TIME: Data file start time in Unix time stamps, i.e. the seconds since Jan 01 1970 (UTC).
SENSOR: Sensor serial ID
DATA_TYPE: see below
HASH: Unique identifier for a recording.
Data types/Data file content
time
For all datatypes, time is the time in Unix time stamps, i.e. the seconds since Jan 01 1970 (UTC).
temperature
In-ear body temperature.
The temperature measured by the in-ear sensors in °C. If the sensor is properly applied in the ear, it measures the core body temperature. If the temperature is lower than the expected body temperature, this can be a sign that the sensor is not applied right or the wrong size.
y: values in °C
heart_rate
Heart Rate
Heart rate is the average number of heartbeats measured by the number of contractions of the heart per minute (bpm).
y: values in bpm
quality_max
Quality
Quality index calculated on the in-ear sensor. It is a measure for the reliability of the currently calculated heart rate values.
y: values in a.u.
tech_perfusion
Perfusion index derived from the infrared PPG signal.
A PPG signal's amplitude (AC) is typically alternating around an offset (DC). The AC part of the signal is for example used for detecting the heart beat. The ratio of AC/DC of the infrared PPG signal is called perfusion index. It could be described as an indicator of how 'strong' the pulse is that is currently measured and therefore an indicator for the signal quality.
y: values in %
perfusion
Perfusion index derived from the infrared PPG signal.
Same as above, but re-evaluated together with SpO2 values (see below).
y: values in %
spo2
SpO2
SpO2 is a measure for the oxygen saturation of the blood. It is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin.
y: values in %
ppg_med
PPG Medical
High pass filtered PPG signal that shows the PPG signal like typically used to be shown by other medical devices.
y: values in a.u.
acc_deviation
Average acceleration deviation from earth gravity
The average deviation of the acceleration magnitude from earth gravity. The larger this value, the larger the motion of the in-ear sensor.
y: values in g
theta_phi (not yet available)
Angular position in polar coordinates theta and phi
y: values in rad
vital_packet_counter
BLE Packet Counter
A counter for the received Bluetooth Low Energy (BLE) packages.
y: values in a.u.
errors
Sensor Errors (This file is generated only if the sensor device reported any error states)
Received error states from the sensor device.
y: There are 8 possible errors, each of which is represented in one column. A value of 1 means that the respective error was received.
ppg_ir: Infrared PPG LED error
ppg_red: Red PPG LED error
acc_axes: Accelerometer error
unknown_battery_curve: Unknown Battery curve (battery level may be wrong)
ppg_green: Green PPG LED error
ppg_order: PPG rawdata sent in wrong order
thermometer_defective: Temperature measurement defect
citp: If the PPG signal contained unexpected outliers. This error leads to a short sensor reset, to continue normal operation.