The Collaborative Aging Research Using Technology Initiative: An Open, Sharable, Technology-Agnostic Platform for the Research Community

Abstract

Introduction: Future digital health research hinges on methodologies to conduct remote clinical assessments and in-home monitoring. The Collaborative Aging Research Using Technology (CART) initiative was introduced to establish a digital technology research platform that could widely assess activity in the homes of diverse cohorts of older adults and detect meaningful change longitudinally. This paper reports on the built end-to-end design of the CART platform, its functionality, and the resulting research capabilities.

Methods: CART platform development followed a principled design process aiming for scalability, use case flexibility, longevity, and data privacy protection while allowing sharability. The platform, comprising ambient technology, wearables, and other sensors, was deployed in participants' homes to provide continuous, long-term (months to years), and ecologically valid data. Data gathered from CART homes were sent securely to a research server for analysis and future data sharing.

Results: The CART system was created, iteratively tested, and deployed to 232 homes representing four diverse cohorts (African American, Latinx, low-income, and predominantly rural-residing veterans) of older adults (n = 301) across the USA. Multiple measurements of wellness such as cognition (e.g., mean daily computer use time = 160-169 min), physical mobility (e.g., mean daily transitions between rooms = 96-155), sleep (e.g., mean nightly sleep duration = 6.3-7.4 h), and level of social engagement (e.g., reports of overnight visitors = 15-45%) were collected across cohorts.

Conclusion: The CART initiative resulted in a minimally obtrusive digital health-enabled system that met the design principles while allowing for data capture over extended periods and can be widely used by the research community. The ability to monitor and manage health digitally within the homes of older adults is an important alternative to in-person assessments in many research contexts. Further advances will come with wider, shared use of the CART system in additional settings, within different disease contexts, and by diverse research teams.

Keywords: Aging; Digital biomarkers; Pervasive computing; Remote monitoring; Smart home.

Fig. 1

The CART initiative's end-to-end system. The CART front end (shown on the left side of the “firewall”) represents the sensors, data collection hub computers, and supporting applications that operate in participant homes. The CART back end (shown on the right side of the “firewall”) represents how the data are stored and processed after they have been uploaded from the hub computers in participant homes. API, application programming interface; CART, Collaborative Aging Research Using Technology; DMZ, demilitarized zone; EHR, electronic health record; GPS, Global Positioning System; VPN, virtual private network.

Fig. 2

Overview of sensors, devices, and data streams that can be integrated into the CART platform to monitor several health and wellness domains. CART, Collaborative Aging Research Using Technology; EHR, electronic health record.

Fig. 3

Examples of the intuitive graphical interface used for platform installation and maintenance. a The main page acts as a portal to access information about the sensors and hub computer assigned to the participant home. b An example page for checking the status and connectivity of the PIR sensors (accessed under the “Devices” tab on the main page). c An example spider graph for setting and maintain where the PIR sensors are located (e.g., room) in the participant's home (accessed under the “Home” tab on the main page). d An example showing the status of the hub computer assigned to the participant's home (accessed under the “Settings” tab on the main page). PIR, passive infrared.

Fig. 4

Illustrations showing example sensor data for a CART participant. a Data illustration showing the weekly averaged daily computer use over 3 years from 2015 to 2018. Computer use was collected by the WorkTime software installed on the participant's computer. Darker blue suggests more computer use while lighter yellow suggests less computer use. The participant did not use their computer on week 22 of 2017. b Data illustration showing sedentary patterns in hours over a year. Sedentary time was calculated by the wearable device. Each circle represents a week, from Monday to Sunday. Blue lines suggest longer sedentary time while red lines suggest shorter sedentary time. c Data illustration showing the number of transitions to rooms (bathroom, bedroom, kitchen, living room) over 21 days. The number of transitions between rooms was calculated using the PIR motion sensors placed in each room. On average, this participant went to the kitchen and living room more and went to the bathroom least. d Data illustration showing sleep duration in hours during the COVID-19 pandemic from February 1 to May 21, 2020 in Oregon. Sleep duration was collected from the wearable device. The participant had a decline in sleep duration during the COVID-19 pandemic. The events of COVID-19 (first confirmed case, stay-at-home order) are highlighted in gray. e Data illustration showing variability of heart and respiratory rate for a night using data collected from the Emfit sleep mat. The participant had a drop in respiratory rate around 2:30 a.m. f Data illustration showing the probabilities of room transition routes over 1 month. Room transition routes (e.g., kitchen to living room) were detected using the PIR motion sensors in each room. The dashed lines indicate lower probability routes, while the solid line indicates higher probability routes that the participant would take over 1 month. CART, Collaborative Aging Research Using Technology; PIR, passive infrared.

Fig. 5

Examples of how the sensors and technologies are installed in research participant homes. a A hub computer that is used to collect data from several of the sensors and securely transmit the data to the CART servers. b A contact door sensor (circled in yellow) that reports when the door is open and when the door is closed. c A PIR motion sensor (circled in yellow) that reports when an individual is in the room and when no one is present in the room. d A digital scale recording participant weight and body mass composition (fat, muscle, and bone mass). e A driving sensor plugged into the OBD-II adapter of a vehicle that records several metrics about driving such as, but not limited to, the number of driving trips per day, the beginning and ending time for each trip, the duration spent driving on surface streets, the duration spent driving on highway roads, the number of hard breaks per trip, and the number of hard accelerations per trip. f A consumer grade actigraphy watch that monitors the activity level and sleep of the wearer. g A sleep mat placed under a mattress that measures sleep duration and sleep stages amongst several other metrics about an individual's sleep. h Use of the electronic pillbox that records when the doors were opened and/or closed. As a note, a PIR motion sensor (circled in yellow) is also visible in this image. CART, Collaborative Aging Research Using Technology; PIR, passive infrared.