Elon Musk is hoping to have his startup Neuralink ready to help people by 2021.

Neuralink is the Tesla Inc (NASDAQ:TSLA) CEO’s plans to create a company that allows human brains to operate alongside machines. Elon Musk says that he expects to have some of the tech ready in the next four years.

During a piece with Wait But Why, Elon Musk says that this first line of technology from Neuralink will help those that have suffered from certain injuries. This means that those hurt by stroke, cancer lesion, congenital may be able to get help with the company’s new devices.

One of the major problems that Neuralink will face is limited bandwidth. The technology to quickly interact with the human brain isn’t available yet. However, growing advancements in these fields mean that the industry may be ready by 2034, if it can advance at the same rate that computers do.

The next major problem that Neuralink will face is implantation of the device. Open-skull surgery isn’t widely available and can be expensive. It also isn’t something that many would likely want to go through. To get around this, the Elon Musk startup is looking for a non-invasive way to have its tech communicate with human brains.

The lofty goals of Neuralink means that someday humans may be able to directly communicate with each other and computers with just a thought. However, this is likely still a long ways off due to current limits in technology.

Elon Musk announced his plans to start Neuralink late last month. There has been some concern that the Tesla Inc and SpaceX CEO may be stretching himself to thin with all these different efforts.