Studies using the RADAR-base platform generate a large amount of high and low quality data from wearable devices and smartphone technology. All the raw data is stored in HDFS to allow for scalability. Queries can be executed directly on this file system or a data cut can be exported to csv files. In both cases the data adheres to a strict schema that describes the fields for each record in detail.
The RADAR-base platform is build for flexibility. Based on the hypotheses, you decide which data is relevant for your study and which sensors you want to use to collect this data. The platform provides connectors for several smartphone sensors and wearable devices. If the sensor is already supported (see this page for a full list), you can start right away.
Is the device that you want to use for your study not supported by RADAR-base yet? Feel free to build an additional connector, custom to your study design. Here you can find the instructions how to develop connectors for new devices or third party APIs.
Set up your study
Four concise steps to start a remote monitoring study
1 Install the RADAR-base infrastructure
2 Build and configure the RADAR-base Android applications
From the Android source code it is simple to build and publish custom mobile applications for your study. You will need Android Studio to build the source code and a developers account for the Google Play Console.
Depending on your research question and privacy restrictions, you decide which sensors will be activated and customize settings like sampling frequency and granularity of the data. All available settings are described on the Readme pages of the plugins (example). Google Firebase ‘Remote Config’ is used for easy and flexible configuration, which can be created for free with a Google account. To link your app to your Remote Config console, please follow these instructions.
The Firebase Remote Config is also used to configure the connection to your RADAR-base infrastructure.
After configuration and building, the apps can be published on the Google Play store. This can be done without listing the app in the Play store catalogue, such that only invited participants can install the app.
3 Participant recruitment and onboarding
The RADAR-base platform provides a user management portal that enables clear study design, participant and device registration and a simple onboarding process.
To start a clinical trial or a research study you can register participants and link them to their corresponding devices. The portal offers a device catalogue from which supported devices can be selected. After you register a new participant, the management portal will generate a unique QR code. Invite participants to install the app on their smartphone and self-register by scanning the QR code with the app.
4 Start remote data collection
After successful setting up all components and configuration of relevant parameters, remote data collection can start. Data will be streamed to your server continuously. The RADAR-base platform also enables you to specify alerts and notifications for researchers or participants. These are especially useful to warn researchers if data is not being collected or not being streamed to the server for a predefined period due to e.g. connection errors. This allows the researchers to intervene quickly and reduce potential data loss. Configurable notifications also enable researchers to remind participants of study specific tasks or indicate that the battery status of participants wearable device gets low.
There are several approaches for data output. You can choose to download raw data (e.g. in csv format) to explore and develop customized algorithms or enable machine learning. Alternatively, you can view aggregated data on the dashboard. The interactive dashboard visualizes study wide compliance and connectivity of individual patients. Zooming in on data from specific sensors allows in-depth data visualization in configurable time frames.