Oran Knowlson, a British teenager with a severe type of epilepsy called Lennox-Gastaut syndrome, became the first person in the world to trial a new brain implant last October, with phenomenal results – his daytime seizures were reduced by 80%.

“It’s had a huge impact on his life and has prevented him from having the falls and injuring himself that he was having before,” says Martin Tisdall, a consultant paediatric neurosurgeon at Great Ormond Street Hospital (Gosh) in London, who implanted the device. “His mother was talking about how he’s had such a improvement in his quality of life, but also in his cognition: he’s more alert and more engaged.”

Oran’s neurostimulator sits under the skull and sends constant electrical signals deep into his brain with the aim of blocking abnormal impulses that trigger seizures. The implant, called a Picostim and about the size of a mobile phone battery, is recharged via headphones and operates differently between day and night.

“The device has the ability to record from the brain, to measure brain activity, and that allows us to think about ways in which we could use that information to improve the efficacy of the stimulation that the kids are getting,” says Tisdall. “What we really want to do is to deliver this treatment on the NHS.”

As part of a pilot, three more children with Lennox-Gastaut syndrome will be fitted with the implant in the coming weeks, followed by a full trial with 22 children early next year. If this goes well, the academic sponsors – Gosh and University College London – will apply for regulatory approval.

Tim Denison – a professor of engineering science at Oxford University and co-founder and chief engineer of London-based Amber Therapeutics, which developed the implant with the university – hopes the device will be available on the NHS in four to five years’ time, and around the world.

The technology is part of a growing number of neural implants being developed to treat a wide range of conditions, including brain cancer, chronic pain, rheumatoid arthritis, Parkinson’s, incontinence and tinnitus. These devices are more sophisticated than previous implants in that they do not just decode the brain’s electrical activity, but regulate it. It is also a sector in which Europe is taking on the US in a race to develop the life-changing tech.

Amber is not the only company working on brain implants to treat epilepsy. NeuroPace in California has developed a device that responds to abnormal brain activity and has been approved for over-18s by the US regulator. However, the battery is not rechargeable and has to be replaced with surgery after a few years. Other devices are placed in the chest, with wires running up to the brain, and have to be refitted as a child grows.

Mention brain chips and most people think of Elon Musk’s startup Neuralink, also based in California. It has just implanted a brain chip in a second person with a spinal cord injury. The device uses tiny wires thinner than a human hair to capture signals from the brain and translate them into actions.

The implant has been tweaked after a number of the wires moved out of position in the first person to receive it in January, Noland Arbaugh, who is paralysed from the neck down. It has enabled him to control a mouse cursor on a computer screen by thinking, which he says feels like a Star Wars Jedi “using the Force”.

Other US companies, such as Synchron, backed by Bill Gates and Jeff Bezos, have also recently implanted brain-computer interfaces (BCIs) in people who cannot move or speak.

But scientists say those implants simply decode electrical signals. By contrast, a number of US, UK and European companies are, like Amber, working on modulating the signals in what is called “BCI therapeutics” – or deep brain stimulation to treat illnesses. Amber’s implant is also used in academic trials for Parkinson’s disease, chronic pain and multiple system atrophy, which causes gradual damage to nerve cells in the brain. The company has also sponsored an initial trial in Belgium treating incontinence, with promising results.

Another sort of tech will be tested in humans in a clinical trial starting in a few weeks, using the first brain implant made of graphene, the “wonder material” discovered at Manchester University two decades ago.

A medical team at Salford Royal hospital will place a device with 64 graphene electrodes on the brain of a patient with glioblastoma, a fast-growing brain cancer. It will stimulate and read neural activity with high precision so that other parts of the brain are not damaged when the cancer is cut out. The implant is removed after surgery.

“We’re using the interface to delineate where the glioblastoma is, and to resect it [cut it out] without affecting functional areas like language or cognition,” says Carolina Aguilar, co-founder and chief executive of Inbrain Neuroelectronics, a Barcelona-based company which developed the implant with the Catalan Institute of Nanoscience and Nanotechnology and Manchester University.

Traditionally, platinum and iridium have been used in implants but graphene, made of carbon, is ultra-thin, not harmful to human tissue and able to decode and modulate very selectively.

Inbrain plans to conduct clinical trials with a similar implant, powered by artificial intelligence, for people with Parkinson’s disease, epilepsy and speech problems caused by strokes.

Prof Kostas Kostarelos, who is the chair of nanomedicine at Manchester University as well as a co-founder of Inbrain and chief trial investigator for the glioblastoma trial, says the company aims to “develop a more intelligent implantable system”.

Devices powered by AI, with 1,024 electrical contacts, will “help deliver the best therapy for each patient without the neurologists needing to programme all these contacts individually, like today,” he says.

Inbrain is collaborating with the German pharma firm Merck to use its graphene device to stimulate the vagus nerve, which is responsible for various bodily functions including digestion, heart rate and breathing, to treat severe chronic inflammatory, metabolic and endocrine diseases such as rheumatoid arthritis.

Galvani Bioelectronics, set up in 2016 by Britain’s second-biggest pharmaceutical firm, GSK, and the Alphabet subsidiary Verily Life Sciences, has a lead therapy that aims to treat rheumatoid arthritis by stimulating the splenic nerve. Galvani has begun clinical trials with patients in the UK, the US and the Netherlands, and first results are expected within six to 12 months.

The market for bioelectronics, which fuses biological science and electrical engineering, is worth $8.7bn now and forecast to reach more than $20bn (£15bn) by 2031, according to Verified Market Research. This area focuses on the peripheral nervous system, which carries signals from the brain to the organs and back. Add in brain-focused neuromodulation and BCI, and the total market could be worth more than $25bn, Aguilar believes.

While neuromodulation companies in the US have been making waves with devices targeting chronic pain and sleep apnoea, there is a growing number of startups in Europe. MintNeuro, a spinout from Imperial College London, is working on next-generation chips that can be combined into tiny implants, and partners with Amber. Funded by an Innovate UK grant, its first project is to develop an implant to treat mixed urinary incontinence.

Neurosoft in Geneva has developed devices in the shape of thin metal films on stretchable silicone that, because they are soft, put less pressure on the brain and blood vessels. It is targeting severe tinnitus, which affects 120 million people worldwide.

Nicolas Vachicouras, its chief executive, says: “Even though tinnitus often starts with damage to the ears, typically due to loud noise … it can cause changes in the brain’s wiring and becomes in effect a neurological disorder.”

Newronika, founded in 2009 by 13 neurosurgeons, neurologists, engineers and other scientists from Milan’s Policlinico research centre and the University of Milan, has developed a rechargeable deep brain neurostimulator to treat Parkinson’s disease. It is capable of closed-loop stimulation, which adapts moment by moment to the patient’s condition, and is still being tested in patients.

“When it comes to getting therapies on to the NHS and distributed globally, Europe and the UK can go head to head with the United States,” says Denison. “It’s a fair race and we’re going to go for it.”