by Dr. Ryan Neely, Ph.D.
The term “neurotechnology” or “neurotech” is becoming increasingly more common as neuroscience concepts mature from the lab bench into the hands of patients and consumers. However, the term encompasses many types of devices and systems and it can be hard to keep track of what’s out there. In general, neurotechnology refers to any type of technology that interfaces with the brain or other parts of the nervous system, whether to monitor neural activity or modify it in some way (while some consider psychoactive medicines “neurotechnology,” we won’t discuss them here). While many of the headline-grabbing advances in the field seem like science fiction come to life, the reality is that neurotechnology has been in use for decades in ways that create positive impacts for people and patients. In this post, we’ll review some general categories of neurotechnologies, and include some examples of mature, established devices as well as some new technology that’s on the horizon. We’ll review the following types of neurotechnologies:
- Therapeutic neurostimulation
- Bioelectronic Medicine/Electroceuticals
- Neuroprosthetics/Brain-Computer Interfaces
At Elemind, we’re excited about what the future of neurotechnology has to offer, and by the end of this post we hope you will be too!
Therapeutic Neurostimulation
The language of the brain and nervous system is electricity: electrical impulses traveling between neurons carry information that form the basis for muscle movement and cognition. Unsurprisingly, researchers and clinicians have been investigating ways of applying electricity to the body in order to influence how the nervous system works and treat disease. The first commercial pacemaker, an implanted device that shocks the heart to help it maintain a steady rhythm, was introduced in the 1960’s (fun fact - some of these devices were nuclear powered and are still in operation today). Soon after, researchers began investigating other uses for these devices. In 1968, the Medtronic neurostimulator was approved to treat chronic pain by applying electric pulses to the spinal cord. Additional uses soon followed, including stimulation of the sacral nerve in the pelvis to treat urinary incontinence and deep brain stimulation to treat symptoms of Parkinson’s disease. Although the technology has matured since the 60’s (including swapping plutonium for modern batteries), the basic neurostimulator design is relatively unchanged. Regardless of the application, most neurostimulators consist of a sealed battery and electronics (about the size of a pack of gum) - this is typically implanted under the skin near the chest. From there, a wire or “lead” runs to the site of stimulation and terminates in one or more electrodes: basically exposed metal tips that deliver electrical charge to the nerve or brain tissue nearby. Most of these devices operate in “open-loop,” meaning they are programmed to deliver stimulation continuously or on a fixed schedule. Recent advances have led to the design of “closed-loop” systems, which are capable of sensing a pathological state and stimulating only when necessary. Two examples of this kind of system are the Neuropace device, which stimulates the brain when it detects the onset of an epileptic seizure, and the Inspire Sleep system, which stimulates the hypoglossal nerve to open the airway when it detects breathing obstruction in individuals with obstructive sleep apnea.
Bioelectronic Medicine/Electroceuticals
The emerging field of Bioelectronic Medicine (sometimes referred to Electroceuticals) seeks to take advantage of an improved understanding of how the brain monitors and controls organs and organ systems. New research has demonstrated how the brain, through the autonomic nerves (think “fight or flight” system), can influence the function of the immune system, digestion, energy balance, and even blood clotting. These technologies look to replace traditional drug-based approaches to treating disease by tapping into the “thermostats” that control things like immune reactions or kidney function. The basic concept is this: if nerves are carrying information to and from the brain that monitor and control these organs, can we listen in and block or amplify these signals to correct dysfunction? Although researchers are working on a number of different approaches, many of the concepts envision small, wireless devices that are placed on or around the nerves that connect to target organs. Some exciting early demonstrations of this concept have come from the Feinstein Institute in New York, where scientists demonstrated that electrical stimulation of the vagus nerve (in the neck) for only a few minutes each day could reduce symptoms of rheumatoid arthritis (RA) and Crohn's disease. Both of these debilitating conditions are caused by overactive immune cells that attack and destroy the patient’s healthy tissue, and clinical trials demonstrated that stimulation of the vagus nerve generated a signal that reduced immune reactivity, creating meaningful improvements for patients. Many of these new treatments are still in the research phase and rely on advances in scientific understanding of disease, but also require new materials and electronics that can interface with the small and delicate nerves traveling to and from organs. Studies are still in progress to better understand how recording signals from these nerve pathways might allow clinicians to predict and prevent the course of disease. Still, early results are promising and bioelectronic medicines may pave the way for more effective and targeted treatments for an entirely new population of patients in need.
Neuroprosthetics/Brain-Computer Interfaces
One of the more sensational forms of neurotechnology is known as Brain-Computer Interfaces (BCI), also referred to as Brain-Machine Interfaces (BMI) or Neuroprosthetics. Unlike therapeutic neurostimulators, BCI systems seek to encode or decode information from the brain, and sometimes both. Movies such as The Matrix, Inception, and Transcendence have depicted BCIs as portals that connect consciousness to the internet and create worlds where humans can do battle or meld with artificial intelligence, for better or worse. In the real world, companies like Elon Musk’s Neuralink have captured headlines with ambitions to augment human cognition by directly linking the brain with AI, blurring the lines between science fiction and future reality. However fantastic these claims may seem, BCIs implanted in the brain for the purpose of controlling computers have actually been under development since the 90’s. In 2005, the first human patient was implanted with a Utah array, a 10 x 10 grid of electrodes that penetrate the first several millimeters of brain tissue, roughly the size of a postage stamp. The purpose of these early trials was to restore some form of mobility to paralyzed individuals by decoding (“reading”) brain signals (such as neurons firing) that correspond to instructions to move various body parts. These systems have improved substantially through the tireless work of researchers as well as laudable effort and risk-taking on the part of early volunteers. Today, implanted BCI systems (which are still mostly in the research stage) are used by immobile patients to surf the internet, send email, control robotic arms, and even reanimate paralyzed limbs with specially-designed muscle stimulation sleeves.
It should be noted that perhaps the most commercially successful form of BCI to date is the kind that encodes (writes) information into the brain: the cochlear implant, which has been used to restore hearing to millions of otherwise deaf individuals. These devices translate sounds detected by a microphone into electrical impulses, which are interpreted by the brain as sounds. Some implants stimulate the auditory nerve, but for patients with nerve dysfunction or damage, these implants stimulate the auditory brainstem directly. These devices are a great example of the life-changing impacts neurotechnology can create.
The Future of Neurotechnology
What does the future hold for neurotechnology? Many companies are working to solve the hard problem of developing materials and devices that can be placed inside the brain or on nerves, and do so safely with years of reliable lifetime. This can be a long road of development, and may be limited at first to patients in great need. However, advances in computation and electronics are giving non-invasive wearables the power and sophistication to interact with the brain in ways that were previously not possible, without the need for surgery. At Elemind, we’re building on the electroencephalogram (EEG) - a technology that scientists have been studying for decades as a means to read brain activity from the outside of the head. Whereas laboratory EEG systems used to require racks of equipment, we’ve taken advantage of modern, high-efficiency electronics to build an EEG system that can be worn comfortably on your head. Taking things a step further, we’re adapting efficient algorithms developed by scientists at MIT to track fluctuations in neural activity - which can occur at rates of up to 100 times per second - so we can know the state of the brain at any given time. This allows us to send quick pulses of sound at exactly the right time to amplify signals related to sleep, or to collide with signals that might be keeping you awake. We’re excited to use neurotechnology to help our users fall asleep, and we think that sleep is just the beginning! Although the future seems harder and harder to predict, we feel confident that neurotechnology has an exciting part to play.