amorphous magnetostrictive material AMAG and various types of piezoelectric materials (PZT, LiNbO3 and Ga-As), the magnetostrictive-piezoelectric structure was optimized. 4) An ME harvester has been developed for a magnetocardiograph system, the sensitive element of which is a magnetostrictive-piezoelectric structure. Experimental dependences of the ME effect at the resonant frequency f=59.4 kHz were obtained, the maximum output voltage was U=0.4 mV, and the ME voltage coefficient was α=32.64 V/(cm*Oe). For effective interaction of the frequency signals of the ME harvester structure and cardiac activity, it is necessary to use electrical modulation of the signal, since the experimental dependences were obtained at the resonant frequency f = 59.4 kHz, and the frequency of the magnetic field of the heart is in the range of 0.1 Hz - 1 Hz. The results are presented in: 1. Lobekin V.N., Ivasheva E.E., Bichurin M.I., Kafarov R.G., Karachinov V.A., Kondrashov A.G. “Magnetoelectric harvester in the magnetocardiograph system”, BULLETIN OF NOVGOROD STATE UNIVERSITY, 2023 (in print) and 2. Zueva E.A. “Development of an energy harvesting system based on the magnetoelectric effect”, PROCEEDINGS OF THE VNKSF-27 CONFERENCE AND ABSTRACTS, 2023. 5) The physical principles of creating an ME magnetocardiograph have been developed, which will have high magnetic sensitivity, low noise characteristics, high dynamic range, high reliability, high quality factor at resonance, simple design, good resistance to external influences and the ability to carry out non-invasive measurements.

Publications

1. Bichurin M.I., Sokolov O.V., Ivanov S.V., Ivasheva E.E., Leontiev V.S., Lobekin V.N. and Semenov G.A. Modeling the Magnetoelectric Composites in a Wide Frequency Range Materials, Materials 2023, 16(17), 5813 (year - 2023) https://doi.org/10.3390/ma16175813

2. Ivasheva E. E., Leontiev V. S., Bichurin M. I. & Koledov V. V. Application of Heat Treatment to Optimize the Magnetostrictive Component of a Magnetoelectric Composite Journal of Communications Technology and Electronics, Journal of Communications Technology and Electronics (year - 2023) https://doi.org/10.1134/S1064226923040034

3. Ivasheva E. Е., Leontiev V. S., Kovalenko D. V., Bichurin M. I. Методы увеличения магнитоэлектрического эффекта в композитных структурах: обзор ВЕСТНИК НОВГОРОДСКОГО ГОСУДАРСТВЕННОГО УНИВЕРСИТЕТА, Вестник НовГУ. 2023. 3(132). 462-469 (year - 2023) https://doi.org/10.34680/2076-8052.2023.3(132).462-469

4. Ivasheva E.E. Термомагнитная обработка аморфного сплава для магнитоэлектрических применений МАТЕРИАЛЫ КОНФЕРЕНЦИИ ВНКСФ-27 И ТЕЗИСЫ ДОКЛАДОВ, Сборник тезисов, материалы Двадцать седьмой Всероссийской научной конференции студентов-физиков и молодых ученых (ВНКСФ-27, Екатеринбург): материалы конференции, тезисы докладов: В 1 т.Т.1 – Екатеринбург – Ростов-на-Дону: издательство АСФ России, 2023. (year - 2023)

5. Zueva E.A. Разработка системы сбора энергии на магнитоэлектрическом эффекте МАТЕРИАЛЫ КОНФЕРЕНЦИИ ВНКСФ-27 И ТЕЗИСЫ ДОКЛАДОВ, Сборник тезисов, материалы Двадцать седьмой Всероссийской научной конференции студентов-физиков и молодых ученых (ВНКСФ-27, Екатеринбург): материалы конференции, тезисы докладов: В 1 т.Т.1 – Екатеринбург – Ростов-на-Дону: издательство АСФ России, 2023. (year - 2023)

6. - Магнитоэлектрический датчик магнитного поля -, 216369 (year - )

Annotation of the results obtained in 2022
The main scientific results obtained in the first stage of the work: 1) By carrying out computer simulation, complex theoretical and experimental studies, theoretical and experimental dependences of the ME coefficient on voltage and the dependence of voltage on frequency for layered symmetric and asymmetric magnetostrictive-piezoelectric structures Metglas-ZTS, Metglas-LiNbO3, Metglas-GaAs. The main relationships for the voltage ME coefficients for the low-frequency direct ME effect in the mode of various types of oscillations (longitudinal, transverse, thickness, bending, shear, torsional modes) are obtained. A comparative analysis of the results of theoretical and experimental studies of symmetric and asymmetric magnetostrictive-piezoelectric structures is presented. The results are presented in Mirza Bichurin, Oleg Sokolov, Sergey Ivanov, Viktor Leontiev, Dmitriy Petrov, Gennady Semenov and Vyacheslav Lobekin "Physics of Composites for Low-Frequency Magnetoelectric Devices" Sensors 2022, 22, 4818. 2) Experimental graphs of dependences of the ME voltage coefficient on frequency without heat treatment and with annealing from 200℃ to 500℃ of the amorphous alloy AMAG493, which is the material of the magnetostrictive phase of the magnetostrictive-piezoelectric structure, are presented. Heat treatment of the magnetostrictive component makes it possible to increase the ME voltage coefficient by more than 40%, and an increase in the magnitude of the constant magnetizing field H is also observed, in comparison with samples in which the magnetostrictive components were not subjected to annealing. An increase in the ME voltage coefficient directly affects the sensitivity of sensors whose operation is based on the ME effect. 3) A measuring stand with a screen-camera and an imitation of cardiac activity has been prepared. A study of methods for recording biosignals of the human body was carried out, on the basis of which a method for measuring biosignals was selected, taking into account a comprehensive study of the ME effect in a highly sensitive ME element based on a magnetostrictive-piezoelectric structure. 4) A layout of the ME magnetic field sensor for magnetocardiography has been developed, consisting of a highly sensitive ME system, which includes the ME magnetostrictive-piezoelectric FeGaB-PZT structure, a low-noise amplifier and an excitation coil, and a signal processing unit, which includes signal converters, a peak detector, programmable signal generator, fast operational amplifiers, instrumentation amplifier, ADC and development board. For the ME sensor for magnetocardiography, an equivalent, structural and functional diagram has been developed. An application has been filed for a utility model "Magnetoelectric magnetic field sensor", registration number No. 2022130534, filing date 11/24/2022.

Publications

1. Ivasheva E. E., Leontiev, V.S., Bichurin M.I., Koledov V.V. Применение термообработки для оптимизации магнитострикционной компоненты магнитоэлектрического композита Радиотехника и электроника, - (year - 2023)

2. Mirza Bichurin, Oleg Sokolov, Sergey Ivanov, Viktor Leontiev, Dmitriy Petrov, Gennady Semenov and Vyacheslav Lobekin Physics of Composites for Low-Frequency Magnetoelectric Devices Sensors, Sensors 2022, 22, 4818. (year - 2022) https://doi.org/10.3390/s22134818