Data overview

This vignette provides an overview of the data stored in an mpathsenser database by import(). The database scheme is shown below.

Figure 1: mpathsenser database scheme. The underlined fields constitute the primary key of the table.

As can be seen in Figure 1, the database can be divided into roughly two parts: meta-data and sensor-specific data. Meta-data stores data about the study itself, the participants, and the processed files. On the other hand, sensor-specific tables store the values from the sensors, which are linked to the meta-data.

The tables below describes what meta-data is collected for every sensor. Sensor-specific collected data is provided in the subsequent tables. Tables for Garmin direct sensing are provided in a separate section.

Note that primary keys are underlined in the tables below.

Meta-data

Study

This table contains information about the study itself. The data from this table can be accessed using get_studies().

Variable	Type	Description
study_id	character	ID of the study.
data_format	character	Name indicating which data format is used.

Participant

This table contains information about the participants. The data from this table can be accessed using get_participants().

Variable	Type	Description
participant_id	character	Unique ID of the participant.
study_id	character	ID of the study.

ProcessedFiles

This table is not normally needed for users of this package, but is essential to import() as it keeps tracks of which files have already been imported. The data from this table can be accessed using get_processed_files().

Variable	Type	Description
file_name	character	Name of the JSON file containing the raw data.
participant_id	character	Unique ID of the participant.
study_id	character	ID of the study.

Sensor-specific tables

The tables below describe the data collected for each sensor. The data from these tables can be accessed using get_data().

Accelerometer

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
x (deprecated, removed from db)	double	Acceleration force along the x axis (including gravity) measured in $m/s^2$. When the device is held upright facing the user, positive values mean the device is moving to the right and negative mean it is moving to the left.
y (deprecated, removed from db)	double	Acceleration force along the y axis (including gravity) measured in $m/s^2$. When the device is held upright facing the user, positive values mean the device is moving towards the sky and negative mean it is moving towards the ground.
z (deprecated, removed from db)	double	Acceleration force along the z axis (including gravity) measured in $m/s^2$. This uses a right-handed coordinate system. So when the device is held upright and facing the user, positive values mean the device is moving towards the user and negative mean it is moving away from them.
x_mean	double	Mean value of the acceleration force along the x axis over a specific time window.
y_mean	double	Mean value of the acceleration force along the y axis over a specific time window.
z_mean	double	Mean value of the acceleration force along the z axis over a specific time window.
x_median	double	Median value of the acceleration force along the x axis over a specific time window.
y_median	double	Median value of the acceleration force along the y axis over a specific time window.
z_median	double	Median value of the acceleration force along the z axis over a specific time window.
x_std	double	Standard deviation of the acceleration force along the x axis over a specific time window.
y_std	double	Standard deviation of the acceleration force along the y axis over a specific time window.
z_std	double	Standard deviation of the acceleration force along the z axis over a specific time window.
x_aad	double	Average absolute deviation of the acceleration force along the x axis over a specific time window.
y_aad	double	Average absolute deviation of the acceleration force along the y axis over a specific time window.
z_aad	double	Average absolute deviation of the acceleration force along the z axis over a specific time window.
x_min	double	Minimum value of the acceleration force along the x axis over a specific time window.
y_min	double	Minimum value of the acceleration force along the y axis over a specific time window.
z_min	double	Minimum value of the acceleration force along the z axis over a specific time window.
x_max	double	Maximum value of the acceleration force along the x axis over a specific time window.
y_max	double	Maximum value of the acceleration force along the y axis over a specific time window.
z_max	double	Maximum value of the acceleration force along the z axis over a specific time window.
x_max_min_diff	double	Difference between the maximum and minimum values of the acceleration force along the x axis over a specific time window.
y_max_min_diff	double	Difference between the maximum and minimum values of the acceleration force along the y axis over a specific time window.
z_max_min_diff	double	Difference between the maximum and minimum values of the acceleration force along the z axis over a specific time window.
x_mad	double	Median absolute deviation of the acceleration force along the x axis over a specific time window.
y_mad	double	Median absolute deviation of the acceleration force along the y axis over a specific time window.
z_mad	double	Median absolute deviation of the acceleration force along the z axis over a specific time window.
x_iqr	double	Interquartile range of the acceleration force along the x axis over a specific time window.
y_iqr	double	Interquartile range of the acceleration force along the y axis over a specific time window.
z_iqr	double	Interquartile range of the acceleration force along the z axis over a specific time window.
x_neg_n	double	Number of negative values in the acceleration force along the x axis over a specific time window.
y_neg_n	double	Number of negative values in the acceleration force along the y axis over a specific time window.
z_neg_n	double	Number of negative values in the acceleration force along the z axis over a specific time window.
x_pos_n	double	Number of positive values in the acceleration force along the x axis over a specific time window.
y_pos_n	double	Number of positive values in the acceleration force along the y axis over a specific time window.
z_pos_n	double	Number of positive values in the acceleration force along the z axis over a specific time window.
x_above_mean	double	Number of values above the mean in the acceleration force along the x axis over a specific time window.
y_above_mean	double	Number of values above the mean in the acceleration force along the y axis over a specific time window.
z_above_mean	double	Number of values above the mean in the acceleration force along the z axis over a specific time window.
x_energy	double	Energy of the signal along the x axis is computed by taking the mean of sum of squares of the values in a window in that particular axis.
y_energy	double	Energy of the signal along the y axis is computed by taking the mean of sum of squares of the values in a window in that particular axis.
z_energy	double	Energy of the signal along the z axis is computed by taking the mean of sum of squares of the values in a window in that particular axis.
avg_res_acc	double	Average resultant acceleration over the window is computed by taking average of the square roots of the values in each of the three axis squared and added together.
sma	double	Signal magnitude area is defined as the sum of absolute values of the three axis averaged over a window.

Activity

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
confidence	integer	Acceleration force along the x axis (including gravity) measured in m/s^2.
type	character	Type of activity recognized. Possible types of activities are: IN_VEHICLE - The device is in a vehicle, such as a car. ON_BICYCLE - The device is on a bicycle. ON_FOOT - The device is on a user who is walking or running. WALKING - The device is on a user who is walking. RUNNING - The device is on a user who is running. STILL - The device is still (not moving). TILTING - The device angle relative to gravity changed significantly.

AirQuality

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
air_quality_index	integer	A score of the current air quality index.
air_quality_level	character	Air quality categorisation from EPA: <0 Unknown 0-50 Good 50-100 Moderate 100-150 Unhealthy for sensitive groups 150-200 Unhealthy 200-300 Very unhealthy >300 Hazardous Taken from https://en.wikipedia.org/wiki/Air_quality_index#United_States
place	character	Name of the monitoring station.
latitude	variable	Latitude of the monitoring station.
longitude	variable	Longitude of the monitoring station.

AppUsage

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data. Because each record contains a single app but one measurement contains multiple apps, apps within the same measurement share the same measurement_id but added with a suffix “_” and a number starting from 1.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	character	The end time of the measurement. Represented in 24-hour time as 00:00:00.000000.
start	character	Start time of the of sampling window of this app, represented as an ISO 8601 date. This can vary slightly from the general start time.
end	character	End time of the of sampling window of this app, represented as an ISO 8601 date. This can vary slightly from the general end time.
usage	integer	A map of names of apps and their cumulative usage in seconds.
app	character	The last part of the application package name. For instance, “com.facebook.katana” would become “katana”.
package_name	character	The full application package name.
last_foreground	character	The time at which the application was last in the foreground. If the app had not yet been in the foreground, this is NA. Represented as an ISO 8601 date.

Battery

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
battery_level	integer	The battery level in percent.
battery_status	character	The charging status of the battery: Full, charging, discharging, unknown.

Bluetooth

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data. Because each record contains a Bluetooth device but one measurement contains devices, records within the same measurement share the same measurement_id but added with a suffix “_” and a number starting from 1.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
start_scan	character	The time at which the scan started. Represented as an ISO 8601 date.
end_scan	character	The time at which the scan ended. Represented as an ISO 8601 date.
advertisement_name	character	The bluetooth advertising name of the device.
bluetooth_device_id	character	The bluetooth id of the nearby device.
bluetooth_device_name	character	The bluetooth name of the nearby device.
bluetooth_device_type	character	The type of bluetooth device: classic dual le unknown
connectable	boolean	Is the device connectable? As SQLite does not support booleans, this is represented as an integer where ‘0’ denotes false and ‘1’ denotes true.
rssi	integer	The Received Signal Strength Indicator (RSSI) signal strength to the device in decibels referenced to one milliwatt (dBm) ranging from 0 to -100.
tx_power_level	integer	The power level of the device in percentage.

Calendar

This sensor was deprecated but for historical reasons is preserved in mpathsenser.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data. Because each record contains an event but one measurement contains multiple events, events within the same measurement share the same measurement_id but added with a suffix “_” and a number starting from 1.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
event_id	character	The unique identifier for this event.
calendar_id	character	The identifier of the calendar that this event is associated with.
title	character	The title of this event.
description	character	The description for this event.
start	character	Indicates when the event starts. Represented as an ISO 8601 date.
end	character	Indicates when the event ends. Represented as an ISO 8601 date.
all_day	boolean	Indicates if this is an all-day event.
location	character	The location of this event.
attendees	character	A list of attendees’ name for this event. If multiple attendees are present, then these are separate by a comma.

Connectivity

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
connectivity_status	character	The status of the connectivity. One of the following values: bluetooth: Device connected via Bluetooth ethernet: Device connected to ethernet network mobile: Device connected to cellular network vpn: Device connected to a VPN wifi: Device connected via Wi-Fi none: Device not connected to any network unknown (error)

Device

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
device_id	character	An identifier that is unique to the particular device on which this data was collected. Note that this ID will change if the user performs a factory reset on their device.
hardware	character	The hardware type from which this data was collected (e.g. ‘iPhone 7,1’ for iPhone 6 Plus).
device_name	character	Device name as specified by the OS.
device_manufacturer	character	Device manufacturer as specified by the OS.
device_model	character	Device model as specified by the OS.
operating_system	character	Device OS as specified by the OS.
platform	character	The platform type from which this Datum was collected. Either Android or iOS.
operating_system_version	character	The version of the operating system.
sdk	character	The version of the Sofware Development Kit (SDK) of Android or the iOS (Darwin) kernel.

Error

This sensor was deprecated but for historical reasons is preserved in mpathsenser.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
message	character	An error message from a sensor.

Geofence

This sensor type has not yet been implemented in m-Path Sense, but is included here for completeness.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
center	character	The centre of the geofence as a GPS location.
dwell	integer	The dwell time of this geofence in milliseconds. If an object is located inside this geofence for more than a pre-specified number of milliseconds, the dwell event is fired.
name	character	The name of this geofence.
radius	double	The radius of the geofence in meters.
state	character	The possible states of a geofence event: enter, exit, dwell.

Gyroscope

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
x	double	Rate of rotation around the x axis measured in rad/s. When the device is held upright, this can also be thought of as describing ‘pitch’. The top of the device will tilt towards or away from the user as this value changes.
y	double	Rate of rotation around the y axis measured in rad/s. When the device is held upright, this can also be thought of as describing ‘yaw’. The lengthwise edge of the device will rotate towards or away from the user as this value changes.
z	double	Rate of rotation around the z axis measured in rad/s. When the device is held upright, this can also be thought of as describing ‘roll’. When this changes the face of the device should remain facing forward, but the orientation will change from portrait to landscape and so on.

Heartbeat

The Heartbeat sensor is not so much a sensor, but rather a signal that is sent to the m-Path server to let it know that it is still active. If such a signal was not received after a certain period of time (configurable), a notification is sent to the phone that data collection has stopped and that the app should be reopened. Note that even if a heartbeat is present, it does not guarantee that data can actually be collected.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
period	integer	The period of heartbeats per minute. Defaults to 5 minutes.
device_type	character	The type of device.
device_role_name	character	The role name of the device in the protocol.

InstalledApps

Deprecated due to package visibility constraints (see https://developer.android.com/training/package-visibility), the apps’ use of the permission needed to collect this information is subject to approval from the Google Play Store.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data. Because each record contains a single app but a measurement contains multiple apps, apps within the same measurement share the same measurement_id but added with a suffix “_” and a number starting from 1.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
Installed apps	character	The name of an installed app.

Keyboard

This sensor type has not yet been implemented in m-Path Sense, but is included here for completeness.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
start	character	Timestamp of when the first key is pressed. Represented as an ISO 8601 date.
end	character	Timestamp of when the last key is pressed. Represented as an ISO 8601 date.
body	character	The text body of the typed message.

Light

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	character	The time at which the sample of the data ended, represented as an ISO 8601 date.
mean_lux	double	The average light intensity of the sample in lux.
std_lux	double	The standard deviation of the light intensity of the sample in lux.
min_lux	double	The minimum light intensity of the sample in lux.
max_lux	double	The maximum light intensity of the sample in lux.

Location

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
latitude	variable	The latitude of this position in degrees normalized to the interval -90.0 to +90.0 (both inclusive).
longitude	variable	The longitude of the position in degrees normalized to the interval -180 (exclusive) to +180 (inclusive).
altitude	double	Altitude in meters above the WGS 84 reference ellipsoid. The altitude is not available on all devices. In these cases the returned value is 0.0.
accuracy	double	The estimated horizontal accuracy of the position, radial, in meters.
vertical_accuracy	double	Estimated vertical accuracy of this location, in meters.
speed	double	The speed at which the devices is traveling in meters per second over ground. The speed is not on all devices. In these cases the returned value is 0.0.
speed_accuracy	double	The estimated speed accuracy of this position, in meters per second. The speed accuracy is not on all devices. In these cases the returned value is 0.0.
heading	double	The heading in which the device is traveling in degrees. Only available on Android. The heading is not on all devices. In these cases the returned value is 0.0.
heading_accuracy	double	The estimated bearing accuracy of this location, in degrees. Only available on Android.
is_mock	boolean	Is the location currently mocked. Always false on iOS.

Memory

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
free_physical_memory	double	Amount of free physical memory in bytes.
free_virtual_memory	double	Amount of free virtual memory in bytes.

Noise

This sensor has currently been removed from m-Path Sense due to sampling issues. Moreover, background sampling capabilities have been restricted by both Android and iOS due to privacy concerns.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	character	The time at which the sample of the data ended, represented as an ISO 8601 date.
mean_decibel	double	Mean decibel of sampling window.
std_decibel	double	Standard deviation (in decibel) of sampling window.
min_decibel	double	Minimum decibel of sampling window.
max_decibel	double	Maximum decibel of sampling window.

Pedometer

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
step_count	integer	Cumulative number of steps as measured by the phone’s operating system since the last reboot.

PhoneLog

This sensor was removed from m-Path Sense because Google Play does not allow apps to access the call log anymore. This is due to privacy concerns.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
call_type	character	Type of call: answered_externally blocked incoming missed outgoing rejected voice_mail unknown
datetime	character	Date & Time of the call.
duration	integer	Duration of call in microseconds.
formatted_number	character	The formatted version of the phone number (if available).
name	character	The name of the caller (if available).
number	character	The phone number

Screen

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
screen_event	character	Whenever a screen change occurs, one of three states: SCREEN_ON SCREEN_OFF SCREEN_UNLOCKED

TextMessage

This sensor was removed from m-Path Sense because Google Play does not allow apps to access text messages anymore. This is due to privacy concerns.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
address	character	The receiver address of this message.
body	character	The text body of this message.
text_date	character	The date this message was created.
date_sent	character	The date this message was sent.
is_read	boolean	Whether the message is read by the user.
kind	character	The kind of message: draft received sent
size	integer	The size in bytes of the body of the message.
state	character	The state of the message: delivered fail none sending sent

Timezone

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
timezone	character	The current time zone of the device. See https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Weather

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
country	character	Abbreviation of the country. For instance, Belgium is “BE”.
area_name	character	City name.
weather_main	character	Group of weather parameters (Rain, Snow, Clouds etc.)
weather_description	character	Weather condition within the group.
sunrise	character	Sunrise time. Represented as an ISO 8601 date.
sunset	character	Sunset time. Represented as an ISO 8601 date.
Latitude	variable	The latitude of this position in degrees normalized to the interval -90.0 to +90.0 (both inclusive).
Longitude	variable	The longitude of the position in degrees normalized to the interval -180 (exclusive) to +180 (inclusive).
pressure	integer	Atmospheric pressure on the sea level in hPa.
wind_speed	double	Wind speed in metres per second.
wind_degree	double	Wind direction in degrees (meteorological).
humidity	integer	Humidity in percentage.
cloudiness	integer	Cloudiness in percentage.
rain_last_hour	double	Rain volume for the last 1 hour in millimetres.
rain_last_3hours	double	Rain volume for the last 3 hours in millimetres.
snow_last_hour	double	Snow volume for the last 1 hour in millimetres.
snow_last_3hours	double	Snow volume for the last 3 hours in millimetres.
temperature	double	Temperature in Celsius.
temp_min	double	Minimum temperature in Celsius at the moment. This is minimal currently observed temperature (within large megalopolises and urban areas).
temp_max	double	Maximum temperature in Celsius at the moment. This is maximal currently observed temperature (within large megalopolises and urban areas).

Wifi

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
ssid	character	Wi-Fi service set ID (SSID) of the connected network.
bssid	character	Basic service set identifier (BSSID) of the connected network.
ip	character	The internet protocol (IP) address of the connected network.

Garmin sensor tables

The following tables describe data collected from Garmin wearable devices as they are represented in the mpathsenser. These sensors provide high-resolution physiological and movement data. See also the m-Path manual for more information on the raw data.

GarminAccelerometer

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
x	double	Acceleration force along the x axis measured in milli-g (gravitational force).
y	double	Acceleration force along the y axis measured in milli-g (gravitational force).
z	double	Acceleration force along the z axis measured in milli-g (gravitational force).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminActigraphy

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	character	The end time of the measurement. Represented as an ISO 8601 date.
instance	character	Instance identifier for the actigraphy measurement (e.g., ‘Actigraphy1’, ‘Actigraphy2’, ‘Actigraphy3’).
total_energy	integer	Accumulated magnitude of acceleration during the measurement period.
n_zero_crossing	integer	Number of zero crossings detected during the measurement period.
time_above_threshold	double	Time in seconds spent above the configured activity threshold.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminBBI

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
bbi	integer	Beat-to-beat interval in milliseconds. This represents the time between consecutive heartbeats.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminEnhancedBBI

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
bbi	integer	Beat-to-beat interval in milliseconds. This represents the time between consecutive heartbeats.
status	character	Status of the BBI measurement (e.g., ‘highConfidence’, ‘lowConfidence’).
gap_duration	integer	Duration of any gap in the BBI measurement in milliseconds.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminGyroscope

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
x	double	Rate of rotation around the x axis measured in degrees per second.
y	double	Rate of rotation around the y axis measured in degrees per second.
z	double	Rate of rotation around the z axis measured in degrees per second.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminHeartRate

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
bpm	integer	Heart rate in beats per minute.
status	character	Status of the heart rate measurement (e.g., ‘LOCKED’, ‘SEARCHING’).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminMeta

Garmin direct sensing data is by default pulled to the phone at most every 2 minutes. However, every timestamp in the Garmin tables represents the time of the actual underlying measurement, not the time at which it is pulled to the phone. This table provides information of the moments data is pulled to the phone, along with counts of the number of measurements collected for each sensor type during that period.

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
time_from	character	Start time of the metadata collection period. Represented as an ISO 8601 date.
time_to	character	End time of the metadata collection period. Represented as an ISO 8601 date.
n_accelerometer	integer	Number of accelerometer measurements collected during this period.
n_actigraphy_1	integer	Number of actigraphy measurements from instance 1 collected during this period.
n_actigraphy_2	integer	Number of actigraphy measurements from instance 2 collected during this period.
n_actigraphy_3	integer	Number of actigraphy measurements from instance 3 collected during this period.
n_bbi	integer	Number of BBI measurements collected during this period.
n_enhanced_bbi	integer	Number of enhanced BBI measurements collected during this period.
n_gyroscope	integer	Number of gyroscope measurements collected during this period.
n_heartrate	integer	Number of heart rate measurements collected during this period.
n_respiration	integer	Number of respiration measurements collected during this period.
n_skin_temperature	integer	Number of skin temperature measurements collected during this period.
n_spo2	integer	Number of SpO2 measurements collected during this period.
n_steps	integer	Number of step measurements collected during this period.
n_stress	integer	Number of stress measurements collected during this period.

GarminRespiration

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
bpm	integer	Respiration rate in breaths per minute. Will show as 0.0 if unavailable, see status.
status	character	Status of the respiration measurement.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminSkinTemperature

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
temperature	double	Skin temperature in degrees Celsius (0-65°C, 0.0 if unavailable).
status	character	Status of the temperature measurement.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminSPO2

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
spo2	integer	Blood oxygen saturation level in percentage (0%-100%, ≤25% indicates resting, 0% if unavailable).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminSteps

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	integer	The end time of the measurement. Represented as an ISO 8601 date.
step_count	integer	Number of steps taken during the measurement period.
total_steps	integer	Cumulative total number of steps since the last reset (generally at midnight).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminStress

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
stress	integer	Stress level score. Higher values indicate higher stress levels.
status	character	Status of the stress measurement (e.g., ‘valid’, ‘offWrist’, ‘largeMotion’).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminWristStatus

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
status	character	Status indicating whether the device is being worn on the wrist (e.g., ‘ON_WRIST’, ‘OFF_WRIST’).
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).

GarminZeroCrossing

Variable	Type	Description
measurement_id	character	Uniquely generated measurement ID. Currently not present in the data.
participant_id	character	Unique ID of the participant.
date	character	The date of the measurement. Represented as a character as YYYY-MM-DD.
time	character	The start time of the measurement. Represented in 24-hour time as 00:00:00.000000.
end_time	character	The end time of the measurement. Represented as an ISO 8601 date.
total_energy	integer	Total energy expenditure during the measurement period.
n_zero_crossing	integer	Number of zero crossings across the average total acceleration detected during the measurement period.
deadband	integer	Deadband (threshold) value required for a zero crossing to count, in milli-g. Defaults to 0 if not set.
mac_address	character	MAC address of the Garmin device (Android) or UUID (iOS).