NIH Researchers Track Disease with Pocket PCs

In December 2001, NASA and NIH scientists gathered in Monterey, California, to plan research projects on the spatial and temporal patterns of infectious disease risk. This research was to be based on modeling the interactions among environmental, epidemiological, entomological, and socio-economic parameters for a variety of diseases in specific locations. It would use NASA-developed technologies, but would not be limited to remotely-sensed data or imagery.

As a result of this meeting, field investigators tested mobile PCs with Global Positioning System (GPS) receivers, Geographic Information Systems (GIS), and digital imaging hardware and software for the collection of site-specific health and environmental field data. The goal was to identify the NIH scientists’ hardware, software, and imagery needs and determine how NASA technologies could fill them.

Mobile platforms

Field and laboratory data collection, whether environmental or health-related, is a critical element in epidemiological research. Mobile computing platforms such as Pocket, Handheld, or tablet PCs are rapidly gaining in popularity for recording and analyzing all types of field and laboratory data. Mobile PCs are currently capable of supporting more than just PDA tasks, as they also run software that performs word processing, statistical analysis, and communications functions. In addition to these capabilities, they support basic GIS software and support GPS receivers and digital cameras.

Pilot program

Four HP Jornada 567s were distributed to the pilot investigators in January–May 2002. The initial systems were based on the HP Jornada 567 because it was the only Pocket PC at that time with an integrated CF slot, an outdoor-viewable display, and a digital camera (available on a CF card). Another important feature of the Jornada was the small secondary battery, which can sustain the unit for a short period of time. This backup battery allows the user to carry multiple main batteries and switch them as they become depleted without jeopardizing the data in RAM.

The initial systems consisted of an HP Jornada 567, a Magellan 315 GPS receiver, serial cables to attach the GPS receiver to the Jornada, an HP 640 x 480-pixel CF digital camera, and ArcPad 6.0 software, from ESRI, Inc. (http://www.esri.com/software/arcpad).

The biggest user complaint was related to power capacity and the potential for (or actual) data loss. The main battery did not have enough power to support the Pocket PC for a full day of data collection. The users also lost data when they allowed the battery to completely drain. The complaints about the cabled GPS receiver led to the specification of a CF GPS receiver. While a cabled GPS receiver that was separate from the Pocket PC provided more user flexibility, and its onboard battery spared the Pocket PC’s battery, the users found that holding both a GPS receiver and a Pocket PC at once was too awkward.

Because production of the HP Jornada was going to be discontinued, another Pocket PC would be needed for subsequent deployments. The next choice was the Compaq iPAQ, which requires an expansion sleeve to provide a CF slot, needed for the GPS receiver, the camera, and CF memory cards. But the iPAQ had more storage than the Jornada, and it did not need a backup battery.

A fifth pilot investigator was added in May 2002, and received the new system configuration that consisted of a Compaq iPAQ 3850, a Type II CF Expansion Pack Plus (which includes an additional battery), a Pretec CF GPS receiver (http://www.pretec.com), a Nexicam 800 x 600-pixel digital camera Expansion Pack (http://www.nexian.com), a 64 MB CF memory card, an Aquapac PDA Classic Plus+ waterproof pouch (http://www.aquapac.net), and an ESRI ArcPad 6.0 license. This iPAQ was 135 x 84 x 16mm (thicker with the Pack) and weighed 190g without the Expansion Pack, With the Expansion Pack it was much heavier because of the extra battery. This iPAQ had a built-in secure digital (SD) slot, but was otherwise very similar to the HP Jornada.