1.Is waveguard original a certified medical device?
wave guard
Yes, the waveguard original caps are CE-certified as a Class I medical device and have FDA 510(k) clearance, for Canada these caps have been issued a class II device certification and FDA clearance under 510(k) and MDL. Note that some waveguard original caps created as a custom work or used for MEG, MRI, etc., might be exempt from medical device certification in your region. Please contact your distributor or nearest sales representative for further details on your cap model.
2.How do active electrodes relate to active shielding?
wave guard
Both active shielding and active electrodes aim to improve the signal-to-noise ratio of EEG recordings in non-shielded environments (e.g., electro-magnetically shielded Faraday booth) and ensure that the signal reaches the amplifier with minimal loses. However, they achieve this aim differently. Active electrodes amplify weak scalp signals before any transfer at the skull and then transmit these signals to the amplifier. Amplified signals are less susceptible to noise, therefore improving signal quality. However, this method has its limitations.
Despite the signal being amplified, it is still affected by the surrounding noise (e.g., 50Hz outlet noise) and suffers from the resistance of the cable. As a result, when an active electrode system is used in an environment with high electromagnetic noise, the final signal arrives at the amplifier with this electromagnetic noise with some loss of the original signal. In contrast, active shielding achieves the same objective by not allowing the external noise to reach the cable in the first place.
In addition, the very high input impedance of the eego amplifier ensures that the EEG itself is not impacted. Thus, active shielding achieves the exact same objective, without placing active electronics directly on the head, and at the same time keeping the cost of the cap reasonable while ensuring subject comfort.
Key benefits of active shielding:
• Good signals, even when your impedances are high
• Robust against 50/60 Hz environmental noise
• No need for expensive and fragile pre-amplifiers at the cap
Reference papers for further reading:
1. Kaul, H., Sylvester, D., & Blaauw, D. (2002, April). Active shields: A new approach to shielding global wires. In Proceedings of the 12th ACM Great Lakes symposium on VLSI (pp. 112-117).
2. Pizzamiglio, S., Abdalla, H., Naeem, U., & Turner, D. L. (2018). Neural predictors of gait stability when walking freely in the real-world. Journal of NeuroEngineering and Rehabilitation, 15(1), 11.
3.What are some benefits of the equidistant layout when compared to the (extended) 10-20 layout?
wave guard
The equidistant layout has some major advantages as compared to the traditional (extended) 10-20 layout.
First, the equidistant layout achieves a more homogeneous pressure distribution over the head. This is especially important for high-density setups (128 and more electrodes) and for dry electrode caps.
Secondly, the use of an equidistant layout also reduces the dependence on all electrodes in a dry cap or high density cap, for example, in an EEG recording with an electrode count of 32 channels or higher, the information from the neighbouring electrodes can be used to compensate for electrode(s) with bad contact.
Finally, the equidistant layout provides the best coverage of the head and is heavily utilized for source reconstruction purposes.
4.What are the best disinfection practices for the waveguard caps?
wave guard
General guidelines on cap disinfection and maintenance are covered in the waveguard user manuals that are provided with each system. Please note that the use of disinfectants over long periods of time might affect the longevity of the cap.
How to disinfect your waveguard cap:
1. Mix 4% of the disinfectant liquid with 96% distilled water in a bucket. (These quantities are stated for Korsolex Extra only, refer to guidelines from providers)
2. Wear protective gloves.
3. Completely submerge the cap in the liquid. Be careful to not wet the connectors.
4. Pull out the cap and submerge it again in the solution. Repeat this procedure at least 5 times.
5. Leave the cap submerged in the disinfectant for about 15 minutes.
6. Remove the cap from the bucket and rinse the net with distilled water.
Which disinfectants can be used for the waveguard caps: We have tested the waveguard caps against a list of disinfectants and can therefore only recommend from that list.
Some disinfectant solutions that we have tested our caps against are as below:
waveguard touch cap: Korsolex Extra (BODE Chemie)
waveguard gel, waveguard connect and waveguard nets:
Cidex OPA (by Advanced Sterilization Products) or Metricide, Cavicide (by Metrex), Pursept AF (by Schülke & Mayr), Sekusept activ (by Ecolab), or Korsolex Extra (by BODE Chemie).
5.What is the difference between gel-based and saline-based electrode systems?
wave guard
EEG studies use gel-based or saline-based solutions to achieve good electrode-skin contact. Gel-based and saline-based solutions have different advantages, which makes them suitable for different applications.
A traditional gel-based solution can be easily used in most application use-cases that are not time sensitive, where each measurement can last even upto 8-10 hours (for example, in sleep studies).
A saline-based solution is easier to use in the case of high-density electrode measurements (where gelling can be time-consuming for more than 64 electrodes) as well for cases where application time is crucial, the EEG measurement time in the case of saline nets have to be kept restricted to a period of 2-3 hours and the nets can be cleaned, resoaked in saline water between recordings.
The biggest difference between the two solutions is the application time. Normally it takes 30 minutes to 1 hour to achieve desired impedance in a gel-based electrode system, this time will differ based on the number of electrodes in the cap. The same procedure for saline-based electrode systems takes less than 15 minutes.
Finally, saline nets are easier to clean as compared to gel caps.
6.Does the eego system provide good signal quality?
eego system
Yes, eego is a state-of-the-art amplifier specifically designed to provide excellent signal quality in a variety of setups that make use of gel-based, saline-based or dry EEG caps. Our amplifiers have a high input impedance (> 1GΩ) which allows the signal quality to not suffer even at high impedance levels (>5 kΩ). The active shielding technology implemented in our systems further reduce the impact of cable artifacts even in demanding mobile setups.
7.Why are impedances noticed to be higher in dry caps as compared to conventional gel caps?
eego system
Dry caps and dry electrode technology are intended to support fast application times and use-cases that demand rapid EEG acquisitions without the usage of water or gel. Due to this, impedances can be generally higher for dry caps as compared to conventional gel caps.
To ensure optimal electrode-skin contact, the waveguard touch cap uses multi-pin Ag/AgCl-coated dry electrodes. The height of these multi-pin electrodes increase as one moves from the frontal to occipital regions to allow for good electrode-skin contact, even in areas with higher hair density.
Additionally, the eego software has an impedance threshold where the lower and higher limits can be adjusted as suitable for end-users and their use-cases, the eego amplifier also handles higher impedances very well due to the high input impedance (> 1GΩ) and the active shielding technology helps to keep recordings robust against movement or electromagnetic artifacts. Finally, an additional 'Quality Check' option is built into the eego software to allow users to focus on hardware-input signal quality and a reliability index, without spending too much time improving impedances for individual electrodes.
8.Can eego monitor the electrode skin impedance in parallel to the EEG recording?
eego system
The eego system can record signals from multiple sources like ECG, EOG, skin conductivity, respiration rate, etc., along with EEG. Some caps have EOG drop leads incorporated into the cap. Other signal sources could be recorded with either passive bipolar electrodes or through auxiliary electrodes connected to the sensebox adapter.
All of the signals from the EEG referential channels, active sensors and bipolars is available to the user on the same data-view. The impedance check can be performed before the recording starts. On the 'Online EEG' view of the eego software, a color-coded square label gives an indication of the last measured impedance value for that channel.
9.Is your eego system CE Certified?
eego system
The eegoTM amplifier in use within your solution comes with a CE class IIa certification. Both the hardware components and the eego software comply with the Council Directive 93/42/EEC concerning medical devices (MDD). The eego system also has FDA 510(k) clearance. This lends all users the flexibility and the confidence to carry forward their research with our CE-marked devices.
Please make sure to check with the distributor in your region for further details.
10.What is the durability of my waveguard cap?
waveguard
All waveguard caps are manufactured with high-quality, durable materials. There are no exposed wires in the caps as all wires are contained inside the cap fabric. Each waveguard cap also comes with integrated and pre-labelled electrode channels which makes fast application possible.
The waveguard touch cap and waveguard nets are designed to last for 250 recording and cleaning cycles, whereas the waveguard original cap can withstand 500 cycles of recording and cleaning. That said, we would like to emphasize that cap maintenance plays a huge role in extending the lifecycle of each cap in use.
11.How can I import a .cnt file into my analyses platform such as Matlab or Python?
waveguard
The eego software allows users to export their EEG data in a variety of formats such as 32 or 64bit .cnt, .eeg, .edf+ etc. Below, we focus on the .cnt type of exports as it is our native format.
We provide several pre-compiled importers for Matlab as well as plugins for toolboxes such as EEGLAB that are used routinely for EEG analyses. They are available directly for download on our website: http://download.ant-neuro.com/matlab/
How to work with the EEGLAB plugin:
- Download the EEGLAB plugin for your platform from the link above
- Place this downloaded folder under the ‘plugins’ subfolder of your EEGLAB version
- Make sure to set the path correctly to ensure that the functions get called
- More information can be found here: https://eeglab.org/others/EEGLAB_Extensions.html#To_install_or_update_an_EEGLAB_extension
How to open the .cnt file on EEGLAB:
- Launch EEGLAB by typing out ‘eeglab’ on the MATLAB command window
- In the consequent window that launches click on ‘File’ ---> ‘Import Data’ ---> ‘Using EEGLAB functions and plugins’ ----> ‘From ANT EEprobe .CNT file’ [Top figure]
- The corresponding window allows you to choose the .cnt file to analyze further. By default, the eego software exports data to the location Documents ---> Eego ----> export
- Once the file is loaded, you see the file information (Start/End epochs, sampling frequency etc) available to you [Bottom figure]
How to proceed if the above steps do not work for you:
Given that there are many possible combinations of operating systems, MATLAB versions and installation paths that can each result in a different binary, the source code is also made available to the users. We advise that incase you run into issues, the plugin is compiled from the source code provided via our sourcefurge page: https://sourceforge.net/projects/libeep/
How to open a .cnt file in Python:
https://gitlab.com/smeeze/libeep
Once again, we suggest that the instructions provided on this link are used to compile the importer from scratch for your Operating system and Python version.
12.How do I get my neo system connected to the internet?
neo monitor
The back-pane of the neo monitor has to be wedged out to access the ports secured underneath it. The LAN port is available in this section which needs to be connected to an Ethernet cable for internet access.
Each delivered neo system comes with a set of tools that can be employed to remove the back-pane.
13.Is my waveguard cap compatible with external amplifiers?
neo monitor
The waveguard caps come in a variety of layouts, electrode and connector types. All our caps are available in (extended)10-20 or equidistant layouts. Specifically, waveguard connect caps: Available with standard connectors (DB25, 3M etc) to enable direct connections to all major clinical EEG systems such as Neurosoft®, NicoletOne®, Nihon Kohden®, Mitsar®, Micromed® etc.
waveguard original, touch, net caps: These caps are recommended to be used in combination with the eego amplifier to take advantage of the active shielding technology.
We do provide adapters that might suit your use-case, and we would be happy to get in touch with you for custom requests. Please contact your nearest sales representative or distributor for more details.
14.Is the waveguard cap comfortable to wear during EEG recordings ?
waveguard
ANT Neuro’s caps come in different sizes covering a variety of age groups and head circumferences. The gel caps (waveguard original) come with silicone rings placed underneath each electrode channel, which sits comfortably on the subject’s scalp. The dry caps (Waveguard touch) consist of multi-pin electrodes that have adapted pin-height to allow for electrode-skin contact even in areas where the density of hair is higher. The waveguard nets come with sponges at each electrode channel as well which ensures subject comfort over extended durations.
The caps are made of high-quality Coolmax fabric which is stretchable and thus more comfortable even for extended experiment durations. Our cap design incorporates actively shielded electrodes instead of active electrodes, therefore the weight of the EEG cap is significantly reduced and allows the subject to remain mobile.
15. What are some best practices when it comes to using the waveguard touch caps ?
waveguard
The waveguard touch cap range consists of multi-pin dry electrodes coated with Ag/AgCl. These caps can directly be applied on the subjects' head without prior preparation. To ensure that signal quality is good, the following would be our recommendation:
a. Ensure that the impedances of the “REF” and “GND” channels of your cap have acceptable impedance values (atleast in the range of 50-60kOhms). This will lead to good impedances overall in all the other channels.
b. Make sure to gently pat down on the dry cap once it is applied onto the subject's scalp. This will help achieve better electrode-skin contact.
c. The areas with exposed skin can be cleaned with an alcohol pad prior to cap application to improve electrode impedances. For example, around the mastoid areas or on the frontal channels.
d. These practices can be paired with the right use and understanding of the features provided within the Dry EEG module in the eego software. Options such as the 'Artifact detection' and 'Artifact correction' views support the user in making the best use of their dry caps.
The waveguard touch cap can also be used for mobile, sports science experiments but it is advised to consider the limitations of any dry EEG system in physically intensive setups.
16. What do I need to have installed for the Support Team to remotely log into my PC?
waveguard
To log in remotely via the support account to a customer desktop remotely, the Teamviewer application must be used. This application already comes pre-installed on all devices supplied with the system. In case you do not have Teamviewer installed , you can proceed to downloading the "Teamviewer Host" application from the internet.
Once the application is downloaded and opened, you will be asked to communicate the user id and password that is shown on screen to the support engineer in charge. Please find the link to the Teamviewer software below:
https://www.teamviewer.com/en/
17.How can the eego system be used for all kinds of stationary or mobile experiments successfully?
eego system
The eego system provides enough flexibility and independence to the end-user, which makes it possible for researchers to include a wide range of target groups ranging from babies to the elderly.The eego system is a portable solution that consists of a battery-powered amplifier, protective soft shell and a recording device (usually a tablet).
This setup weighs less than 2 kilograms and is compact enough to be able to fit it all into the eego sports backpack. Our waveguard caps in combination with the eego amplifier make for an actively shielded system. This means that the recorded EEG signal is robust against a majority of interference sources in the external environment such as cable artifacts, movement-related artifacts, electromagnetic interference etc.
The eego software is Lab Streaming Layer (LSL) compatible which allows users to stream data out of this platform, and enables them to pull in software events into the EEG data view without the use of additional hardware.
The eego amplifier also has a trigger input port which can receive hardware/TTL triggers from 3rd party applications such as stimulus presentation platforms like e-prime or Presentation.
Users can therefore incorporate the system into a variety of innovative experimental setups.In addition, the eego system comes with a complimentary software development kit (SDK) that can be programmed to allow the eego amplifier to stream data to external platforms (such as MATLAB, OpenVibe and other custom platforms). Such features make it a front-runner in application areas related to BCI, neurofeedback, movement science studies, and virtual reality experiments.
18.How can TTL triggers and software events be sent to the eego system?
eego system
The eego system is capable of receiving TTL triggers and network events in the following manner:
a. TTL triggers are sent through trigger adapters connected to the 'Trigger' port of the eego amplifier
b. Software events can be sent to the eego software which is Lab Streaming Layer (LSL) compatible.
Receiving TTL triggers:
The eego system has the ability to receive TTL triggers via the built-in trigger port of the amplifier. Triggers can be sent by using the DB25 or BNC adapters. These cables can be connected to either a simple push-button device or a stimulus PC which can send triggers to the EEG data while recording is ongoing.
Receiving Network events:
The other way of sending events to the eego system is without the use of any hardware connections. This can be done by using Lab Streaming layer (LSL). By connecting all your devices to the same network, you can send software events to your eego system. To do this, you can select the "Enable Network Events" option in your eego software under Application Options. Once you enable this option, the software will show you all incoming event streams that are available on your network and you can select the stream of interest to pull markers into the eego software. You can read more about LSL via the link attached below:
https://github.com/sccn/labstreaminglayer
19.What level of modularity and flexibility can be expected from the eego system in different application contexts?
eego system
The eego mylab and eego sports packages are ready to be employed in your research or clinical setting.
For studies involving high-density recordings eego amplifiers support 32 and/or 64-channel recordings when employed independently but two or more amplifiers may be cascaded to support up to 256-channel recordings. Along with this, the software is also programmed to accommodate all compatible hardware setups where you can start recording simply by choosing the Device Type at your disposal.
20.In which data formats can I export my EEG recordings from the eego software?
eego system
The eego software allows data to be exported to several common file formats that ensure compatibility with your software of choice. The supported file formats include the following :
EEProbe 64bit extended .cnt
EEProbe 32 bit legacy .cnt
Neuroscan .cnt
ASCII .asc
BrainVision .eeg
EDF+ .edf
the eeprobe .cnt formats are our native format and we would recommend this as the export format. Please note that the Neuroscan, Brain Vision and EDF+ file formats are 3rd party formats, and certain limitations in functionality may apply for those export formats. In case of a question, do not hesitate to reach out to support@ant-neuro.com.
21.How can I measure external sensors along with EEG with my eego system ?
eego system
eegoTM has the ability to record additional physiological signals such as temperature, respiration rate, acceleration and galvanic skin response through auxiliary channels. In addition to this, it can also record standard bipolar channels such as EOG, ECG and EMG. These sensors need to be connected to a sense box (XS-271) as shown below, this adapter box can accommodate up to 6 inputs.
Each amplifier can support a maximum of 24 inputs via four cascaded sensebox connections. To set up the auxiliary sensors in the eegoTM software the amplifier layout can be modified to specify which particular bipolar (passive) and auxiliary (active) channels are part of the physical setup and define their connection order. You can refer to the eego extensions user manual in more detail on how to set up your auxiliary and bipolar channels with the help of the eego software.
22.What does the artifact reduction in the eego software actually do to correct noisy and unclean channels?
eego system
When acquiring data from dry electrodes, you may not be able to get all channels to a satisfying signal quality level. For this reason, the eego software comes with a "dry EEG module" that can be included as part of your license, and very much recommended to be used when acquiring data with our waveguard touch caps. The module can be accessed via the application options in the eego software. This module allows you to set a threshold value for detecting peak-to-peak artifacts. The module also allows you to view your data with the help of four different views as explained below:
1. Raw EEG view: The incoming data stream is displayed without employing any processing or filtering applied (unless filters are activated in the pre-selected montage).
2. Artifact Detected view: Here, the channels with detected artifacts can be made transparent to better visually distinguish them from the non-artefactual channels.
3. Artifact Corrected view: Data at channels that have an artifact is corrected based on available information from the neighbouring non-artifactual channels.
4. Virtual Channels: This includes a 21-channel montage that displays the spatially interpolated data in a 10/20 layout on your screen.
To find more detailed information on the artifact correction algorithm implemented within the eego software, please refer to the publication below:
Graichen, Uwe, et al. "SPHARA-a generalized spatial Fourier analysis for multi-sensor systems with non-uniformly arranged sensors: Application to EEG." PloS one 10.4 (2015): e0121741.
23.How to access applications (TeamViewer) on your neo system?
neomonitor
To let our Support personnel into the neo system remotely, you would first need to log into the Admin account and use the Windows search bar to launch the TeamViewer application. The user could also swipe up on the bottom ribbon bar of the system and search for TeamViewer via the Windows search options.
Most neo systems already have TeamViewer (Host) version installed for our easy access, incase not already installed, the user can download the TeamViewer Host version from here: https://www.teamviewer.com/en/download/windows/
24.How to check filter settings on your neo system filter settings?
neomonitor
To look through the filter settings activated on the neo system, the user needs to enter the 'Technical Setup' Workflow. This is available on the top right menu of the neo home screen. To enter this workflow, a password prompt of 0000 should be entered by the user.
Once the user enters this workflow, they need to expand the 'General Settings' option. They can then browse through the default settings for application options such as Language, Units, Impedance and Signal Quality, Filter, and export settings.
In the Filter settings option, the low-cut and high-cut frequency are set by default to 0.3 and 30Hz respectively. The Notch filter frequency remains at 50Hz. Do note that all filter values are changeable for the user.
25.How can I send and use annotations on neo?
neomonitor
To use Annotations during recording and review on neo, the user can create their own custom annotations via the Technical Setup workflow. The Technical setup workflow can be entered from the menu available on the right side of the neo home screen, and the password to enter this workflow is usually 0000.
The user can create their own annotations by click on the '+' symbol and specify both a description and colour for the annotation. It is important to check the boxes under 'Monitoring' and 'Review' to make sure that the annotations are seen in both phases.