Abstract: Health data collection poses unique challenges in rural areas of the developing world. mHealth systems that are used by health workers to collect data in remote rural regions should also record contextual information to increase confidence in the fidelity of the collected data.
We built a user-friendly, mobile health-data collection system using wireless medical sensors that interface with an Android application. The data-collection system was designed to support minimally trained, non-clinical health workers to gather data about blood pressure and body weight using off-the-shelf medical sensors. This system comprises a blood-pressure cuff, a weighing scale and a portable point-of-sales printer. With this system, we introduced a new method to record contextual information associated with a blood-pressure reading using a tablet's touchscreen and accelerometer. This contextual information can be used to verify that a patient's lower arm remained well-supported and stationary during her blood-pressure measurement. In a preliminary user study, we found that a binary support vector machine classifier could be used to distinguish lower-arm movements from stationary arms with 90% accuracy. Predetermined thresholds for the accelerometer readings suffice to determine whether the tablet, and therefore the arm that rested on it, remained supported. Together, these two methods can allow mHealth applications to guide untrained patients (or health workers) in measuring blood pressure correctly.
Usability is a particularly important design and deployment challenge in remote, rural areas, given the limited resources for technology training and support. We conducted a field study to assess our system's usability in Kolar town, India, where we logged health worker interactions with the app's interface using an existing usability toolkit. Researchers analyzed logs from this toolkit to evaluate the app's user experience and quantify specific usability challenges in the app. We have recorded experiential notes from the field study in this document.
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