Elon Musk's controversial biotechnology startup Neuralink opened up recruitment for its first human clinical trial Tuesday, according to a company blog.

After receiving approval from an independent review board, Neuralink is set to begin offering brain implants to paralysis patients as part of the PRIME Study, the company said. PRIME, short for Precise Robotically Implanted Brain-Computer Interface, is being carried out to evaluate both the safety and functionality of the implant.

Trial patients will have a chip surgically placed in the part of the brain that controls the intention to move. The chip, installed by a robot, will then record and send brain signals to an app, with the initial goal being "to grant people the ability to control a computer cursor or keyboard using their thoughts alone," the company wrote.

Those with quadriplegia due to cervical spinal cord injury or amyotrophic lateral sclerosis (ALS) may qualify for the six-year-long study -- 18 months of at-home and clinic visits followed by follow-up visits over five years. Interested people can sign up in the patient registry on Neuralink's website.

Musk has been working on Neuralink's goal of using implants to connect the human brain to a computer for five years, but the company so far has only tested on animals. The company also faced scrutiny after a monkey died in project testing in 2022 as part of efforts to get the animal to play Pong, one of the first video games.

In May, Neuralink tweeted that it had received FDA clearance for human clinical trials, with the approval acknowledged by the agency in a statement. The opening of human trials also comes over a month after the brain chip startup raised $280 million in a fundraising round led by Founders Fund, a San Francisco-based VC firm established by Peter Thiel, the controversial billionaire who was also a co-founder at PayPal.

"We're extremely excited about this next chapter at Neuralink," the company wrote at the time on X, the Musk-owned social media platform formerly known as Twitter.

Musk has forecast human trials at the startup at least four times since 2019, yet the company didn't seek FDA approval until 2022. At that time, the agency rejected the bid, according to a March Reuters report, citing safety concerns about parts of the implant migrating to other parts of the brain and possible brain tissue damage when the devices are removed. Musk said at a December recruiting event that Neuralink has submitted "most" of its paperwork to the US Food and Drug Administration and could begin testing on humans within six months.

But employees told Reuters in December that the company is rushing to market, resulting in careless animal deaths and a federal investigation.

Neuralink did not respond to CNN's request for comment.

Before Neuralink's brain implants hit the broader market, they'll need regulatory approval. The FDA put out a paper in 2021 mapping out the agency's initial thoughts on brain-computer interface devices, noting the field is "progressing rapidly."