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This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 23 March 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It surveys invasive and noninvasive brain-machine interface technologies for controlling external devices without limb-operated interfaces. The technologies covered include EEG, MEG, fMRI, NIRS, and implanted electrode arrays. It concludes that noninvasive electrical monitoring is the most promising near-term approach. In the long term, it favors invasive single-neuron cortical connections that use optical stimulation or chip-based arrays.
UNCLASSIFIED/ ;<F&lil: 8FFI1iltlit '11815 8HL'/ microelectric design of chronic neural implants. In 2006, Fetz et al. illustrated an intracranial operated neural implant that could function as neural prosthetic to assist upper limb movement for individuals that suffered from spinal cord injuries. The intriguing part of the Fetz design is its ability to function as an autonomous battery operated device. This is a departure from traditional BMI devices that are cumbersome and difficult to operate. Clearly this is a step forward in the development of microwire electrode design applications (Reference 44). Figure 5 illustrates the schematic flow chart of the Fetz MEMS neurochip, also called a programmable system-on-chip (PSoC) architecture. Programmable System on Chip Architecture IR module ( Memory J (Memory J l l l (__P_;_;_o"-t--J---• I l ! Secor~dary PSoC ------ l W~ £.e~ ~ ~ VJ '= ~ ~ " ~ ry ll llM,crow,re elec1<0des EMG electrodes Figure 5. Schematic of the Neurochip Functional Blocks. Parallel Psoc microcontrollers record neural and muscle signals to independent memory modules. Primary PSoC also controls a constant-current stimulator circuit and communicates via IR to a PC or hand-held POA. (Reference 44) Traditional PSoC designs operate on a high power consumption and short battery life of radiotelemetry systems (Reference 46). In the Fetz study, researchers implanted electronic devices that collected data in unrestrained monkeys. The system operated without the power limiting and cumbersome restraints exhibited by these previous systems. For this design, an on board spike processing and a stimulator circuit were employed to allow for real-time bidirectional interface with the nervous system. After several modifications, Fetz et al. successfully created a device that was able to simultaneously record electromyogram (EMG) activity and neural activity at the implant. The lithium battery operated power source and electronic data systems were skillfully packaged within a compact percutaneous (inner skin) titanium casing that was attached to a monkey's skull; the entire implant weighed only 56 g. Neural data was acquired from 12 microwire electrodes chronically implanted in the primary motor cortex. Leads run subcutaneously from the head casing to a connector on the monkey's back. Two pairs of stainless-steel wires were inserted percutaneously into the forearm muscles where they were attached to an EMG signal recorder (Reference 44). 15 UNCLASSIFIED/,'f81il 8ffl@Itllt ~:!I! 8HLY
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 36 pages are in the text index: search them above, or from the library's search.