The thought of connecting our brains with the computer, be able to communicate wirelessly without speaking a word, be able to fantasise and do things we have never thought before and many more, makes us feel powerful something we have imagined and portrayed in Sci-Fi movies.Well these all fantasies can be true now, Neuralink — The Latest tech innovation from Elon Musk from his firm Neuralink which aims developing tech around neural interfaces.
The Neuralink N1 a 4mm-square chip, is implanted into the skull which 1024 channels or electrodes that interface with the brain. It is able to communicate wirelessly with Bluetooth low energy to the any of the devices or to the outside world thereby sending signals to and from the brain.
The current goal of this device is to help with neurological disorders, which are rooted in the inability of the brain to connect with nerves around the body. These include epilepsy and Parkinson’s disease, but also paraplegia and quadriplegia following injuries to spinal nerves. But is it limited to curing only diseases? Well certainly no. It can do certainly do many many other things and these will unravel with time as the chip upgrades.
The chip is a ingenious and remarkably innovative piece of work that brings many disciplines and domains of technology under on hood like Software Engineering, Embedded Engineering, Neuroscience, Electrical Engineering, Mechanical systems, etc. Let's see what this technology is capable of and how it works on a very broad level.
The Neuralink is based on based on a custom architecture of chip design and not ARM or x86 simply because it has to work on a very different kind of constrained environment like the human body which can pose several implications. So the chip design in itself is quite different.
The chip is based on spike detection algorithm. It is based on online spike detection mechanism where the chip detects any thresholds received from the 1024 channels and performs Band pass filter and sends the only characteristic shapes over BLE. The raw signal is way more complex and is simplified and is filtered by the Neuralink. Spikes are events happening is the neurons in the brain that represent an activity .These are electical impulses or a kind of digital signal like 0 or 1 that are sent by the neurons to other recipient neurons.
The chip is implanted on to the skull by making a small incision of the shape of a coin on the top of the skull. The fine 1024 threads are engraved into the brain without affecting veins or other blood vessels. The incision is covered using a plastic like material which is durable and looks like flesh. This is a robotic surgery process and is carries by one of Neuralink’s automated systems to carry out the whole process.This is now has been tested on pigs. Later to market the device on humans it requires an FDA approval.
It can help restore movement and communication in case of spinal cord injury patients. In such injuries the neurons to the spinal cord to the brain are damaged thereby hampering communications from brain to the sensory organs.This chip can bridge the gap by linking the electricals signals over this broken connections like a bridge.
The chip does most of the filtering on the device itself, but it can be extended further to send the raw signals over and do the process heavy lifting on a computer or smartphone devices.
Chip Location and Functionalities
The chip is currently implanted in the Cortex region of the brain which houses most of the major activities like motor sensory and visual responses which is 3–4 mm deep but the company promises to scale it to reach deeper levels of the brain like the hypothalamus where it can tap feelings like depression and anxiety. This can be done by increasing the length of the electrodes as company says.
Material Science and Design Challenges
The chip threads are designed to last the test of time and for decades so that they don’t deteriorate since these are basically conductors and insulators. The brain being a very corrosive environment so to prevent the corrosion of electrodes it requires a very robust and thin material, so Silicon Carbide can be used an insulating material. Since the brain is a very constrained environment the thread are very very thin almost the 1/20th the size of a strand of a hair i.e 5 microns. Efforts are being made to make them even thinner to house more electrodes in the same area. But this is big challenge since as the thickness of the strand decreases the cross sectional area will decrease allowing less current to flow through and will make it difficult to sense the signal or impulses.
All the 1024 channels in the device are capable of recording and simulating. It has on chip algorithms to do compression and extracting region of spikes or thresholds that are happening much faster than the brain can process. The signals collected are digitised at 20 KHz. ADC convertors make it to 10 bit resolution that is 1024 channels. Spike detection can be done as fast as 900ns.
Chip Protection from Interferences
Interferences from wireless sources like Wifi, Bluetooth, Radio etc in the frequency band can pose some interference to the chip, but the chip is optimised to work in these frequencies and bandwidths. Also the mechanical packaging is being done maybe with glass or metal prevent it from internal shock and chemical and pressure generated in the brain.
Technology promises such a leap where you can store all your past memories somewhere in a drive and retrieve them later.
Programming Languages on Chip
On low level transistors for chip design Verilog is used. For high level C,C++ and python are used.
All the interaction with the brain are authenticated and encrypted. Sensory modules like the BLE are separated and IO to the brain is protected from attacks and do some penetrating tests.
Why pig is used as model for the initial testing of this chip?
Pigs skull anatomy are somewhat similar to humans as part of the functionality. They require very few resources to be happy so the can be tested across variety of emotions. They have a long snout where most of the sensory neurons are present and the brain houses a huge for it.
The device is scalable to more better reception in terms of increasing the number of electrodes, make them thinner, increase the security. So there is big room for optimizations and scalability.
Simply innumberable. Telepathy, playing games using mind control, controlling objects, detection of incoming diseases and list goes on. It is a Human AI symbiosis.
The company has tested the device on pigs and confirms that there are no side effect of such implantation. It can be upgraded and modified as required with affecting the brain.