Human trials for brain implants get the go ahead

Elon Musk’s biotech startup, Neuralink, has received approval from an independent review board to begin recruiting for its first human clinical trial. Neuralink is set to begin offering brain implants to paralysis patients as part of its PRIME study.

Neuralink is looking for individuals who have quadriplegia due to spinal cord injury or amyotrophic lateral sclerosis and are at least one-year post-injury without improvement, are at least 22 years old and have a consistent and reliable caregiver.

PRIME study

The PRIME study is short for Precise Robotically Implanted Brain-Computer Interface. This is an investigational medical device trial for the startup’s fully implantable, wireless brain-computer interface (BCI), which aims to evaluate the safety of the impact and surgical robot, as well as assess the functionality of the BCI for enabling people with paralysis to control external devices with their thoughts.

During the study, the R1 Robot will be used to surgically place the N1 Implant’s ultra-fine and flexible threads in a region of the brain that controls movement intention. Once in place, the N1 Implant is cosmetically invisible and is intended to record and transmit brain signals wirelessly to an app that decodes movement intention. The initial goal of the BCI is to grant people the ability to control a computer cursor or keyboard using their thoughts alone.

The study is due to take approximately six years to complete. During this time, those taking part in the trial will have regular follow-ups with the team to ensure the Neuralink BCI works as intended. The first stage, the Primary Study, will include nine at-home and clinic consultations over 18 months. After the Primary Study, patients will have to commit to 20 further consultations over five years. Then the BCI Research Sessions will be conducted throughout the trial and require two one-hour sessions every week.


Elon Musk and Max Hodak launched Neuralink back in 2016, and in 2019 the announcement came that it had created these ‘flexible threads’ that can be implanted into a brain, alongside the robot that could perform the implanting.

The news that human trials have been given the go-ahead has caused concern to those who have been keeping up with the Neuralink journey.

So far, the startup has only been testing on animals, but in the past, it has undergone federal investigation for potential animal-welfare violations amid internal staff complaints that the animal testing that was carried out was rushed and caused needless suffering and deaths. In a Reuters report back in December 2022, it was claimed that there were internal complaints at the company that development was being rushed and resulted in botched experiments, meaning failed tests had to be repeated, and increasing the number of animals that were used for testing.

Since beginning animal trials in 2018, it is estimated that the company has killed around 1,500 animals, including pigs, sheep and monkeys, though the figure is a rough estimate as Neuralink doesn’t keep precise records on the number of animals that have been tested on. Though, after the Department of Agriculture’s Office of Inspector General opening an investigation probing violations of the Animal Welfare Act, Neuralink was cleared in March.

What’s happening now?

Neuralink is currently recruiting patients for its first human clinical trial, and has an open Patient Registry, where people can sign up and be notified whether they may qualify for future trials.

While the history of animal testing in the company can be seen as a cause for concern, if the human clinical trial proves successful, this could be a groundbreaking technology that will restore independence and improve lives of those with quadriplegia.