The Methuselarity
A recent issue of Studies in Health Technology and Informatics includes a number of interesting papers on longevity science, or that relate to developing the tools and research community to enable engineered longevity. You might start with an essay by Aubrey de Grey, in which he coins a new term for an aspect of what has in the past been called actuarial escape velocity - the point at which steadily increasing life expectancy rises by more than one year with each passing year:
Aging, being a composite of innumerable types of molecular and cellular decay, will be defeated incrementally. I have for some time predicted that this succession of advances will feature a threshold, which I here christen the 'Methuselarity,' following which there will actually be a progressive decline in the rate of improvement in our anti-aging technology that is required to prevent a rise in our risk of death from age-related causes as we become chronologically older. Various commentators have observed the similarity of this prediction to that made by Good, Vinge, Kurzweil and others concerning technology in general (and, in particular, computer technology), which they have termed the 'singularity.' In this essay I compare and contrast these two concepts.
At present, life expectancy is increasing at about one year for every five years that pass - only 20% of what is needed to keep our expected remaining years of life increasing at the same speed with which we age. That said, it is worth remembering that life expectancy is a statistical construct based on past data - it is a helpful measure of progress, but not necessarily an indication of where we are now. I suspect it lags present medical advances, for example, because their effects on mortality rate might not show up for a decade or more.
In any case, you'll want to take a look at some of the other papers that pertain to the future development path of medical nanorobotics, as laid out by Robert Freitas:
Welcome to the Future of Medicine
This chapter describes the negative consequences of medical technology development and commercialization that is too slow, and makes the case for an immediate large scale investment in medical nanorobots to save 52 million lives a year. It also explains the essence of nanotechnology, its life-saving applications, the engineering challenges, and the possibility of 1000-fold improvement over our current human biological abilities. Every decade that we delay development and commercialization of medical nanorobotics, half a billion people perish who could have been saved.
Maintaining Your Health from Within: Controls for Nanorobot Swarms in Fluids
Molecular electronics and nanoscale chemical sensors could enable the construction of microscopic sensors capable of detecting patterns of chemicals as they flow passively in a fluid. Information from a large number of such devices allow the estimation of properties of tiny chemical sources in a macroscopic tissue volume. Although such devices cannot yet be fabricated, estimates of plausible device capabilities in small blood vessels allow the evaluation of their performance for typical chemicals released by tissues in response to localized injury or infection. The devices can readily discriminate a single cell-sized chemical source from the background chemical concentration, providing high resolution sensing in both time and space. ... These microscopic, programmable devices could also aid treatments, such as precisely targeting drug delivery and improving speed and accuracy of microsurgery.
This paper reports on the most important recent technological event and its significance to the human race: chromallocyte designed by Robert Freitas - a nanorobot that would be capable of replacing chromosomes on a cell by cell basis throughout the body in vivo.The significance of chromallocyte comes from its ability to painlessly reverse the effects of genetic disease and other accumulated damage to our genes thus preventing aging. It could reduce suffering, save lives and enhance human potential. By analogy to the successful effort to put man on the moon, we should aim at chromallocyte landing on the liver by 2039 which would commemorate 70th anniversary of man landing on the Moon. The same strategic planning principle could be applied. We should have a dream with a deadline of 2039.
Note that there is still some debate over the role of nuclear DNA damage in aging - is it important on the time scale of present human life span or not? The consensus appears to be that it is important, but there are those who argue the opposite viewpoint.
Aubrey D.N.J. de Grey (2009). The Singularity and the Methuselarity: Similarities and Differences Studies in Health Technology and Informatics, 149 : 10.3233/978-1-60750-050-6-195