Elon Musk's brain chip firm Neuralink has said it has been given the go-ahead to start carrying out studies on humans.
Neuralink said in a tweet on Thursday it had won the approval of the US Food and Drug Administration (FDA) "to launch our first-in-human clinical study!"
It represents "an important first step that will one day allow our technology to help many people," it said.
The company did not elaborate on the aims of the study, or when trials will start, but said it was not recruiting yet.
Mr Musk, who last year claimed the devices were so safe he would happily use his children as guinea pigs, hopes they will one day help conditions including obesity, autism, depression and schizophrenia, as well as enabling web browsing and telepathy.
The billionaire has said Neuralink would begin human trials at least four times since 2019, but the company only applied for FDA approval early last year.
The agency turned it down then - major issues involved the implant's lithium battery, the possibility of its wires migrating within the brain, and whether the device could be safely removed without damaging brain tissue - and said the concerns needed to be addressed before sanctioning human trials.
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Neuralink, founded in 2016, has been the subject of several federal investigations.
In December last year it reportedly came under investigation for alleged animal welfare violations in its work, claims it has denied.
A total of 1,500 animals died in four years, according to a report, leading to internal complaints that animal testing was being rushed - causing needless suffering and deaths.
Musk increased pressure to accelerate development, staff said, leading to botched experiments that needed to be repeated.
In one case, 25 pigs were reportedly implanted with devices that were the wrong size - with a source telling Reuters news agency this was an error that could have been avoided with more preparation.
Neuralink hopes the implant it is developing will help paralysed people walk again - and cure other neurological issues.
Swiss researchers showed the potential for the technology earlier this week.
A paralysed man from the Netherlands was able to walk simply by thinking about it - thanks to a system of implants which wirelessly transmit his thoughts to his legs and feet.
(c) Sky News 2023: Elon Musk's brain chip company Neuralink says it has won FDA approval for human trials