The problem
People with severe paralysis from amyotrophic lateral sclerosis (ALS), brainstem stroke or spinal cord injury can lose the ability to use their hands, and sometimes to speak. Phones, computers and smart homes could restore some independence, but only if they can be controlled without touch.
Brain-computer interfaces can do that, but the most capable ones require open-brain surgery to place electrodes on or in the cortex. That brings surgical risk and limits how many hospitals and patients can use them.
The product
The Stentrode borrows from heart medicine. Fierce Biotech compares it to a stent for cardiovascular disease: Synchron mounts electrodes on a stent-like scaffold and delivers it by catheter through the jugular vein into the superior sagittal sinus, a large vein running alongside the motor cortex. There is no craniotomy.
Once in place, the electrodes detect motor intent from inside the blood vessel, and the system records and transmits those signals wirelessly out of the brain to decoding software. Synchron calls the result Digital Motor Outputs: “simple, thought-derived expressions of intent, converted into digital actions on computers,” in the words of founder and CEO Tom Oxley. In practice that means hands-free pointing and clicking.
Synchron has worked to connect this to everyday devices. It was the first BCI company to integrate Apple’s BCI Human Interface Device protocol, a Bluetooth-based iOS link that lets brain activity control iPhone, iPad and Vision Pro through Apple’s Switch Control accessibility feature, with no touch, voice or eye tracking needed. It has also shown control of Amazon’s Alexa and integrations with NVIDIA’s Holoscan platform and OpenAI.
How it works
- Access. A catheter enters the jugular vein in the neck.
- Deploy. The Stentrode expands against the wall of the superior sagittal sinus.
- Sense. Electrodes record motor signals from the adjacent cortex.
- Transmit. The system sends the signals wirelessly out of the body.
- Decode. Software converts intended movements into clicks and selections.
- Connect. Commands drive phones, tablets, headsets and smart home devices.
Timeline
| Date | Milestone |
|---|---|
| 2022 | Australian trial in five people completed |
| 2024 | First use of Apple Vision Pro and Amazon Alexa with a BCI |
| Sep 2024 | COMMAND 12-month results at the Congress of Neurological Surgeons: primary safety endpoint met |
| 2025 | First native thought-controlled iPad experience using Apple’s BCI HID protocol |
| Nov 2025 | $200 million Series D led by Double Point Ventures |
| Mar 2026 | Inside BCI reports Synchron in active talks with the FDA on pivotal trial design |
| 2026 | INTENT early feasibility study (NCT07543367) lists five US sites and 10 planned participants |
Impact and numbers
COMMAND, supported by the NIH BRAIN Initiative, enrolled six people with severe, chronic paralysis of both arms at Mount Sinai in New York, the University at Buffalo and UPMC in Pittsburgh with Carnegie Mellon University. All six met the primary endpoint: no device-related serious adverse events resulting in death or permanent increased disability over 12 months. There were no serious adverse events related to the brain or blood vessels. Doctors deployed the device accurately and reached the target motor cortex in every patient, with a median procedure time of 20 minutes. Motor intent signals were captured consistently and turned into digital actions.
“This minimally-invasive approach has the potential to unlock BCI technology at scale for the millions of patients with paralysis,” said co-principal investigator Elad Levy of the University at Buffalo.
Investors agree. The November 2025 Series D raised $200 million from backers including ARCH Ventures, Khosla Ventures, Bezos Expeditions, the Qatar Investment Authority and Australia’s National Reconstruction Fund. Synchron is also building a cognitive AI division in New York to train models that learn from brain data to decode thought in real time, and a San Diego engineering hub for its next-generation interface. “We’ve built the first non-surgical brain-computer interface designed for everyday life for people with paralysis,” Oxley said when the round closed.
The device is already being used for everyday tasks in trials. MedTech Dive reported that one participant with ALS controlled his smart home through Amazon Alexa and used the implant to move the cursor on Apple Vision Pro, the kind of mainstream access the company is aiming for.
Honest caveats
Evidence status. Ten implants in total, and COMMAND was a six-patient early feasibility study focused on safety. How well people can communicate over years is not yet established.
No approval. The FDA has granted only investigational exemptions. The pivotal trial design and endpoints are still under discussion, and Inside BCI notes regulators’ expectations for such endpoints are largely unsettled.
Lower bandwidth. Avoiding open surgery simplifies the safety case, but Inside BCI notes that the device “records from fewer neurons than cortical implants,” which may limit the functional outcomes it can show. Rivals such as Neuralink accept open-brain surgery for richer data.
Privacy and ethics. Synchron trains AI models on brain data and links to Apple, Amazon, NVIDIA and OpenAI platforms. That makes consent, data ownership and security of neural data central questions, along with long-term support for implanted users.
What’s next
Synchron plans to accelerate pivotal trials, prepare for commercial launch and develop a next-generation, catheter-delivered, high-channel “whole-brain interface.” The INTENT feasibility study is recruiting at sites in Jacksonville, Buffalo, New York, Pittsburgh and Dallas, with completion estimated in 2029.
Why it matters for Europe and green buyers
For Europe, Synchron is the benchmark that European projects such as INBRAIN in Barcelona and CEA’s WIMAGINE in Grenoble are measured against, and its catheter approach uses skills found in every European stroke centre.
For India, where neurosurgical capacity is limited, a BCI placed by interventional neurologists rather than through open-brain surgery could eventually be easier to scale. For the world, giving people with paralysis control of mainstream phones and computers is a direct gain in accessibility and inclusion.
Sources & image credits
- MedTech Dive, “Synchron’s brain-computer interface tech meets safety goal”, September 2024. https://www.medtechdive.com/news/synchrons-brain-computer-interface-safety-trial/728494/
- Fierce Biotech, “Synchron’s brain-computer interface clears year-long safety study”, September 2024. https://www.fiercebiotech.com/medtech/synchrons-brain-computer-interface-clears-year-long-safety-study
- MassDevice, “Synchron raises $200M Series D to support BCI commercialization, next-gen tech”, November 2025. https://www.massdevice.com/synchron-raises-200m-seriesd-bci-commercialization/
- Synchron, “Synchron Raises $200 Million Series D to Advance Brain-Computer Interface Technology” (via Neurofounders), November 2025. https://www.neurofounders.co/press-releases/synchron-raises-200-million-series-d-to-advance-brain-computer-interface-technology
- Inside BCI, “FDA’s One-Trial Default Lands Just as BCI Companies Approach Pivotal Studies”, 22 March 2026. https://insidebci.com/policy/2026-03-22-fdas-one-trial-default-lands-just-as-bci-companies-approach-pivotal-studies/
- ClinicalTrials.gov, NCT07543367, “INdependence Through Endovascular Neuroprosthetic Technology (INTENT): an Early Feasibility Study”. https://clinicaltrials.gov/study/NCT07543367
- Synchron, “News” (press and announcements list). https://synchron.com/news
- Wikimedia Commons, “Stentrode Device”. https://commons.wikimedia.org/wiki/File:Stentrode_Device.jpg
Images: “Stentrode Device”, Christinecooch, 2020, CC BY-SA 4.0, via Wikimedia Commons.
