PRIME Study Progress Update

In January, we conducted the first human implantation of our brain-computer interface (BCI). We were able to detect the participant’s neural signals shortly after the implantation surgery, and since then, he has used our end-to-end BCI system for various applications, like playing online chess and Sid Meier's Civilization VI*. 

This marks a significant milestone towards making BCI technology available to potentially restore autonomy to millions of people with unmet medical needs. We’ve prepared this blog post to share a high-level snapshot of where we are as a company: the mission that guides us, the technology we have built, the study we are currently conducting, and the work we have yet to do.

As outlined in our 2022 Show & Tell, Neuralink’s ultimate goal is to create a generalized input / output platform capable of interfacing with every aspect of the human brain. In service of this long term goal, we have spent the last several years building a device intended to interface with various regions of the brain to solve debilitating brain and central nervous system ailments. The first indication we aim to address is the restoration of digital autonomy to people living with quadriplegia due to spinal cord injury (SCI) or amyotrophic lateral sclerosis (ALS) — a capability that we are calling “Telepathy.”

What we’ve built

The current version of the device — the N1 Implant — is an intracortical BCI implant designed to record neural activity through 1,024 electrodes distributed across 64 flexible leads, or “threads,” each of which are thinner than a human hair and capable of being placed independently in the brain. 

While the thin and flexible nature of the threads are designed to decrease participant risk and increase device utility, they also make the threads impractical to manipulate by hand. Therefore, we’ve built a surgical robot — the R1 Robot — designed to reliably and efficiently insert the threads into the cortex, so that the electrodes can be placed near neurons of interest.

Signals acquired by the electrodes are routed to electronics contained in the enclosure of the N1 Implant, which process and wirelessly transmit the neural data to an instance of the Neuralink Application running on an external device, such as a computer. The Neuralink Application decodes and translates the neural data into actions, such as movements of a cursor on a computer screen. The N1 Implant is powered by an onboard battery that is inductively recharged by the N1 Charger. The ability to wirelessly communicate and inductively charge enables the N1 Implant to be surgically implanted under the scalp so that it is cosmetically invisible and used without any physical connectors to external devices.

Our first-in-human clinical trial: The PRIME Study

Building the technologies described above has been no small feat. We constructed in-house microfabrication capabilities to rapidly produce various iterations of thin-film arrays that constitute our electrode threads. We created a custom femtosecond laser mill to manufacture components with micron-level precision. We developed novel hardware and software testing systems, such as our accelerated lifetime testing racks and simulated surgery environment, to stress test and validate the robustness of our technologies. We performed many rehearsals of our surgeries to refine our procedures and make them second nature. We built our own animal care infrastructure to satisfy testing requirements for our medical devices while going above and beyond the highest standards for the care and use of laboratory animals. We continuously engaged and collected feedback from people with lived experience with quadriplegia through our Patient Registry, our Consumer Advisory Board, and various patient advocacy groups to shape the design of our technologies.

As a result of this immense preparation, we announced approval from the FDA in May 2023 to launch our first-in-human clinical study, and in September 2023 we officially began recruiting for our PRIME Study (short for Precise Robotically Implanted Brain-Computer Interface) — a groundbreaking investigational medical device trial to evaluate the safety of our implant and surgical robot, and assess the initial functionality of our BCI for enabling people with quadriplegia to control external devices with their thoughts.

Our first human implantation was conducted in a paralyzed adult as part of our PRIME Study and performed at Barrow Neurological Institute in Phoenix, Arizona. The surgery went extremely well, and the participant was able to go home the following day. The participant’s recovery since the surgery has been very smooth. 

We chose to partner with Barrow based on their extensive expertise in caring for patients with complex neurological conditions. With more than 300 active clinical trials currently underway, Barrow is committed to advancing the field of neuroscience and ensuring patients have access to an array of innovative treatment options and the most advanced and compassionate care. 

According to Michael T. Lawton, MD, president and CEO of Barrow Neurological Institute, “This operation is an impressive engineering feat and an important advancement in neurosurgery because it paves the way for new, non-biological treatments for patients with severe neurological impairments. The PRIME Study will likely be viewed as ushering in an era of brain-computer interface, or direct interaction between thoughts and implantable technology.”

Francisco A. Ponce, MD, Chief of Stereotactic and Functional Neurosurgery at Barrow Neurological Institute and the principal investigator at Barrow for the PRIME Study, said, “Barrow is dedicated to improving the quality of life of our patients and we are proud to be part of this landmark research that leverages novel medical and BCI technologies to potentially impact the lives of people with quadriplegia in a profound way.”

In advance of the procedure, a functional magnetic resonance imaging (fMRI) study was performed to pin-point regions of the participant’s brain that are active when they attempt to move their hand and arm. The fMRI data were used to locate the target zone on the participant’s precentral gyrus, a cortical region associated with executing hand movements.

At a high level, the surgery involved a neurosurgeon exposing the target region of the cortex (e.g., scalp incision, craniectomy, durectomy), the R1 Robot performing the insertions of threads of the N1 Implant, and the neurosurgeon mounting the body of the N1 Implant in the craniectomy and closing the scalp.

Approximately 18,000 people suffer a spinal cord injury each year in the United States. And, it's estimated that 302,000 people living in the United States have experienced a traumatic spinal cord injury.

“When an injury occurs to the brain or spinal cord, it can disrupt the normal functioning of the entire nervous system. This can affect a person’s ability to perform everyday tasks. We remain hopeful that a BCI device may enable a digital bridge between the brain and spinal cord to potentially improve the quality of life for people with severe spinal cord injuries,” commented Rory Murphy, MD, neurosurgeon and associate professor in the Department of Neurosurgery at Barrow Neurological Institute and an investigator at Barrow for the PRIME Study.

We’re still in the early stages of the PRIME Study and plan to provide additional updates as we continue to work with our first participant, as well as other participants in the future. Over time, we plan to launch new studies in different geographies, and continuously improve our technologies based on learnings from clinical trials as we look to maximize the number of people we can potentially help.

* We do not guarantee any benefit by participating in the PRIME Study.