CARWatch

An open-source framework for improving objective saliva sampling in the field.

News

Release2026-06-30

CARWatch Android app updated to v3.0.1

The CARWatch Android app now has a refreshed design and updated participant workflows. The new release adds a study-details step during onboarding, clearer navigation, daily alarm and sample status overviews, pending wake-up and end-of-day alerts, and support for bedtime/evening sample reminders.

Get it on Google Play

Release2026-06-04

CARWatch iOS app released

The CARWatch iOS app is now available on the App Store! Let us know if you have any feedback or questions.

Download on the App Store

What is CARWatch?

CARWatch is an open-source framework for supporting saliva sampling field studies. It combines mobile applications for Android and iOS used during data collection with a web-based Study Manager.

The framework was originally developed as a single Android app for cortisol awakening response (CAR) research and has since been expanded into a broader cross-platform ecosystem for studies in which saliva samples are collected in the field.

Why CARWatch?

The cortisol awakening response is a widely used marker in psychoneuroendocrine research, but its assessment is highly time-critical. Even short delays between awakening and sampling can systematically distort CAR estimates and contribute to inconsistent findings in field studies.

CARWatch was developed to support more objective recording of sample events outside the lab. Barcode scans document sample events with timestamps, automated reminders support protocol adherence, and QR codes transfer predefined study settings to the app.

The CARWatch Framework Ecosystem

The CARWatch ecosystem consists of the following components:

Study Manager

A web-based study manager for study setup, generation of study materials, and processing of exported log files. Available online.

Android App

The Android app for reminders, awakening reports, and barcode-based recording of sampling events. Available on Google Play.

iOS App

The iOS app for reminders, awakening reports, and barcode-based recording of sampling events. Available on the App Store.

Workflow

The typical workflow of using CARWatch is the following:

Configure the study: Define the study settings in the web-based Study Manager.

Prepare study materials: Generate barcodes and QR codes and distribute them to the participants along with all other study materials.

Download and initialize the app: Study participants download the app from Google Play or the App Store and configure it by scanning the QR code.

Use the app: Study participants use the app during data collection to report awakening and record saliva sample intake.

Share and process the exported logs: After the study, participants share log files with the study personnel. Afterwards, the log files can be processed locally in the web-based Study Manager without storing any data on servers!

Overview of the CARWatch workflow from study preparation to data processing

Further Information

Additional information and resources related to CARWatch.

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Contact

Interested in using CARWatch in your own study or research project? Contact us at robert.richer@fau.de.