Elon Musk's brain implant company, Neuralink, said on Thursday it received the green light from the U.S. Food and Drug Administration to begin its first in-human clinical trial, a critical milestone after previous struggles to gain approval. Musk has predicted at least four times since 2019 that the medical device company will begin human trials for a brain implant to treat serious conditions like stroke and blindness. Yet the company, which was founded in 2016, only sought FDA approval in early 2022, and the agency rejected the application, seven current and former employees told in March. According to the staff, the FDA had pointed to Neuralink a few concerns that needed to be addressed before approving human trials. Major issues included the device's lithium battery, the possibility of the implant's wires being displaced within the brain, and the difficulty of safely removing the device without damaging brain tissue. Thursday's FDA approval came as US lawmakers urged regulators to investigate whether the formation of a panel overseeing animal testing at Neuralink had contributed to the failed and rushed experiments. Neuralink has already been the subject of federal investigations. Last year, the USDA's inspector general began investigating possible violations of the Animal Welfare Act, which governs how researchers treat and test certain animal species, at the request of a federal prosecutor. The company has killed nearly 1,500 animals, including more than 280 sheep, pigs and monkeys, following experiments since 2018, previously reported. The investigation also looks at the USDA's oversight of Neuralink. In a tweet on Thursday, Neuralink said it's not yet open for a clinical trial. "This is the result of the incredible work the Neuralink team has done in close collaboration with the FDA and represents an important first step that will one day enable our technology to help many people," the company said in a tweet on Thursday. Over the years, Musk has publicly outlined an ambitious plan for Neuralink. Late last year, she made headlines by saying she was so confident in the safety of the device that she would be willing to place them on her own children. Musk envisions both disabled and healthy individuals getting surgical implants quickly at local centers. These devices aim to improve a range of conditions, from obesity, autism, depression and schizophrenia to web browsing and telepathy. Gotopnews.com