Microsoft Word Kurzweil, Ray The Singularity Is Near doc

So What's Left?
Let's consider where we are, circa early 2030s. We've eliminated the heart, lungs, red and white 
blood cells, platelets, pancreas, thyroid and all the hormone-producing organs, kidneys, bladder, liver, lower 
esophagus, stomach, small intestines, large intestines, and bowel. What we have left at this point is the skeleton, skin, 
sex organs, sensory organs, mouth and upper esophagus, and brain. 
The skeleton is a stable structure, and we already have a reasonable understanding of how it works. We can now 
replace parts of it (for example, artificial hips and joints), although the procedure requires painful surgery, and our 
current technology for doing so has serious limitations. Interlinking nanobots will one day provide the ability to 
augment and ultimately replace the skeleton through a gradual and noninvasive process. The human skeleton version 
2.0 will be very strong, stable, and self-repairing. 
We will not notice the absence of many of our organs, such as the liver and pancreas, since we do not directly 
experience their operation. But the skin, which includes our primary and secondary sex organs, may prove to be an 
organ we will actually want to keep, or we may at least want to maintain its vital functions of communication and 
pleasure. However, we will ultimately be able to improve on the skin with new nanoengineered supple materials that 
will provide greater protection from physical and thermal environmental effects while enhancing our capacity for 
intimate communication. The same observation holds for the mouth and upper esophagus, which constitute the 
remaining aspects of the digestive system that we use to experience the act of eating. 
Redesigning the Human Brain.
As we discussed earlier, the process of reverse engineering and redesign will also 
encompass the most important system in our bodies: the brain. We already have implants based on "neuromorphic" 
modeling (reverse engineering of the human brain and nervous system) for a rapidly growing list of brain regions.
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Researchers at MIT and Harvard are developing neural implants to replace damaged retinas.
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Implants are available 
for Parkinson's patients that communicate directly with the ventral posterior nucleus and subthalmic nucleus regions of 
the brain to reverse the most devastating symptoms of this disease.
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An implant for people with cerebral palsy and 
multiple sclerosis communicates with the ventral lateral thalamus and has been effective in controlling tremors.
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"Rather than treat the brain like soup, adding chemicals that enhance or suppress certain neurotransmitters," says Rick 
Trosch, an American physician helping to pioneer these therapies, "we're now treating it like circuitry." 
A variety of techniques is also being developed to provide the communications bridge between the wet analog 
world of biological information processing and digital electronics. Researchers at Germany's Max Planck Institute 
have developed noninvasive devices that can communicate with neurons in both directions.
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They demonstrated their 
"neuron transistor" by controlling the movements of a living leech from a personal computer. Similar technology has 
been used to reconnect leech neurons and coax them to perform simple logical and arithmetic problems. 
Scientists are also experimenting with "quantum dots," tiny chips comprising crystals of photoconductive 
(reactive to light) semiconductor material that can be coated with peptides that bind to specific locations on neuron cell 
surfaces. These could allow researchers to use precise wavelengths of light to remotely activate specific neurons (for 
drug delivery, for example), replacing invasive external electrodes.
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Such developments also provide the promise of reconnecting broken neural pathways for people with nerve 
damage and spinal-cord injuries. It had long been thought that re-creating these pathways would be feasible only for 
recently injured patients, because nerves gradually deteriorate when unused. A recent discovery, however, shows the 
feasibility of a neuroprosthetic system for patients with long-standing spinal-cord injuries. Researchers at the 
University of Utah asked a group of long-term quadriplegic patients to move their limbs in a variety of ways and then 

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observed the response of their brains, using magnetic resonance imaging (MRI). Although the neural pathways to their 
limbs had been inactive for many years, the patterns of their brain activity when attempting to move their limbs was 
very close to those observed in nondisabled persons.
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We will also be able to place sensors in the brain of a paralyzed person that will be programmed to recognize the 
brain patterns associated with intended movements and then stimulate the appropriate sequence of muscle actions. For 
those patients whose muscles no longer function, there are already designs for "nanoelectromechanical" systems 
(NEMS) that can expand and contract to replace damaged muscles and that can be activated by either real or artificial 
nerves.