Written by Dr. David G. Stork
Rambus Fellow, Computational Sensing and Imaging Group, Rambus Labs
On Monday, April 13, the Defense Advanced Research Program Administration (DARPA) held a one-day Neural Engineering and System Design BootCamp outside Washington DC. Phillip Alvelda, Program Manager in the Biological Technologies Office of DARPA and organizer of the event, reminded the roughly 130 invited participants that DARPA had a history of conceiving and catalyzing such industry changing technologies as the ARPAnet (the foundation for the Internet), global positioning system (GPS), self-driving cars, and others; he said that DARPA had recently concluded that machine-brain interfaces are poised to become another such industry changing technology. The Boot Camp brought leaders to present the latest progress in component technologies, explore collaborations, and help strategize the way forward for this promising field, ultimately to commercialization. I was privileged to be one of just 13 participants invited to present and I spoke on the potential applications of Rambus’ lensless smart sensor technology in this emerging field.
Hundreds of thousands of deaf- or hearing-impaired people rely on hearing aids employing cochlear implants, an early brain-interface technology. MacArthur “Genius” Fellow Shiela Nirenberg of the Cornell Medical School described early progress in an analogous arena: retinal implants to overcome retinal blindness. In her system, small cameras mounted on a patient’s eyeglasses send signals to a special chip implanted in the patient’s retina, thereby stimulating the retina and restoring (low-resolution) vision.
Perhaps the greatest excitement at the Boot Camp centered on the recent development of opto-genetics: the use of genetically modified harmless viruses to make living nerve cells (neurons) rapidly glow or fluoresce as they fire, that is, send signals. Professor Ed Boyden of MIT, one of the pioneers of opto-genetics, discussed how special microscopes could monitor the activity of neurons in the cortex or outer brain layer of small animals such as shrews and mice. His goal is to extend these techniques to enable monitoring larger areas of the brain. Although complex, expensive and bulky microscopes have been used to monitor the activity of perhaps 10,000 nerve cells in small patches of the cortex of a brain, there seems to be no way for these lensed approaches to scale to cover large areas of a brain.
Last year, some in the neuroscience community reached out to us here at Rambus to explore the application of our lensless smart sensor technology for reading the activity of nerve cells in the cortex of active brains. While this is still an area of early exploration, I believe our lensless smart sensor technology may be able to cover significant portions of a cortex and monitor the activity of hundreds of millions, or ultimately billions, of nerve cells simultaneously. Such an unprecedented scale of sensing has the potential to provide new insights into brain function, much the way rapid large-scale genetic sequencing is revolutionizing biology and medicine. Someday, too, our sensors may be components in new classes of brain interfaces to detect and alleviate debilitating neural ailments such as epilepsy and Alzheimer’s disease, as well as in brain interfaces so people can control electronic devices just by thinking.
There are many challenging problems ahead, including the development of biological inert materials for implants, high-speed high-resolution CMOS photosensors, new classes of diffractive optics, and sophisticated signal processing algorithms for both collecting and analyzing such biological “big data.” This technology area is highly interdisciplinary and the Boot Camp was unique in that experts in design thinking explained techniques for strategizing and integrating the diverse knowledge, methods and terminologies of the component disciplines.
I and other participants left the Boot Camp with renewed vigor and commitment toward exploring and developing innovative brain interface technologies.