Properly realized, nanorobots will be able to treat a host of diseases and conditions. While their size means they can only carry very small payloads of medicine or equipment, many doctors and engineers believe the precise application of these tools will be more effective than more traditional methods. For example, a doctor might deliver a powerful antibiotic to a patient through a syringe to help his immune system. The antibiotic becomes diluted while it travels through the patient's bloodstream, causing only some of it makes it to the point of infection. However, a nanorobot -- or team of nanorobots -- could travel to the point of infection directly and deliver a small dose of medication. The patient would potentially suffer fewer side effects from the medication.
Several engineers, scientists and doctors believe that nanorobot applications are practically unlimited. Some of the most likely uses include:
- Treating arteriosclerosis: Arteriosclerosis refers to a condition where plaque builds along the walls of arteries. Nanorobots could conceivably treat the condition by cutting away the plaque, which would then enter the bloodstream.
Nanorobots may treat conditions like arteriosclerosis by physically chipping away the plaque along artery walls.
- Breaking up blood clots: Blood clots can cause complications ranging from muscle death to a stroke. Nanorobots could travel to a clot and break it up. This application is one of the most dangerous uses for nanorobots -- the robot must be able to remove the blockage without losing small pieces in the bloodstream, which could then travel elsewhere in the body and cause more problems. The robot must also be small enough so that it doesn't block the flow of blood itself.
- Fighting cancer: Doctors hope to use nanorobots to treat cancer patients. The robots could either attack tumors directly using lasers, microwaves or ultrasonic signals or they could be part of a chemotherapy treatment, delivering medication directly to the cancer site. Doctors believe that by delivering small but precise doses of medication to the patient, side effects will be minimized without a loss in the medication's effectiveness.
- Helping the body clot: One particular kind of nanorobot is the clottocyte, or artificial platelet. The clottocyte carries a small mesh net that dissolves into a sticky membrane upon contact with blood plasma. According to Robert A. Freitas, Jr., the man who designed the clottocyte, clotting could be up to 1,000 times faster than the body's natural clotting mechanism [source: Freitas]. Doctors could use clottocytes to treat hemophiliacs or patients with serious open wounds.
- Parasite Removal: Nanorobots could wage micro-war on bacteria and small parasitic organisms inside a patient. It might take several nanorobots working together to destroy all the parasites.
- Gout: Gout is a condition where the kidneys lose the ability to remove waste from the breakdown of fats from the bloodstream. This waste sometimes crystallizes at points near joints like the knees and ankles. People who suffer from gout experience intense pain at these joints. A nanorobot could break up the crystalline structures at the joints, providing relief from the symptoms, though it wouldn't be able to reverse the condition permanently.
- Breaking up kidney stones: Kidney stones can be intensely painful -- the larger the stone the more difficult it is to pass. Doctors break up large kidney stones using ultrasonic frequencies, but it's not always effective. A nanorobot could break up a kidney stones using a small laser.
Nanorobots might carry small ultrasonic signal generators to deliver frequencies directly to kidney stones.
- Cleaning wounds: Nanorobots could help remove debris from wounds, decreasing the likelihood of infection. They would be particularly useful in cases of puncture wounds, where it might be difficult to treat using more conventional methods.
In the next section, we'll see how nanorobots will navigate through the circulatory system.