By Ian Ransom, Contributor
Gleaning insights into the workings of the brain was once a matter of opening up the skull, but neuroscientists now have less invasive ways of decoding the symphony of neural activity.
A slew of medical technology firms have developed implants that can be inserted into brain tissue and attach themselves to neurons, the specialized cells that transmit nerve impulses. The implants, known as brain-computer interfaces (BCIs), can both record activity for “translation” by external computers or stimulate it with electrical impulses. The medical possibilities created by BCIs are gradually coming to light, promising solutions to sufferers of motor disorders and neurological conditions including Alzheimer’s and cerebral palsy.
Diving Into the Jungle of the Brain
The brain, however, is not the most gentle of landscapes. Its hot and moist environment has often been likened to a coastal jungle by scientists and would seem anathema for delicate pieces of sophisticated technology. Scar tissue resulting from the insertion of implants tends to build up on electrodes and cause a gradual decline in signal quality and, ultimately, the rejection of the device.
Creating implants that can withstand the harsh conditions over the long haul is a major challenge in itself, but one that Synchron, a firm based in Australia and Silicon Valley, believes it has solved with its Stentrode device. The Stentrode avoids the need for open brain surgery by being inserted with a stent through a vein in the back of the neck. Once placed in the brain’s motor cortex, the stent splays out to plant electrodes into the blood vessels’ walls where it can record neural signals. The recorded signals are transmitted wirelessly to an external decoding unit, which translates the “signatures” of a person’s intended action. The translated signatures can then be used to control external equipment, such as robotic arms.
“If the brain’s functioning then we want to be able to get that information out and use it to control things that patients might have lost…the aim is to return them to normal [function] as much as possible.”
—Dr. Nicholas Opie, founder and chief technology officer, Synchron
“If the brain’s functioning then we want to be able to get that information out and use it to control things that patients might have lost,” says Dr. Nicholas Opie, Synchron founder and chief technology officer. “That obviously depends on the patient. But the aim is to return them to normal [function] as much as possible.”
Synchron announced last September it had successfully implanted the Stentrode into a human and began its first clinical trial to assess the device’s potential to restore motor function in people with severe paralysis. Several patients are now implanted with the device and initial results will be reported later in 2020. The startup plans to test the device on patients with a range of conditions, including spinal cord injury, stroke, muscular dystrophy, and motor neuron disease/amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease. While other brain implants have limited shelf lives due to the problems of scar tissue, Opie says the Synchron was designed to last a lifetime.
“It’s very early stages and we don’t have evidence to back that up, but we’re slowly getting it as time rolls on and more people get implanted,” he says.
BCIs Draw Investment From the Pentagon and Silicon Valley
Synchron is the first among a number of BCI startups to successfully launch a clinical trial—but it will not be the last. Funding is pouring into the field, with the Pentagon’s research arm, Defense Advanced Research Projects Agency, distributing more than $65 million among six different organizations in 2017. Texas-based startup Paradromics is one of them and hopes to start clinical trials with its BCI in 2021. Paradromics’ goal is for its BCI to act as a speech prosthetic, helping the many people with speech disabilities communicate.
“We’re specifically building a chip that records and stimulates electrical activity because it’s something that’s been shown in the clinic to work,” founder Matt Angle told Forbes last April.
“I think where the future of BCI is going is even to look at things like anxiety, depression, schizophrenia, [and] obsessive-compulsive disorders.”
—Matt Angle, founder, Paradromics
“I think where the future of BCI is going is even to look at things like anxiety, depression, schizophrenia, [and] obsessive-compulsive disorders. There are many different ways that these could develop.”
Technology entrepreneur Elon Musk is also a big investor in the fledging industry, having pumped some $100 million into BCI developer Neuralink. The startup aims to collect as much data from the brain as possible using “neural lace,” a mesh of ultra-thin electrodes that are inserted into the brain by a neurosurgical robot. Neuralink said last year that its technology had already been successfully tested on rats and monkeys.
AI Helps Connect the Dots in Mapping the Brain
Footage of paraplegics manipulating robotic arms by mind control has caused great excitement about the possible medical applications of the devices. Sufferers of Parkinson’s disease have long benefited from deep brain stimulation surgery in which implants shoot electrical impulses to the brain’s motor cortex, which can help alleviate disabling tremors and improve movement.
Yet mapping the human brain is a painstaking process and implants can only scrape a very small part of the surface. Each electrode connected to a BCI is generally only able to tap into a handful of neurons at any one time. Neuralink says it has developed an implant capable of receiving neural signals via more than 3,000 electrodes and transmitting them wirelessly. That would make it the most efficient data collector among the current generation of BCIs. However, when weighed against the brain’s estimated 88 billion neurons, researchers have their work cut out.
The process of getting approval from regulators to conduct clinical trials is also time-consuming and arduous, so there is unlikely to be a flood of BCIs rushing into medical practice in the near future. Still, every piece of data gleaned from neural signals is invaluable and machine learning programs are able to help fill in the “gaps” by identifying patterns and correlations between neural activity and their outcomes. Such correlations allow neuroscientists to pinpoint the areas of the brain for which stimulation might unlock a reliable response, in turn accelerating the development of medical applications. Researchers like Dr. Opie are mindful of the challenges, but are convinced that BCIs for sufferers of neurological conditions might end up as ubiquitous as hearing aids for the hard of hearing.
“There’s certainly some good research around the world that has shown their possibilities and potential benefits,” he says. “A lot of the work that’s been done on brain machine interfaces has given us confidence. I certainly don’t think it’s a fairytale. It’s on the horizon.”