The study of methods for downsizing the implanted part, including the receiving coil of inductive energy transfer system, is one of currently topical areas of implantable medical devices development. At the same time the miniaturization of the receiving inductance coil decreases the system resistance to displacements, i.e. leads to an increase in the power drop when the relative position of the receiving and transmitting inductance coils changes. Therefore it is necessary to develop methods for downsizing the receiving inductance coil that allow maintaining the required resistance to displacements. In this work, a method of receiving inductance coil downsizing is proposed, based on simultaneous size change, receiving coil downsize and transmitter coil upsize. An algorithm of inductance coil designing that provides for obtaining specified stability for a given range of displacements is taken as a principle of developed method. The algorithm output is used for receiving coil size minimizing that consists in a coordinated change of receiving and transmitting inductance coils size to a certain limiting point, upon reaching which further size change while maintaining the specified output characteristics is impossible. The developed method is verified by numerical modeling. According to calculation results it has been established that the size (outer radius) of receiving coil can be decreased by 30 %. It was demonstrated that the limiting point is reached when the critical coupling between the coils occurs at a given (nominal) axial distance in the absence of lateral displacements. If the coupling between the coils is higher than critical at the nominal axial distance, it is possible to downsize the receiving inductance coil.
-
Key words:
wireless power transmission, optimization algorithm, coil pair, geometric optimization, implantable medical devices
-
Published in:
BIOMEDICAL ELECTRONICS
-
Bibliography link:
Aubakirov R. R., Danilov A. A. Using the strong coupling effect to reduce the size of the receiving coil without reducing the stability of the inductive energy transfer system to implants. Proc. Univ. Electronics, 2024, vol. 29, no. 6, pp. 819–831. https://doi.org/10.24151/1561-5405-2024-29-6-819-831. – EDN: DJLEVK.
-
Financial source:
the work has been supported by the Ministry of Education and Science of the Russian Federation (Agreement no. 075-15-2024-555 dated 04/25/2024).
Rafael R. Aubakirov
National Research University of Electronic Technology, Russia, 124498, Moscow, Zelenograd, Shokin sq., 1
Arseny A. Danilov
National Research University of Electronic Technology, Russia, 124498, Moscow, Zelenograd, Shokin sq., 1
1. Khan S. R., Pavuluri S. K., Cummins G., Desmulliez M. P. Y. Wireless power transfer techniques for implantable medical devices: A review // Sensors. 2020. Vol. 20. Iss. 12. Art. No. 3487. DOI: 10.3390/s20123487 EDN: YGBYJK
2. Haerinia M., Shadid R. Wireless power transfer approaches for medical implants: A review // Signals. 2020. Vol. 1. Iss. 2. P. 209-229. DOI: 10.3390/signals1020012 EDN: HOEOKR
3. Lee T.-S., Huang S.-J., Dai S.-H., Su J.-L. Design of misalignment-insensitive inductive power transfer via interoperable coil module and dynamic power control // IEEE Trans. Power Electron. 2020. Vol. 35. No. 9. P. 9024-9033. DOI: 10.1109/TPEL.2020.2972035 EDN: RHCRRB
4. Operation of inductive charging systems under misalignment conditions: A review for electric vehicles / V.-B. Vu, A. Ramezani, A. Triviño et al. // IEEE Trans. Transp. Electrif. 2022. Vol. 9. No. 1. P. 1857-1887. DOI: 10.1109/TTE.2022.3165465
5. Cortes I., Kim W.-J. Lateral position error reduction using misalignment-sensing coils in inductive power transfer systems // IEEE/ASME Trans. Mechatron. 2018. Vol. 23. No. 2. P. 875-882. DOI: 10.1109/TMECH.2018.2801250
6. An LCC-SP compensated inductive power transfer system and design considerations for enhancing misalignment tolerance /j. Yang, X. Zhang, K. Zhang et al. // IEEE Access. 2020. Vol. 8. P. 193285-193296. DOI: 10.1109/ACCESS.2020.3032793 EDN: DLHVQB
7. Karimi M. J., Schmid A., Dehollain C. Wireless power and data transmission for implanted devices via inductive links: A systematic review // IEEE Sensors Journal. 2021. Vol. 21. No. 6. P. 7145-7161. DOI: 10.1109/JSEN.2021.3049918 EDN: PJYMVD
8. Covic G. A., Boys J. T. Inductive power transfer // Proc. IEEE. 2013. Vol. 101. No. 6. P. 1276-1289. DOI: 10.1109/JPROC.2013.2244536
9. Safety-optimized inductive powering of implantable medical devices: Tutorial and comprehensive design guide / N. Soltani, M. ElAnsary, J. Xu et al. // IEEE Trans. Biomed. Circuits Syst. 2021. Vol. 15.No. 6. P. 1354-1367. DOI: 10.1109/TBCAS.2021.3125618
10. Schormans M., Valente V., Demosthenous A. Practical inductive link design for biomedical wireless power transfer: A tutorial // IEEE Trans. Biomed. Circuits Syst. 2018. Vol. 12.No. 5. P. 1112-1130. DOI: 10.1109/TBCAS.2018.2846020
11. Singer A., Robinson J. T. Wireless power delivery techniques for miniature implantable bioelectronics // Adv. Healthcare Mater. 2021. Vol. 10. Iss. 17. Art. ID: 2100664. DOI: 10.1002/adhm.202100664 EDN: DOUXIF
12. The microbead: A highly miniaturized wirelessly powered implantable neural stimulating system / A. Khalifa, Y. Karimi, Q. Wang et al. // IEEE Trans. Biomed. Circuits Syst. 2018. Vol. 12.No. 3. P. 521-531. DOI: 10.1109/TBCAS.2018.2802443
13. Freeman D. K., Byrnes S. J. Optimal frequency for wireless power transmission into the body: Efficiency versus received power // IEEE Trans. Antennas Propag. 2019. Vol. 67. No. 6. P. 4073-4083. DOI: 10.1109/TAP.2019.2905672
14. A modified wireless power transfer system for medical implants / Y. Ben Fadhel, S. Ktata, Kh. Sedraoui et al. // Energies. 2019. Vol. 12. Iss. 10. Art. No. 1890. DOI: 10.3390/en12101890
15. An algorithm for the computer aided design of coil couple for a misalignment tolerant biomedical inductive powering unit / A. A. Danilov, R. R. Aubakirov, E. A. Mindubaev et al. // IEEE Access. 2019. Vol. 7.P. 70755-70769. DOI: 10.1109/ACCESS.2019.2919259