Remote Control of Brain Activity Using Ultrasound
Dr. William J. Tyler is an Assistant Professor in the School of Life Sciences at Arizona State University, is a co-founder and the CSO of SynSonix, Inc., and a member of the 2010 DARPA Young Faculty Award class.
Every single aspect of human sensation, perception, emotion, and behavior is regulated by brain activity. Thus, having the ability to stimulate brain function is a powerful technology.
Recent advances in neurotechnology have shown that brain stimulation is capable of treating neurological diseases and brain injury, as well as serving platforms around which brain-computer interfaces can be built for various purposes. Several limitations however still pose significant challenges to implementing traditional brain stimulation methods for treating diseases and controlling information processing in brain circuits.
For example, deep-brain stimulating (DBS) electrodes used to treat movement disorders such as Parkinson’s disease require neurosurgery in order to implant electrodes and batteries into patients. Transcranial magnetic stimulation (TMS) used to treat drug-resistant depression and other disorders do not require surgery, but have a low spatial resolution of approximately one centimeter and cannot stimulate deep brain circuits where many diseased circuits reside.
These illustrations show the surgical invasiveness of deep-brain stimulating electrodes (left) and depict the low spatial resolutions conferred by transcranial magnetic stimulation (right). (Image: Tyler Lab)
To overcome the above limitations, my laboratory has engineered a novel technology which implements transcranial pulsed ultrasound to remotely and directly stimulate brain circuits without requiring surgery. Further, we have shown this ultrasonic neuromodulation approach confers a spatial resolution approximately five times greater than TMS and can exert its effects upon subcortical brain circuits deep within the brain.
A portion of our initial work has been supported by the U.S. Army Research, Development and Engineering Command (RDECOM) Army Research Laboratory (ARL) where we have been working to develop methods for encoding sensory data onto the cortex using pulsed ultrasound.
Through a recent grant made by the Defense Advanced Research Projects Agency (DARPA) Young Faculty Award Program, our research will begin undergoing the next phases of research and development aimed towards engineering future applications using this neurotechnology for our country’s warfighters. Here, we will continue exploring the influence of ultrasound on brain function and begin using transducer phased arrays to examine the influence of focused ultrasound on intact brain circuits. We will also be investigating the use of capacitive micromachined ultrasonic transducers (CMUTs) for use in brain stimulation. Finally, to improve upon spatial resolution, we will examine the use of acoustic metamaterials and hyperlenses to study how subdiffraction limited ultrasound influences brain wave activity patterns.
How can this technology be used to provide our nation’s Warfighters with strategic advantages? We have developed working and conceptual prototypes in which ballistic helmets can be fitted with ultrasound transducers and microcontroller devices to illustrate potential applications as shown below. We look forward to developing a close working relationship with DARPA and other Department of Defense and U.S. Intelligence Communities to bring some of these applications to fruition over the coming years depending on the most pressing needs of our country’s defense industries.
Above illustrations show a ballistic helmet fitted with four ultrasound transducers (left) and another functional prototype for achieving human brain stimulation using a single element transducer (bottom-right), as well as a list of potential applications relevant to the defense industry. (Image: Tyler Lab)