Neuralink's brain chip has been implanted into a second patient as part of early human trials, Elon Musk told podcast host Lex Fridman on Saturday. The company hasn't disclosed when the surgery took place or the name of the recipient, according to Reuters.

Musk said 400 of the electrodes on the second patient's brain are working out of 1,024 implanted. "I don't want to jinx it but it seems to have gone extremely well," he said. "There's a lot of signal, a lot of electrodes. It's working very well." 

The device allows patients with spinal cord injuries to play video games, use the internet and control electronic devices using their thoughts alone. In May, the company announced that it was "accepting applications for the second participant" in trials following FDA approval. 

The original Neuralink implant patient, Nolan Arbaugh, described the surgery as "super easy." In a demo, the company showed how Arbaugh was able to move a cursor around the screen of a laptop, pause an on-screen music device and play chess and Civilization VI.

Arbaugh himself participated in the marathon podcast with Musk and Fridman. He said that the device allows him to make anything happen on a computer screen just by thinking it, helping reduce his reliance on caregivers. 

However, problems cropped up shortly after his surgery when some of electrodes retracted from his brain. The issue was partly rectified later on by modifying the algorithm to make the implants more sensitive. Neuralink told the FDA that in a second procedure, it would place the implant’s threads deeper into the patient’s brain to prevent them from moving as much as they did in Arbaugh’s case.

Neuralink previously tested its implant in animals, including chimps, and some of those testing practices have been the subject of federal investigations. 

Despite those issues, the company said it had over 1,000 volunteers for its second surgical trial. Musk said he expects Neuralink to implant its chips in up to eight more patients by the end of 2024.  

There’s a reason smartwatches haven’t replaced clinically validated gear when you visit the hospital — accuracy and reliability are paramount when the data informs medical procedures. Even so, researchers are looking for ways in which these devices can be meaningfully used in a clinical setting. One project in the UK has explored if a Garmin Venu 2 and dedicated companion app could be used to free up doctors and nurses, six minutes at a time.

The Six Minute Walk Test (6MWT) is used to diagnose and monitor a number of cardiovascular maladies. This includes conditions like Pulmonary Hypertension that, if left untreated, are eventually fatal. “[The test has been] a cornerstone of hospital practice and clinical trials for decades all around the world as [...] a marker of how well the heart and lungs are working,” project leader Dr. Joseph Newman told Engadget. While a change in a blood test marker might be clinically relevant, he said “it’s probably more important to someone that they can walk to the shop and back.” 

The test requires a patient walk on a flat, hard surface for six minutes straight, which stresses the heart enough to measure its capacity. A professional tests the patient’s heart rate and blood oxygen levels at the start and end. While it’s simple and reliable, "it’s not perfect,” according to Dr. Newman. “This is why we’ve looked to change it in two important ways," he said, "can we make it shorter [...] and digitize it for remote use?"

After all, six minutes is a lifetime in a clinical setting, and patients dislike having to schlep all the way to their hospital just to walk up and down a corridor. It’s why Newman and Lucy Robertson — both researchers at the Royal Papworth Hospital in Cambridge — began looking for ways to revolutionize the test. They wanted to see if the test could be shortened to a single minute, and also if it could be carried out by a patient at home using a Venu 2. 

The watch was connected to a secure and dedicated clinical trial platform built by Aparito – a Wrexham-based developer – for testing. This was then sent out to patients who were instructed to wear the watch and walk outdoors to complete their own tests. “They’re asked to walk on flat, even, dry, relatively straight roads rather than in laps or circuits,” Dr. Newman said, with patients walking at their own natural pace.

“We carried out a product appraisal early on in the research process and were open-minded as to the brand or model,” said Dr. Newman. “Garmin came out on top for a few reasons; we can access raw data as well as Garmin’s algorithmically-derived variables,” he said. Because the research was being funded by a charity, the British Heart Foundation, the watch had to offer good value for money. It helped that Garmin, with its established health research division, gave the team “confidence in the accuracy of the sensors,” not to mention the fact that Aparito feels that “the Garmin SDK is relatively easy to work with,” he added. 

But while Garmin is in use right now, there’s no reason this setup couldn’t eventually work with a number of other brands. “As long as the technology works, it’s accurate, reliable and patients accept it, then we’re not tied to any brand,” he said.

There are several benefits in giving patients the ability to run the tests at home: it’s more representative of the demands of their actual life, and patients can retake the test at regular intervals, making it easier to track that person’s health over time. “We can see real value in providing patients with pulmonary hypertension with an app and smartwatch to monitor their progress,” Dr. Newman said. “It’s unlikely to ever fully replace the need for in-person hospital reviews, but it will likely reduce their frequency.”

The results of the study right now suggest cutting the test to one minute has no detrimental effect on its outcome or accuracy, and that patients are far more likely to run the test regularly if they’re able to do so at home. “It’s likely that the upfront costs of wearables [to a hospital] may be offset by the longer term reduction in hospital visits,” Dr. Newman said. If that turns out to be right, it means clinicians can better focus their time and efforts where their expertise is more valuable.

There’s a reason smartwatches haven’t replaced clinically validated gear when you visit the hospital — accuracy and reliability are paramount when the data informs medical procedures. Even so, researchers are looking for ways in which these devices can be meaningfully used in a clinical setting. One project in the UK has explored if a Garmin Venu 2 and dedicated companion app could be used to free up doctors and nurses, six minutes at a time.

The Six Minute Walk Test (6MWT) is used to diagnose and monitor a number of cardiovascular maladies. This includes conditions like Pulmonary Hypertension that, if left untreated, are eventually fatal. “[The test has been] a cornerstone of hospital practice and clinical trials for decades all around the world as [...] a marker of how well the heart and lungs are working,” project leader Dr. Joseph Newman told Engadget. While a change in a blood test marker might be clinically relevant, he said “it’s probably more important to someone that they can walk to the shop and back.” 

The test requires a patient walk on a flat, hard surface for six minutes straight, which stresses the heart enough to measure its capacity. A professional tests the patient’s heart rate and blood oxygen levels at the start and end. While it’s simple and reliable, "it’s not perfect,” according to Dr. Newman. “This is why we’ve looked to change it in two important ways," he said, "can we make it shorter [...] and digitize it for remote use?"

After all, six minutes is a lifetime in a clinical setting, and patients dislike having to schlep all the way to their hospital just to walk up and down a corridor. It’s why Newman and Lucy Robertson — both researchers at the Royal Papworth Hospital in Cambridge — began looking for ways to revolutionize the test. They wanted to see if the test could be shortened to a single minute, and also if it could be carried out by a patient at home using a Venu 2. 

The watch was connected to a secure and dedicated clinical trial platform built by Aparito – a Wrexham-based developer – for testing. This was then sent out to patients who were instructed to wear the watch and walk outdoors to complete their own tests. “They’re asked to walk on flat, even, dry, relatively straight roads rather than in laps or circuits,” Dr. Newman said, with patients walking at their own natural pace.

“We carried out a product appraisal early on in the research process and were open-minded as to the brand or model,” said Dr. Newman. “Garmin came out on top for a few reasons; we can access raw data as well as Garmin’s algorithmically-derived variables,” he said. Because the research was being funded by a charity, the British Heart Foundation, the watch had to offer good value for money. It helped that Garmin, with its established health research division, gave the team “confidence in the accuracy of the sensors,” not to mention the fact that Aparito feels that “the Garmin SDK is relatively easy to work with,” he added. 

But while Garmin is in use right now, there’s no reason this setup couldn’t eventually work with a number of other brands. “As long as the technology works, it’s accurate, reliable and patients accept it, then we’re not tied to any brand,” he said.

There are several benefits in giving patients the ability to run the tests at home: it’s more representative of the demands of their actual life, and patients can retake the test at regular intervals, making it easier to track that person’s health over time. “We can see real value in providing patients with pulmonary hypertension with an app and smartwatch to monitor their progress,” Dr. Newman said. “It’s unlikely to ever fully replace the need for in-person hospital reviews, but it will likely reduce their frequency.”

The results of the study right now suggest cutting the test to one minute has no detrimental effect on its outcome or accuracy, and that patients are far more likely to run the test regularly if they’re able to do so at home. “It’s likely that the upfront costs of wearables [to a hospital] may be offset by the longer term reduction in hospital visits,” Dr. Newman said. If that turns out to be right, it means clinicians can better focus their time and efforts where their expertise is more valuable.