Effect of magnetic core and higher operational frequency on sensitivity in frequency shift detection in wireless passive minimally invasive Intracranial Pressure Monitoring

In this paper we study the effect of magnetic core in both the implant and the external reader antenna and higher operational frequency of the implant for wireless passive Intracranial Pressure Monitoring (ICP). Implant and external reader antenna are inductively coupled. ICP can be monitored through the change of implant resonance frequency or external reader antenna input impedance phase dip. We demonstrate that improvement in the sensitivity of ICP monitoring through change of implant resonance frequency can be done by resonating implant at higher frequency. Moreover we perform measurement in biological environment by placing pig skin of 5 mm ± 1 mm between implant and external reader antenna.