FIGURE 6.1 Life expectancy: 2011 estimates by CIA World Factbook. SOURCE: CIA. 2011. World Factbook. Available at https://www.cia.gov/library/publications/the-world-factbook/rankorder/2102rank.xhtml.
which determined that germs are the underlying cause of most infectious diseases, leading to the development of effective antibiotic drugs.
The primary causes of death today (heart disease, cancer, diabetes, and neurodegenerative diseases) are diseases that are more prevalent at older ages. The success of modern medicine has therefore created a series of new challenges, requiring further innovation.
Many of these challenges are being met using optics and photonics instrumentation, which is providing scientific insights into the underlying molecular biology causing these diseases as well as quantitative new diagnostic instruments to help steer effective interventional therapies.
In low-income countries, infectious diseases, such as tuberculosis, malaria, and AIDS, remain leading causes of death. This is due in large part to the absence of low-cost diagnostic tests that can detect these diseases at an early stage when the infections can be more easily contained and cost-effective intervention strategies can be employed. (See Figure 6.1.)
A patient entering the emergency room (ER) with chest pains or a severe headache almost invariably receives a high-resolution, three-dimensional scan using CT or magnetic resonance imaging (MRI) as an initial diagnostic screening, which can assist in the diagnosis of a heart attack, pulmonary embolism, or stroke. CT and MRI both use photons with wavelengths for which the human body is very