A low-cost, "wireless", portable, physiological monitoring system to collect physiological measures during operational team tasks

Functional teams exhibit dynamic patters of behavior in the pursuit of their collective goals. In general, the outcome of these patterns of behavior can be subjectively ranked or scored based on a number of performance criteria; and for most applications this remains the preferred method of evaluating team performance and efficacy. In the military domain, almost all operational tasks are team-based. For this reason alone, it is meritorious to explore the potential for objective metrics to quantify the effectiveness of team behaviors. Generating objective measures would arguably enable more accurate evaluation of the team's capabilities, enhance predictability of real-world performance, and, within the training domain, improve the instructor's ability to identify areas in need of improvement (as well as plan the optimal course of instructional intervention). Because of this potential value, numerous efforts have been made to objectively measure team performance along behavioral or cognitive dimensions. However, most such efforts have failed owing to the inherent ambiguity, diversity, and complexity of team-based tasks. Those that have succeeded generally fall within domains of team tasks where team members are restricted to limited, rule-based courses of action (such as airline pilot / co-pilot teams). Physiological measures are an area receiving more recent attention as a possible source for objective team-based metrics. Deriving team-based metrics from physiological measures has several potential benefits. First, these measures are inherently quantitative. Second, they can be collected in real-time, contributing to continuous evaluation of team performance. Third, they provide equivalent information from each and every member on the team. For example, one can collect heart rates, respiration rates, and electroencephalographic data from everyone on the team. Work in this area has, however, been limited primarily due to three major issues. First, as described above assessing team performance is made difficult by the tasks' inherent ambiguity, diversity, and complexity. Second, thus far basic correlations between team performance and physiological measures from members of the team have not been firmly established. Third, there is a lack of portable, robust, and affordable technologies with which to collect physiological data from all members of a team (which itself limits progress on the second major issues). To ameliorate the third of these major issues and thereby create opportunities to address the second, we describe here a low-cost "wireless" PDA-based, 16 channel physiological monitoring system. This system includes 16 single-ended EEG channels or 8 differential channels capable of supporting user specified combinations of such measures as ECG, respiration, EGG, and EOG. Except for the construction of a low-cost amplifier for EEG signals, this system is assembled entirely from commercially available technologies, resulting in a total price below $5,000 (U.S.) per unit. Our devices are based on an iPAQ h5550 Pocket PC equipped with a dual-slot PC card expansion pack (Hewlett-Packard). We use one 16 bit PCMCIA PC cards (model 6062E, National Instruments), and run the device using software written in the LabView programming environment (National Instruments). All physiological data can be stored locally and/or downloaded in real-time via 802.11b wireless communication protocols. Optional future configurations may include expansion to 32 EEG channels. Future design modifications will also include the addition of user controlled electronic switching between single-ended and differential recording modes.