In the last issue of TVPM, we compared humans with machines in order to ‘weigh’ which one sees better, is stronger, faster, more reliable, and overall better at handling ‘jobs’ that people are required to do within today’s monetary system. We did that to highlight just how easily many humans could already be freed-up from boring and repetitive jobs that machines are much better equipped to manage, allowing those humans to instead use their brain to discover, enjoy, relax and improve (their lives, society, etc.).
Today, we will look at how humans use machine-like devices to replace many of their organs and body functions. This is a vitally important field to understand, as these mechanical alternatives often mean the difference between life and death, while they are also more resilient and performance enhancing, providing their recipients with better health, along with providing a solution for organ donor scarcity.
Mechanical Body Parts for Humans
What ‘organic’ human body parts can we replace with mechanical ones that can render a better outcome, from performance to durability?
Let’s go from toes-to-head, looking closely at legs, stomach and heart, eyes and nose, and everything in between. Keep in mind that we will only be focusing on non-biological body part replacements here, as we will tackle biological enhancements and replacements in another article later in this series.
Limbs and Movement:
In order for us humans to walk, we need healthy bones, lots of muscles, strength, coordination and flexibility. To mimic what a leg does, as well as how it communicates with the brain and the rest of the body, turns out to be quite a challenge. Multiple 3D-printed prostheses have been developed recently and, although they represent a very cheap (in terms of energy and materials) means to quickly replace a missing limb, they are not nearly as advanced as a mechanical prosthesis, because mechanical limbs allow for much more flexibility and adaptability for movement.
One such mechanical leg is Genium X3. It is waterproof, the battery last 5 days and, more importantly, it detects pressure and its position in space, adapting to different kinds of movements: from riding a bike, running, driving, or even swimming.
Such mechanical legs can even be jointed at the hip via a 3D Hip Joint System that results in a three-dimensional hip movement to compensate for pelvic rotation. The result is a symmetrical, natural walking pattern. Watch this video demo to see it in action – https://www.youtube.com/watch?v=zgWRrDTakaY
Thus, the leg becomes complete from the hip, while also serving more capabilities than a normal prosthesis as it acts as a shock absorber, adapts to uneven terrain, provides a smooth rollover from heel to toe, and even allows for multi-axial motion (which means even more mobility and comfort), plus the materials it’s made from give it a ‘spring to your step’, meaning that it compresses when you apply weight and propels you forward as your foot rolls.(source)
Some mechanical lower limbs, like BIOM, are now able to communicate directly with one’s biology to adapt its movements (it can connect directly to nerves to understand how the person wishes to move). This is a ‘huge step’ towards properly integrating these mechanical devices to a human’s biology with a more natural connectivity. Imagine wearing a stiff, non-mechanical leg. How hard would it be to move around? Keep in mind that you need to feel the pressure on your artificial leg to walk smoothly, you need to have the flexibility of movement to avoid tripping or to change the direction of your walking, and so on. Today’s mechanical legs can understand how you move and respond accordingly, allowing people without legs to do nearly anything that a natural legged person can do.
As a side note, mechanical legs can be coated with a silicon covering to look almost identical to real legs, as shown in this video – https://www.youtube.com/watch?v=H1-yVu4JJLY
In addition to helping those with missing legs, these machines are also helping those that suffer from paralysis. Exoskeletons are already in use for such cases. The exoskeleton ‘senses’ the wearer’s body position, and balance points, triggering movement according to these inputs and, thus, allowing people who otherwise cannot move to walk again. This technology is still in its early stages, so it is more of a prototype, but will improve significantly over a very short period of time, as most technologies do these days.(source)
Today’s mechanical arms use similar technologies to provide for control and connect to the human body. Sensors detect muscle movement and tension, or are connected directly to nerves, and that feedback is translated into the robotic arm’s movement. One extraordinary example is a man who can control two mechanical arms and shoulders, through multiple sensors from the mechanical arms to different nerves on his body. Even though the arms / shoulders are very complex and able for different kinds of motions, the control system development is still in its early stages, so it’s slow and very simple.(source)
You see, when these mechanical prostheses are attached to the body, the body needs to have well-functioning muscles or nerves to communicate with them. The brain sends commands to the muscles and nerves, and they, in turn, activate the mechanism of the arm (or leg, or other devices). If those muscles and nerves are also damaged, then it becomes more difficult to find a solution, although nerve and muscle transplants from a different part of the body are now possible, too.(source)
However a new kind of connectivity between mechanical devices and the human body is increasingly being tested: a direct connection of such devices with the brain, fully bypassing other parts of the body. To put it simply, this technology is basically reading brain patterns, and then associating them with the movements of a mechanical limb. So, if you imagine picking up a cup and putting it on a shelf, and then repeat this a couple of times, this technology can directly analyze your brain’s activity, learn your specific brain patterns for that kind of movement, and then translate them into physical movements of the robotic arm.(source)
Imagine the same technology being applied to exoskeletons, mechanical legs, or even used for controlling wheelchairs, driving, and many other devices. Thus, with only ‘the power of the mind’, it’s now becoming possible for people to control different kinds of devices that allow them to move, reach, grasp, etc..
Another fascinating compliment to this field is artificial muscles. These are basically pneumatic ‘bladders’, precisely controlled by air flow, that bring more flexible and natural movement to mechanical limbs. We did an entire article on artificial muscles a while back, which you can read here, but check out TVPM’s video playlist showcasing its use in limbs to see how natural movements become when assisted by this technology.
While these technologies are generally used to replace missing limbs, they can also enhance performance of existing limbs to ease movement, and improve strength and performance. Imagine similar devices that may help you walk farther distances, climb under more difficult conditions, or to control devices from a distance with your brain.
Alongside 3D printing, limbs are becoming more easily replaced with mechanical alternatives, and with further advancement in software and materials, mechanical movement will become more natural, and simply a matter of ‘thinking about it’.
Joints and Bones:
Although we can’t call these mechanical, we should mention that there are already many procedures that allow for joint replacements (hips, knee, shoulder, disc) or bone replacements with varying material alternatives than biological structures.
These examples are just a sampling, but there may already be ‘mechanical’, non-biological alternatives for all joint and bone replacement needs.
To replace the functionality of a biological organ with a mechanical device is far more complex and sophisticated than replacing limbs, since organ functionality often means the difference between life and death. One can live without legs and arms, but not without a heart or a liver.
Your kidneys’ main function is to act as a filtration system for your blood; removing toxins from your body by transferring them to the bladder, where they are later evacuated from the body during urination. Kidney failure occurs when the kidneys lose the ability to sufficiently filter waste from the blood. Many factors can interfere with kidney health and function, such as toxic exposure to environmental pollutants and chemical food preservatives, certain diseases and ailments, and physical kidney damage. If your kidneys cannot manage their task, your body becomes overloaded with toxins. Left untreated, this can lead to kidney failure and may result in death.(source)
People can live without one kidney, but not without both. Over one million people die from kidney failure every year, while around 1.4 million are currently helped by an artificial kidney called a dialysis machine.(source) However, that also means keeping the patient connected to a huge machine without the ability to move or have a normal life. But now, a cup-of-coffee sized device has been invented and is nearly ready to be tested in patients. It is designed to last for the life of the recipient and should be ready for trial in 2017.(source)(source) https://www.youtube.com/watch?v=gtsHDY5S21A
Another small implantable artificial kidney is set to be tested in human trials in 5 – 6 years, according to this company. There are other mechanical replacements for kidneys that are not as small, but have already shown success in their first clinical trials. These are not designed for implant, but for wearing them on a belt, allowing patients much more mobility and a more normal life compared to dialysis.(source)
A mechanical replacement for kidney function has been available for many years. The challenge now is to make it smaller and smaller.
Nearly all of ‘the good stuff’ in what you eat and drink eventually passes through your liver, an organ that performs over 500 different functions. Although the liver is the only human organ that can fully regenerate from as little of 25% of it, incidences of liver failure can still occur.
One interesting fact is that because the liver performs many complex functions in and for the body, there is no properly tested mechanical device to replace its functions, at least so far. Although clinical trials have already begun for such devices, their potential is yet to be confirmed.(source) However, these devices make use of actual liver cells contained within devices that are externally connected to the human body to achieve liver functions, so it may be more accurate to regard these as biological devices, rather than mechanical ones.
The pancreas’ main function is the production of insulin, which then control the levels of glucose (sugars) in the blood. When this fails (Type 1) or becomes reduced (Type 2), there is more glucose in the bloodstream than normal, and the result is a serious condition known as diabetes. All Type 1 and some Type 2 diabetes cases require insulin intake, affecting 371 million people worldwide, and that number is expected to rise to 552 million by 2030. Although humans can live without a pancreas, they must take insulin and pills that contain digestive enzymes for the rest of their lives in order to survive that.(source)
There is a new mechanical device designed to control the distribution of synthetic insulin in an automated way, and it looks very promising after the first clinical trial, keeping subjects within a safe blood glucose range for 80 percent or more of the time.(source)
But there is also one device that has no mechanical parts, using a gel that isolates a reservoir of insulin. The gel hardens and softens in real-time response to fluctuating glucose levels within the body, allowing insulin to be released from the reservoir precisely when needed. Human trials of this pump are due to commence in 2016.(source)
The spleen is another organ that humans can live without, as the liver would take over many of its functions. However, the body would then lose some of its ability to fight infections.(source)
The spleen’s function is to keep the blood ‘clean’ of toxins. A mechanical device can do this today, as it’s able to provide the basic functionalities that a spleen provides to the body by eliminating the vast majority of infectious ‘bugs’ from blood (bacteria and fungi). It can clean all of your blood in about 5 hours, although it’s not a portable device and you would need to be hospitalized for the duration of the procedure. But don’t forget, you can live without a spleen.(source)
Can we replace the human stomach, small intestine and large intestine (basically most of the digestive system) with a mechanical one? Not really, but there are mechanical models of the human digestive system which mimic the ‘real’ thing quite well.
In order for you to digest food, there is a series of events that have to take place: from the saliva that mixes up with the food, mastication (chewing into smaller bits) and muscular contractions (moving it from one place to another), to the stomach’s acid and bacteria in the gut (intestines), and eventually, the transportation of ‘good stuff’ from the broken-down food into the bloodstream.
There are a few teams of engineers around the world that have built mechanical models of the entire digestive system. These are generally used for drug testing, and more, but there is also a robot that can actually digest food and extract energy from it for mechanical movement. It does that with the help of bacteria and before it suffered a non-related mechanical problem, it was able to ‘survive’ for 7 continuous days by collecting and digesting food.(source) https://www.youtube.com/watch?v=ooGTNpZKAZY
Could such a system be used in humans to replace their entire digestive system? I doubt it, but the interesting fact about humans is that they can basically survive without any parts of the digestive system except the small intestine, and even the small intestine is still functional at about 19% of its total length. You would have to be fed intravenously if you had no functional small intestine.(source)
So far, there is no mechanical alternative for the human digestive system, but perhaps other non-mechanical and biological alternatives exist, as we will discuss in an upcoming article on enhancing human biology.
The function of the lungs is to transport molecules that are ‘good’ for us (oxygen) from the atmosphere to the blood, and take the ‘bad’ molecules (carbon dioxide) from our bloodstream and exhale them out into the atmosphere. You can live with just one lung, and without both for about 30 seconds. That is a dark joke, but do not despair. There are machines that can keep you alive even if both of your lungs fail.
Lung diseases are the third leading cause of death, with over 3 million deaths a year and over 329 million people affected by various lung diseases worldwide.(source)
There are several technologies that can replace some of the lungs’ functions for a short period of time: hours or days, in cases of some particular surgeries where the patient’s lungs are not functional, or for a period of months for patients waiting for a lung transplant.(source) These are usually big, external machines that are only efficient when they are properly monitored and the patient is connected to them in a hospital. The most time that anyone has lived with such an artificial lung was for 5 months.(source)
So how about a real replacement for the lung; one that is small and can do the job without the patient being immobilized to a bed? There are several prototypes already. One is called Biolung, which is a soda-can sized device that uses ‘heart power’ to pump blood into its chamber where oxygen and carbon dioxide are exchanged across a plastic membrane. The oxygen-rich blood then returns to the body. The device is designed for implant and has no moving parts. Biolung has been tested in sheep, resulting in better survival rates and less lung injury than a conventional ventilator. It is expected to be tested in humans about 2 years from now.(source) This device isn’t designed for long term use, however. It’s only intended for a couple of months use by patients awaiting a lung transplant, but it is an important piece of technology due to its small size and ability to be implanted within the patient.
Another team is working on a years-long solution for mechanical device lung replacement. They’ve been working on this device for the past 20 years and have recently received a four-year, $2.4 million grant from the National Institutes of Health (NIH) to support research and development for the artificial lung. They say that such devices could be in use within the next 5 – 10 years.(source) The ‘downside’, if there can be one in a situation where your life depends on such a device, is that while it allows for certain mobility and use from home (not being hospitalized), this kind of device still has to be closely monitored by doctors and is still unable to support the mobility one has with biological lungs.(video)
AmbuLung is designed with all of these flaws in mind and the team behind it want to create a fully functional lung that allows normal mobility for patients over long-term use. They started the project in 2012, and animal trials should be concluded by June of this year. If all goes well, human trials will begin shortly after that. However, they’re not just using mechanical parts for this. To achieve this performance on such a small implantable scale, they also employ living cells within a design that is ‘mechanically and mathematically’ driven for optimizing the function of a new kind of device that, they say, may completely revolutionize artificial lung functionality.
The heart is the organ that pumps blood throughout our body, providing the total organism with oxygen and nutrients, while also assisting with the removal of metabolic wastes – substances left over from excretory processes which cannot be used by the organism (they are surplus or have lethal effect), and must therefore be excreted. This includes nitrogen compounds, excess water, CO2, phosphates, sulfates, etc.).
As with any other organ, the heart comes with a predisposition for harmful mutations. When genetic ‘errors’ occur, a human can be born with a non-standard heart structure; one that can result in either the death of the human or a variety of issues that the human must deal with for the rest of her/his life. Environmental factors, such as various diseases or certain drugs that the mother has/takes, have been shown to correlate with numerous heart structure errors. Even with a good heart, multiple issues can later arise with this organ. These issues are so numerous and impactful that the number one cause of death in the world is heart failure. It kills more than 17.3 million people every year.
Lucky for us, there are several artificial hearts out there that have already proven to not only completely replace the heart’s functions for a particular period of time, but there have been continuous steady improvements in artificial heart designs, providing better results over increasingly shorter periods of time.
Over the past 45 years, around 1,400 artificial hearts of 13 different designs have been implanted in heart failure patients. By far, the most used model is SynCardia, with over 96% of the total models used. Artificial hearts are mainly designed to be used as a temporary alternative until a ‘real’ heart becomes available for transplantation. The longest period that anyone has lived with an artificial heart was four years. One-third of those who currently use SynCardia have had it for more than a year. There are people with artificial hearts who enjoy boxing, hiking, and other sports; living a relatively normal life, but often a more active one than those with a real heart.(source)
A new type of artificial heart has been specifically engineered for long-term use (5 – 10 years or more) or, given enough improvements, perhaps even permanent replacement. BiVACOR is a small artificial heart designed to completely replace all biological heart functions. Since it’s as small as a fist, it can also be used in children. It has a single moving part and relies on magnetic levitation for precision, avoiding mechanical wear over time. Due to its simplicity, it is much less prone to malfunctions. BiVACOR was developed by a team of doctors and engineers and, so far, has been successfully tested on sheep and cows. They are now raising money toward improvements and future clinical trials on humans. The device could be ready for humans in 3 – 5 years.(source)(source)
BiVACOR and SynCardia both require the recipient to carry a battery pack that is currently about of the size of a toaster, but it pretty much provides them with all of the freedom of movement that a normal heart does.
SMALLER AND ‘DISPOSABLE’ ORGANS
As you can see, nearly all the main organs can be substituted with mechanical alternatives. However, there are still parts like the reproductive system, skin, arterial and venous systems, and other smaller items that are not yet replaceable by non-biological mechanical devices. That may be due to there being much less need for it, since these are not normally life-threatening parts or because there are already plenty of treatments, cures, or other biological enhancements available for those parts.
To be fair, there are artificial valves, artificial veins for use in bypass situations, and other small ‘plumbing’ fixes with other materials and small mechanisms, but I do not see the advantage in trying to list all of them here, as there are so many types of procedures and alternatives.
MOUTH AND NOSE
Is there a way to replace the mouth with a mechanical one? One that can chew, talk, swallow? The mouth is more than that, though, as it communicates with the nose, it has a tongue, produces saliva, and is all about muscles, jaws and air flow. It may be completely ‘unreasonable’ to think of the mouth as a separate part of the body that could be fully replaced with a mechanical or a biological alternative, but as you saw above, parts of the cranium can already be printed using various non-biological materials and implanted, while artificial teeth have existed for many decades now.
The trachea and esophagus, crucial for breathing and swallowing food and liquid, along with other small parts of the throat, are already in development for biological alternatives,. and we will talk about those in a separated article about bio-engineering. However, there are mechanical alternatives for some of the functions of the larynx, a crucial part of the throat involved in breathing, sound production, and protecting the trachea against food aspiration. In patients with larynx cancer, the entire larynx can be removed and, with the help of a device implanted in their throat, the person’s ability to speak can be restored. You see, when the larynx is removed, the vocal cords (voice box) are also removed with it. We talk by vibrating our vocal cords while exhaling air through them. The resulting sound is then fine-tuned by tongue, lip and jaw movements, resulting in sound vibrations that we interpret as ‘speech’.
This voice restoration device is basically a vibrating piece of silicon that replaces the voice box There are a few alternatives out there for vocal cord replacement, as showcased in these 3 videos – https://www.youtube.com/playlist?list=PLGW2heHH7L3Nvxd3L0npTDNfYAB6kMghF
Mechanical alternatives for the nose and tongue, organs that provide our smell and taste sensors, are being developed, but as a combination of biological and mechanical parts. In addition, they are not being designed to replace biological human noses or tongues, but rather for other ‘bio-sensor’ applications. There are already various treatments and biological solutions for restoring the loss of these senses, while these device designs are far more sensitive and better suited to applications other than human body implementation, which may never be done due to better bio-engineering alternatives for enhancing one’s senses.
Although external hearing aids (sound amplifiers) have been available for decades, there are newer devices called ‘cochlear implants’ that can actually ‘restore’ hearing to a certain degree, even in some completely deaf people. What this means is that, even if the internal ear has become damaged or nonfunctional, hearing can still be revived by implanting this digital device, which then communicates directly with the auditory nerve, the only biological component that it needs to be intact. It converts sound from outside to a digital format, and then transforms this digital data into specific stimulations to the auditory nerve which we humans interpret as hearing.
There are a variety of cochlear implant devices available, allowing people renewed access to medium to higher frequency sounds.(source)
EYES AND THE BRAIN
Perhaps the sense we rely on most is sight. When sight goes dark, it completely changes the lifestyle of that human being. Is it possible to replace our eyes with mechanical ones?
The challenge with replacing such a complex organ with a mechanical device is huge. I want to try to fully explain why, or else you may not fully appreciate the challenges of developing a device for vision or, more interestingly, alternatives for such a device that may instead rely on sound or taste.
Color and interpretation.
There are 3 types of biological receptors within your eye that are suited to detecting only 3 particular light wavelengths: red, blue and green. That comprises all of the light wavelengths we humans can directly detect – no more, no less – only 3! So how is it that we can see so many colors? Well, colors don’t actually ‘exist’, per se. Color is to light wavelengths what sound is to vibrations.
Sound: Vibrations from a source can travel through a medium, such as air or water, and can be ‘felt’ by someone or something. When someone vibrates their vocal cords, through air, and the vibrations reach our ears, we culturally interpret those vibrations as certain sounds (we might describe it as speech, music, rhymes, pleasant or not, etc.). But those same vibrations, from the same object and through the same medium, can be interpreted in other ways that you may never have considered before. One example of this is schlieren imaging. This method allows for auditory vibrations to be visualized with photons, similar to how we see light wavelengths. Vibration waves are not ‘heard’, but instead ‘visualised’. If one claps his hands, you will hear the clap, but someone else can visualise it with a schlieren device. Same event, same vibrations, different sensors – different interpretations.
Color: The same thing goes for how we see. First, check out this short, animated video, because I ‘see’ no way to explain this further without its help. 😉 – https://www.youtube.com/watch?v=l8_fZPHasdo
So, colors are human concepts/words to describe how we humans perceive different light wavelengths, because wavelengths of light can be ‘sensed’ in many different ways, with many different sensors/senses and devices. Example: here’s a photo. You and I see a ‘green’ landfill, but there is at least one human who sees in grey and hears this. There is no green for him.
Why? Because some of his biological sensors are different and he can’t interpret light wavelengths as color. Instead, he has a chip implanted in the back of his head with a digital sensor that converts light waves into sounds that he can hear. He ‘hears’ light waves as you ‘see’ them. Again, same photo, same light waves, different sensors – different interpretations. You interpret them as green, while he hears that sound.
He cannot understand what you mean by color. For him, the way one dresses ‘sounds’, not appears. Watch this TED video with him explaining all this – http://www.ted.com/talks/neil_harbisson_i_listen_to_color?language=en#t-546948
An Android app has been developed to allow you to experience, in a way, what this guy experiences when he ‘sees’ the world. The app uses your phone’s camera, converting the ‘colors’ it sees into sounds.
In this ‘sense’, you cannot explain to a blind person what color is, any more than explaining to a deaf person what music is, or any more than trying to understand what it’s like to feel the magnetic field of the earth for us, the ‘normal’ ones. You can draw the planet’s magnetic field to represent it as a visual map, but that’s like drawing sound waves for a deaf person and expecting them to understand how those soundwaves ‘feel’, or asking a deaf person to look at sheet music and understand the song as you hear it. So don’t be fooled into thinking that staring at a map of Earth’s magnetic field will help you understand how the field ‘feels’ to a bird that readily detects it.
We may never be able to help blind people ‘see’ the world as we do, because we all ‘see’ the world in different ways, while being blind for a long period of time and then suddenly detecting light waves would produce a different kind of interpretation for the brain. This applies similarly to the sense of hearing or taste/smell, as well, since a life-long deaf person who gains the hearing sense will not understand language by its sounds. He/she will not be able to talk on the phone right away, because he/she first needs to learn how to associate these noises that we are so familiar with, the spoken language, with the sign language and lip reading that they were accustomed to before.
So, to create a replica of the eye, you first must understand that the brain is doing most of the work when it comes to seeing. Once you do, you can invent devices that ‘see’ via sound or other means, as I will exemplify.
To replicate what the eye does.
Sensing lightwaves: Different parts of the eye can become damaged, non-functional, so different methods are needed for restoring ‘sight’. Imagine the mechanism of sight as a complex set of sensors and wires, each having its own function within the system. If one of these wires or sensors stops working, there are mechanical solutions for replacing at least some of their functionality to make the system work again. As an example, if the light sensors inside your eye no longer work, or are missing, but the entire system from them to the brain works, then the challenge would be to replace these defective biological sensors with a device that simulates their functionality by connecting the light from outside with the rest of your biological system.
One way this is currently done is through a small video camera that ‘sees’ the world, and transmits wireless signals to a small chip that replaces the light biological sensors. The video camera basically communicates with the electronical device implanted inside the eye, which then activates the rest of the biological system for vision. There are limitations to this approach, in that one basically ‘sees’ variations of light and dark. It’s not as vivid as ‘normal’ eyes see, and the person will need to learn how to decode them to be able to use this new ‘sight sense’.
This type of device worked in two-thirds of the blind patients that participated in clinical trials, and some of the patients who could finally see were even able to read letters.(source)
There are more examples of replacing various parts of the visual system, and you can read about those in more detail here and here. All of them produce, at most, a grey pixelated image, providing a system for formerly blind humans to distinguish between dark and light, with nuances in between. It’s not close to how biological eyes work, but is still quite remarkable, considering how complex our vision sense is.
But what if you bypass the entire sight system and connect devices directly to the brain? Well, this can be done, too. New technologies can connect a video camera directly to ‘electronical devices’ implanted in the brain’s visual cortex, enabling people to ‘see’ without any part of the biological system for sight. Clinical trials for this technology are expected to begin in a year or so.(source 1, 2)
All of these lightwave interpreting technologies are rather similar, in the sense that they collect light waves and convert them into signals that the brain interprets as light and dark regions, that can then be learned to be differentiated into separated forms and shapes.
You can even ‘see’ with your tongue, highlighting how ‘seeing’ is actually a process that the brain creates while being stimulated by other organs, like the tongue in this case. With this technology, a camera detects lightwaves and transforms them into an electrical pattern that is sensed by the tongue through a device that you need to keep inside your mouth. Although this device does not connect with the ‘visual’ part of your brain, it allows you to convert lightwaves into patterns that you can feel, so you are basically ‘seeing’ with your tongue.(source)
Similarly, blind people can ‘see’ with sound, not like the guy who can differentiate colors with sound, but in a more complex way, allowing blind people to interpret lightwaves via different sound types. The way the sound is constructed, from tone to duration, creates a sort of alphabet and a ‘visual’ description of the world. This sound alphabet is then used to convert what a video camera sees into sounds that can be perceived and understood by the blind. The process is complex and extremely interesting, as it was shown how the people using this technology had the ‘visual’ part of their brains activated when they imagined the scene in front of them. The technology works so well that blind people can even distinguish facial emotions, as seen in this TED presentation – https://www.youtube.com/watch?v=jVBp2nDmg7E
So, the brain may be more of a ‘task’ organ than a sensing one, and the task of ‘seeing’ is basically interpreting, in a particular way, inputs from different organs, such as the tongue, ears, or a direct connection of electronic sensors to the brain.
When we go about attempts to restore ‘vision’ through mechanical devices, we must understand why this is such a complex task and why there might be other alternatives for ‘seeing’.
Many motor and sensory ‘achievements’ of the brain can already be fine tuned or restored, as we have seen how the brain can ‘see’ by being connected directly to an electronic device that bypasses biological stimulation. A motor function example could be Parkinson disease, in which people experience involuntary movements that even make it difficult to walk. When implanted, thin pieces of metal that release a tiny amount of energy into the brain can basically ‘get rid of’ Parkinson’s specific involuntary movements, as showcased in this short documentary – https://www.youtube.com/watch?v=zCwhBsdHIV0
There are many brain implant devices aimed at restoring normal body/brain functions, as you can read in more detail on Wikipedia, but all of them are either sensory or motor-related. However, there are other brain functions, like the encoding of memory, that can be restored or repaired with the help of electronic devices. This is a new field of prostheses where the focus is on the brain’s cognitive functions (basically thinking) with the aim of replacing damaged neurons with electrical devices that can perform some of their tasks. There are only animal trials, so far, for the technologies that I am going to highlight, but they are worth mentioning as this may open completely new doors as to how we can ‘fix’ the brain, or even enhance its functions.
In 1953, a patient by the name of Henry Molaison underwent a surgical procedure to alleviate epileptic seizures. The procedure partially destroyed the part of his brain that we call “hippocampus”. The result was reduced epileptic seizures, but something unexpected also happened: Henry could no longer form long-term memories. As an interesting fact, almost all brain functions were discovered by similar situations, where people with a damaged brain exhibited different symptoms or were impaired in different ways. I recommend this BBC documentary that looks at the history of such ‘random’ discoveries.
Thus, the Henry Molaiso’s life was basically destroyed by the surgery, while it helped doctors better understand what that part of the brain does.
We now know that the hippocampus is the first area of the brain that is affected in people with Alzheimer’s disease, which makes people unable to form or retain long-term memories, among other impairments.
The hippocampus is basically a bunch of neurons that, to simplify it a lot, receive and transmit electronic signals from one part of the brain to another. A team of scientists analyzed these signals for years to develop computational models that can understand and replicate what outputs the hippocampus sends out for a particular input. Basically, if this series of letters and numbers (34vfmf843) goes into the hippocampus, then this series (99800uuioo) is the output, which the hippocampus transmits to other parts of the brain. In that sense, they understood how to decrypt and encrypt these signals so that, in theory, they could build a tiny device that can take inputs and properly output them further into the brain’s system, replacing what the parts of the hippocampus once did.
They started to experiment with living neurons, and it worked. The tiny devices were able to replicate parts of the hippocampus. They then went further and tested it in mice. They trained the mice to press a lever for a reward, in a way that the hippocampus was actively involved in performing the task. They recorded the hippocampus activity and the signals it receives and transmits. They then injected a drug into the mice to impair some of their hippocampal function and, upon re-testing, observed that the mice performed at only 50% of their former accuracy, which is as good as random. However, when they implanted these tiny devices into the mice brains to simulate their own hippocampus functions while on the drug, the mice performed almost as well as they had before receiving the drug. If you have the time, you can read the entire study here.
They repeated the study with monkeys, this time for the prefrontal cortex area of the brain, and impaired short memory functions in this region to then replace that functionality with these tiny computational devices and observe the same results as in the mice. The entire study can be read here.
Although this has not been tested on humans yet, clinical trials on humans are expected to begin soon. This approach is very promising for dealing with diseases like Alzheimer’s and other memory-related diseases, as well as for providing significant insight on how some of the brain’s functions work. We may eventually learn how to replace many other damaged brain functions with mechanical devices. How far will this go, I have no idea, but I suppose no one does.
By replacing parts of the human body with ‘mechanical’ and/or electronic devices, we can not only significantly improve the functionality of numerous human parts, but also reduce immense pressures on current organ transplant systems where, instead of relying on ‘borrowing’ parts from other people (mostly dead ones), which can be rejected by the recipient’s body, we are becoming better able to substitute them with mechanical alternatives, thus moving closer to satisfying the huge demand for replacement parts by people suffering without them.
One very important thing to mention is that, even while these solutions exist and are readily available, many people are still allowed to die within today’s monetary system, just because they cannot afford them. It still requires a whole lot of silly ‘pieces of paper’ to have your life saved.
I wonder how overall development of these mechanical alternatives for body parts would increase in a world where research and development is no longer ‘impaired’ by money and where the primary drive for people evolves into the well-being of humans and the environment, as advocated by The Venus Project.