e4client

Custom client for the E4 wristband from Empatica. Developed for https://www.fh-joanneum.at, based on https://github.com/empatica/empalink-sample-project-android. Project description: https://github.com/j05t/e4client/blob/master/project_description.pdf. A 64 bit build is not supported by the Empatica SDK.

Version 0.1 APK files available for download at

• https://github.com/j05t/e4client/releases/tag/0.1
• https://play.google.com/store/apps/details?id=com.jstappdev.e4client

<img src="https://github.com/j05t/e4client/blob/master/Screenshot_0.jpg" alt="Screenshot" width="22%" height="22%" /> <img src="https://github.com/j05t/e4client/blob/master/Screenshot_1.jpg" alt="Screenshot" width="22%" height="22%" /> <img src="https://github.com/j05t/e4client/blob/master/Screenshot_3.jpg" alt="Screenshot" width="22%" height="22%" />

<img src="https://github.com/j05t/e4client/blob/master/Screenshot_4.jpg" alt="Screenshot" width="22%" height="22%" /> <img src="https://github.com/j05t/e4client/blob/master/Screenshot_2.jpg" alt="Screenshot" width="22%" height="22%" /> <img src="https://github.com/j05t/e4client/blob/master/Screenshot_5.jpg" alt="Screenshot" width="22%" height="22%" />

Setup:

Google Fit: https://console.cloud.google.com/apis/credentials

• Create OAuth2 key and insert Android Studio SHA1 fingerprint
• https://developers.google.com/android/guides/client-auth
• Configure Google Fit consent screen

Edit apikeys.properties

• Insert SciChart License: https://www.scichart.com/

todo:

• Calculate average heart rate from blood volume pulse
• Validate HRV metrics: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624990/
• Use foreground service for Bluetooth connection
• Full Google Fit sync (only session metadata works currently)
• Check median/average filters for correctness

https://support.empatica.com/hc/en-us/articles/360030058011-E4-data-IBI-expected-signal

https://stackoverflow.com/questions/22583391/peak-signal-detection-in-realtime-timeseries-data

https://stackoverflow.com/questions/31753062/calculate-heart-rate-from-ecg-stream-java-nymi-band

https://www.researchgate.net/figure/HRV-time-domain-measures_tbl1_320078994

https://link.springer.com/article/10.1007%2Fs00521-019-04278-7

https://terpconnect.umd.edu/~toh/spectrum/Smoothing.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624990/