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Data points and signals that can be collected using D4L Collect

This page offers an overview of the signals and data points that can be collected using D4L Collect.

Device Device type Data point/sensor signal Raw or processed Data transfer protocol Configuration mode in D4L Collect
Dexcom G7 Continuous glucose monitor (CGM) * Estimated glucose value (in blood) Processed API CBR
Estimote Beacon Indoor positioning Distance (via UWB) Raw BLE, UWB * ARS
Indoor positioning RSSI – Received Signal Strength Indicator (used to determine distance) Raw BLE ARS
Mobile phone’s internal sensors Inertial measurement unit (IMU) Acceleration Raw BLE ARS
Inertial measurement unit (IMU) Angular velocity Raw BLE ARS
Inertial measurement unit (IMU) Magnetic field Raw BLE ARS
Movella/Xsens DOT Inertial measurement unit (IMU) Via the Custom mode 1 and the Rate quantities data streaming mode: angular velocity Raw BLE (up to 60 Hz)
Manual export for 120 Hz data		 ARS
Inertial measurement unit (IMU) Via the Custom mode 1 and the Rate quantities data streaming mode: euler angles Processed BLE (up to 60 Hz)
Manual export for 120 Hz data		 ARS
Inertial measurement unit (IMU) Via the Custom mode 1 and the Rate quantities data streaming mode: free acceleration Processed BLE (up to 60 Hz)
Manual export for 120 Hz data		 ARS
Inertial measurement unit (IMU) Via the Rate quantities data streaming mode: acceleration Raw BLE (up to 60 Hz)
Manual export for 120 Hz data		 ARS
Samsung Galaxy Watch 6 Smartwatch Acceleration Raw BLE ARS
Smartwatch Angular velocity Raw BLE ARS
Smartwatch Magnetic field Raw BLE ARS
Smartwatch Activity detection: PASSIVE, ASLEEP, EXERCISE, UNKNOWN Processed BLE CBR
Smartwatch Daily calories Processed BLE CBR
Smartwatch Daily distance Processed BLE CBR
Smartwatch Daily floors Processed BLE CBR
Smartwatch Daily steps Processed BLE CBR
Smartwatch Electrocardiogram (ECG) Raw BLE ARS
Smartwatch Heart rate Processed BLE ARS & CBR
Smartwatch Interbeat interval (IBI) Processed BLE CBR
Smartwatch Skin temperature Processed BLE CBR
Smartwatch Blood oxygen saturation (SpO2) Processed BLE ARS
Smartwatch Health Services data points:
1) Absolute elevation
2) Total positive elevation
3) Total negative elevation
4) Minimum speed
5) Maximum speed
6) Average speed
7) Speed
8) Steps per minute
9) Minimum steps per minute
10) Maximum steps per minute
11) Average steps per minute		 Processed BLE ARS
Fitbit Charge 6 Fitness tracker Intraday activity data, calories burned Processed API CBR
Fitness tracker Intraday activity data, steps * Processed API CBR
Fitness tracker Intraday data for breathing rate * Processed API CBR
Fitness tracker Intraday data for heart rate * Processed API CBR
Fitness tracker Intraday data for heart rate variability * Processed API CBR
Fitness tracker Intraday data for SpO2 metrics * Processed API CBR
Fitness tracker Daily data for sleep * Processed API CBR
Fitness tracker Daily data for skin temperature * Processed API CBR
Apple HealthKit Platform for users to manage and track their health information Active energy Processed Data is stored locally on the device CBR
Platform for users to manage and track their health information Step count Processed Data is stored locally on the device CBR
Platform for users to manage and track their health information Walking and running distance Processed Data is stored locally on the device CBR
Platform for users to manage and track their health information Sleep (only available with an Apple Watch) Processed Data is stored locally on the device CBR

Important: (*) To collect data points marked with an asterisk, a specialised research project agreement must be established between the device manufacturer (for example, Dexcom, Samsung), the research partner, and Data4Life.

More info: Websites of the device manufacturers

Apple HealthKit

Fitbit Web API

Estimote UWB Beacons

Movella/Xsens DOT (IMU)

Samsung Galaxy Watch 6

List of abbreviations and concepts

Abbreviation Term Explanation
API application programming interface Connection between computers or between computer programs. A type of software interface offering a service to other pieces of software. Can handle larger amounts of data and is not limited by proximity.
ARS active recording session Configuration mode in D4L Collect: time-limited, activity-specific data collection.
BLE Bluetooth Low Energy Wireless communication technology designed for low power consumption. Designed for short-range, low-power wireless communication between devices (for example, IoT devices and wearables).
CBR continuous background recording Configuration mode in D4L Collect where data is continuously collected around the clock.
configuration mode Data collection method configured by researchers in Research Studio to define how, when, and how frequently data should be collected.
data transfer protocol Method by which data is transmitted from the sensor or wearable device to the D4L Collect app.
IMU inertial measurement unit Electronic device that measures and reports a body's specific force, angular rate, and sometimes the orientation of the body. IMUs use a combination of accelerometers, gyroscopes, and sometimes magnetometers.
UWB ultra-wideband Radio technology that can use a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum.

Please note: D4L Collect is continuously evolving, with an expanding ecosystem of devices, sensor signals, and data points for modern digital health research.

Last Update: May 22, 2026

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