© Copyright by Neurobit Systems 2010-2021
Neurobit Recorder (record.exe) is a simple but useful
enables physiological signals collected with equipment by Neurobit
Systems to be recorded. 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. Install driver software for USB chip by FTDI, as described in the device quick start guide. Connect the computer to the device and turn it on. The computer should detect the device and install the driver necessary for its USB module.
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 the Next button in lower right-hand corner of the window. The tabs contain options which depend on a selected device. These are the General tab with general device options and several tabs with settings for individual measurement channels. Additional tabs may also appear for some devices, e.g. Test tab. The Record tab enables recording 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 the 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 the measurement devices supported by the application is selected here.
Output format - 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. Therefore 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 the Browse folders button below the file field. The path and file name selected in the browse window will be copied to the "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 the 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 Check for updates during startup option. Then exit the application to save the settings on disc (they will be loaded at next sessions).
Link type - the 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 abovementioned 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.
Mains power frequency [Hz] - sets the 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 the user's geographic location (country) set in the system ("Control Panel"/"Regional and Language Options"/Location), when the Neurobit Driver starts for the first time, or when a user has changed the geographic location in the system since the 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 sometimes be necessary, for example:
Silent mode - turns off sound signaling of events (artifacts etc.) in the
device during measurements.
Visual signaling is not influenced. (The option is insignificant on the devices without sound transducer.)
Device services button - opens the application that provides device service functions, especially firmware updates.
Neurobit Optima devices have versatile measurement channels, which functions can be defined by a user. It should be taken into consideration, that the appearance and available settings of some parameters (e.g. Measurement range) may depend on other parameters (e.g. Channel function). When you change superior parameter, its dependent parameters are set to defaults.
Channel enable - checkbox enabling the measurement channel.
A short label for the channel (e.g. "EEG Cz"), which may be used by an application.
It is filled in automatically when the channel profile is changed manually on a channel tab (to an option other than "User defined"), and/or when the EEG cap connection is modified with settings on the cap tab (the cap enable, a set of connections, or site connected to a channel).
A label set this way can be changed manually afterwards. (The vhannel label is limited to 16 characters. It can be empty.)
You can enter here your short description of the transducer used (e.g. "AgAgCl electrode"), which may be used by an application. (This description is optional. It is limited to 80 characters.)
The profile enables the default parameters for some basic types of physiological signals to be set in one step (the fields of those parameters are then locked).
In order to freely set all parameters by yourself select the "User defined" option. It unlocks the rest of the parameters without changing them. (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, then select the "User defined" profile and make the required minor changes.)
It enables the measurement of voltage (default) or another physical quantity to be selected.
For voltage signals, this option enables the signal delay to be minimized or frequency bandwidth to be maximized. E.g. for the "Linear phase sharp" option the frequency bandwidth (in Hz) is 40% of the sample rate, and the signal delay of analog-to-digital conversion is 19 samples. For the "Linear phase mild" characteristic, the bandwidth is 30% of the sample rate, with an 11 sample delay.
Measurement range - selects the upper limit of signal values that
can be measured.
A higher range protects against clipping of high amplitude signals, while a lower range makes measurement more sensitive, thus reducing the quantization noise of analog-to-digital conversion.
(Note when the Channel function is set to measure conductance: the unit 1uS (micro Siemens) equals 1micromhO used in electrophysiology.)
Range minimum - the lower limit of measured signals (a read-only value which depends on the Measurement range setting).
Sample rate - selects number of output signal samples per second.
A higher sample rate enables faster signals to be measured, whereas a lower sample rate reduces high frequency noise, as well as the computational load of the processor and the size of the recorded signal files.
Lower limit frequency - selects the lower limit of frequency band, in which the signal is measured. Lower values enable slower signals to be measured, 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 DC offset is not removed for such a setting and could saturate the amplifier.
Power interference filter - turns on or off the device's mains
power interference filter.
(The filter notch frequency is set by the Mains power frequency option on the General tab.)
This option disconnects the sum voltage in the channel from the common voltage feedback amplifier (generating virtual ground potential). It has 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 defines the connection of the negative ("-") input of the given channel to a common reference electrode. (It applies only to channels with the function set to "Voltage".)
For Neurobit Optima[+] BT/USB devices:
There is an option of "Internal connection" to the common reference. Negative inputs of channels with such a selection are electronically linked together inside the device, and a common reference electrode should be connected directly to any of those inputs. No external jumper is necessary.
(If a so called "linked ears" circuit is used, the 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 another for EOG measurement on channels C and D), the second one requires "External connection" tp be set for the corresponding channels. And the negative inputs of the 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 the 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 a galvanic connection to the body (e.g. with a piezoelectric respiration sensor).
IMPORTANT: Even if the negative inputs are not linked internally in the device, proper setting of the Common reference field is necessary for correct electrode-skin impedance readings on the Test tab.
EEG cap connection - shows the 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 the connections of cap electrodes to individual measurement channels to be controlled.
Cap enable - enables the cap interface.
Immediately after checking this option all of the measurement channels are automatically:
If necessary, individual channel settings can be modified manually afterwards.
Unchecking this option does not change the settings on the channel tabs, except for EEG cap connection, which is set to "None" (and a corresponding change in the channel label).
Set1-5 - current set of cap sites linked to individual channels. The selected sites are shown in the Connections section of the tab.
5 available sets for 4 channel device enable all 19 sites of the International 10-20 EEG System (and one additional site) to be covered. It facilitates full QEEG evaluations (divided into 5 steps), among other things.
Connections - this section enables the connections of individual channels to the cap sites for the current set to be selected. (The lists of sites available for consecutive channels were chosen to maximize the number of practically useful combinations of sites for the available number of device channels.)
Site selections are disabled for channels, which are disabled or set to a function other than "Voltage".
Note: For channels connected to the cap, the general purpose positive inputs (A+, B+ and so on) should not be used. However it is possible to connect only some channels to the cap, and use others independently from the cap.
This tab enables input circuit connections and electrode-skin impedances for enabled channels to be tested before an 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 impedance on the + and - inputs of the differential channel. For channels with a non-voltage measurement setting, there is one set of indicators of connection resistance between + and - inputs of the channel. The indicators for disabled channels are inactive. Each set of indicators includes a bar gauge and digital value of impedance (resistance).
The bar gauges for channels with a voltage measurement setting change their colors depending on the impedance level:
Test button - initiates a 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 the Stop button (which replaces the Test button while a test is running).
IMPORTANT: For multi-channel measurements of voltage signals (for example EEG), suitable settings of the 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.
The state indicators shown on this tab can have up to four states:
Link - the state of the data link between measurement device and the computer.
It is red if the link is lost. This condition usually appears when the wireless device moves out of the communication range. If the device is quickly brought closer to the computer, the link will be restored and the session will continue. (If the communication disruption lasts for longer than about 60 seconds, the session will end.)
Battery - the state of the batteries in the wireless device.
If the indicator turns red (batteries flat), the device will turn off shortly. To avoid this situation it is recommended to replace the batteries, when the indicator turns yellow (batteries become weak).
Pause - not used for Neurobit Optima(+).
Common voltage - indicator of common voltage interference.
The so-called common voltage on the 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 the dynamic range of the amplifier. To avoid uncontrolled conditions of poor signal quality, Neurobit Optima(+) supervises the common voltage and indicates when it is too high (the indicator turns red). In most cases the cause of this condition is a lack of electrical contact between the Virtual Ground (VG) line and the examined subject's body.
Channel A - the state of the signal in channel A.
In moments, when the signal goes beyond the measurement range, this indicator turns red. It is usually caused by bad electrical contact of a sensor or high amplitude interference. This condition could also occur with a correct connection and input signal if too small measurement range was set for the channel.
The yellow indicator means the lack of a signal. This condition is detected when the measured signal is many times lower than the measurement range for a long time (consult the equipment manual for specific limits). Depending on the 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 a short circuit of the electrodes of both channel inputs (maybe due to an excessive amount of conductive gel). This condition may also occur with correct connections, as a result of too large a measurement range set for the channel.
Channel B-E - states of signals in channels B-E, similar as for the channel A.
Record button - initiates recording.
If the output file already exists, question about its rewriting appears. Other messages may also be shown, for example if the link between the device and computer cannot be established.
When physical measurement starts, the recording progress info appears above the button, and the state indicators become active. During the recording most of the configuration and the menu options are locked.
If the Realtime signal view option is 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 the Timescale menu options to adjust the plots.
Note: Possible changes of EDFbrowser settings are not preserved between consecutive recordings.
If the Time limit was set on the Session tab, recording will be stopped automatically, when that period expires. The session can also be stopped manually at any time with the Stop button replacing the Record button.
The only physical limit of the recording time is free space on disc, 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 a higher sample rate or more active channels the data size will increase proportionally.
Load device settings (F3) - loads device configuration saved earlier in a file.
Settings on the Session tab remain unchanged, apart from the 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 more channels or options, than stored in the given
file, they are set to defaults.
The settings on the Session tab remain unchanged.
Save device settings (F2) - saves device configuration in a file.
The settings on the Session tab are not stored, apart from the 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 update.
(The service window can also be opened with the Device services button on the General tab.)
Exit - closes the application.
It gives access to the application documentation (F1), license and information about the manufacturer.