Near-field Inductive Coupling Link To Power a Three-Dimensional Millimeter-Size Antenna for Brain Implantable Medical Devices

Near-field Inductive Coupling Link To Power a Three-Dimensional Millimeter-Size Antenna for Brain Implantable Medical Devices

Near-field Inductive Coupling Link To Power a Three-Dimensional Millimeter-Size Antenna for Brain Implantable Medical Devices 170 177 IEEE Transactions on Biomedical Engineering (TBME)

Near-field Inductive Coupling Link To Power a Three-Dimensional Millimeter-Size Antenna for Brain Implantable Medical Devices

Near-field inductive coupling link can establish a reliable power source to a battery-less implantable medical device based on Faraday’s law of induction. In this paper, the design, modeling and experimental verification of an inductive coupling link between an off-body loop antenna and a 0.9 mm3 three-dimensional (3D) bowtie brain implantable antenna is presented. To ensure reliability of the design, the implantable antenna is embedded in the cerebral spinal fluid (CSF) of a realistic human head model. Exposure, temperature and propagation simulations of the near electromagnetic (EM) fields in a frequency-dispersive head model were carried out to comply with the IEEE safety standards. Concertedly, a fabrication process for the implantable antenna is proposed, which can be extended to devise and miniaturize different 3D geometric shapes. To verify the performance of the inductive link in a biological environment, in-vitro measurements of the fabricated prototypes were conducted in a pig’s head and piglet. The measurements of the link gain demonstrated -35.83 dB in the pig’s head and -30.81 dB in piglet. Thus, the in-vitro measurement results showed that the proposed 3D implantable antenna is suitable for integration with a miniaturized battery-less brain implantable medical device (BIMD).