title: Toward a distributed free-floating wireless implantable neural recording system.
abstract: To understand the complex correlations between neural networks across different regions in the brain and their functions at high spatiotemporal resolution, a tool is needed for obtaining long-term single unit activity (SUA) across the entire brain area. The concept and preliminary design of a distributed free-floating wireless implantable neural recording (FF-WINeR) system are presented, which can enabling SUA acquisition by dispersedly implanting tens to hundreds of untethered 1 mm3 neural recording probes, floating with the brain and operating wirelessly across the cortical surface. For powering FF-WINeR probes, a 3-coil link with an intermediate high-Q resonator provides a minimum S21 of -22.22 dB (in the body medium) and -21.23 dB (in air) at 2.8 cm coil separation, which translates to 0.76%/759 μW and 0.6%/604 μW of power transfer efficiency (PTE) / power delivered to a 9 kΩ load (PDL), in body and air, respectively. A mock-up FF-WINeR is implemented to explore microassembly method of the 1×1 mm2 micromachined silicon die with a bonding wire-wound coil and a tungsten micro-wire electrode. Circuit design methods to fit the active circuitry in only 0.96 mm2 of die area in a 130 nm standard CMOS process, and satisfy the strict power and performance requirements (in simulations) are discussed.
authors.lastname: Pyungwoo Yeon
authors.lastname: Xingyuan Tong
authors.lastname: Byunghun Lee
authors.forename: Abdollah
authors.initials: A
authors.lastname: Mirbozorgi
authors.forename: Bruce
authors.initials: B
authors.lastname: Ash
authors.forename: Helmut
authors.initials: H
authors.lastname: Eckhardt
authors.forename: Maysam
authors.initials: M
authors.lastname: Ghovanloo
mesh_terms: D002540:Cerebral Cortex / Q000502:physiology; D004567:Electrodes, Implanted; D004867:Equipment Design; D006801:Humans; D064926:Neurophysiological Monitoring / Q000295:instrumentation*; D019736:Prostheses and Implants; D059015:Wireless Technology