Enlarge /. Elon Musk shows off the latest version of his company's implants.
On Friday, Elon Musk gave an update on what is probably his third most important company: Neuralink. Neuralink had been fairly unremarkable prior to that time last year (especially when compared to Tesla and SpaceX) when Musk first detailed the company's goals and progress. And the goals were striking: a mass-market brain implant that could be operated on by a robot on the same day.
With this year's update, little has changed in the overall plan, but many small details have been optimized over the past 12 months. And progress has been made with Musk introducing his audience to a group of pigs who were already wearing the version 0.9 of his implants he proposed. The human tests should follow shortly.
Designs on the brain
One of the big differences between this year and last year is the overall design of the implant and its supporting hardware. The original goal had been to keep the operation partly simple by minimizing the size of the hole that had to be made in the skull. This meant a small diameter implant that didn't necessarily have to be placed near the neurons it interacted with and would require a connection to separate hardware behind the ear. All of this added to the complication and would necessarily require running some wires across the surface of the brain.
Most of it has been simplified. Right now, implants don't target anything deep in the brain, only things near the surface of the cerebral cortex, the outermost layer at the front of the brain. A neurosurgeon employed by Neuralink was on site (like last year, just so you knew he was a surgeon) and said there are many motor and sensory processes that go through the cortex and therefore can be targeted by implants . Musk followed suit by saying that the only way to "resolve" blindness and deafness is to focus on the cortex.
As in the old design, approximately 1,000 electrodes are inserted into the targeted collection of neurons and these are connected to an implant above the surface of the brain. In this case, however, they do so in the shortest possible route so that the wires no longer have to be routed across the surface of the brain. The behind-ear hardware is gone as well. Instead, there will be a single implant that spans the skull, essentially replacing part of it.
Musk showed one of the implants and it's a big rethink. He said it was 23mm in diameter (although it didn't have a specific radius or diameter) and about 8mm thick – the latter was chosen as a close match with the thickness of human skulls. The device looks like a very thick coin or miniature hockey puck and contains all of the hardware required to keep the implant functional. This includes a battery big enough for all-day use and the hardware needed for wireless inductive charging. There are also support chips, mostly from wearables, that control charging and enable wireless communication via bluetooth.
The central feature, however, is still Neuralink's custom chip, which can be used to identify and transmit patterns of neural activity. Individual neurons eavesdropping on the electrodes communicate by firing a series of so-called "spikes" – brief bursts of electrical activity that contrasts with background noise. According to Musk, Neuralink's chip is programmed with a series of spike templates that correspond to common behaviors in actual neurons. The chip picks up the analog electrical activity recorded by the electrodes, converts it to digital data, identifies activity peaks, and then finds the template tip that best matches the activity.
This enables a code to be transmitted that identifies the template, which results in enormous compression compared to the complicated, noisy neural activity. This is essential for a device that communicates over a low bandwidth interface such as Bluetooth.
With the chip, the electrodes can also be used to stimulate neurons, although Musk didn't go into the details. Probably a little more effort is required than passive reading of your activities, which can limit usability.
The team still relies on a robot to manipulate the toughest parts of the implant, using a microscope to identify blood vessels and avoid them when electrodes are inserted into the brain. The prototype of a robot that Neuralink demonstrated last year and that could easily be mistaken for an interrogation droid no longer exists. In its place is a clean, white, very medical-looking design – one with all of the tools and pointed parts necessary to poke a hole in a person's skull that is not visible when not in use. While the team is still working on adapting the robot to reach deeper areas in the brain, the initial focus on the cortex makes the robot's job a little easier for now.
Musk promised that the surgery would only take about an hour, no general anesthesia would be required, and the recipient could go home with their implant the same day.
Musk then introduced the first recipients of the current implant design: a group of pigs. Of course, there was a control animal waddling happily in front of the camera and eating from its handler's hand. A second pig followed, who previously had an implant but had since removed the device. Musk stressed that this is important as employees may want to upgrade their implants, especially as the company plans to keep improving its hardware.
That should have been followed by a pig with a functional implant, but Gertrude was shy, which annoyed an animal technician and joked Musk about the dangers of living demos. Eventually she came out and Neuralink was able to show that it could eavesdrop on neurons receiving signals from sensory cells in the animal's snout. Another pig was brought out with two implants; A device listened to the animal's proprioception system and the team was able to pinpoint the position of the animal's leg with some degree of accuracy.
Next stop: people?
Like last year, Musk said the goal of the presentation was to attract good people to work at Neuralink, which currently employs around 100 people. But he definitely dropped some hints that things are getting closer if he is about to start marketing. First, he mentioned that Neuralink had received a Breakthrough Device award from the Food and Drug Agency, which is responsible for approving medical implants. This allows the company to have an ongoing dialogue with the FDA to determine the type of data that needs to be collected in order for Neuralink to ensure that approval is ultimately granted.
Musk also said it plans to start testing quadriplegics. This follows in the footsteps of some previous work, including people who have successfully placed a brain implant to control a robotic arm. Getting approval for human trials with quadriplegics is relatively easy because no other treatments are available to them. Musk did not indicate when these experiments could begin.
At the moment we only have a few data recorded from wild pigs and not a lot of technical details on how it was obtained. To some extent, this does not mean much obvious progress from last year's presentation, or much progress from where the research community is already at.
But that really doesn't capture the situation very well. While the field has been able to place a large number of implants in the brains of animals over the years, I cannot recall any leaving an animal that was visibly indistinguishable from its non-implanted counterparts, like these pigs. And Neuralink's hardware is designed to be manufactured on a scale unlike the typical production of an academic research lab.
The company has shown a lot of creativity and flexibility just as critically. It has a solid solution to the problem of compressing the intricate data the hardware is going to collect, and the team has made some important changes to its designs compared to a year ago that seem to simplify the implant and the surgery it requires Spot. And that is significant progress within a year.
That's not to say that Neuralink is set for an easy path to success. In the future there are still plenty of difficult problems and years of safety and effectiveness testing. However, the update offers some very real reasons for optimism.