1. I would like to start a study using the headband, who should I contact?

If you want to start a study using the headband, please send us a request using this link: https://.dreem.com/contact?to=research

2. What is the regulatory status of the headband?

The Dreem 3 headband is registered as an FDA Class II Medical Device in the USA. For the rest of the world, the Dreem 3 headband is usually used as an investigational device in research studies. The Dreem headband also has a consumer CE marking.

3. What are the authorized payment methods?

You can pay via paypal or bank transfer.

4. Is the headband suitable for children?

The only blocking point would be fit. The Dreem 3 headband is designed to fit head perimeters between 520-620mm (20,47"-24,41"). To ensure good signal quality, the headband must be properly adjusted, the tighter it is, the better the signal quality. For pediatric studies, it is therefore not the age of the child which needs to be taken into account but rather head size. While the headband can fit adolescents well, it may vary from one child to another in younger populations (under 11s).

5. Do you have an API?

We do not have a public or private API for the moment.

6. I would like to run a study with auditory closed-loop stimulation

At the present time, auditory stimulations are unavailable for the Dreem3 product.
Previous research partnerships we worked on, involving auditory stimulation, needed a significant amount of work between the researchers and the software team at Dreem, as there were no programmable API to modify audio stimulation parameters. We cannot provide this service anymore. If it was core features in the first – consumer centric – version of the headband, we evolved toward a research version of the headband which does not include them.

1. How can I manage Dreem user accounts?

The creation of a Dreem administrator account will allow you to manage Dreem user accounts. One admin account will allow you to access to the Dreem Portal from which it is possible to manage recording performed with multiple users accounts.

2. Can I synchronize the headband with another device?

Resynchronizing several devices is not a straightforward process, as each device has its own errors in terms of sampling. When Dreem records sleep, it uses its internal clock that samples at approximately 250Hz with a non-linear error of + or - 3Hz through the nights. Therefore, if you want to perfectly align the Dreem device’s EEG traces with a PSG for instance, you will need to go through a resynchronization process. This resynchronization process involves running an algorithm for resynchronizing the data. We work with an ubuntu timestamp associated with each point of measure to enable resynchronization. For the resynchronization process, we can simply send you the code to be run on Python. Please contact us for further details.

3. What if my patients don't have WiFi or a smartphone?

It is possible to configure WiFi on the headband using a smartphone before giving it to your patients. They can then launch a recording using the power button located on the top arch of the headband. The headband can store up to 100 hours of recordings without any WiFi connection. However, the headband needs to be plugged in and connected to WiFi so that data can be transferred to servers and accessed on the "Dreem Portal".

4. Can I use the same headband for several participants?

Yes, you can use the same headband for several participants. Each participant has to be attached to a user account, and each headband can be used for several user accounts. Please see cleaning recommendations in the dedicated section.

5. What do I need to use the headband?

At first, you will need a smartphone with the Alfin app to 1) connect the headband to the WIFI, so nights recorded on the headband are sent on the server and are available on the Dreem Quality Check Portal. 2) Pair the headband to user account.
Once these two steps are performed, the smartphone is neither required to start a recording nor to upload nights on the servers.

6. Can I transfer my data with a cable if I don't have a WiFi connection?

Unfortunately not. The data is only transferable via WiFi.

7. Is it necessary to have WiFi access to upload the data?

Yes. However, the headband can store up to 30 nights or 100 hours before being overwritten.

8. Do I need WiFi to start my night?

No, you can start your night using the Dreem Alfin.

9. Do I need the app to start my night?

it is possible to start a recording with the App but not necessary. You can start your night by using the headband’s power button (triple push).

10. Can I schedule the beginning of the night’s recording in advance?

No, the beginning of the night cannot be scheduled in advance or started automatically/remotely.

11. If multiple individuals are wearing headbands, is there a way to link them all to one device controlled by the researcher, instead of each participant having the device linked to their personal phone?

One smartphone can be used to link multiple user accounts to their associated headband. To connect headband A to user account A, you will have to log into the app with the user’s credential A, then pair the headband and app together through bluetooth. Sign off the app, and repeat with headband B and user account B.
Note, that if the participants take the headband home, the data will not be uploaded as a WIFI connection is required. (See question 8).

12. If multiple individuals are wearing headbands, is there a way to differentiate each recording on the Dreem Portal?

Each individual will log in the Aflin app using unique user credentials attributed by the researcher. On the Dreem Portal each recording is associated with a user and a headband.

13. Does calibration need to be done prior to each use?

No it does not. A live EEG section on the application can help the subject to verify that the headband is well positioned though.

14. What are the battery life and the charging time of the device?

The average battery life of Dreem 3 is of ~ 25 hours. The charging time is 3h30 min when fully discharged.

1. What is the sampling rate of the data files?

The EEG sampling frequency of the headband is 250Hz. The accelerometer and pulse sensor sampling frequencies are 50Hz.

2. Is it possible to check the quality of the signal?

You can check the signal quality during a recording by looking at the live EEG displayed on the app. If your subject or patient is relaxed with closed eyes, alpha rhythm should be visible. We cannot provide you with an impedance value.
Offline EEG quality is available on the Dreem Portal.

3. What is the displayed channel on the live EEG in the app?

The EEG derivation displayed in the app is the one with the best signal quality.

1. How can I clean the headband?

70% isopropyl alcohol wipes can be used to clean the headband and the sensors. Also, this often has a beneficial effect on electrodes impedance.

2. What is the headband’s warranty?

Our warranty covers the Dreem headband for two years. Refurbished headbands are covered for 6 months.

1. What is the size of the recording after one night?

After one night, the raw data file of the recording (.h5 file) is around 70MB.

2. What's your policy in terms of data privacy?

Dreem follows GDPR rules. Please note that for your study, Dreem subjects' accounts will be created with dummy names, age, and gender. Only the principal investigator or authorized personnel will have access to the correspondence table that contains both the identity of the subjects and identifiers. Dreem won't have access to any personal data.
Upon request, data can be deleted at any time during the study. At the end of the study (or after a few months depending on the agreement), Dreem will delete all the recordings from its server.

3. How is data transferred and where is it stored?

Data is available in multiple formats, all of which are open and can be analyzed and/or processed with adequate tools. The unprocessed raw data is available as binary blobs. Once processed they are stored as HDF5 files and/or EDF.
Currently, recordings must go through our servers in order for them to be accessible. The storage pipeline is as follows: First, the recording is created and stored in the headband on its internal storage. Once the recording is over and the headband is plugged in and connected to WiFi, the recording is uploaded to our servers and deleted from the headband. The raw recordings are then accessed and processed by our internal services, making them available for download afterward.
The actual storage for these records is Amazon S3. For EU users, all our servers and storage capabilities are located in an AWS region located within the EU. Data access permissions are granted only to you and certain members of our team.

4. For how long can I hold data in the headband?

The headband can hold around 100 hours before overwriting the recorded data. That means you shall be able to recover all (or most of) the data, of 30 nights without WiFi (unuploaded data).

5. Can I upload the data to my phone and then synchronize them with the cloud after several days?

The headband upload data directly through Wifi with no transit through the App. Hence, you can not store data on your phone.

6. What format are the recordings in?

You can download several type of data under different formats as follow:
- Raw data encoded in binary blobs (.tar.gz). (Unfiltered)
- Raw data in h5 format. (Unfiltered)
EEG and 3D accelerometer data in EDF format. This is usually the preferred format for researchers wanting to import the file in their scoring software or for researchers using EEGlab on Matlab or a specific EEG toolbox on Python. The filtering procedure to transform an .h5 into a .edf is as follows: 1) An order 2 butterworth bandpass between 0.4 and 18Hz. 2) Three notches filter for 50Hz, 60Hz and 62.5 Hz of order 3
- Hypnogram in a time series format (.TXT). Sleep stages, which are determined by the sleep staging algorithm every 30s epochs, are listed chronologically in this file.
- Sleep metrics report in .CSV. It contains general information about the record (record number, start time, duration, channel quality) and sleep metrics (WASO, TST, sleep stage duration etc).

7. Is it possible to store the data on local servers?

The data is accessible on our external online "Dreem Portal", and you are encouraged to download and store it on your servers.

1. What is the “Dreem Portal” for? Can I manipulate my data with it?

Please note that our “Dreem Portal” tool provides you with a way to look at the recordings, check their quality and download under different formats (cf Q6). It’s not a scoring software, if you want to manipulate your data, you have to download them and use your own software.

2. Can I score the data by myself?

Yes. You can download your data in .edf and score it by yourself, using your own software.

3. Can extra sensors be added on demand or is there a possibility to integrate them to the Dreem headband by ourselves?

Adding extra-sensors requires to go through a resynchronization procedure that is not straightforward. It is, therefore, usually difficult to integrate extra sensors.

4. What is the post process on filters?

The .edf files that are provided have the following filters: 0.4-35Hz and Notches. The raw (binary blobs) and .h5 files are not filtered.

5. Does the headband have a GPS?

No, the headband doesn’t have GPS. But as smartphones do, Dreem can obtain the localization information in the app (in order to know the timezone). This information is not saved.

6. Can I integrate my own sounds in the headband and play them during my recordings?

We do not have an API, so this is not possible.

7. Can we use the headband and make recordings continuously?

No, this is not possible because the battery of the headband has a lifespan of approximately 25 hours and it is impossible to make recordings when the headband is in charge. The only way to record continuously is to alternate between several headbands.

8. Is the data accessible in real time?

No, the data is not accessible in real time but at the end of each night, once the headband is plugged in and connected to the WiFi. The data needs to be transferred to our servers first. The only data accessible in real time is that of the live EEG but this data cannot be used for rigorous research, it is only an indicator allowing the user to determine if the electrodes are in place in real time.

1. How many clinical trials Dreem has been involved in?

The device has been used in 5 clinical trials so far:
NCT03725943 (France, n=31), NCT03657329 (US, n=67), NCT04262791 (US, n=56), NCT02956161 (France, n=24), NCT03953196 (Belgium, n=48)
The device has also been included in many academic research protocols (>50).

2. Have the algorithms for determining sleep stages been validated? Has the data been published?

Yes, the paper was recently published in the peer-reviewed journal 'Sleep'. Data is also available.
Ref: Arnal & al, 2020, The Dreem Headband compared to Polysomnography for EEG Signal Acquisition and Sleep Staging, Sleep
DOI: 10.1093/sleep/zsaa097