LONDON — Sarah de Lagarde was rushing to a train in September 2022 when she slipped and fell through a gap between the platform and the train. For 15 horrifying minutes, she was stuck on the tracks undetected. Two trains ran over her.

She survived, but her right arm and the lower portion of her right leg had to be amputated. Lying in a hospital bed after multiple surgeries, de Lagarde, who just a month earlier had hiked Mount Kilimanjaro with her husband, Jeremy, wondered what the rest of her life would be like. “I had thought I was invincible,” de Lagarde, a public relations executive at an investment firm in London, said in an interview.

She began thinking about what she could do. “I said, ‘OK, I lost this, I need a replacement, and it’s not going to be like some dud that has no function,'” she said. Eighteen months later, de Lagarde, now 44, has regained some sense of normalcy thanks to major advancements in prosthetics that incorporate artificial intelligence.

She has a new arm and hand, which she uses confidently to open containers, make morning coffee, water plants and put her clothes on hangers. Her 9-year-old daughter, Daphne, will sometimes hold the hand as they walk down the street. The prosthetic hand, the most important and intricate piece, is powered by machine learning, a form of AI that excels at pattern recognition and making predictions based on past behavior.

TikTok uses machine learning for its recommendation algorithm. The advancements show h.