Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Programmable Blood.
One pervasive system that has already been the subject of a comprehensive conceptual 
redesign based on reverse engineering is our blood. I mentioned earlier Rob Freitas's nanotechnology-based designs to 
replace our red blood cells, platelets, and white blood cells.
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Like most of our biological systems our red blood cells 
perform their oxygenating function very inefficiently, so Freitas has redesigned them for optimal performance. 
Because his respirocytes (robotic red blood cells) would enable one to go hours without oxygen,
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it will be interesting 
to see how this development is dealt with in athletic contests. Presumably the use of respirocytes and similar systems 
will be prohibited in events like the Olympics, but then we will face the prospect of teenagers (whose bloodstreams 
will likely contain respirocyte-enriched blood) routinely outperforming Olympic athletes. Although prototypes are still 
one to two decades in the future, their physical and chemical requirements have been worked out in impressive detail. 
Analyses show that Freitas's designs would be hundreds or thousands of times more capable of storing and 
transporting oxygen than our biological blood. 
Freitas also envisions micron-size artificial platelets that could achieve homeostasis (bleeding control) up to one 
thousand times faster than biological platelets do,
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as well as nanorobotic "microbivores" (white-blood-cell 
replacements) that will download software to destroy specific infections hundreds of times faster than antibiotics and 
will be effective against all bacterial, viral, and fungal infections, as well as cancer, with no limitations of drug 
resistance.
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Have a Heart, or Not.
The next organ on our list for enhancement is the heart, which, while an intricate and 
impressive machine, has a number of severe problems. It is subject to a myriad of failure modes and represents a 
fundamental weakness in our potential longevity. The heart usually breaks down long before the rest of the body, often 
very prematurely. 
Although artificial hearts are beginning to be feasible replacements, a more effective approach will be to get rid of 
the heart altogether. Among Freitas's designs are nanorobotic blood cells that provide their own mobility. If the blood 
moves autonomously, the engineering issues of the extreme pressures required for centralized pumping can be 
eliminated. As we perfect ways to transfer nanobots to and from the blood supply, we will eventually be able to 
continuously replace them. Freitas has also published a design for a complex five-hundred-trillion-nanorobot system, 
called a "vasculoid," that replaces the entire human bloodstream with nonfluid-based delivery of essential nutrients and 
cells.
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Energy for the body will also be provided by microscopic fuel cells, using either hydrogen or the body's own fuel, 
ATP. As I described in the last chapter, substantial progress has been made recently with both MEMS-scale and 
nanoscale fuel cells, including some that use the body's own glucose and ATP energy sources.
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With the respirocytes providing greatly improved oxygenation, we will be able to eliminate the lungs by using 
nanobots to provide oxygen and remove carbon dioxide. As with other systems, we will go through intermediate stages 
where these technologies simply augment our natural processes, so we can have the best of both worlds. Eventually, 
though, there will be no reason to continue with the complications of actual breathing and the burdensome requirement 
of breathable air everywhere we go. If we find breathing itself pleasurable, we can develop virtual ways of having this 
sensual experience. 
In time we also won't need the various organs that produce chemicals, hormones, and enzymes that flow into the 
blood and other metabolic pathways. We can now synthesize bio-identical versions of many of these substances, and 
within one to two decades we will be able to routinely create the vast majority of biochemically relevant substances. 
We are already creating artificial hormone organs. For example, the Lawrence Livermore National Laboratory and 
California-based Medtronic MiniMed are developing an artificial pancreas to be implanted under the skin. It will 

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monitor blood glucose levels and release precise amounts of insulin, using a computer program to function like our 
biological pancreatic islet cells.
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In human body version 2.0 hormones and related substances (to the extent that we still need them) will be 
delivered via nanobots, controlled by intelligent biofeedback systems to maintain and balance required levels. Since 
we will be eliminating most of our biological organs, many of these substances may no longer be needed and will be 
replaced by other resources required by the nanorobotic systems.