pyEmpatica

Parties Involved

Institution: Munroe Meyer Institute in the University of Nebraska Medical Center
Laboratory: Virtual Reality Laboratory
Advisor: Dr. James Gehringer
Developer: Walker Arce

Motivation

This Python library was written to facilitate biometric data collection from an Empatica E4. It also includes windowed sample collection, threaded error handling, and on-wrist detection.

Installation

This library is available for installation over pip using: pip install pyEmpatica

For developers, clone this repository, cd into the directory using either your virtual environment or your local environment, and run: python setup.py install

To actually utilize this library the Empatica Streaming Server is required, meaning this library is only compatible with Windows systems.

Usage

As of version 1.0.3 of the E4 Streaming Server, it seems there are issues with connecting the Empatica E4 for data collection. Follow this workaround to alleviate this issue.

from pyempatica import EmpaticaClient, EmpaticaE4, EmpaticaDataStreams, EmpaticaServerConnectError
import time


try:
    client = EmpaticaClient()
    print("Connected to E4 Streaming Server...")
    client.list_connected_devices()
    print("Listing E4 devices...")
    time.sleep(1)
    if len(client.device_list) != 0:
        e4 = EmpaticaE4(client.device_list[0])
        if e4.connected:
            print("Connected to", str(client.device_list[0]), "device...")
            for stream in EmpaticaDataStreams.ALL_STREAMS:
                e4.subscribe_to_stream(stream)
            print("Subscribed to all streams, starting streaming...")
            e4.start_streaming()
            for i in range(0, 10):
                time.sleep(1)
                if not e4.on_wrist:
                    print("E4 is not on wrist, please put it on!")
                if e4.client.last_error:
                    print("Error encountered:", e4.client.last_error)
                    break
            e4.suspend_streaming()
            e4.disconnect()
            e4.close()
            print("E4 Errors")
            for key in e4.client.errors:
                print("\t", key, ":", e4.client.errors[key])
            print("E4 connection closed, saving readings...")
            e4.save_readings("readings.txt")
            print("Readings saved to readings.txt...")
        else:
            print("Could not connect to Empatica E4:", client.device_list[0])
    client.close()
    print("Cleaning up connections...")
except EmpaticaServerConnectError:
    print("Failed to connect to server, check that the E4 Streaming Server is open and connected to the BLE dongle.")

Before running this script, ensure the Empatica Streaming Server is up and running. This library is currently only compatible with Windows due to the Streaming Server dependency.

Citation

@misc{Arce_pyEmpatica_2021,
      author = {Arce, Walker and Gehringer, James},
      month = {8},
      title = {{pyEmpatica}},
      url = {https://github.com/Munroe-Meyer-Institute-VR-Laboratory/pyEmpatica},
      year = {2021}
}