Novel Integrated Circuit Could Wirelessly Power Brain Sensors
Novel wireless power techniques led to the first generation of an integrated circuit (IC) that could power an intra-cranially implanted electrocorticography (ECoG) sensing and stimulation system, which is being developed by researchers at the Center for Sensorimotor Neural Engineering (CSNE), an NSF-funded Engineering Research Center (ERC) with headquarters at the University of Washington.
The wireless power portion addresses an early barrier to developing an ECoG system, which is how to power the electronics while they are implanted inside brain tissue on a long-term basis. In addition to providing long term neural-interfacing capabilities, this project could provide power solutions for many other implanted devices.
ECoG is a promising brain sensing technique that provides better signals than electroencephalography (EEG), which is measured from outside the skull. An advantage of ECoG is that it is less invasive than arrays which use needle-like electrodes to penetrate brain tissue. Currently, ECoG is only used for short periods of time because there is no way to power the system on a long-term basis and the electrodes are gradually encapsulated by scar tissue. If CSNE can overcome those challenges, ECoG could become the neural interfacing technique of choice for long-term brain interface applications, such as control of prosthetic limbs.
CSNE’s approach is to wirelessly power the system, building on novel wireless power techniques developed by CSNE researchers. The first integrated circuit was a multi-investigator effort among three CSNE labs. In the next generation, the Center plans to keep wireless power at 13MHz and move communication to 915MHz. Decoupling these functions will simplify the design space, while improving power and communication performance. Interactions within the CSNE are enabling physiology, circuit design, materials science for electrode design, and electromagnetics to come together to address a problem that would have been impossible for any single investigator to tackle.