There could be multiple versions of this device type, not only from Elon Musk’s company, but also from other companies.
The device would most likely use magnets, to move a tiny computer that runs off a magnetic field, which would require that a magnetic field be applied to the head always. The magnets could also be used to guide the tiny computer through the veins and into the brain.
The concept of using AI to connect with the brain isn’t a new concept. It has been discussed thoroughly in the invention documentation for Artificial Telepathy. In Artificial Telepathy, the AI would be an open architecture, that would have multiple layers to supplement the multiple inputs, and subsequent outputs back into the brain from the computing device.
The best type of cybernetics device is going to involve some surgery, and it isn’t currently allowed in the United States. I wouldn’t invest into his technology, because I think it’s unlikely that Congress will ever approve any technologies to be used for medical research purposes if there is not already a dependency on computers, such as dependency on BCIs to communicate. So basically, the market share for this type of invention is most likely very small, limited to individuals who will waive all liabilities and receive the implant illegally. Once implanted, it is unlikely that it would be an issue legally, however if it could be proved that the technology was in use – there could be laws that outlaw the use of the technology if it isn’t clearly visible. And I’m not opposed to the technology.
The device would also need a way to communicate with a host device that runs the systems that interprets the radio waves being emitted from the device to the host device, and subsequently send back radio signals that are then converted into electrical impulses, all getting their power from magnets or electromagnets.