FLEX is a wireless control box (FLEX controller) that works with EMOTIV’s Flex Cap system. It combines the wireless technology of EMOTIV’s award-winning EPOC X headset with the high-density and flexible sensor placement found in traditional EEG head-cap systems. The sensors can be placed in any of the 74 openings in the head cap in the standard 10-20 positions—allowing configurations for specific experiments or participant characteristics.

FLEX 2 features:

• Choice of gel or saline-based sensor kits — for optimal conductivity and signal quality.

• Up to 32 EEG channels — provides high-density EEG coverage.

• Ear clip sensors (gel only) — for referencing signals.

• Bluetooth 5.2 — Transmits up to 256 SPS uncompressed, 16-bit data per channel.

• Wireless connectivity — connect seamlessly to your PC or Mac

• Rechargeable — up to 6 hours of battery life

• Choice of pre-configured (saline only) or non-configured caps — provides easy set-up or flexible positioning.

• Choice of Flex Cap sizes — for comfort and conformity.

For the EPOC Flex Quick Start Guide, go to https://www.emotiv.com/setup/epoc-flex/

EMOTIV does not warrant, guarantee or make representations concerning the content of this document. All information is provided ‘as is’ without express or implied warranties of any kind, including, without limitation, the warranties of merchantability, quality and title. EMOTIV reserves the right to change the content of this document and the features or functionalities of its products and services at any time without obligation to notify anyone of such changes.

Copyright

Copyright© 2023 EMOTIV. All rights reserved.

Brainwear® is a registered trademark.

• FLEX is a consumer product; it is not intended to be used as a medical device or in hazardous environments.

• FLEX is designed for use at room temperature; rapid changes in temperature will affect the performance of the amplifiers and increase the noise floor.

• WARNING: Do not submerge FLEX in water. Every effort has been made to stop water from entering FLEX and protect the electronics inside. However, FLEX is not waterproof.

• WARNING: FLEX is powered by a lithium-polymer battery that is rated for operation in <50°c (<122°F) environments. It is not user-replaceable. If you suspect that there is a fault with the battery, please contact EMOTIV Support.

• WARNING: Do not open the FLEX enclosure. Doing so will void the warranty and can damage the headset.

• ‌WARNING: Do not charge FLEX while wearing the device. If you want to operate while tethered, we recommend using FLEX with Extender.

Précautions de Sécurité

• FLEX est un produit de consommation; il n'est pas destiné à être utilisé comme appareil médical ou dans des environnements dangereux.

• FLEX est conçu pour une utilisation à température ambiante; des changements rapides de température affecteront les performances des amplificateurs et augmenteront le bruit de fond.

• AVERTISSEMENT: ne plongez pas l' FLEX dans l'eau. Tous les efforts ont été faits pour empêcher l'eau de pénétrer dans l' FLEX et protéger l'électronique à l'intérieur. Cependant, FLEX n'est pas étanche.

• AVERTISSEMENT: FLEX est alimenté par une batterie au lithium polymère conçue pour fonctionner dans des environnements <50°c. Il n'est pas remplaçable par l'utilisateur. Si vous pensez qu'il y a un problème avec la batterie, veuillez contacter le support EMOTIV.

• AVERTISSEMENT: n'ouvrez pas le boîtier du l' FLEX. Cela annulerait la garantie et pourrait endommager l' FLEX.

• ‌AVERTISSEMENT: ne chargez pas l' FLEX lorsque vous portez l'appareil. Si vous souhaitez fonctionner en mode connecté, nous vous recommandons d'utiliser FLEX avec Extender.

EMOTIV products are intended to be used for research applications and personal use only. Our products are not sold as Medical Devices as defined in EU directive 93/42/EEC and are not designed or intended to be used for diagnosis or treatment of disease.

‌EMOTIV has tested FLEX 2.0 and confirms:

This device complies with the radio equipment directive (2014/53/EU).

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

• Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.

• Consult the dealer or experienced person for help.

Please Note: Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.

‌This Class B digital apparatus complies with Canadian ICES-003.

Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.

This device contains license-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and Economic Development Canada’s license-exempt RSS(s). Operation is subject to the following two conditions:

1. This device may not cause interference.

2. This device must accept any interference, including interference that may cause undesired operation of the device.

L’émetteur/récepteur exempt de licence contenu dans le présent appareil est conforme aux CNR d’Innovation, Sciences et Développement économique Canada applicables aux appareils radio exempts de licence. L’exploitation est autorisée aux deux conditions suivantes:

1. L’appareil ne doit pas produire de brouillage;

2. L’appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d’en compromettre le fonctionnement.

Radiation Exposure Statement: This equipment complies with the IC RSS-102 radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with a minimum distance of 20 cm between the radiator and your body.

User Manual

FLEX is charged and tested before shipping—so you can start using it straight away.

Charging the Battery

To maximize the use of your FLEX, we recommend fully charging its battery before taking recordings. If the ON/OFF LED is not blue when you turn your FLEX on, it requires charging.

To charge the battery:

1. Plug the USB-C charging cable into the USB-C port.

2. Then, connect the other end of the USB-C charging cable to a power outlet or your PC/Mac.

The time it takes to recharge the battery fully depends on the remaining capacity of the lithium polymer battery. Charging can take up to four hours. Charging the battery is faster if you connect the FLEX Controller to a dedicated USB port.

If your FLEX is unused for a long period of time, the battery may completely deplete of charge. If this happens, you may need to charge it for 24 hours.

If you have any issues charging FLEX, please contact the EMOTIV Support team.

FLEX Charging Behavior

EMOTIV has worked to improve on the existing packaging and now FLEX ships in a travel case to align with our other products. We have actively worked to minimize the waste plastic used in our packaging.

Flex is sold in three different configurations and is available with three sizes of head cap Small(54), Medium(56), and Large(58), other sizes are available on request. The different configurations are listed below:

1. Flex Gel Kit

2. Flex Saline Kit

3. Flex Saline Pre-configured Kit

The FLEX gel kit includes 34 multi-rode gel sensors. The sensors are made from sintered Silver/Silver Chloride to minimize sensor impedance and ensure they are fully compatible with gel electrolytes. Each sensor wire is crimped and fitted to the connector housing. The wires are labeled A-G and J-Q.

Multi-rode gel sensor

Ear Clips

The FLEX Gel Kit includes two ear clips to hold the sensors in place on the ears. The clips can be removed once the gel has hardened on the ears.

Your FLEX kit includes 34 sensors connected to 16 red wires, 16 blue wires, and two black wires.

Wire Color Coding

The wires are color-coded, making it easier to identify the channel name in PRO and find the corresponding sensor on the cap. For example, if the contact quality is low on channel LA, this will correspond with the blue A wire.

Each wire is labeled with the channel letter it is connected to. All wires are crimped with a JST gold-plated crimp, which helps improve the EEG signal quality.

Wire Lengths

The sensor wires come in two lengths:

• The wires for channels A-G (front of FLEX Cap) are 300mm, and

• The wires for channels J-Q (back of FLEX Cap) are 150mm.

The different wire lengths minimize excess while allowing for any sensor configuration.

FLEX has 16 channels on the left + CMS* input and 16 channels on the right + DRL** output. The channels are positioned in two rows: rows A-H and J-Q, with an empty position above the CMS/DRL.

*CMS = common mode signal **DRL = driven right leg

FLEX also includes:

• Power Switch. The power switch is located next to the USB connector on the bottom edge of the unit. Move it to the right to turn it on and left to turn it off.

• Power Indicator. The power LED located below the logo indicates power on or off.

• Charge Status. The charge LED, located next to the USB-C connector, shows you the current battery status of the Flex Controller.

The FLEX saline kit includes 34 saline sensors. Each sensor is silver/silver chloride plated and has three prongs to grip the sensor felts—the same as EPOC X.

Hydrating the Sensor Felts

To hydrate the sensor felts:

1. Place them in a glass;

2. Cover the felts in saline solution and soak.

3. When the sensor felts are thoroughly soaked, remove them from the glass and squeeze out the excess fluid.

4. They are now ready to be inserted into the sensors.

Rehydrating the Sensors During an Experiment

Saline sensors will start to dry out during an experiment. The time they take to dry out will depend on the environment you’re working in. The contact quality map in PRO will show any changes to the contact quality during your experiment. For example, the contact quality will change from green to orange as the felts dry out.

You can top up saline at individual sensors without interrupting your experiment. To top up the sensor felts, add a few drops of saline to each felt through the opening at the top of each sensor. After a few seconds, you will see the contact quality at each sensor improve.

TIP: If you want to slow evaporation, we recommend adding a few drops of glycerine to your saline solution.

To insert the sensors into the FLEX Cap, we recommend placing it onto a mannequin head and inserting the sensors through the openings before placing it onto your participant’s head. It can take up to an hour to position all the sensors in your chosen configuration.

Inserting Sensors Steps

Repeat these three steps for all of the sensors in your chosen configuration.

Choosing the right FLEX Cap for your study is essential for achieving accurate EEG measurements.

To choose the right size of FLEX Cap for your participant, measure their head circumference, as shown in the image below. Once you have their measurement, choose a FLEX Cap from the range of sizes available — 54cm, 56cm, and 58cm sizes (whichever size is closest to their head circumference).

Fit the FLEX Cap to your participant’s head like you would fit a swimming cap.

1. Place the FLEX Cap over your participant's forehead, ensuring the pocket for the FLEX Controller is at the back of the head.

2. Stretch FLEX Cap to the back of their head.

3. Make sure their ears are placed through the ear holes.

4. If your participant has long hair, make sure that it is spread out evenly across their head so that there are no thick sections. Your participant’s hair must not be tied up during the experiment.

When the FLEX Cap is on your participant’s head, they should feel the pressure of each sensor against their scalp. If they do not feel pressure from the sensors on their scalp, there might not be enough tension in the FLEX Cap. If this happens, then try fitting a smaller FLEX Cap or move the chin strap to see if it becomes more tense.

The FLEX Cap follows the 10-20 system and has 74 positions. The cap has two pockets for securing the FLEX Controller in place — one is below Cz and the other is lz.

The FLEX Cap is made from black high-comfort material and is available in sizes 54cm, 56cm and 58cm. A pre-configured version is available in the 56cm size only.

If you need a different size, hole position, material, or cut, please contact EMOTIV Support.

EMOTIV offers a pre-configured saline FLEX Cap, with all 32 sensors fitted — per the default layout in PRO. The wires are cut to the right length and tied down. This montage matches the default sensor configuration in PRO. Sensors are placed on the 10-20 system and provide good coverage across the head.

To minimize motion artifacts during your experiments, keeping excess wires secured to reduce their movements is essential. Once you've fitted all the sensors to the FLEX Cap, we recommend using the tagger pins and tagger tool (supplied with your FLEX kit) to tidy up the wiring by 'sewing' them into place. Another option is to place a shower cap, another Flex Cap, or a swimming cap over the top of the FLEX Cap to minimize wire movements.

Tagger pins and tool

How to Tidy the Wires

There are two places on the FLEX Cap to position the FLEX controller — at the top (Cz) or the rear (lz). See the images below.

If you’re doing a sleep study or your participant needs a headrest (e.g., they use a wheelchair), we recommend positioning the FLEX Controller at the top of the FLEX Cap.

How to Fit the FLEX Controller

1. Choose the position you want the FLEX Controller to be in.

2. Place the FLEX Controller in the pocket with the EMOTIV logo facing you.

3. Stretch the Flex Cap fabric over the FLEX Controller and around the edge of the EMOTIV logo (the circle).

4. The FLEX controller is now secured into place and ready to be used.

To achieve a high signal quality, you need to minimize impedance between the gel sensors and the scalp. Here are some tips to help you achieve the best quality signal:

Your participant should not use hair gel or other additives before fitting the sensors as these products can cause impedances.

• When cleaning the sensors or adding gel to the sensors, ensure you have enough light to see what you’re doing.

• Clean and abrade the skin under each sensor, then apply the electrolytic gel.

• You can use any conductive gel on the sensors, but some gels are better suited due to their viscosity or for a particular experiment. For example, when conducting a sleep study, using a gel that takes a long time to dry out is essential.

Suitable Electrolyte Gels

Salty or salt-free electrolyte gels can be used on the gel sensors. Here is a list of suitable products that you can use:

• SuperVisc (clear, high-viscosity, salty)

• Lectron III-10 (clear, medium-viscosity, salty)

• Abralyt HiCl (abrasive, high-viscosity, salty)

• Abralyt 2000 (abrasive, high-viscosity, non-salty)

• Nuprep Gel (abrasive, high viscosity, non-salty)

• Ten20 (opaque, high-viscosity, salty)

Preparing the Gel Sensors for Your Experiment

When preparing gel sensors for your experiment, you will need the following items:

• Cotton swabs,

• Isopropyl alcohol 70%,

• An abrasive electrolyte gel, such as Abralyt 2000,

• Conductive electrolyte gel, such as SuperVisc or Ten20,

• A plastic syringe without a needle (20ml), and

• Tissues to remove excess gel.

Cleaning Your Participant’s Skin

1. Move the hair below the sensor opening to one side, ensuring clear access to the scalp.

2. Add isopropyl alcohol to a cotton swab.

3. Gently rotate the cotton swab tip on your participant’s scalp to degrease the skin.

Abrading Your Participant’s Skin

1. Dip a cotton swab in abrasive gel.

2. Place the cotton swab into the sensor opening and rotate it gently on your participant’s scalp to abrade the skin. Do not apply too much pressure to your participant’s scalp. This process should be painless and not irritate the skin.

Filling the Sensors with Electrolyte Gel

1. Open the sensor.

2. Fill a syringe with electrolyte gel.

3. Insert the syringe into the open sensor and then push the gel out. When doing this, ensure that you make contact between the scalp and the sensor. Most electrolyte gels take a few minutes to permeate the skin.

4. Check the signal quality in PRO after preparing each sensor. The contact quality should be green.

Take the white connector at the end of the red wires and plug it into the right-hand side of the FLEX controller. Repeat this process for the blue wires on the left-hand side.

Once you've plugged the wires into FLEX, double-check that they're all in the right place.

Connector and blue wires on the right-hand side of the FLEX Cap

Connector and blue wires on te left-hand side of the FLEX Cap

To achieve the best quality signal, you need to minimize impedance between the saline sensors and the scalp. Here are some tips to help you achieve the best quality signal:

• Ensure that your participant has washed their hair before your experiment. They should not use hair conditioner, or other products, before the experiment as these products can cause impedances.

• When cleaning the sensors or adding the saline to the sensors, ensure you have enough light to see what you’re doing.

The number of sensors and wire positions fitted to the connectors is flexible. As a default, all 32 sensors + 2 reference sensors are fitted to the two connectors.

• On the left-hand side are 16 blue sensor wires and the black CMS wire.

• On the right-hand side are 16 red sensor wires and the black DRL wire.

The sensor names (A-Q) match the pin positions (A-Q) on the connector, as shown below.

Each connector has an empty position above the black reference wires. The connectors are standard 18-position, but only 17 positions are loaded with wires.

Please do not insert the connector into the empty position.

How to Remove Unneeded Sensors from the Connector

Sensors that you don’t need for your experimental montage can be removed.

To remove unneeded sensors:

1. Use a thin-flat screwdriver or tweezers to lift up the connector’s plastic tab(s). Lifting the tab will release the crimp locking mechanism.

2. Pull the wire until you see the gold color of the crimp.

3. Then, remove the reference wire.

How to Insert Sensor Wires to the Connector

To insert a sensor wire to the connector:

1. Place the crimp lock upwards, then

2. Insert the wire and then pull it to ensure it’s locked in place.

You can clean the FLEX Cap in a washing machine at 30°c (86°F/warm setting) using a mild detergent. When it’s clean, allow it to air dry.

You can also hand wash the FLEX Cap with a mild detergent, such as children’s shampoo. After handwashing it, rinse the FLEX Cap with clean water, then remove excess water with a paper towel and air dry.

Do not put the FLEXCap in the dryer.

Do not iron the FLEXCap.

Do not disinfect or bleach the FLEXCap. Strong oxidizing agents or bleach can reduce the life of the FLEXCap.

After finishing your experiment, you can wash the FLEX Cap and sensors together to avoid removing and reinserting the sensors between experiments. To do this, you need to:

1. Remove the FLEX Cap, with the sensors attached, from your participant.

2. Unplug the sensor wires from the FLEX Controller.

3. Remove the FLEX Controller from the FLEX Cap and place to one side.

4. Place the connectors in a bag and seal it with a rubber band. Doing this will protect the connectors from accidental splashes while holding them out of the water.

5. Handwash the FLEX Cap and sensors using a mild detergent, such as children’s shampoo.

6. Allow the FLEX Cap and sensors to air dry before your next experiment.

After you’ve finished your experiment, you must clean the sensors immediately. Clean the sensors quickly by rinsing them under a running tap to remove the gel residue. If you do not remove the gel from the sensors, it can harden, impeding the quality of the EEG signals for your next experiment.

If the gel does dry out:

• Soak the sensors in water for 30 seconds. Then rinse again or scrub gently with a soft toothbrush.

• If the gel is difficult to remove, try soaking the sensors in water with a mild detergent (such as children’s shampoo). After soaking, rinse the sensors under a running tap and dry the sensors with a towel or tissue.

WARNING

Do not soak the gel sensors in saline solution or chloride. Doing this will corrode the sensors.

Do not use an autoclave or other hot sterilization methods, as this can damage the wire insulation.

You can purchase replacement sensor felt packs from the EMOTIV online store.

Saline sensors should only be subjected to saltwater while they are in use. After use, you must rinse the sensors with clean water to remove the salty residue. Doing this will prolong the life of the sensors. After rinsing, dry the sensors with a towel or tissue.

Saline Sensor Felts Warning

Do not leave the sensor felts in the saline sensors. Leaving wet sensor felts in the saline sensors will corrode them. Store used sensor felts separately from unused ones.

You can purchase replacement sensor felt packs from the EMOTIV online store.

When your FLEX is not in use, remove all the sensors from the FLEX Cap and ensure that everything is clean and dry before storing. Flex is shipped with a travel case to keep it protected and keep it organized between uses.

Unable to Achieve Contact Quality on Any Channel

There could be two reasons for this happening:

1. The sensor trees are not plugged into the FLEX controller; or

2. The reference sensors are not connected to your participant. Please make sure there is contact with both DRL and CMS.

The Input Channel is Always Black

There could be two reasons for this happening:

1. There is no contact quality (see above); or

2. There could be an error with your FLEX Controller. If this is the case, please contact EMOTIV Support.

EMOTIV Support

If you are encountering problems with your FLEX or have any technical questions, the EMOTIV Support team can assist you. Visit the Contact Support page of the EMOTIV website and submit your query.

EMOTIV Knowledge Base

EMOTIV Knowledge Base provides useful information and solutions for common tasks related to EMOTIV’s headsets, software and user accounts.

FAQs

EMOTIV’s FAQs provide answers to some of the most common questions asked by the EMOTIV community.