Current work in the lab in the area of next-gen electrical brain computer interfaces (BCIs) revolves around a new neurotech tool we have recently developed which we call BISC (Bioelectronic Interface System to the Cortex) and which we use to gain an unprecedented window into the brain. BISC is a subdurally implanted µECoG 12×12 mm in area with front-end analog electronics, an on-chip controller, wireless powering, and a radio frequency transceiver fully integrated on a single CMOS substrate. With 65,536 recording and 16,384 stimulation channels, 1,024 simultaneous recording channels, and a total thickness of only 50 µm rendering it mechanically flexible and conformal to the brain surface, BISC serves as a platform technology which we leverage for the highest spatiotemporal resolution characterization of neural activity and potential for medical translation. And the BISC chip serves as a base to build up and package additional custom 2D and 3D materials to quickly iterate and create a plethora of neurotech electronic interface tools useful for specific studies and applications.
Compared to other BCI approaches, BISC pushes the envelope of volumetric implant efficiency, electrode density, and area coverage while being minimally invasive, reducing tissue damage and allowing longer term operation in vivo. Unlike other systems that assemble discrete components for signal acquisition, conditioning, and transmission which can limit channel count and that often implant long wires and peripherals leading to bulky and invasive form factors restricting movement and behavior, causing tissue damage, and increasing the risk of infection, BISC assembles all this onto a single ASIC. Our initial studies have targeted the visual cortex for achieving a closed loop system to restore vision in addition to successful recordings from the somatosensory and motor cortices
This project offers many exciting opportunities for those interested in the fundamental neuroscience question of unraveling the link between spatiotemporal neural activity and behavior. For those interested in clinical translation, we have ongoing efforts with our collaborators, leading neurosurgeons and neuroscience labs at Columbia and around the world, to use this new neurotech tool in various animal models and achieve human translation to hopefully alleviate many conditions. For materials engineers, this work is an exciting challenge at the forefront of medical device technology involving encapsulation, packaging, electrochemical materials, mechanical and biochemical tissue interfaces, and manufacturing scale up, yield, and reliability. While for circuit designers this work is at the forefront of large scale, wireless, low power, and low noise integrated system design. And finally, for those interested in computational neuroscience and data science, the BISC platform is offering up many unprecedented opportunities to apply cutting edge techniques like machine learning to decode neural activity with exciting opportunities for many publications in all these areas.
Optical imaging systems have a crucial role for studying brain function in animal models. However, traditional optical microscopy systems are inherently limited by their small volumetric coverage due to absorption and scattering of light. In contrast, photoacoustic imaging uses light to excite tissue, where a portion of the absorbed energy causes rapid heating, generating a wideband acoustic signal that is far less affected by scattering and absorption.
