Design of portable microfluidic cytometry devices for rapid medical diagnostics in the field

Design of portable microfluidic-cytometry devices for measurements in the field (e.g. initial medical diagnostics and recommended actions for first responders and search and rescue teams) requires careful design in terms of power requirements and weight to allow for true portability. True portability with high-throughput microfluidic systems also requires sampling systems with minimal need for sheath hydrodynamic focusing both to avoid the need for large amounts of sheath fluid and to enable higher volumes of actual sample, rather than conventional sheath/sample combinations. Weight/power requirements dictate use of super-bright LEDs as light sources and very small silicon photomultiplier sensors, with tightly integrated electronics that can both be powered by small batteries or regenerative power sources such as solar. GPS-based positioning, and telecommunications (including possible satellite–based, if cellphone towers are not nearby) to export data to other medical facilities. Microfluidic-cytometry also requires judicious use of small sample volumes and appropriate statistical sampling to permit real-time (typically in less than 10-15 minutes) initial medical decisions, not just raw data, for first responders in the field who may need results which include on-board expert medical systems. The portable system should be robust for extreme environments and should be modular and flexible to allow for multiple applications and for plug-in repairs if subsystems should become damaged. For example, one or two drops of blood obtained by pin-prick should be able to provide statistically meaningful results for use in making real-time medical decisions without the need for blood fractionation, which is not realistic in the field.