Transcranial pulsed ultrasound (TPU) uses low intensity, low frequency ultrasound (LILFU) as a method to stimulate the brain. In 2002, Dr. Alexander Bystritsky proposed the idea that this methodology contained therapeutic benefits.
Beginning in 2008, Dr. William Tyler and his research team from Arizona State University began an investigation and development of this alternative neuromodulation without the harmful effects and risks of invasive surgery. They discovered that this low-power ultrasound is able to stimulate high neuron activity which allows for the manipulation of the brain waves through an external source.
Starting point is this Wikipedia entry
Unlike deep brain stimulation or Vagus nerve stimulation, which use implants and electrical impulses, TPU is a noninvasive and focused procedure that does not require the implantation ofelectrodes that could damage the nervous tissue. Its use is applicable in various fields including but not limited to medical and military science. Although this technology holds great potential to introducing new and beneficial alternatives to conventional brain manipulation, it is a relatively young science and has certain obstructions to its full development such as a lack of complete understanding and control of every safety measure.
Research and applications
Most of the research as of 2010 revolved around projects to utilize TPU as a method of treating neural disorders and improving cognitive function. However, in 2012 Dr. Tyler also began research on ultrasound’s potential to stopping seizures. Dr. Tyler and his team still continue to improve their knowledge of brain stimulation therapy and hope to provide a strong foundation in the implementation of such methods.
Scientists continue to test a variety of mammals such as humans, monkeys and mice on positively effecting the treatment of epilepsy, Parkinson’s disease, chronic pain, coma, dystonia, psychoses and depression through the less harmful, unconventional approach of TPU. Although the potential for this treatment covers a wide variety of benefits, it is a young science and will take a great amount of time to become officially implemented into our medical society.
Defense Advanced Research Projects Agency (DARPA) is undergoing research to develop a helmet that could control the minds of soldiers through the use of TPU. It would have the potential to control a soldier’s stress and anxiety levels with the click of a remote controlled button. Sound waves would target specific areas of the brain to stimulate activity in regions only a few cubic millimeters in size. This would allow them to target very specific areas of the brain with great accuracy and without inflicting damage to its surroundings. A prototype of this device is currently being worked upon to better the ability and potential of soldiers.
Conventional ultrasound used for anatomical analysis typically uses a wave frequency of about 20 MHz to penetrate the bodily tissue and produce images. In comparison, the low frequency of TPU has a sub-thermal exposure of about 5.7 MHz. By significantly reducing the wave frequency, excitable tissue can be manipulated without overexposure or detectable damage. Scientists have discovered that focusing on targeted brain regions in animals has been proven to alter their behavior, their cells’ electrical properties (electrophysiology), and theirsynaptic plasticity, which is essentially the neuron’s ability to function.
For instance, when focused on the motor cortex of mice, TPU has been shown to induce paw movements without changing the structure or function of that area of the brain. This proves that this method is capable of controlling brain activity at a high cognitive level. It is clear that shorter waves are able to activate neuron activity while longer waves inhibit it. However, the mechanism responsible for this reaction is yet to be discovered. A recent leading hypothesis is the mechanical manipulation of stretch-sensitive membranes actually stimulates certain voltage-gated ion channels, such as sodium or calcium, thus modulating neuronal activity.
Clinical trials have been used to determine any outstanding harmful effects. Although no subjects have displayed long-term neurological abnormalities as a result of these tests, this is a relatively new procedure and has not been studied enough to predict long term side effects. Even though it is a safer alternative to surgery because it is non-invasive, ultrasound always holds the potential to unintentionally disarrange the neurons in a harmful way and cause minor hemorrhages after long-term exposure.
Opposing high-frequency ultrasound, LILFU holds the following benefits: lower absorption in tissue, greater physical penetration depth in tissue, stronger particle deflections, significantly better acoustic penetration and power in bone, greater influence in kinetic effects, immediate/short-term effect results, longer/persistent effects after procedure and a higher degree of patient safety.
- Hameroff, Stewart. “Transcranial ultrasound (TUS) effects on mental states: A pilot study” (PDF). Elsevier. Retrieved 25 October 2013.
- “Ultrasound Shown To Exert Remote Control Of Brain Circuits”. ScienceDaily. Brain Circuits. Retrieved 23 October 2013.
- Tyler, William. “Our Research in the News”. Tyler Laboratory. Retrieved 10 November 2013.
- Tyler, William. “Research Program Summary”. The Virginia Tech Carilion School of Medicine and Research Institute. Retrieved 23 October2013.
- Dillow, Clay. “DARPA Wants to Install Transcranial Ultrasonic Mind Control Devices in Soldiers’ Helmets”. Popular Science. Bonnier Corporation. Retrieved 21 February 2016.
- Tyler, Dr. William J. “Remote Control of Brain Activity Using Ultrasound”. Armed with Science. U.S. Defense Department. Retrieved21 February 2016.
- Daffertshofer, M. “Transcranial low-frequency ultrasound-mediated thrombolysis in brain ischemia: increased risk of hemorrhage with combined ultrasound and tissue plasminogen activator: results of a phase II clinical trial”. PubMed. Retrieved 13 November 2013.
- “Why low-frequency Ultrasound?”. UltraPuls. Retrieved 13 November 2013
PI: Doris Ying Tsao
California Institute of Technology
Title: “Dissecting human brain circuits in vivo using ultrasonic neuromodulation”
BRAIN category: Next Generation Human Imaging (RFA MH-14-217)
In rodents, monkeys and eventually humans, Dr. Tsao’s team will explore use of non-invasive, high resolution ultrasound to impact neural activity deep in the brain and modify behavior.
Program Director, Neural Engineering at the National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH)
Staff, Multi-Council Working Group
Dr. Ludwig is the Scientific Lead for the Translational Devices Program at NINDS, is a Co-Lead of the Project Team responsible for developing and executing three of the six NIH Funding Opportunities Announcements for the B.R.A.I.N. Initiative, and led a trans-NIH planning team in developing the ~$250M Stimulating Peripheral Activity to Relieve Conditions (SPARC) Program to stimulate advances in neuromodulation therapies for organ systems.
Professor, Biology and Biological engineering, Caltech
Director, Tsao Lab
Doris Ying Tsao is a systems neuroscientist interested in the neural mechanisms underlying primate vision i.e. how visual objects are represented in the brain, and how these representations are used to guide behavior. She is investigating mechanisms at multiple stages in the visual hierarchy. Techniques we use include: electrophysiology, fMRI, electrical microstimulation, anatomical tracing, psychophysics, and mathematical modeling.
Tyler Lab of Neuroscience and Neurotechnology
Ultrasound for Functional Brain Mapping and Neuromodulation
Stemming from our intellectual interests on how physical forces influence neuronal signalling and brain function, we began developing noninvasive methods for mapping and modulating brain activity patterns using low-intensity, low-frequency ultrasound (LILFU). Ultrasound is a mechanical pressure wave that can be safely and nonivasively focused to millimeter scale regions of the intact human brain. Ultrasound can be used to visualize neural activity through photoacoustic tomography or similar spectroscopic approaches or even more readily by conventional Doppler blood flow imaging. In these cases, the neural signals reported by ultrasound are hemodynamic and closely related to the same ones reported by fMRI BOLD imaging. However, ultrasound technology is far more portable and far less expensive comapred to MR, CT, PET or other known human brain imaging techniques. Thus we have anticpated that ultrasound for brain mapping efforts can provide the largest and most diverse data sets since it can (and is already) more broadly deployed than any of the aforementioned brain imaging technologies.
Other advantages of ultrasound are that it can be focused through the skull to any discrete region of the brain with millimeter accuracy. Ultrasound has a technology architecture already in place, which is readily capable of providing real-time data reporting structural and functional activity maps of the human brain. Further, ultrasound has been long known capable of modulate the activity of cells by acting through thermal and/or nonthermal mechanisms of action. Through our studies on the nonthermal (mechanical) actions of ultrasound on brain circuits we discovered ultrasonic neuromodulation (UNMOD) methods for nonivasively stimulating brain cirucits with ultrasound. Now we are leading efforts to translate our technology through multi-national, multi-institutional, and multi-organization efforts on functional brain mapping and noninvasive
Stimulating the brain with sound? With the aid of his graduate students, William Tyler, Assistant Professor of Neurobiology and Bioimaging in the School of Life Sciences, researches how Ultrasonic Neuromodulation provides a novel approach to delivering noninvasive therapies for a host of neurological, psychiatric, and/or developmental disorders. This video was produced and edited by ASU New College student, Alexander D. Chapin, a videographer/editor in the Office of Knowledge Enterprise Development.
Ultrasonic Neuromodulation: in situ threshold for motor response in a rat model, Aubry
Focused Ultrasound Foundation | 2012