Artificial body parts are here today, but they still have a long way to go before they can rival our original equipment. As the movie Repo Men reminds us, total body replacement is on the way, but in the meantime, scientists and technologists are taking small steps toward the development of a complete cyborg. Let's take a look at artificial organs you can use today, and what's in store for the future.
Heart
Today: It's only temporary. If you want a mechanical ticker now, don't get too attached to it because it's only temporary. Internal artificial hearts such as the AbioCor (pictured above) exist today, but because of the tendency to form stroke-inducing blood clots, they're limited to heart patients waiting around for organ transplants.
Tomorrow: The race is on for a permanently implantable artificial heart, and French transplant specialist Alain Carpentier says his model will be ready for clinical trials by 2011, and for actual use as an alternative to heart transplants in 2013. He already has a prototype, using electronic sensors and made of chemically treated animal tissues that he calls pseudo-skin.
Beyond: Smaller, smarter. Scientists are aiming for a miniaturized artificial heart controlled by minuscule processors that determine how quickly the heart needs to beat. It will be equipped with sensors that detect artery blockage and will notify its patient and the doctor of any impending malfunctions. Maybe it will even be able to do those notifications via Twitter.
Liver
Today: liver assist devices. Of the 16,000 people waiting for liver transplants, there are only about 6,500 transplantable livers available each year. Unlike the movie Repo Men, there are currently no implantable artificial livers, but researchers are developing ELAD, an Extracorporeal Liver Assist Device that resides outside the body. Mimicking a normal liver, it cleanses the blood of toxins and waste, and produces albumin and clotting factors. It's not all artificial, though, with the secret sauce inside being "immortalized human liver cells," interlaced with tiny tubes through which the patient's blood flows. The current technology offers a temporary replacement for the liver while a awaiting a donor.
Tomorrow: stem cell combo. Boston company HepaLife is working on a "bioartificial" liver using a proprietary line of liver stem cells. Once the patient's blood is separated into plasma and blood cells, a external bioreactor unit with those stem cells inside can reduce levels of toxic ammonia by 75% in less than a day.
Beyond: BioEngine's implantable hybrid system uses liver stem cells grown on a special three-dimensional framework of micro tubing running through the cells. The ultimate goal is to create a complete implantable liver replacement.
Hand
Today: off the hook. Today's artificial hands have come a long way from the days of Captain Hook. Using what's called myoelectric linking, the prosthetic limb picks up electrical impulses from remaining muscle fibers on the arm, transmitting those impulses to articulating fingers and a thumb. They're attached to the stub by suction, belts or cuffs, and some can be expensive, costing upwards of $35,000. More reasonably priced is the i-Limb, an $18,000 artificial hand with articulating fingers and thumb, each with its own motor.
Tomorrow: SmartHand is a bioadaptive hand that can actually feel. Its 40 sensors communicate back and forth directly with the brain using nerve endings in the arm. The hand sends its sensory input to the brain, and the brain sends instructions for movement to the hand. The result? It can pick up a plastic water bottle without crushing it, or pour a drink without spills.
Beyond: Direct route. Researchers are working on permanently implanting an artificial hand directly to the bone in the arm, a process called "osseointegration." That will eliminate much of the inconvenience and discomfort currently associated with artificial limbs. Further improving the experience will be smaller and more efficient batteries, and lifelike materials that will more closely resemble real skin, and be capable of more accurate communication between hand and brain.
Lungs
Today: a bulky box. About the closest you'll get to an artificial lung today is a clunky heart-lung machine next to your hospital bed. These ECMO (extracorporeal membrane oxygenation) machines are designed for temporary use, while a patient recovers from infections or trauma.
Tomorrow: the MC3 BioLung is a soda-can-shaped implantable device that uses the heart's pumping power to move blood through its filters. It's designed to work alongside a natural lung, exchanging oxygen from the air with carbon dioxide from the bloodstream. So far, it's been tried on sheep, where six of the eight animals on the BioLung machine survived for five days. Human trials are expected within the next couple of years.
Beyond: artificial heart/lung. Scientists are concentrating on a dual-function device that pumps blood and oxygenates it at the same time, similar to an internal heart/lung machine.
Eye
Today: no Geordi glasses yet. Nearsighted or farsighted? Wear glasses or contact lenses, or get some laser surgery. Missing an eye? Glass eyeballs have been around for centuries. There's no cyborg eye available yet, but there certainly is a lot of research going on.
Tomorrow: artificial retinas. The Argus II Retinal Prosthesis is deep into its research phase, and it works with a tiny camera, a video processor worn on the belt, and 60 electrodes implanted on the optic nerve. So far, all it creates is a murky image where only patterns of light and dark are visible. The experimental procedure costs $100,000 and might be covered by insurance. If it's not? Pay up, or look out for the Repo Men.
Beyond: bionic eyes. Work is now underway for special contact lenses that give you superpowers. Beyond that (I'm speculating here), as the camera/optic nerve link is perfected, resolution will be much sharper, way beyond the vision of a hawk. Infrared vision, panning and zooming, night vision and telescopic vision will be possible. The link between eye and brain could be also used for video viewing and hyper-realistic simulations. Maybe a small eye could be implanted in the back of the head, simulating the unique capabilities of my third grade teacher
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