Conway McLean, DPM

A famous television program from long ago portrayed a military man, repaired with all manner of artificial body parts after being badly injured in the line of duty. These high-tech replacement parts allowed him to perform extraordinary feats. The hardware implanted into his body apparently cost about 6 million dollars since that was the name of the show. Although that isn’t much money in today’s terms, it is easy to spend that on many implantable technologies. We are now capable of inserting all manner of replacement parts, sensors and monitors (and not those taken from some other human, aka organ donation).

Implantable technologies are here, and there are many permutations. The use of screws and metal plates to fix some broken bone is old news, an everyday occurrence. But what about the insertion of microchips into your hand, allowing you to pay for your coffee by waving your hand over the card reader, as people are able to do with their phone? Or perhaps you would like the computer chips that allow an electronic key to start a car implanted in your other hand. This is a real procedure, although not yet common, which has been performed and is available.

Relevant to any discussion on human implants is the topic of amputations. Statistically, most of the implantation of artificial or man-made body parts occurs due to this unfortunate event, be it a hand, leg, foot, etc. But all the studies, all the papers, treat lower extremity amputations very differently from upper. Trauma is the second leading cause of amputation, but only an eighth of the time as compared to amputation due to vascular disease, which is the most common. And this kind of amputation is almost always performed on the lower extremity, i.e. the leg, or foot, and mostly in the elderly. Another segment of this population is those who have lost a foot or leg due the complications of diabetes.

A result of this difference is upper extremity amputations are typically performed in younger people, involved in some dangerous activity. They are also commonly male, with many years ahead of them as wage-earners. Returning them to the work force and equipping them to support themselves, financially and literally, is important to society. The research has been extensive with exciting gains made in the design of new prosthetics, which are synthetic, man-made limbs.

Prosthetic designs have progressed dramatically, with many people choosing to move away from the older technologies. Although many of these are still in use, they are often much simpler and able to do far less. Some of the newest, most technologically advanced systems allow the owner to simply think about doing something, for example picking up a cup…..and they are able to do it. This is the most exciting frontier in prosthetics, the creation of a neural interface. This boils down to the ability of the brain to control an artificial limb. Although still highly experimental and hugely expensive, the technology is here.

The next major goal is to allow machines to convey, however imperfectly, information about what that arm encounters, directly to the brain. In simple terms, restoring sensation, like the touch of an artificial hand to a cup of hot tea giving the individual a feeling of warmth. This appears to be a monumental task, but does entice us with the chance to radically transform the lives of those needing these limbs.

These are surgical procedures, in which neural implants must be inserted into the brain. In essence, you are sticking a pile of nails into the brain, which is then, understandably, unhappy. These devices don’t last long since our bodies fight their presence. They last a few years. And performing a craniotomy every few years to put a fresh set in is no way optimal. A significant challenge is to create an implant that will last for forever, figuratively speaking.

Elon Musk has spent significant money and effort into developing his “Neuralink” which he hopes to begin implanting into humans soon. Thin wires are placed into the brain, the goal being to record and stimulate brain activity. The medical applications should be numerous, such as treating serious spinal-cord injuries and neurological disorders.

The Neuralink, like most of the other ‘Brain-Computer-Interface’ technologies, provides for this communication via the insertion of these electrodes into some specific area, an invasive procedure. The objective is to have a patient try to move their arm, or more accurately think about moving their arm, and have this thought activate some man-made device, specifically a mechanical arm picking up the patient’s coffee cup. We are now able to take signals from the appropriate part of the brain and infer what action the individual wanted to perform. The easier part is performing the action, closing the fingers upon the cup sufficiently without breaking it.

Although the Neuralink system is considered the best brain-sensing technology in development, it requires surgery, like most of the technologies being researched. The hope is that the thin, flexible wires employed by the Neuralink can adjust to the convoluted surface of the brain and cause less problems. Other groups are studying non-invasive methods of sensing specific brain signals. One is utilizing infrared light and ultrasonic waves to peer into the body.

Perhaps the most exciting but still highly theoretical concept is tissue engineering, whereby needed body parts are grown in a lab. This has been imagined in numerous movies, but is no longer the stuff of fiction. This is a real science, the growing of replacement organs in the lab to replace damaged or diseased tissue. With recent advances in genetics, and their manipulation, this seems achievable.

We have already become accustomed to wearable technology, the smart watches and Fitbits. The market for these devices shows no signs of abating, especially the health monitoring component. Implanted technology is the next logical step. The days of carrying your car keys literally “in” your hand are near.

It is the belief of many experts that human beings are now capable of improving their physical selves, of giving themselves an “upgrade” of sorts, through the incorporation of these advanced technologies. The day when we can grow a replacement liver or kidney may not be that far off. If research into genetic manipulation continues, the ability to create a new organ may no longer be the stuff of Hollywood science fiction. The cost of some this work, unimaginable, but the abilities of the six million dollar man may not be that far off.

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula. Dr. McLean’s practice, Superior Foot and Ankle Centers, has offices in Marquette and Escanaba, and now the Keweenaw following the recent addition of an office in L’Anse. McLean has lectured internationally, and written dozens of articles on wound care, surgery, and diabetic foot medicine. He is board certified in surgery, wound care, and lower extremity biomechanics.