Next-generation chips could shrink neural implants, reducing need for surgery

In 2024, British teenager Oran Knowlson became the first person to trial Picostim, a smartphone battery-sized device that stimulates neurons in the brain to treat a severe form of epilepsy. Developed by Oxford-based Amber Therapeutics, the device was implanted into his skull and has reduced Knowlson’s daytime seizures by 80%.

Just months later, after Kevin Hill had a similar device fitted for Parkinson’s, he told the BBC he felt like he had “been cured”. A matchbox-sized implant in his chest, wired to an electrode deep in his brain, stimulates the region of his brain responsible for tremors and motor symptoms.

These are far from the only conditions that could be treated with neural implants. Emerging evidence suggests that deep brain stimulation could also benefit people with drug-resistant depression, substance addiction, cognitive conditions caused by strokes, Alzheimer’s, and countless other neurological conditions.

But today’s devices are relatively large, so require invasive surgery. And the high development costs, which are in the hundreds of millions, limits who can benefit from them.

These issues have kept the neural implant market “stuck in the past” says Dr Dorian Haci, CEO of MintNeuro, a spinout designing specialised chips that will sit inside the implants. These new ‘brains’ for brain implants could unlock cheaper devices that are up to 1,000 times smaller than current technologies. 

All in on brain chips

One in six people in the UK live with neurological conditions. Such conditions are a leading cause of disability, while a 2024 Economist Impact report estimates that they cost the UK a staggering £96 billion each year, including the financial burden on health systems and lost productivity for patients and carers.

For cases where drugs aren’t beneficial – like Knowlson’s and Hill’s – a growing community of startups, medical device companies and academics are developing neural implants that connect directly to the brain, spinal cord or nerves elsewhere in the body. Via tiny electrodes, the implants sense, stimulate or otherwise modify neurons’ activity and firing patterns.

One company making waves among this community is MintNeuro, which spun out from Professor Tim Constandinou’s bioelectronics lab at Imperial College London in 2022. After 15 years of research with neuroscientists and clinicians, the research group had seen that available devices were effective but large and power-hungry.

In their view, the electronics inside were ripe for an upheaval. With more advanced semiconductor chips inside, neural implants could become less invasive and cheaper.

As a PhD student in Constandinou’s lab at the time, Haci took up the mantle of applying the research to real-world devices. He was awarded an Enterprise Fellowship in 2021 by the Royal Academy of Engineering’s Enterprise Hub and took advantage of the coaching and mentoring in entrepreneurship, as well as training in fundraising, sales, team building and other key skills for founders. The funding also allowed him to concentrate on building the business venture, while collaborating with the research group to develop the technology. He later started the company in 2022.

With a background in electrical engineering, Haci is a self-described “technology geek”. As well as his fascination for the brain and its mysteries, he was driven to work in neurotechnology for personal reasons. Both of his grandmothers had neurological disorders – one had epilepsy, the other had Parkinson’s.

The next silicon revolution

Often, under the hood of the biggest advances in computing are a new generation of silicon chips. We can thank NVIDIA’s graphics processor units (GPUs) for powering much of the AI boom. Low-power chips designed by Cambridge-based Arm are inside nearly every smartphone. And Intel became a household name in the 1990s with its ‘Intel Inside’ slogan plastered on Windows desktop PCs.

The next silicon revolution could upend the world of brain implants. “We want to be the enablers of the next wave in neural implants,” says Haci. “We want to be the next Intel, Arm or NVIDIA.”

There is a gap in the market. Commissioning custom chips is expensive, so companies often end up stitching together off-the-shelf components. The extra circuitry needed to make them compatible adds to their size and power needs.

To meet safety regulations, device designers have to add on even more electronic components. For example, implants have to withstand physical impacts (say, if someone is accidentally hit in the head with a ball) – and only stimulate the brain with a safe level of current.

MintNeuro is tackling both problems. Its toolbox of modular chips are designed to combine seamlessly inside neural implants – whether to sense activity, stimulate the brain, manage onboard power, or wirelessly communicate data to an external device. 

The company designs the advanced semiconductor architectures underpinning these tiny systems. These chip designs are then manufactured by one of the world’s leading foundries, TSMC, the Taiwan Semiconductor Manufacturing Company. Taiwan is estimated to produce a whopping 90% of the world’s most advanced chips: TSMC makes most of them (including for chip designers NVIDIA and Arm).

The chips are also designed to meet global standards for neural implants off the bat, making it easier for medical device companies to meet safety standards and bringing down the cost of R&D. “We see ourselves as the chipmakers for the neural implant industry,” says Haci.

At the core of the UK’s neurotech community

So far, the MintNeuro team has received over £14 million in R&D funding before spinning out from Imperial and is currently involved in no less than five projects with collaborators around the UK and worldwide.

Alongside Amber Therapeutics and Imperial College London, the company is working on an Innovate UK-funded project, GOLD, to co-develop a "neural chipset” designed to target multiple therapeutic applications – including for mixed urinary incontinence, epilepsy, and Parkinson's – and integrate it into the next-generation version of the Picostim. The new version, says Haci, will be smaller, lower power and with new functionalities (but they’re not allowed to say exactly what these will be just yet).

The UK’s new ‘moonshot’ research agency, the Advanced Research Invention Agency (ARIA), has also funded three projects in which the MintNeuro is a partner. One of these, with Texas-based Motif Neurotech and Rice University, will be a fully wireless neural implant for neuropsychiatric disorders such as severe depression.

The fact that MintNeuro is involved in so many of the projects in ARIA’s Precision Neurotechnologies programme “speaks volumes to both the quality of the work and the critical role MintNeuro is playing in the UK ecosystem”, said Jacques Carolan, the programme director, when the projects were announced.

In a promising environment, if a technological shift is indeed ahead of us, the potential for impact is enormous. “We all know someone who’s dealing with this today,” says Haci. “I'm grateful to have the opportunity to be working in this field … to have the opportunity to help millions of people that suffer from these conditions.”

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