DARPA is interested in environmental information such as maps, real-time intelligence, and location tracking of other troops, as well as the emerging area of “warfighter readiness.” Here, a wearable would tell users about their physiological state—whether a fighter is properly hydrated, over stressed, or suffering from cognitive fatigue.
The military has already deployed one such readiness device called a blast gauge, which essentially does in-field triage to monitor for traumatic brain injuries. The small devices are worn on the helmet, shoulder, and chest to measure blast exposure and cue medics for initial response.
Blast Gauge (above) was developed under a DARPA contract by the Rochester Institute of Technology (RIT) to measure the wearer’s exposure to blast exposure. (Image: DARPA)
IDTechEx, which held a wearable technology conference in Santa Clara, Calif. this week, pinned the market for medical-focused wearables at $15 billion this year with expectations of growth to $40 billion by 2026. But biosensor marking for the military has its own unique requirements, including multiplexing abilities, reversibility, real-time information, sensitivity, and reliability.”
DARPA has invested in a bioelectronics medicine program called ElectRx to “advance understanding of the anatomy and physiology of specific neural circuits and their role in health and disease.” ElectRx aims to create a “fully closed loop neural modulation” that would monitor biomarkers and peripheral nerve activity to increase the effectiveness of deployed fighters.
“Much like a thermostat monitors, an ElectRx device would monitor and recognize when the system is moving away from homeostasis and into a diseased state. Eventually, a regulator would provide therapeutic stimulus, then a modulator would signal nerves,” Wu said.
Wu noted that a version of this technology—a vagus nerve stimulator from Houston, Texas-based Cyberonics—already exists. In that case, a pacemaker-like device sends stimulation through a flexible wire. That lead connects to the vagus nerve (a cranial nerve responsible for parasympathetic control digestive tract and heart), which carries the stimulation the rest of the way to the brain.
The first phase of ElectRx research is a fundamental study/mapping of neural circuits and preliminary development of minimally invasive neural and bio-interface technologies with “unprecedented levels of precision, targeting and scale,” DARPA’s project website states. Wu said the project will focus on diseases and medical issues prominent in combat situations.
“Using the peripheral nervous system as a medium for delivering therapy is largely new territory and it’s rich with potential to manage many of the conditions that impact the readiness of our military and, more generally, the health of the nation,” Doug Weber, the ElectRx program manager and a biomedical engineer.
- A team at Circuit Therapeutics will further develop its experimental optogenetic methods for treating neuropathic pain, building toward testing in animal models.
- A team at Columbia University in New York City will study the use of non-invasive, targeted ultrasound for neuro modulation and chronic intervention.
- Teams at the Florey Institute of Neuroscience and Mental Health will map the nerve pathways that underlie intestinal inflammation, with a focus on determining the correlations between animal models and human neural circuitry. They will also explore the use of neuro stimulation technologies based on the cochlear implant as a possible treatment for inflammatory bowel disease.
- A team at the Johns Hopkins University (Baltimore), led by Jiande Chen, aims to explore the root mechanisms of inflammatory bowel disease and the impact of sacral nerve stimulation on its progression. The team will apply a first-of-its-kind approach to visualize intestinal responses to neuromodulation in animal models.
- A team at the Massachusetts Institute of Technology (Cambridge, Mass.), led by Polina Anikeeva, will aim to advance its established work in magnetic nanoparticles for localized, precision in vivo neuromodulation through thermal activation of neurons in animal models. The team’s work will target the adrenal gland and the splanchnic nerve circuits that govern its function. To increase specificity and minimize potential side effects of this method of stimulation, the team seeks to develop nanoparticles with the ability to bind to neuronal membranes. Dr. Anikeeva was previously a DARPA Young Faculty Awardee.
- A team at Purdue University (West Lafayette, Ind.), led by Pedro Irazoqui, will leverage an existing collaboration with Cyberonics to study inflammation of the gastrointestinal tract and its responsiveness to vagal nerve stimulation through the neck. Validation of the mechanistic insights that emerge from the effort will take place in pre-clinical models in which novel neuromodulation devices will be applied to reduce inflammation in a feedback-controlled manner. Later stages of the effort could advance the design of clinical neuromodulation devices.
- A team at the University of Texas, Dallas, led by Robert Rennaker and Michael Kilgard, will examine the use of vagal nerve stimulation to induce neural plasticity for the treatment of post-traumatic stress. As envisioned, stimulation could enhance learned behavioral responses that reduce fear and anxiety when presented with traumatic cues. Dr. Rennaker is a U.S. Marine Corps veteran who served in Liberia, Kuwait and Yugoslavia.
Optogenetics provides efficacy, yet reduces or eliminatesside effects by virtue of the combined selectivities of the gene therapy and illumination distribution. By transducing the specific circuit with an opsin and delivering light only to the desired region, a new optogenetic therapy is achieved. Using gene therapy and sophisticated illumination device design, such therapies are within our reach and hold the promise to transform neurological intervention.
Optogenetics is a transformational technology that allows control of specific neurons and drives their activity. Using optogenetics, we are able to gain insights on how the nervous system functions in normal and diseased states.
Optogenetics requires two key components: A light-sensitive protein, or opsin, and light. Depending on the wavelength, light can either activate neurons with excitatory opsins, inhibit neurons with inhibitory opsins, or initiate cellular signaling cascades (OptoXR). Adjusting the location, strength and color of the light allows for great control of the proteins. The opsin toolbox thus provides great flexibility and specificity for modulating neuronal activity.