Diagnostic Solutions to Global Health Challenges

Two core deficiencies in existing biomedical infrastructure and technologies motivates our work with NBC systems. First among these unmet clinical needs, is a lack of access to diagnostic testing, and hence results, to dictate the proper course of treatment for ill individuals, such as HIV positive populations. The majority of the world’s population lives in the developing world where there is little, if any, regular access to a healthcare provider, much less a well-equipped clinical laboratory. In these environments, pharmacologic therapeutic interventions may exist due to humanitarian efforts, but a lack of diagnostic equipment prevents these drugs from being appropriately dispensed. In these resource-scarce settings, rapid and cheap diagnostic and prognostic tests create the ability to identify individuals who may be best helped by the available therapeutics.

Alternatively, in more developed regions, the most prominent causes of death change to heart disease and cancer as life expectancy is increased. Here, the unmet clinical need is no longer accessibility, but rather diagnostics that identify the disease in its early stages with sensitivity and selectivity. Similar to resource-scare settings, tests that are inexpensive and rapid remain important, but these diagnostic schemes must also meet additional requirements. First, they must monitor many different analytes concurrently—this so called “disease fingerprinting” allows clinicians to make much more timely and accurate diagnoses.

A second requirement is portable tests that can be used in the doctor’s office or ambulance, that is, the point-of-care. These decrease the time from diagnosis to therapy which has the potential to improve overall patient outcomes. These considerations to making rapid, reliable, rugged, multiplexed, portable, and inexpensive diagnostic aids command quality results. The easily remembered acronym COMMAND QUALS summarizes the most commonly cited attributes of coherently designed sensors and serve as design parameters when designing POC diagnostic systems. All integrated approaches for use in both developed and resource-scare settings seek to create devices and assay platforms that are:

• Cheap - keeping costs low increases access to diagnostic testing;
• Obvious - simple and easy user-interfaces allows use by unskilled operators;
• Miniaturized - devices with reduced footprint are amenable to POC use;
• Multiplexed - the ability to quantitate a number of different analytes concurrently increases the ability to effectively make diagnoses;
• Automated - built-in sample processing, reagent handling, and data interpretation further promotes widespread access of diagnostic aides;
• Non-perishable - rugged designs survive difficult storage, shipping, and handling as well as extreme temperatures; eliminating the so-called ‘cold-chain’ also increases access to such systems; 1 year half-lives are desirable;
• Dependable - the design should have an extremely low rate of failure and be highly reproducible, similar to six sigma and GLP quality control designs;
• Quick - short turnaround time (TAT) gives information to physicians quickly which is especially important in emergency room environments;
• Unobtrusive - non-invasive diagnostic specimens and sampling procedures reduces patient testing antipathy, making regular screening events possible;
• Adaptable – modular devices have the ability to quantitate a variety of analytes (cells, proteins, nucleic acids, small molecules, ions);
• Limited - small reagent and sample volumes decrease costs and minimize requirements of biohazard waste disposal and environmental impact; and
• Self-contained - reagent and power integration makes for a smaller device footprint; a closed system prevents exposure to biohazard waste.