EnerCage: A Smart Experimental Arena With Scalable Architecture for Behavioral Experiments

• Published in: IEEE transactions on biomedical engineering Vol. 61; no. 1; pp. 139 - 148
• Main Authors: Jow, Uei-Ming, McMenamin, Peter, Kiani, Mehdi, Manns, Joseph R., Ghovanloo, Maysam
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.01.2014
• Subjects: Algorithms; Animals; Arrays; Behavior, Animal - physiology; behavioral neuroscience; Biotelemetry; Coils; Couplings; Electric Power Supplies; environmental enrichment; Equipment Design; Magnetic sensors; Male; Miniaturization - instrumentation; Mobile communication; Neurosciences - instrumentation; planar spiral coils (PSCs); Prostheses and Implants; Rats; Rats, Long-Evans; Telemetry - instrumentation; User-Computer Interface; wireless power transmission; Wireless Technology - instrumentation
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2013.2278180

Wireless power, when coupled with miniaturized implantable electronics, has the potential to provide a solution to several challenges facing neuroscientists during basic and preclinical studies with freely behaving animals. The EnerCage system is one such solution as it allows for uninterrupted electrophysiology experiments over extended periods of time and vast experimental arenas, while eliminating the need for bulky battery payloads or tethering. It has a scalable array of overlapping planar spiral coils (PSCs) and three-axis magnetic sensors for focused wireless power transmission to devices on freely moving subjects. In this paper, we present the first fully functional EnerCage system, in which the number of PSC drivers and magnetic sensors was reduced to one-third of the number used in our previous design via multicoil coupling. The power transfer efficiency (PTE) has been improved to 5.6% at a 120 mm coupling distance and a 48.5 mm lateral misalignment (worst case) between the transmitter (Tx) array and receiver (Rx) coils. The new EnerCage system is equipped with an Ethernet backbone, further supporting its modular/scalable architecture, which, in turn, allows experimental arenas with arbitrary shapes and dimensions. A set of experiments on a freely behaving rat were conducted by continuously delivering 20 mW to the electronics in the animal headstage for more than one hour in a powered 3538 cm 2 experimental area.