Inductive pulse transmission by amplitude modulation using thin-film and electroplated microcoils

Abstract

Inductive links are widely used for implanted biomedical applications, and with amplitude modulation their use can be expanded to the transmission of pulse trains for deep brain stimulation (DBS). Using a passive envelope detector and an integrated coil, pulse trains can be obtained with high fidelity across a load representing brain tissue. To improve the system design, a comparison is made between thin-film and electroplated coils for receiving signals. Using our inlaid electroplating process, the coil resistance can be greatly reduced, which translates to increased output levels at the load at a few megahertz. One feature of our inductive link is enhanced output from the electroplated coils at system resonance. Various rectification methods provide flexibility in obtaining desired system performance. With this technique, the implanted components for DBS could be reduced to an integrated coil and a few components.