Core body temperatures are obtained from ingestible and, of course, disposable, Jonah core temperature sensors, which are contained in a capsule about the size of a multi-vitamin. Jonah only weighs 1.6 grams. Once activated and swallowed, transmission begins immediately. Data are transmitted telemetrically to the VitalSense Monitor, which can be worn in a waist pack or slipped into a pocket. The mean transit time for the capsules is between 2,0 and 1,5 days.
Dermal temperatures are transmitted from waterproof, hypo-allergenic patches. Transmission range is approximately 1 meter for the ingestible sensor and 2 meters for the patches. The patented redundant transmission scheme for the sensors significantly decreases the number of lost data points. Accuracy is about 0,1°C with 0,01°C resolution.
In the normal mode, each VitalSense monitor can track and record data from up to 10 sensors that have been associated with the monitor, while rejecting signals from other sensors that may be within range. When it is in Medic Mode the monitor will detect and record signals from any VitalSense sensor that is within reception range.
VitalSense was designed at the request of, and in partnership with, the United States Army Research Institute of Environmental Medicine to support the US Army's Warfighter Physiological Status Monitoring Programme, which emphasizes "wear and forget" technology. As a part of this programme, VitalSense was initially used to monitor United States Army Rangers. On the battlefield or in the air, under extreme hot or cold temperatures, VitalSense delivers real time critical temperature data to improve the health and safety of the troops.
VitalSense proved to be a real lifesaver in a recent study of wildland firefighters in Montana. The study was designed to evaluate heat stress in high intensity work environments. Canadian coaches used VitalSense to evaluate the physiological status of Canadian triathletes training for all three legs - swimming, biking and running - of their event in the 2004 summer Olympics. In another athletic related study, Nike is using VitalSense to test heat dissipation in clothing.
Since receiving 510K clearance from the FDA on April 22, 2004 VitalSense has been incorporated into a number of on-going clinical studies. Those in early stages of design and testing include menopausal hot flash monitoring, ovulation detection, and sepsis detection in hospitals. Health care implications for the latter are far reaching as there are approximately 700.000 cases of sepsis each year, 25 percent of which result in mortalities.
Hospitals monitor core body temperature, heart rate and other vital signs to detect the onset of sepsis. Early detection of sepsis increases the likelihood of successful treatment, and VitalSense will enable the medical staff to pick up critical changes in those parameters earlier than they would with normal, manual monitoring. In addition, Mini Mitter is exploring telemedicine options for the VitalSense system.