By Mil & Aero staff
ARLINGTON, Va. – U.S. military researchers are working with six organizations to develop non-invasive or minimally invasive neural interfaces to connect the brains of warfighters to computers or other digital devices to enable fast, effective, and intuitive hands-free interaction with military systems.
Officials of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are working with Battelle Memorial Institute in Columbus, Ohio; Carnegie Mellon University in Pittsburgh; Johns Hopkins University Applied Physics Laboratory in Laurel, Md.; Palo Alto Research Center (PARC) in Palo Alto, Calif.; Rice University in Houston; and Teledyne Technologies in Thousand Oaks, Calif. on the Next-Generation Nonsurgical Neurotechnology (N3) program.
These wearable interfaces to connect human brains with computers ultimately could enable diverse national security applications such as control of active cyber defense systems and swarms of unmanned aerial vehicles, or teaming with computer systems to multitask during complex missions, DARPA officials say.
The DARPA N3 project seeks to develop a nonsurgical neural interface system to broaden the applicability of neural interfaces to the able-bodied warfighter.
Until now, neural interfaces that connect human brains to computers and other digital equipment have been surgically invasive and used primarily to help restore functions and skills to injured warfighters. The N3 project, however, seeks to enable neural recording and stimulation with sub-millimeter spatial resolution in healthy warfighters.
Neural interfaces could enable warfighters to multitask more efficiently, and interact with autonomous and semi-autonomous systems -- particularly future systems equipped with artificial intelligence (AI), researchers say.
The problem with human-machine neural interfaces today is how surgically invasive they are. State-of-the-art high-resolution single-neuron or neural-ensemble neural interfaces are invasive, and require surgical implantation of metal or silicon-based electrodes into brain tissue or on the surface of the brain.
The burden of surgery and associated risks are too high for this approach on able-bodied individuals. The N3 program aims to overcome these issues by developing a nonsurgical neural interface that is safe for human use, and that has high spatiotemporal resolution and low latency to enable function on par with current microelectrode technology.
DARPA wants the interface to be bidirectional and integrate technology for neural recording (read out) and neural stimulation (write in), and should be agnostic to military systems that would use it.
This neural interface either will be completely external to the body or will include a non surgically delivered nanotransducer that will serve as a signal transducing intermediary between neurons and the external recording and stimulating device.
The Battelle team aims to develop a minutely invasive interface that pairs an external transceiver with electromagnetic nanotransducers that convert electrical signals from the neurons into magnetic signals that flow between the human subject and an external transceiver to enable bidirectional communication.
The Carnegie Mellon will develop a noninvasive device that uses ultrasound waves to guide light into and out of the brain to detect neural activity and stimulate specific cell types.
The Johns Hopkins team is working with a noninvasive coherent optical system to from the brain. The system will measure optical path-length changes in neural tissue that correlate with neural activity.
The PARC team is developing an acousto-magnetic device for writing to the brain by pairing ultrasound waves with magnetic fields to generate localized electric currents for neuromodulation.
The Rice University team is working on a minutely invasive, bidirectional system for recording from and writing to the brain. An interface records by using diffuse optical tomography to infer neural activity by measuring light scattering in neural tissue. It writes with a magneto-genetic approach to make neurons sensitive to magnetic fields.
The Teledyne team is developing a noninvasive, integrated device that uses micro optically pumped magnetometers to detect small, localized magnetic fields that correlate with neural activity. The team will use focused ultrasound for writing to neurons.
The major technological challenge is to interact with neural tissue through the skull while maintaining high spatial and temporal resolution, using either a non invasive interface or minutely invasive interface, DARPA officials say.
Non invasive interfaces will involve sensors and stimulators that do not breach the skin. Minutely invasive approaches, meanwhile, will permit nonsurgical delivery of a nanotransducer delivered to neurons of interest.
Transducers should be small enough so as not to cause tissue damage or impede the natural neuronal circuit, and will be external to the skull. Non invasive and minutely invasive approaches will be necessary to overcome issues with signal scattering, attenuation, and signal-to-noise ratio.
The contractors will deliver integrated bidirectional brain-machine interface systems, with sensor (read) and stimulator (write) subcomponents integrated into a device external to the body. Minutely invasive approaches also will develop the external subcomponents and integrated devices that interact with the internal nanotransducers.
The N3 program will include a computational and processing unit that must provide decoded neural signals for control in a military application. It must also provide the capability to encode signals from a military application and deliver sensory feedback to the brain.
The N3 program will provide as long as four years of funding to deliver a nonsurgical neural interface system and is divided into three sequential phases: a one-year base effort, and two 18-month option periods.
