CARWatch

Plan saliva sampling studies, record sampling times, and analyse your data with open-source tools for researchers and participants.

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Saliva sampling, from study setup to analysis

CARWatch connects study preparation, participant guidance, and data processing in one open-source research framework. It was developed for cortisol awakening response (CAR) research and also supports other saliva sampling protocols.

Sampling times matter in field studies. Reminders guide participants, barcode scans timestamp sampling events, and structured logs help researchers review timing and protocol adherence.

Workflow

Study personnel use the browser-based Study Manager to configure the study and generate barcode labels and participant QR codes, then print and prepare the sampling materials. Participants use the CARWatch app on an Android or iOS smartphone together with the labelled tubes, QR code, and instructions supplied by the study team. Follow the getting-started guide for materials, app setup, and data processing.

1
Plan and prepare: Study personnel configure the sampling schedule in the Study Manager, print barcode labels and participant QR codes, and distribute the prepared materials.
2
Set up the app: Participants install the Android or iOS app and scan their study QR code. Walk through the sampling procedure together.
3
Record sampling events: Participants follow reminders, report awakening, and scan each sample barcode when collecting saliva.
4
Export and analyse: Participants export their logs and share them with the study team. Study personnel process logs in the browser or use R and Python to combine sampling records with laboratory measurements.

Overview of the CARWatch workflow from study preparation to data processing

The CARWatch Framework Ecosystem

Use the Study Manager to prepare your study, the mobile apps to record sampling events, and R or Python for reproducible analysis.

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.

Python Package

A Python package for loading, converting, validating, and analyzing CARWatch logs and saliva data. Available on PyPI.

R Package

An R package for processing CARWatch logs, assessing sampling-time compliance, and analyzing saliva data. Available on CRAN.

Scientific background

The original CARWatch smartphone application was introduced by Richer et al. (2023) in Psychoneuroendocrinology. The paper describes the original application and its evaluation; the framework has since expanded to include additional platforms and analysis tools.

Read the original paper · Citation and scientific background

News

CARWatch R package now on CRAN

Version 1.0.1 of the CARWatch R package is now available on CRAN. It supports processing sampling logs, assessing sampling-time compliance, merging laboratory measurements, and analysing saliva data. Install it in R with install.packages("carwatch").

View the package on CRAN
CARWatch Python package released

Version 1.0.0 of the CARWatch Python package is now available. It provides tools for loading, converting, validating, and analysing CARWatch logs and saliva data.

View the release on GitHub
CARWatch iOS app updated to v1.1

Version 1.1 of the CARWatch iOS app is now available on the App Store.

Download on the App Store
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.

Updated CARWatch Android app screens Get it on Google Play
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

Project and contact

Project and research enquiries: Robert Richer at robert.richer@fau.de.