Elon Musk said Wednesday that his brain tech startup Neuralink hopes to implant its system in a second human patient within “the next week or so.” Executives also said the company is making changes to address the hardware problems it encountered with its first participant.

Neuralink is building a brain-computer interface, or a BCI, that aims to help patients by using breakthrough paralysis-control technology. The company’s first system, called Telepathy, involves 64 “threads” that are inserted directly into the brain. The threads are thinner than a human hair and record neural signals through 1,024 electrodes, according to Neuralink’s website.

BCIs have been studied in academia for decades, and several other companies including Synchron, Paradromics and Precision Neuroscience are developing their own systems. No BCI company has received approval from the U.S. Food and Drug Administration to commercialize their devices.

In a livestream with Neuralink executives on Wednesday, Musk said the company is hoping to implant its device in the “high single digits” of patients this year. It is not clear when or where those procedures will take place.

A spokesperson for Neuralink was not immediately available for comment.

In January, Neuralink implanted its BCI in its first human patient, 29-year-old Noland Arbaugh, at the Barrow Neurological Institute in Phoenix, as part of a clinical study approved by the FDA.

Neuralink said in an April blog post that the surgery went “extremely well.” However, in the weeks following the procedure, Neuralink said some threads from the implant retracted from Arbaugh’s brain. The company reportedly considered removing the implant, but the problem hasn’t posed a direct risk to the patient’s health and safety, according to The Wall Street Journal.

Musk and the Neuralink executives on the livestream said only around 15% of the channels in Arbaugh’s implant are functional. Even so, he uses the BCI to watch videos, read and play chess and other video games — sometimes up to 70 hours per week.

For upcoming implants, the company said it is working to mitigate retraction and measure it more closely. Neuralink president DJ Seo said one way it plans to do so is by sculpting the surface of the skull to minimize the gap under the implant.

Neuralink also plans to insert some threads deeper into the brain tissue and track how much movement occurs, according to the company livestream. Dr. Matthew MacDougall, head of neurosurgery at Neuralink, said it will insert threads “at a variety of depths” now that it knows retraction is a possibility.

“The FDA will continue to monitor the safety of those enrolled in the study for Neuralink’s implant device through required, regular reports,” an FDA spokesperson told CNBC in a statement.