What can we help you with?

The patches can be mounted anywhere on the body, but some signals can only be recorded in certain locations.



If you’ve received a wired ECG/RES patch, pictured below, make sure to attach to standard off-the-shelf ECG electrodes. Temporary ECG/RES Patch

We recommend placing the short-end electrode on the sternum, and the long-end electrode at a distance of approximately 12-15 cm away from the former as show in the diagram: ECG/RES Patch Placement

The best signal amplitude will be achieved by mimicking a Lead II in a standard 6-lead ECG, which amounts to an angle of approximately 60 degrees relative to the shoulders. This will also work for the respiration Role. Check the Signal Quality guide for more information.

ECG/RES Patch (Final - Disposable)

The temporary patch is just that … temporary. You will soon receive disposable ECG/RES patches like this: ECG/RES Patch

They will operate exactly as the wired version but will be disposable and will not require additional ECG electrodes.

PPG Patch (Disposable)

The IMU and PPG Patches look quite alike so make sure you grab the right one. The PPG Patch can be distinguished from the IMU patch by the LED array and the bottom. The IMU patch, on the other hand, has no sensor array in the opening. When in doubt, place a Sensor Dot configured as a PPG Role in the Patch. If it’s a PPG patch you will see a green and red LED light up. In theory, the PPG Patch can be placed anywhere but we recommend the following locations for best signal quality:

  • Behind the ear (red and infrared channel)
  • Upper-arm (green channel)
  • Forehead (red and infrared channel)
  • Wrist (green channel)
  • High on the chest (green and red channel)

ECG/RES Patch Placement

Note that both skin-tone and body type may influence the quality of the signal and some experimentation may be needed. Check the Signal Quality guide for more information.

IMU Patch (Disposable)

The IMU Patch is a simply adhesive mount. It’s placement is completely dependent on the application: ECG/RES Patch Placement

Note that areas of high impact (e.g. ankles during running) may show increased signal saturation. Check the Signal Quality guide for more information.

Once you have ended an experiment, follow along with the steps below to download all data from your Sensor Dots and reset them so they are ready for the next experiment.


Make sure the Composer application is open and the Dock is connected to your computer via the provided USB cable. Next, place your Sensor Dots back into the Dock. The Dock will automatically start downloading all data on each Sensor Dot, one-by-one, as indicated by the red status LED. After the data download has completed, the Sensor Dot will be reset so it’s ready for a new experiment.

A download of multiple Sensor Dots with long recordings may take time. Please be patient and refrain from taking Sensor Dots off the dock while the download is still in progress as this may result in loss of data!

Where is my data stored

Your data will be uploaded to the Byteflies cloud so it is always accessible from your account. At this time, this functionality is not yet active, stay tuned for an update.


Your data will be stored on your local drive as CSV files in ~/Documents/byteflies-data.


Your data will be stored on your local drive as CSV files in %userprofile%/Documents/byteflies-data.

OS Independent

On both macOS and Windows, your data will be stored according to the following structure:

Experiment Name & ID / Recording ID / Sensor Dot Name and ID / data_stream.csv

data_stream can be any of the following:

ECG: electrocardiogram PPG_GREEN: photoplethysmography, green channel PPG_RED: photoplethysmography, red channel PPG_IR: photoplethysmography, infrared channel RES: respiration ACM_X: acceleration, x-axis ACM_Y: acceleration, y-axis ACM_Z: acceleration, z-axis GYR_X: rotation, x-axis GYR_Y: rotation, y-axis GYR_Z: rotation, z-axis

The CSV files can be opened with any text or spreadsheet editor. Each file contains a single column of data with two special rows:

row 1: recording start time as UNIX timestamp row 2: sampling frequency in Hertz (Hz) row 3+: data

Unit Conversion

The values in the CSV files currently reflect the raw output of the sensor. To convert to more human readable units, you can use the following conversion factors:

ECG Role

  • ECG: Multiply by 0.000048 and round to two decimal points for a value in mV
  • ACM: Divide by 8192 for a value in g; range is ± 4g

PPG Role

  • PPG: Multiply by 0.00114 and round to one decimal point for a value in µA
  • ACM: Divide by 8192 for a value in g; range is ± 4g

RES Role

  • ECG: Multiply by 0.000048 and round to two decimal points for a value in mV
  • RES: Divide by 200 and round to one decimal point for a unitless value
  • ACM: Divide by 8192 for a value in g; range is ± 4g

IMU Role

  • ACM: Divide by 4096 for a value in g; range is ± 8g
  • GYR: Divide by 16.384 for a value in ‘degrees’; range is ± 2000 degrees/sec

Note that we will soon reflect the proper units in the CSV files and in the Byteflies cloud. To learn more about which signals will be recorded based on the Sensor Dot configuration, check the roles and Signal Quality pages.


Any time your Sensor Dots are on a Dock that is connected to a powered-on computer, they are charging, as indicated by the blue status LED.

Next, you will probably want to examine your data, so keep reading.

The LED on each Sensor Dot informs you on the status of the device and if any actions should be taken. When an experiment was setup in the Composer, the LED color will be the color that was assigned automatically. This color is referred to as ‘role color’ in the below animations.

While in the dock While out of the dock
Charging (slow blinking - blue) Connected to Composer (role color)
Fully Charged (solid - blue) Recording (double blink - role color)
Transferring Data (solid - red) Idle (single blink - role color)
Resetting (off) Low Battery (slow blinking - red)

After you decided on the signal that you want to measure, you need the complementary patch that enables the Sensor Dot to capture it. Byteflies patches are adhesive, disposable mounts that connect a Sensor Dot to the body and the Sensor Dot connects magnetically to the patch. Each patch is compatible with one or more roles which is explained here. Neither Patches nor Sensor Dots are currently waterproof. Do not shower or bathe with either!

When placing a Sensor Dot into a Patch, pay attention that the connection is magnetic and only one orientation is allowed. ECG/RES Patch

Depending on the role you assign to a Sensor Dot in the Composer application as explained here, different combinations of signals will be measured. We will gradually enable customized configurations of these roles, so check back from time to time.

Electrocardiogram Role (ECG):

The ECG Role records the following signals, and should be used with the ECG/RES Patch:

  • ECG at 250 Hz
  • Accelerometer (3-axis) at 50 Hz

Respiration (RES):

The RES Role records the following signals, and should be used with the ECG/RES Patch:

  • Respiration at 125 Hz
  • ECG at 125 Hz
  • Accelerometer (3-axis) at 50 Hz

Photoplethysmography (PPG):

The PPG Role records the following signals, and should be used with the PPG Patch:

  • PPG Green channel (535 nm) at 100 Hz
  • PPG Red channel (660 nm) at 100 Hz
  • PPG Infrared channel (940 nm) at 100 Hz
  • Accelerometer (3-axis) at 50 Hz

Inertial Measurement Unit (IMU)

The IMU Role records the following signals, and should be used with the IMU Patch:

  • Accelerometer (3-axis) at 100 Hz
  • Gyroscope (3-axis) at 100 Hz

An Experiment assigns specific roles to each Sensor Dot that is in-use, which can then be used to start a new recording. An experiment can contain more than one recording!

Follow along with these steps to start a new Experiment:

Set up a new Experiment

  1. Connect the Dock to your computer with the provided USB cable. Make sure all your Sensor Dots are in the Dock. Dock & Sensor Dots
  2. Start the Composer application and log in with your Byteflies account if you aren’t already. Log-in Screen
  3. Click New Experiment and add a name and (optional) description for the Experiment. New Experiment View

Assign Roles to your Sensor Dots

  1. To start using one of your Sensor Dots, take it out of the Dock first and click Add a Dot once it becomes available. Add Sensor Dot
  2. Give the Sensor Dot a name (optional) and select a role for your Sensor Dot. Assign a Role
  3. A new virtual Sensor Dot will appear next to your Avatar. Drag and drop it onto the avatar. Note that the color of the LED on your Sensor Dot is reflected on the avatar. Drag Sensor Dot to Avatar
  4. Select an appropriate patch, peel off the adhesive protection and place it on the same location as indicated on the avatar. Snap the Sensor Dot into the Patch.
  5. Verify that you’re getting a good signal in the live stream window. In case of issues, please check here to troubleshoot your signal.
  6. Click Confirm. Confirm Sensor Dot Configuration
  7. Repeat these steps for all Sensor Dots you want to add to this Experiment.

Please note that your Sensor Dots have to remain within range of the Dock to assign them to an Experiment! Also try to limit interference from other Bluetooth enabled devices such as smartphones by not placing them in close proximity to the Dock.

Finalize your Experiment and start a Recording

  1. Click Create Experiment to save your Sensor Dot Roles. Create Experiment
  2. The new screen that appears is your live view into your Experiment, and from now on referred to as the Manage Experiment screen. In that screen, you can switch between the Add Notes view and Live Stream view for all your active Sensor Dots via the buttons in the upper-right hand corner. Live Stream View
  3. To instruct your Sensor Dots to start recording, click the red Record button in the upper-left hand corner. Start Recording

At this time, you can safely close Composer. Your Sensor Dots will keep recording until you instruct them to stop or the battery runs out.

Continue to manage an ongoing experiment to learn more.

You can open the Composer application at any time during an ongoing experiment to verify the live stream(s), add notes, or start/stop a Recording. Make sure all your Sensor Dots are in range of the Docking station. If you did not start an Experiment yet, check here first!

Add Notes

The first view on the Manage Experiment screen that opens when you launch the Composer application while an Experiment is already running is the Notes screen. Here you can add text notes that will be stored in your experiment with a timestamp. The red top banner indicates a Recording is in progress. Add Notes

View the live stream(s)

When you switch to the live stream view, all active streams for your Sensor Dots will show. Note that if you just launched Composer, it may take a couple of seconds for all your Sensor Dots to show up. Live Stream Notes

Manage Recordings

To stop the current recording, simply click the Stop button in the upper-left hand corner (see arrow in previous panel). As long as you don’t click End Experiment (upper-right hand corner), you can start a new Recording as explained before that will be associated with the same Experiment. You can repeat this process as many times as you want but please note that changing the Roles assigned to one or more Sensor Dots will require you to start a new experiment.

End the Experiment

As soon as you have finished recording the data you wanted, launch the Composer application (if it wasn’t already open), and click the End Experiment button in the upper-right hand corner. Composer will go back to the main screen where you get an overview of all your past Experiments and a new experiment can be started. End Experiment

Continue to download your data to learn how to access the data you just recorded.

Currently, you cannot shower, bathe or swim with the Sensor Dots or patches. We are working on a waterproof system for the next version.

First, you need to enroll your Sensor Dots.

Enrollment is a one time process and one of the first steps in Getting Started with your Byteflies kit. Enrollment associates your Sensor Dots with your Byteflies account and it ensures that all of your data is connected to and accessible from your account. The next steps are necessary for now, but in the next versions the enrollment process will become automatic.

  1. Plug-in your docking station with Sensor Dots and login to the Composer.
  2. Click Enroll in the upper left hand corner.
  3. Wait for your Sensor Dots to be discovered. This may take a moment, please be patient.
  4. Now, hit the central Enroll button.

Now you can start creating your experiments and measure signals.

We provide you with the raw data of your experiments, and you can plot them in your favorite software (Python, R, Matlab, Graphpad Prism etc.) or in the open-source kst-plot tool that can be downloaded here*.


Select the appropriate link for your operating system, click the green Clone or download button on the GitHub page, download the zip and open the kst2 application.

Plot Data

  1. Start kst2.
  2. Drag and drop a CSV file onto the kst-plot window.
  3. Click Next.
  4. Add Column 1 to the Selected data, and click Next.
  5. On the next screen, make sure your settings are as follows, and click Next: Add Notes
  6. On the final screen, click Finish.

*We are not affiliated in any way with the developers of kst-plot.

Yes, your Sensor Dots will continue recording while you do with other things. You can open the Composer application again at any time during an ongoing experiment to verify the livestream(s) and add notes. Make sure all your Sensor Dots are in range of the docking station if you want to start/stop a recording.

For now, we recommend to wear the disposable patch for a maximum of 24 hours. We are continuously optimizing our system, so patches will become available that can be worn for prolonged periods of time.

Check here for the latest version of Composer.

There are versions available for both Windows and MacOS

To start measuring signals, you need to assign a role to the Sensor Dot in the Composer application. These are specific configurations that determine which physiologic signals are recorded simultaneously by a single Sensor Dot. Available roles are: Electrocardiogram (ECG), Respiration (RES), Photoplethysmography (PPG) and Inertial Motion Unit (IMU).

To learn more about these roles or signals, check our Science page and which signals are measured per role. We will gradually add new roles, we will let you know as soon as they are ready.

Also check the guides on the patches and where to put them on the body to start measuring.

We’re currently developing our sandbox with samples of the Sensor Dot data. We’ll soon have updates, you can also submit a support ticket if you have specific questions.

The Sensor Dots require the docking station to configure the experiment, to charge and to upload data to the cloud or computer.

When you notice a noisy signal in the Composer livestream, here are some actions that might help you improve the quality:

  • Move the Sensor Dot around in the patch or take it out and put it back in. It could be that the contact was not sufficient to provide a high quality signal.
  • It might also be that the electrodes that you used to attach the wired ECG/RES patch dried out. It’s best to try new ones or to open a new bag.
  • In case of PPG, you can manually set the LED intensity and gain via the light bulb icon. An increase in intensity or gain might amplify the amplitude of the PPG signal. However, be careful since it might also saturate your signal. The default values should be sufficient to provide an acceptable PPG signal for a wide range of people (e.g. skin colors, subcutaneous fat). If they don’t work for you, just play around with the settings until you find the one thats suits you best.
  • A change in body location might also work to increase the PPG signal quality. High quality signals can be obtained on the forehead, upper arm and chest (sternum). The wrist also works, but is more challenging due to the higher changes of movement artefacts.

If you want to know more on how to obtain high quality signals for your prototype, feel free to submit a support ticket.

If you need additional patches, you can order them in our web store.

Our platform is designed to fit a wide range of study designs. To help you assess whether it suits your needs, you can always contact us by email to hello@byteflies.com if you have a project or experiment in mind, or order the low-cost Exploration Kit to test your prototype.