© Copyright by Neurobit Systems 2010-2018
Neurobit Recorder (record.exe) is a simple, yet creating many possibilities
enables to record physiological signals collected wirelessly with equipment by Neurobit
Systems. Data can be stored on a computer disk in European Data Format (EDF) or text files.
They can be imported by many signal analysis or spreadsheet applications, such as
EEGLAB for Matlab,
Polyman or Excel
(including some freeware). For some devices, such as Neurobit Optima, the Neurobit
Recorder can also test electrode-skin impedances & input circuit continuity.
The application is running under Microsoft Windows 10/8/7/Vista/XP systems.
Neurobit Optima[+] Bluetooth devices:
Bluetooth communication port (built-in into a computer or as a USB adapter) compatible with the protocol version 1.1 or newer is required. To install Bluetooth adapter follow Neurobit Optima Quick Start Guide.
Neurobit Optima device should be set in wireless communication range (usually a few meters). Before the use a Bluetooth device should be paired with your computer. Pairing code for Neurobit Optima[+] is 0000. You can learn more about Bluetooth pairing in Windows help.
Neurobit Optima[+] USB devices:
A cable with full size USB type A connector on one end and micro USB type B connector on the other end (the same as for typical cell phone chargers) is required. Connect the computer to the device and turn it on. The computer will detect the device and install necessary drivers for its USB module. The setup is automatic in recent Windows systems. Older ones may require manual setup of drivers from the FTDI website .
Neurobit Lite devices:
Infrared (IR) communication port (built-in into a computer or in form of a USB adapter) compatible with IrDA standard v. 1.0 or newer is required. To install IrDA adapter follow an instruction delivered in its package.
The Neurobit Lite device should be set with IR port oriented towards IR port of your computer, no more than 0.5m from it, without physical obstructions between both entities, preferably on the same axis. There should be no other active IrDA devices nearby.
(In order to uninstall the application the uninstall.bat program from the application folder can be used.)
The main application window is divided into several tabs, which can be selected in the bar below main menu or with Next button in lower right corner of the window. Apart from the common Session tab there are tabs of options depending on a selected device. These are a General tab with general device options and several tabs with settings for individual measurement channels. There may also appear additional tabs for some devices, e.g. Test tab. The Record tab enables to run measurements with configuration set on previous tabs.
As an example, settings for Neurobit Optima+ 4 device are described below. Please consult instruction manual of your device model to learn about available settings.
You can enter here a short session description (up to 80 characters for EDF format), which will be saved in the recording file. (This setting is optional.)
You can enter here a short information about examined person. The information (up to 80 characters for EDF format) will be saved in the recording file. (This setting is optional.)
Recording duration can be given here in hh:mm:ss format (hours and minutes can be omitted). After the specified period of time the recording will be automatically stopped. (If necessary, it is still possible to shorten a recording session, stopping it manually; it is also possible to change time limit during the session.)
If this field is empty (or set to 0), the recording time is not automatically limited (measurement should be stopped manually).
One of measurement devices supported by the application is selected here.
Output format - selects format of the recording file.
EDF is a default. It is one of often used de facto standards for physiological signals.
The alternative text format (Tab Separated Values) needs many times more space, than binary EDF; also generated text files are not compatible with typical physiological signal analysis software. Thus this format should be used only when brief recording of data for spreadsheet or similar general purpose applications is required.)
Many other formats for bio-signal files are in use, e.g. BDF, GDF, EEG, CNT, AVG. If you need a file in another format, you can use one of free EDF converters available in the web, such as EDFbrowser.
Output file - name of the recording file (including its folder
path, if current folder is not used).
In order to browse folders on your computer, you can click Browse folders button below the file field. The path and file name selected in the browse window will be copied to "Output file" field.
Realtime signal view
Check this option if you want to display recorded signals in realtime. It is available only for Output format set to EDF.
NOTE: EDFbrowser freeware should be installed earlier. After the setup run EDFbrowser, in its main menu select the Settings option and click the Other tab. Then set Livestream update interval to 500 mSec, to achieve resonable frequency of plot updates during measurements. You can also set default vertical scale in the Default amplitude field (e.g. 5.00/cm for EEG) and disable the option Check for updates during startup. Then exit the application to save the settings on disk (they will be loaded at next sessions).
Link type - type of link used for communication with the device.
If you have only one turned on Neurobit device paired with your computer or connected to it via USB, you can use the mentioned generalized identifier in this field. Otherwise you need to identify each device unambiguously with its transceiver identifier. To check the identifiers follow instructions given in remarks of the Neurobit Loader help.
Power mains frequency [Hz] - sets mains frequency used in your
country, required for power interference filtering in the device.
For example, most European countries uses 50 Hz mains, while 60 Hz is used in North America. In most cases you can leave the default setting.
NOTES: The power frequency is set automatically, based on user's geographic location (country) set in the system ("Control Panel"/"Regional and Language Options"/Location), when the Neurobit Driver starts the first time, or when a user has changed geographic location in the system since previous start of the driver. The setting is then stored in the system registry. It is common for all applications using Neurobit Driver. Unlike other device settings, the power frequency is not read from design or configuration files.
Nevertheless, manual frequency selection may be sometimes necessary, for example:
Silent mode - turns off sound signalization of events (artifacts etc.) in the
device during measurements.
Visual signalization is not influenced. (The option is insignificant in devices without sound transducer.)
Device services button - opens the application of device service functions, especially firmware upgrade.
Neurobit Optima devices have versatile measurement channels, which functions can be defined by a user. It should be taken into consideration, that appearance and available settings of some parameters (e.g. Measurement range) may depend on other parameters (e.g. Channel function). When you change such superior parameter, all dependent parameters are set to defaults.
Channel enable - enables or disables the measurement channel.
A short label for the channel (e.g. "EEG Cz"), which will be stored in the recording file.
It is filled automatically when channel profile is changed manually on a channel tab (to an option other than "User defined"), and/or when EEG cap connection is modified with settings on the cap tab (the cap enable, a set of connections, or a site connected in a channel).
The label set this way can be still manually extended afterwards. (Channel label is limited to 16 characters. It can be empty.)
You can enter here your short description of used transducer (e.g. "AgAgCl electrode"), which will be stored in the recording file. (This description is optional. It is limited to 80 characters.)
The profile enables to set in one step the default parameters for some basic types of physiological signals (fields of those parameters are locked then).
In order to freely set all parameters by yourself select "User defined" option. It unlocks rest of the parameters without their change. (Thus if you would like to use default settings of most parameters for a specific profile (e.g. EEG) and set only one or two parameters on your own, you can first select that specific profile, next select "User defined" profile and do required minor changes.)
It enables to select measurement of voltage (default) or other physical quantity.
For voltage signals this option enables to minimize signal delay or maximize frequency bandwidth. E.g. for "Linear phase sharp" option the frequency bandwidth (in Hz) is 40% of sample rate, and signal delay of analog-to-digital conversion is 19 samples. For "Linear phase mild" characteristic the bandwidth is 30% of sample rate, with 11 samples delay.
Measurement range - selects upper limit of signal values, which
can be measured.
Higher range protects against clipping of high amplitude signals, while lower range makes measurement more sensitive, thus reduces quantization noise of analog-to-digital conversion.
(Note for Channel function set to conductance measurement: the unit 1uS (micro Siemens) equals 1micromhO used in electrophysiology.)
Range minimum - lower limit of measured signals (read only value depending on Measurement range setting).
Sample rate - selects number of output signal samples per second.
Higher sample rate enables to measure faster signals, whereas lower sample rate reduces high frequency noise, as well as computational load of a processor and size of recorded signal files.
Lower limit frequency - selects lower limit of frequency band, in which signal is measured. Lower values enable to measure slower signals, whereas higher values reduce low frequency noise and shorten transient states after sensor (dis)connection.
Value 0 (DC coupling), if available, should be used with care, as electrode offset, amplifier input offset and similar DC voltages are not removed for such setting.
Power interference filter - turns on or off device's filter of power
(Filter notch frequency is set by Power mains frequency option on General tab.)
The option disconnecting sum voltage in channel from common voltage feedback amplifier (generating virtual ground potential). This option have to be cleared for channels galvanically connected to the body (measuring EEG, EMG, GSR etc. signals on the skin surface). It is recommended to set this option for sensors without galvanic contact to the body (e.g. temperature probe).
This option informs about connection of negative ("-") input of a given channel to a common reference electrode. (This parameter does not apply to channel functions different than "Voltage".)
For Neurobit Optima[+] BT/USB devices:
There is an option of "Internal connection" to common reference. Negative inputs of channels with such selection are electronically linked together inside the device, and a common reference electrode should be connected directly to any of those inputs. No jumper is necessary.
(If so called "linked ears" circuit is used, electrodes on both ears should be connected directly to any negative inputs linked internally.)
If in some application two independent common references are necessary (e.g. one for channels A and B measuring EEG and the other for EOG measurement in channels C and D), the second one requires to set "External connection" for corresponding channels. And negative inputs of corresponding channels should be connected together and to a reference electrode with an external jumper.
For older Neurobit Optima models:
Up to two external common references can be selected. Negative inputs of corresponding channels have to be linked together and to a reference electrode(s) with an external jumper(s).
For all devices:
For bipolar derivations (channels measuring voltage differences between independent pairs of electrodes) the Common reference field should be set to "No connection". The same setting applies to voltage measurements without galvanic connection to the body (e.g. piezoelectric respiration sensor).
IMPORTANT: Even if negative inputs are not linked internally in the device, proper setting of Common reference field is necessary for correct electrode-skin impedance readings on the Test tab.
EEG cap connection - shows EEG cap site connected to the channel for devices equipped with the cap interface. Cap connections are controlled with settings on the EEG Cap tab described below.
Parameters for channels B-E are set similarly as for channel A.
For devices equipped with EEG cap interface this tab enables to control connections of cap electrodes to individual measurement channels.
Cap enable - enables the cap interface.
Just after checking this option all the measurement channels are automatically:
If necessary, individual channel settings can be modified manually afterwards.
Unchecking this option does not change the settings on channel tabs, except EEG cap connection, which is set to "None" (and corresponding change in the channel label).
Set1-5 - current set of cap sites linked to individual channels. Selected sites are shown in the Connections section of the tab.
5 available sets for 4 channel device enable to cover all (but one) sites of the International 10-20 EEG System. It facilitates full QEEG evaluations (divided into 5 steps), among other things.
Connections - this section enables to select connections of individual channels to the cap sites. (The lists of sites available for consecutive channels were chosen to maximize number of practically useful combinations of sites for given number of device channels.)
Site selections are disabled for channels, which are disabled or set to function other than "Voltage".
This tab enables to test input circuit connections and electrode-skin impedances for enabled channels before actual signal recordings. Although optional, execution of the test is recommended.
State indicators (Link, Battery, Pause,
Common voltage, Channel A-E
See similar indicators on Record tab.
For channels with voltage measurement setting there are two sets of indicators of electrode-skin impedances on inputs + and - of the differential channel. For channels with non-voltage measurement setting there is one set of indicators of connection resistance between + and - inputs of the channel. Indicators for disabled channels are inactive. Each set of indicators includes bar gauge and digital value of impedance (resistance).
Bar gauges for channels with voltage measurement setting change their colors depending on impedance level:
Test button - initiates test.
When physical measurement starts, the indicators become active. During the test most of the configuration options are locked. The test can be ended with Stop button, which appears instead of Test button.
IMPORTANT: For multi-channel measurements of voltage signals (for example EEG), suitable settings of Common reference fields on individual channel tabs are necessary for correct electrode-skin impedance readings.
This tab is used to record signals in accordance with configuration set on other tabs.
State indicators shown on this tab can have up to four states:
Link - state of wireless link between measurement device and computer.
It is red, if the link is lost. This condition usually appears when the Bluetooth device goes out of wireless communication range. If the device will be quickly brought closer to a computer, link will be restored and recording will continue. (If lack of communication is longer than about 60 seconds, recording will be ended.)
Battery - state of battery(ies) in measurement device.
If the indicator gets red (batteries flat), the device will turn off in a while. To avoid this situation it is recommended to replace batteries, when the indicator gets yellow (batteries become weak).
Pause - not used for Neurobit Optima(+).
Common voltage - indicator of common voltage interferences.
So called common voltage on inputs, which would strongly interfere with measurement of small electrophysiological signals, is almost totally removed by differential amplifiers. However, it is true only as far as the common voltage is within dynamic range of the amplifier. To avoid uncontrolled conditions of pure signal quality, Neurobit Optima(+) supervises common voltage and indicates when it is too high (the indicator becomes red). In most cases the cause of that condition is lack of electrical contact between Virtual Ground (VG) line and examined subject's body.
Channel A - state of signal in channel A.
At moments, when the signal goes beyond measurement range, this indicator gets red. It is usually caused by bad electrical contact of sensor or high amplitude interferences. This condition could also appear with correct connection and signal, if too small measurement range was set for the channel.
The yellow indicator means lack of signal. This condition is detected when measured signal is many times lower than measurement range for long time (consult the equipment manual for specific limits). Depending on type of signal it may be normal from time to time. If the condition occurs frequently or all the time, it may be caused by short circuit of electrodes of both channel inputs (maybe with excessive amount of conductive gel). This condition may also occur with correct connections, as a result of too large measurement range set for the channel.
Channel B-E - states of signals in consecutive channels, similar as for channel A.
Record button - initiates recording.
If the output file already exists, question about its rewriting appears. They may also be shown other messages, for example if link between the device and computer cannot be established.
When physical measurement starts, recording progress info appears above the button, and state indicators become active. During recording most of the configuration and menu options are locked.
If the option Realtime signal view has been checked on the Session tab,
EDFbrowser is launched in a few seconds. Click the Add signal(s) button
to start presentation of the currently recorded data. If necessary, use the Amplitude
and Timescale menu options to adjust the plots.
Note: Possible changes of EDFbrowser settings are not preserved between consecutive recordings.
If Time limit was set on the Session tab, recording will be stopped automatically, when that period expires. Session can be also stopped manually at any time with Stop button appearing instead of Record button.
The only physical limit of recording time is free space on disk, where output file
Example: For EDF output format each signal sample occupies 2 Bytes. If there are two enabled channels sampled at 250 sps, it yields 2 * 2 * 250 = 1000 Bytes per second, i.e. 3.6 MBytes per hour. For higher sample rate or more active channels data size will proportionally increase.
Load device settings (F3) - loads device configuration saved earlier in file.
Settings on the Session tab remain unchanged, apart from Device name field.
Import device settings (F4) - imports configuration of different, but
adequate device model, to the current device (e.g. from Neurobit Optima 2 to Neurobit Optima 4).
If the current device has got more channels or options, than stored in the given
file, they are set to defaults.
Settings on the Session tab remain unchanged.
Save device settings (F2) - saves device configuration in file.
Settings on the Session tab are not stored, apart from Device name field.
HINT: Apart from manual saving with this option, the application automatically stores current configuration at the beginning of measurement and before exit. This configuration is automatically loaded, when the application is started next time.
Device services - it opens an application of device service functions,
for example firmware upgrade.
(The service window can be also opened with Device services button on General tab.)
Exit - closes the application.
It gives access to the application documentation (F1), license and information about the manufacturer.