PHIT™ – A Personal Health Intervention Toolkit for Building Mobile Health Applications

PHIT is an advanced cross platform software framework targeted at personal self-help research on mobile devices. Following the Subjective and Objective measurement, Assessment, and Plan (SOAP) methodology for health assessment and intervention recommendations, the PHIT platform lets researchers quickly build mobile health research Android and iOS applications. They can (1) create complex data collection instruments using a simple XML schema; (2) use Bluetooth wireless sensors; (3) create targeted self-help interventions based on collected data via XML-coded logic; (4) facilitate cross-study reuse from library of existing instruments and interventions like stress, anxiety, sleep quality, and substance abuse; and (5) monitor longitudinal intervention studies via daily upload to a web-based dashboard portal. For physiological data, Bluetooth sensors collect real-time data with on-device processing. For example, using the Binar HeartSensor, the PHIT platform processes the heart rate data into heart rate variability measures, and plots these data as time-series waveforms. Subjective data instruments are user data-entry screens, comprising a series of forms with validation and processing logic. The PHIT instrument library consists of over 70 reusable instruments for various domains like cognitive, environmental, psychiatric, psychosocial, and substances. Many are standardized instruments, such as the AUDIT, PHQ, and PTSD Checklist. Autonomous instruments like battery and GPS location support continuous background data collection. All data are acquired using a schedule appropriate to the application’s deployment. The PHIT Intelligent Virtual Advisor (iVA) is an expert system logic layer which analyzes the data in real time on the device. This data analysis results in a tailored application of interventions and other data collection instruments. For example, if a user anxiety scores exceeds a threshold, the iVA might add a meditation intervention to the task list to teach the user how to relax, and schedule a reassessment using the anxiety instrument two weeks later to re-evaluate. If the anxiety score exceeds a higher threshold, then an advisory to seek professional help would be displayed. Using an easy to use PHIT scripting language, the researcher can program new instruments, the iVA and interventions to their domain specific needs. The iVA, instruments, and interventions are defined via XML files which facilities faster application development and deployment. The PHIT web-based dashboard portal provides the researcher access to all the uploaded data. After a secure login, the data can be filtered by criteria such as study, protocol, domain and user. Data can also be exported into a comma delimited file for further processing. Research projects using PHIT will be highlighted, including Android and iOS mobile applications. In our experience, a person with modest logic and scripting skills can quickly make use of the toolkit. The PHIT framework has proven to be an extensible, reconfigurable technology that facilitates mobile data collection and health intervention research. Our future plans include instrument development in other domains, additional health sensors, and a SMS notification system. []