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A wireless magnetic resonance energy transfer system for micro implantable medical sensors.

Li X, Zhang H, Peng F, Li Y, Yang T, Wang B, Fang D - Sensors (Basel) (2012)

Bottom Line: The energy transfer efficiency of the four-coil system is greatly improved compared to the conventional two-coil system.In addition, the output current varies with changes in the distance.The whole implanted part is packaged with PDMS of excellent biocompatibility and the volume of it is about 1 cm(3).

View Article: PubMed Central - PubMed

Affiliation: School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing 100044, China. lixiuhan@bjtu.edu.cn

ABSTRACT
Based on the magnetic resonance coupling principle, in this paper a wireless energy transfer system is designed and implemented for the power supply of micro-implantable medical sensors. The entire system is composed of the in vitro part, including the energy transmitting circuit and resonant transmitter coils, and in vivo part, including the micro resonant receiver coils and signal shaping chip which includes the rectifier module and LDO voltage regulator module. Transmitter and receiver coils are wound by Litz wire, and the diameter of the receiver coils is just 1.9 cm. The energy transfer efficiency of the four-coil system is greatly improved compared to the conventional two-coil system. When the distance between the transmitter coils and the receiver coils is 1.5 cm, the transfer efficiency is 85% at the frequency of 742 kHz. The power transfer efficiency can be optimized by adding magnetic enhanced resonators. The receiving voltage signal is converted to a stable output voltage of 3.3 V and a current of 10 mA at the distance of 2 cm. In addition, the output current varies with changes in the distance. The whole implanted part is packaged with PDMS of excellent biocompatibility and the volume of it is about 1 cm(3).

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Related in: MedlinePlus

(a) η of two- and four-coil systems versus angle misalignments at d = 1.5 cm; (b) η of two- and four-coil systems under different lateral shifts at d = 1.5 cm.
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f13-sensors-12-10292: (a) η of two- and four-coil systems versus angle misalignments at d = 1.5 cm; (b) η of two- and four-coil systems under different lateral shifts at d = 1.5 cm.

Mentions: In order to characterize the relationship between energy transfer efficiency and location parameters, η versus angle misalignment and lateral shift at the distance of 1.5 cm are measured and showed in Figure 13(a,b), respectively. The energy transfer efficiency of the two- and four-coil systems is both affected by location parameters obviously and it decreases with the angle misalignments and lateral shifts. Because of magnetic resonant coupling, η of four-coil system is higher than that of two-coil system in the whole range. Our experimental results also reveal that magnetic enhanced resonators can eliminate a part of influence brought by the location misalignment.


A wireless magnetic resonance energy transfer system for micro implantable medical sensors.

Li X, Zhang H, Peng F, Li Y, Yang T, Wang B, Fang D - Sensors (Basel) (2012)

(a) η of two- and four-coil systems versus angle misalignments at d = 1.5 cm; (b) η of two- and four-coil systems under different lateral shifts at d = 1.5 cm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472828&req=5

f13-sensors-12-10292: (a) η of two- and four-coil systems versus angle misalignments at d = 1.5 cm; (b) η of two- and four-coil systems under different lateral shifts at d = 1.5 cm.
Mentions: In order to characterize the relationship between energy transfer efficiency and location parameters, η versus angle misalignment and lateral shift at the distance of 1.5 cm are measured and showed in Figure 13(a,b), respectively. The energy transfer efficiency of the two- and four-coil systems is both affected by location parameters obviously and it decreases with the angle misalignments and lateral shifts. Because of magnetic resonant coupling, η of four-coil system is higher than that of two-coil system in the whole range. Our experimental results also reveal that magnetic enhanced resonators can eliminate a part of influence brought by the location misalignment.

Bottom Line: The energy transfer efficiency of the four-coil system is greatly improved compared to the conventional two-coil system.In addition, the output current varies with changes in the distance.The whole implanted part is packaged with PDMS of excellent biocompatibility and the volume of it is about 1 cm(3).

View Article: PubMed Central - PubMed

Affiliation: School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing 100044, China. lixiuhan@bjtu.edu.cn

ABSTRACT
Based on the magnetic resonance coupling principle, in this paper a wireless energy transfer system is designed and implemented for the power supply of micro-implantable medical sensors. The entire system is composed of the in vitro part, including the energy transmitting circuit and resonant transmitter coils, and in vivo part, including the micro resonant receiver coils and signal shaping chip which includes the rectifier module and LDO voltage regulator module. Transmitter and receiver coils are wound by Litz wire, and the diameter of the receiver coils is just 1.9 cm. The energy transfer efficiency of the four-coil system is greatly improved compared to the conventional two-coil system. When the distance between the transmitter coils and the receiver coils is 1.5 cm, the transfer efficiency is 85% at the frequency of 742 kHz. The power transfer efficiency can be optimized by adding magnetic enhanced resonators. The receiving voltage signal is converted to a stable output voltage of 3.3 V and a current of 10 mA at the distance of 2 cm. In addition, the output current varies with changes in the distance. The whole implanted part is packaged with PDMS of excellent biocompatibility and the volume of it is about 1 cm(3).

Show MeSH
Related in: MedlinePlus