Frequently Asked Questions

High density surface EMG as described in the recent publications on the Biosemi site is possible with the addition of the sEMG accessories. The original model of the high density sEMG probe was made for ActiveOne, so the connector differed. The current version separates the electrode grid from the preamp as in:

• reusable grid
• sEMG preamplifier

Less dense sEMG can be accomplished with an elastic fabric with electrode holders like the EEG cap stretched over a muscle.  This would need to be custom-made, but would not be expensive.

Fine wire EMG would require either spring contact adapters or safety socket leads with inline active headstage. If your fine wire electrodes will be stripped but unterminated, you need spring contacts, and if your electrodes terminate in safety sockets, you need inline adapters.

We expect the new reinforced ActiveTwo active electrodes to last 350-500 uses, based on our experience with the new product so far, and based on automated repeated-strain testing.

The way ActiveTwo electrode sets are built, they are not repairable by the end-user, but we can replace single electrodes for you. We can so this quickly (24 hours plus transit), efficiently, and at low cost (or free under warranty). Electrodes are warranted against material/manufacturing defects for one year, and we charge by the repair after that. We find that offering extended warranties motivates less careful handling, so we don’t offer extended warranties.

Follow the steps in this other FAQ to identify the problem before contacting us to ask about the procedure and the cost of a repair.

We do offer individual EXG pin-type electrodes that you can insert in the cap as substitutes for faulty ribbon cable leads. This would be a short term stop gap solution only. We strongly recommend having a backup set of electrodes on hand after a year or two so that if the first set needs repair, you can continue to run with the other set while the repair is undertaken. You would not need to buy the spare set right away — just budget to have it once the electrodes have had enough use that they may begin experiencing problems. 250-350 recordings is a good mark for when you should have a spare set of electrodes on hand.

You CAN install current versions of ActiView on Windows 10. But, before you do so, if the system was orignally delivered before January of 2017 you should update the firmware on the optical receiver / USB interface so that you do not have to go through the very long and arduous process of installing an unsigned driver on Windows 10.

You can update the firmware using any Windows 7 or 8 computer with the MSWinUSB2 driver installed, even if it is not the computer you have been using for ActiView. If you are just using a Windows 7 or 8 computer to update firmware on the optical receiver / USB interface, there is no need to install the LabVIEW Runtime Engine or ActiView on this computer. You WILL need the LabVIEW Runtime Engine and ActiView on the new Windows 10 computer, but you WILL NOT need to install a driver after the firmware update has been performed.

See the procedure outlined at biosemi.com/ faq/install_USB.htm for detailed instructions.  The section at the bottom marked IMPORTANT is the place to begin.

The positions in these caps come from the Oostenveld and Praamstra 5% system.  See http://robertoostenveld.nl/electrode/ for background and for links to electrode coordinates in a variety of formats. Depending on what software you are using for analysis, we might be able to provide another file format. The Biosemi channel assignments (relating electrode labels to electrode sites in the Oostenveld and Praamstra nomenclature) are below:

ActiveTwo is provided with drivers and host data acquisition software for Windows and Mac computers, and drivers also exist for Linux. Note that certain applications, such as event-related potentials, often require a separate computer to run experimental control / stimulus delivery software.

In brief, the computer requirements for the ActiView data acquisition software are:

• Operating system: Windows 7, 8, or 10 or Mac OS X
• RAM: 8 GB or more
• Hard Drive: recommend 250 GB, but user should anticipate free space needed for data (file size in bytes is approximately = 3 X AD rate in Hz X number of channels X number of seconds recorded)
• Display: 1440 X 900 or higher resolution display
• One free USB port

Note: The ActiveTwo computer DOES NOT NEED A PARALLEL PORT.  A parallel port on the experimental control computer can be used to send stimuli to ActiveTwo.

In addition, the following are recommended for the ActiView computer:

• Network interface and remote storage for data backups
• Accessories such as KVMA switch box, extra monitor / keyboard / mouse, extension cables, etc to permit access to the EEG display from the separate room for the subject

Maybe.  There is no way the EEG system can harm the TMS system, but there are some TMS systems that are essentially useless with some EEG systems.  You need a a suitable combination of features in each to be successful at all in using TMS with EEG.

Desirable attributes:

• Coils designed specifically for use with EEG will have a cable that exits the coil tangential to the head surface so that the coil does not pass close by EEG electrodes and cables.
• A coil to be used with EEG should be passively cooled, since active cooling by means of a fan will induce electromagnetic interference in the EEG.
• The TMS recharge mechanism should be designed to avoid inducing electromagnetic artifacts in the EEG.
• The TMS system should be shielded so that no more than 3 milligauss of electromagnetic interference from the TMS system’s power supply reaches the electrodes and cables.
• The TMS system should be able to produce a TMS pulse in response to an input trigger with a low and predictable latency.  Long, but especially unpredictable latency in responding to an input trigger will result in TMS artifacts that are difficult to impossible to remove from the EEG.

Aside from attributes of the TMS system, there are also important considerations regarding the EEG system in this relationship. See the other FAQ entry on that topic.

No.  There are a few special attributes that are required and others that are desirable.

Required attributes:

• Inputs should be protected so that they are not damaged by the TMS pulse
• Frequency response on all channels should be from DC on the low end, since AC coupled inputs will “ring” when presented with a large voltage transient like the TMS artifact

Desirable attributes:

• Electrodes should have a low-profile so that the TMS coil can be placed as near the head as possible, maximizing penetration depth and current delivery
• It is important for the EEG system to be able to trigger the TMS system at precisely the same phase with respect to the EEG samples each time a stimulus is delivered.  This will improve the performance of artifact removal algorithms

Aside from these attributes of the EEG system, there are also important considerations regarding the TMS system in this relationship. See the other FAQ entry on that topic.

Electrodes and head caps can have positions derived from systems based on the International 1020 System.  When the positions are based on 1020, the labels on the caps and electrodes can either be the actual 1020 position names (such as Fp1, Cz, etc) or they can be what is called ABC, which actually means A1, A2, …A32, B1, B2,…B32, etc  Another way to refer to the ABC labeling is arbitrary alphanumeric.  The 1020 system is not arbitrary because the names are based on anatomical landmarks and the odd=left and even=right numbering is predictable and interpretable.  When you have only one type of cap in your lab, it makes sense to use 1020 labels for caps with positions based on the 1020 system.  However, if you have 32 channel caps AND 64 channel caps, then you might find it useful to be able to use the A1-32 labels for the A cable and the B1-32 labels for the B cable and complementary A1-32 labels on the 32 channel caps and A1-B32 labels on the 64 channel caps.  This way, the A cable can be used for the whole head in 32 channel studies of for just the left side of the head in 64 channel studies.  This does provide a short term savings if you don’t want to have two A cables on-hand, but using 1020 labels on everything is more convenient and at the limit it will not cost any more (because cables that are used less frequently will last longer).

When you purchase a new laboratory instrument, you want to get started using it and producing results as quickly as possible, and nothing helps you accomplish this goal faster than having a trained technician visit your lab to install the system and configure it optimally for your purposes. From our perspective, you will have the best possible experience with our products when the equipment is setup and configured properly and you are properly trained from the beginning. Installation visits are not included in the pricing on our standard price list, but we do generally include an optional installation fee on quotations. We find that customers who receive assistance from the beginning have fewer questions later and have more success using the equipment. We encourage you to invest in this valuable service.  If you would like to arrange an installation and training visit, please contact us!

We will always do our best to respond quickly when you need something urgently.  It helps us immensely if you plan ahead and give us a little advance warning if you foresee a deadline approaching by which you need parts, supplies or repairs to be complete.

For new purchases, we can often pre-order goods for established customers, even before the official institutional PO has been received.  Give us a heads-up as soon as you know that you intend to order items we have quoted you, and if you expect to have the official PO within 30 days, and you agree to let us know if anything changes, we will pre-order the goods for you based on your word.

For repairs, we know how vital our equipment is to your work, so we always do our best to respond quickly to urgent repair requests.  One important point — the earlier we know the date by which a repaired item must be received back, the sooner we can let you know whether we will or will not be able to meet that deadline.  Ultimately, the most valuable thing you can do to ensure we meet your deadlines is to notify us of those deadlines as early as possible!

See our contact details page.

High density surface EMG as described in the recent publications on the Biosemi site is possible with the addition of the sEMG accessories. The original model of the high density sEMG probe was made for ActiveOne, so the connector differed. The current version separates the electrode grid from the preamp as in:

• reusable grid
• sEMG preamplifier

Less dense sEMG can be accomplished with an elastic fabric with electrode holders like the EEG cap stretched over a muscle.  This would need to be custom-made, but would not be expensive.

Fine wire EMG would require either spring contact adapters or safety socket leads with inline active headstage. If your fine wire electrodes will be stripped but unterminated, you need spring contacts, and if your electrodes terminate in safety sockets, you need inline adapters.

We expect the new reinforced ActiveTwo active electrodes to last 350-500 uses, based on our experience with the new product so far, and based on automated repeated-strain testing.

The way ActiveTwo electrode sets are built, they are not repairable by the end-user, but we can replace single electrodes for you. We can so this quickly (24 hours plus transit), efficiently, and at low cost (or free under warranty). Electrodes are warranted against material/manufacturing defects for one year, and we charge by the repair after that. We find that offering extended warranties motivates less careful handling, so we don’t offer extended warranties.

Follow the steps in this other FAQ to identify the problem before contacting us to ask about the procedure and the cost of a repair.

We do offer individual EXG pin-type electrodes that you can insert in the cap as substitutes for faulty ribbon cable leads. This would be a short term stop gap solution only. We strongly recommend having a backup set of electrodes on hand after a year or two so that if the first set needs repair, you can continue to run with the other set while the repair is undertaken. You would not need to buy the spare set right away — just budget to have it once the electrodes have had enough use that they may begin experiencing problems. 250-350 recordings is a good mark for when you should have a spare set of electrodes on hand.

You CAN install current versions of ActiView on Windows 10. But, before you do so, if the system was orignally delivered before January of 2017 you should update the firmware on the optical receiver / USB interface so that you do not have to go through the very long and arduous process of installing an unsigned driver on Windows 10.

You can update the firmware using any Windows 7 or 8 computer with the MSWinUSB2 driver installed, even if it is not the computer you have been using for ActiView. If you are just using a Windows 7 or 8 computer to update firmware on the optical receiver / USB interface, there is no need to install the LabVIEW Runtime Engine or ActiView on this computer. You WILL need the LabVIEW Runtime Engine and ActiView on the new Windows 10 computer, but you WILL NOT need to install a driver after the firmware update has been performed.

See the procedure outlined at biosemi.com/ faq/install_USB.htm for detailed instructions.  The section at the bottom marked IMPORTANT is the place to begin.

The positions in these caps come from the Oostenveld and Praamstra 5% system.  See http://robertoostenveld.nl/electrode/ for background and for links to electrode coordinates in a variety of formats. Depending on what software you are using for analysis, we might be able to provide another file format. The Biosemi channel assignments (relating electrode labels to electrode sites in the Oostenveld and Praamstra nomenclature) are below:

1. In the ActiView software, select About ActiView > Load CFG.
2. Navigate to the folder called Configuring and select the CFG that matches your head caps.  For example, if you have Biosemi standard 32 channel head-caps and want the 10-20 labels to be displayed, the file you want is “10-20system32+8.cfg”.
3. Once this CFG is loaded, go back to the Monopolar display tab in ActiView, and check the Decimation Ratio. This indirectly controls the sampling rate, being a fraction by which the AD rate defined by the speedmode (AD rate on the AD box) is multiplied.  If you are operating in speedmode 4 (2048 Hz on the AD box), then a decimation ratio of 1/4 could be used to arrive at 512 Hz sampling rate to file, for example.
4. After setting the Decimation Ratio, check the settings for the Filters and Reference on the left side of the Monopolar Display tab.  We recommend un-checking (turning off) both of the display filters and setting the Reference to None (Raw). This gives the operator the truest picture of the saved data as data are being recorded.
5. Next, verify that any auxiliary sensors you will be using have been selected in the Auxiliary Sensors tab.  It is best to select (highlight) only the sensors you will be using (or the superset of sensors you may use) so that unused sensor channels are not added to your data file.
6. Save a dummy data file in ActiView by selecting Start File, verifying that the right subset of EEG electrodes is selected (in the example case, A1-32), verifying that the EXG1-8 channels are being added if you want them, and selecting Add Displayed Sensors (the ones you selected before in the Auxiliary Sensors tab).
7. When ActiView asks for a path / file name (it may produce an error message about the default path not existing — just click to close), navigate to the default folder for data to be saved in for this experiment (or if this CFG will serve several experiments, point to the parent folder that contains folders for various experiments) and enter a file name like this “CHANGE THIS FILE NAME AND PATH AS NEEDED”.
8. Click Stop at the top left side of the ActiView screen to stop writing to the dummy data file.
9. Navigate to About ActiView > Save CFG and save the CFG file to the folder where the ActiView software executable is located. If you name this CFG as DEFAULT.CFG, it will be used automatically when ActiView opens. If you will have various CFG files for various experiments, then you should save the new CFG with a name that relates to the associated experiment, and be sure to rename the existing DEFAULT.CFG to _DEFAULT.CFG. By doing this, ActiView will force the operator to select a CFG file each time the ActiView software is opened. One important note – if the operator does not close ActiView at the end of a recording, the CFG file will still be loaded, and the next operator may not notice. For this reason, operators should be vigilant about closing ActiView at the end of a recording, and if they enter the lab to find ActiView open, they should close it, then reopen it so that it will remind them to load the correct CFG for their study.

Since mid-2016, Biosemi has included a black USB virtual serial port trigger cable with each new ActiveTwo system.  The device is depicted below.

Inside the shell of the 37 pin connector is a microchip that appears to the stimulus computer as a virtual serial port but provides 8 bit parallel TTL output to the ActiveTwo trigger input port.  Because it appears as a virtual serial port on the stimulus computer, this cable is a relatively universal solution for triggering ActiveTwo from virtually any software on any platform.  There are a few simple parameters you need to know to send triggers via this device.  For details, see:

• https://www.biosemi.com/faq/USB%20Trigger%20interface%20cable.htm

To use this trigger cable with MATLAB, Roee Gilron at UCSF (thanks, Roee!) provides a code sample at Github:

• https://github.com/roeegilron/BioSemiUSBtrigger

ActiveTwo is provided with drivers and host data acquisition software for Windows and Mac computers, and drivers also exist for Linux. Note that certain applications, such as event-related potentials, often require a separate computer to run experimental control / stimulus delivery software.

In brief, the computer requirements for the ActiView data acquisition software are:

• Operating system: Windows 7, 8, or 10 or Mac OS X
• RAM: 8 GB or more
• Hard Drive: recommend 250 GB, but user should anticipate free space needed for data (file size in bytes is approximately = 3 X AD rate in Hz X number of channels X number of seconds recorded)
• Display: 1440 X 900 or higher resolution display
• One free USB port

Note: The ActiveTwo computer DOES NOT NEED A PARALLEL PORT.  A parallel port on the experimental control computer can be used to send stimuli to ActiveTwo.

In addition, the following are recommended for the ActiView computer:

• Network interface and remote storage for data backups
• Accessories such as KVMA switch box, extra monitor / keyboard / mouse, extension cables, etc to permit access to the EEG display from the separate room for the subject

Maybe.  There is no way the EEG system can harm the TMS system, but there are some TMS systems that are essentially useless with some EEG systems.  You need a a suitable combination of features in each to be successful at all in using TMS with EEG.

Desirable attributes:

• Coils designed specifically for use with EEG will have a cable that exits the coil tangential to the head surface so that the coil does not pass close by EEG electrodes and cables.
• A coil to be used with EEG should be passively cooled, since active cooling by means of a fan will induce electromagnetic interference in the EEG.
• The TMS recharge mechanism should be designed to avoid inducing electromagnetic artifacts in the EEG.
• The TMS system should be shielded so that no more than 3 milligauss of electromagnetic interference from the TMS system’s power supply reaches the electrodes and cables.
• The TMS system should be able to produce a TMS pulse in response to an input trigger with a low and predictable latency.  Long, but especially unpredictable latency in responding to an input trigger will result in TMS artifacts that are difficult to impossible to remove from the EEG.

Aside from attributes of the TMS system, there are also important considerations regarding the EEG system in this relationship. See the other FAQ entry on that topic.

No.  There are a few special attributes that are required and others that are desirable.

Required attributes:

• Inputs should be protected so that they are not damaged by the TMS pulse
• Frequency response on all channels should be from DC on the low end, since AC coupled inputs will “ring” when presented with a large voltage transient like the TMS artifact

Desirable attributes:

• Electrodes should have a low-profile so that the TMS coil can be placed as near the head as possible, maximizing penetration depth and current delivery
• It is important for the EEG system to be able to trigger the TMS system at precisely the same phase with respect to the EEG samples each time a stimulus is delivered.  This will improve the performance of artifact removal algorithms

Aside from these attributes of the EEG system, there are also important considerations regarding the TMS system in this relationship. See the other FAQ entry on that topic.

Electrodes and head caps can have positions derived from systems based on the International 1020 System.  When the positions are based on 1020, the labels on the caps and electrodes can either be the actual 1020 position names (such as Fp1, Cz, etc) or they can be what is called ABC, which actually means A1, A2, …A32, B1, B2,…B32, etc  Another way to refer to the ABC labeling is arbitrary alphanumeric.  The 1020 system is not arbitrary because the names are based on anatomical landmarks and the odd=left and even=right numbering is predictable and interpretable.  When you have only one type of cap in your lab, it makes sense to use 1020 labels for caps with positions based on the 1020 system.  However, if you have 32 channel caps AND 64 channel caps, then you might find it useful to be able to use the A1-32 labels for the A cable and the B1-32 labels for the B cable and complementary A1-32 labels on the 32 channel caps and A1-B32 labels on the 64 channel caps.  This way, the A cable can be used for the whole head in 32 channel studies of for just the left side of the head in 64 channel studies.  This does provide a short term savings if you don’t want to have two A cables on-hand, but using 1020 labels on everything is more convenient and at the limit it will not cost any more (because cables that are used less frequently will last longer).

If you have more than one item to be repaired, we will normally issue a separate work order number for each item.  In that case, it is not necessary to ship the items to us separately.  They can be packed together, assuming you pack carefully and include the documentation we request when we send you the work order number:

• Include the “work order number” on the package and on any documentation in the package.  If a repair is undertaken, the work order number will become the “invoice number” if the repair results in a bill for parts or services.
• Write a note describing the problem you are having with the part and include it in the package with the part you are returning.  We need to be sure that we are focusing on the same problem that you have been experiencing to do the best job of reporting back to you on the status of the product.
• Be sure that the note you include with the shipment references as many of the following as possible: the date of purchase, name of purchaser or customer account number.
• Let us know the address to which repaired parts should be shipped (must be a physical address with a phone number and person’s name).

Before you send anything to us for repair, please contact us so we can assess the situation and be sure that is the best course of action.   Once you have exhausted all available options, we may authorize you to return an item for repair.  At that point, see the steps below under “How to arrange for a repair”.

Many potential questions and problems are covered under the manufacturers’ warranties for the products we sell.  As a general rule, if the item you are trying to use is not broken, then support for that item would either be provided as a part of the original purchase agreement or under an extended service level agreement. See the Service Level Agreements page and the Warranties page for details.

If you feel that you need additional training in the use of the equipment or software that you purchased from us. Please review the upcoming training opportunities under Workshops/Seminars on our Events page and let us know if you do not see a workshop or seminar that covers the topic in which you are interested.

How to arrange for a repair:

1. Review the User / Operator Manual and/or context-sensitive help provided with the product to determine as best you can whether a repair is needed.
2. See the on-line FAQ documents.
3. Contact us to receive additional assistance in identifying possible solutions that may not necessitate the return of the product.
4. Please provide us with the serial number and the model number of the item you request assistance with as well as the data of purchase and the name of the purchaser or your customer account number.
5. Ask us for an “issue number” and refer to that issue number when corresponding with us about this problem.  The issue number will become the “work order number” if a repair is undertaken and the “invoice number” if the repair results in a bill for parts or services.
6. Write a note describing the problem you are having with the part and include it in the package with the part you are returning.  We need to be sure that we are focusing on the same problem that you have been experiencing to do the best job of reporting back to you on the status of the product.
7. Be sure the note you include with the shipment references the date of purchase, name of purchaser or customer account number, the address to which repaired parts should be shipped (must be a physical address with a phone number and person’s name for FedEx to accept it).
8. Wrap any electrode contacts in a paper towel to be sure that they stay dry and to insulate them from metal parts on the connector.
9. Package the product carefully in the original packaging or a comparable container.  Use plenty of packing material (preferably bubble wrap or packing peanuts) to cushion the goods and ensure they do not move around inside the box while it is in transit.  For help on how to package your goods, see the document “How to Pack” at FedEx.com.
10. Ship the goods via traceable courier service to our address and notify us that the package is en route.
11. When contacting us to check on the status of your repair, refer to the issue/work order number.

When you purchase a new laboratory instrument, you want to get started using it and producing results as quickly as possible, and nothing helps you accomplish this goal faster than having a trained technician visit your lab to install the system and configure it optimally for your purposes. From our perspective, you will have the best possible experience with our products when the equipment is setup and configured properly and you are properly trained from the beginning. Installation visits are not included in the pricing on our standard price list, but we do generally include an optional installation fee on quotations. We find that customers who receive assistance from the beginning have fewer questions later and have more success using the equipment. We encourage you to invest in this valuable service.  If you would like to arrange an installation and training visit, please contact us!

We will always do our best to respond quickly when you need something urgently.  It helps us immensely if you plan ahead and give us a little advance warning if you foresee a deadline approaching by which you need parts, supplies or repairs to be complete.

For new purchases, we can often pre-order goods for established customers, even before the official institutional PO has been received.  Give us a heads-up as soon as you know that you intend to order items we have quoted you, and if you expect to have the official PO within 30 days, and you agree to let us know if anything changes, we will pre-order the goods for you based on your word.

For repairs, we know how vital our equipment is to your work, so we always do our best to respond quickly to urgent repair requests.  One important point — the earlier we know the date by which a repaired item must be received back, the sooner we can let you know whether we will or will not be able to meet that deadline.  Ultimately, the most valuable thing you can do to ensure we meet your deadlines is to notify us of those deadlines as early as possible!

See our contact details page.

High density surface EMG as described in the recent publications on the Biosemi site is possible with the addition of the sEMG accessories. The original model of the high density sEMG probe was made for ActiveOne, so the connector differed. The current version separates the electrode grid from the preamp as in:

• reusable grid
• sEMG preamplifier

Less dense sEMG can be accomplished with an elastic fabric with electrode holders like the EEG cap stretched over a muscle.  This would need to be custom-made, but would not be expensive.

Fine wire EMG would require either spring contact adapters or safety socket leads with inline active headstage. If your fine wire electrodes will be stripped but unterminated, you need spring contacts, and if your electrodes terminate in safety sockets, you need inline adapters.

We expect the new reinforced ActiveTwo active electrodes to last 350-500 uses, based on our experience with the new product so far, and based on automated repeated-strain testing.

The way ActiveTwo electrode sets are built, they are not repairable by the end-user, but we can replace single electrodes for you. We can so this quickly (24 hours plus transit), efficiently, and at low cost (or free under warranty). Electrodes are warranted against material/manufacturing defects for one year, and we charge by the repair after that. We find that offering extended warranties motivates less careful handling, so we don’t offer extended warranties.

Follow the steps in this other FAQ to identify the problem before contacting us to ask about the procedure and the cost of a repair.

We do offer individual EXG pin-type electrodes that you can insert in the cap as substitutes for faulty ribbon cable leads. This would be a short term stop gap solution only. We strongly recommend having a backup set of electrodes on hand after a year or two so that if the first set needs repair, you can continue to run with the other set while the repair is undertaken. You would not need to buy the spare set right away — just budget to have it once the electrodes have had enough use that they may begin experiencing problems. 250-350 recordings is a good mark for when you should have a spare set of electrodes on hand.

You CAN install current versions of ActiView on Windows 10. But, before you do so, if the system was orignally delivered before January of 2017 you should update the firmware on the optical receiver / USB interface so that you do not have to go through the very long and arduous process of installing an unsigned driver on Windows 10.

You can update the firmware using any Windows 7 or 8 computer with the MSWinUSB2 driver installed, even if it is not the computer you have been using for ActiView. If you are just using a Windows 7 or 8 computer to update firmware on the optical receiver / USB interface, there is no need to install the LabVIEW Runtime Engine or ActiView on this computer. You WILL need the LabVIEW Runtime Engine and ActiView on the new Windows 10 computer, but you WILL NOT need to install a driver after the firmware update has been performed.

See the procedure outlined at biosemi.com/ faq/install_USB.htm for detailed instructions.  The section at the bottom marked IMPORTANT is the place to begin.

The positions in these caps come from the Oostenveld and Praamstra 5% system.  See http://robertoostenveld.nl/electrode/ for background and for links to electrode coordinates in a variety of formats. Depending on what software you are using for analysis, we might be able to provide another file format. The Biosemi channel assignments (relating electrode labels to electrode sites in the Oostenveld and Praamstra nomenclature) are below:

1. In the ActiView software, select About ActiView > Load CFG.
2. Navigate to the folder called Configuring and select the CFG that matches your head caps.  For example, if you have Biosemi standard 32 channel head-caps and want the 10-20 labels to be displayed, the file you want is “10-20system32+8.cfg”.
3. Once this CFG is loaded, go back to the Monopolar display tab in ActiView, and check the Decimation Ratio. This indirectly controls the sampling rate, being a fraction by which the AD rate defined by the speedmode (AD rate on the AD box) is multiplied.  If you are operating in speedmode 4 (2048 Hz on the AD box), then a decimation ratio of 1/4 could be used to arrive at 512 Hz sampling rate to file, for example.
4. After setting the Decimation Ratio, check the settings for the Filters and Reference on the left side of the Monopolar Display tab.  We recommend un-checking (turning off) both of the display filters and setting the Reference to None (Raw). This gives the operator the truest picture of the saved data as data are being recorded.
5. Next, verify that any auxiliary sensors you will be using have been selected in the Auxiliary Sensors tab.  It is best to select (highlight) only the sensors you will be using (or the superset of sensors you may use) so that unused sensor channels are not added to your data file.
6. Save a dummy data file in ActiView by selecting Start File, verifying that the right subset of EEG electrodes is selected (in the example case, A1-32), verifying that the EXG1-8 channels are being added if you want them, and selecting Add Displayed Sensors (the ones you selected before in the Auxiliary Sensors tab).
7. When ActiView asks for a path / file name (it may produce an error message about the default path not existing — just click to close), navigate to the default folder for data to be saved in for this experiment (or if this CFG will serve several experiments, point to the parent folder that contains folders for various experiments) and enter a file name like this “CHANGE THIS FILE NAME AND PATH AS NEEDED”.
8. Click Stop at the top left side of the ActiView screen to stop writing to the dummy data file.
9. Navigate to About ActiView > Save CFG and save the CFG file to the folder where the ActiView software executable is located. If you name this CFG as DEFAULT.CFG, it will be used automatically when ActiView opens. If you will have various CFG files for various experiments, then you should save the new CFG with a name that relates to the associated experiment, and be sure to rename the existing DEFAULT.CFG to _DEFAULT.CFG. By doing this, ActiView will force the operator to select a CFG file each time the ActiView software is opened. One important note – if the operator does not close ActiView at the end of a recording, the CFG file will still be loaded, and the next operator may not notice. For this reason, operators should be vigilant about closing ActiView at the end of a recording, and if they enter the lab to find ActiView open, they should close it, then reopen it so that it will remind them to load the correct CFG for their study.

Since mid-2016, Biosemi has included a black USB virtual serial port trigger cable with each new ActiveTwo system.  The device is depicted below.

Inside the shell of the 37 pin connector is a microchip that appears to the stimulus computer as a virtual serial port but provides 8 bit parallel TTL output to the ActiveTwo trigger input port.  Because it appears as a virtual serial port on the stimulus computer, this cable is a relatively universal solution for triggering ActiveTwo from virtually any software on any platform.  There are a few simple parameters you need to know to send triggers via this device.  For details, see:

• https://www.biosemi.com/faq/USB%20Trigger%20interface%20cable.htm

To use this trigger cable with MATLAB, Roee Gilron at UCSF (thanks, Roee!) provides a code sample at Github:

• https://github.com/roeegilron/BioSemiUSBtrigger

ActiveTwo is provided with drivers and host data acquisition software for Windows and Mac computers, and drivers also exist for Linux. Note that certain applications, such as event-related potentials, often require a separate computer to run experimental control / stimulus delivery software.

In brief, the computer requirements for the ActiView data acquisition software are:

• Operating system: Windows 7, 8, or 10 or Mac OS X
• RAM: 8 GB or more
• Hard Drive: recommend 250 GB, but user should anticipate free space needed for data (file size in bytes is approximately = 3 X AD rate in Hz X number of channels X number of seconds recorded)
• Display: 1440 X 900 or higher resolution display
• One free USB port

Note: The ActiveTwo computer DOES NOT NEED A PARALLEL PORT.  A parallel port on the experimental control computer can be used to send stimuli to ActiveTwo.

In addition, the following are recommended for the ActiView computer:

• Network interface and remote storage for data backups
• Accessories such as KVMA switch box, extra monitor / keyboard / mouse, extension cables, etc to permit access to the EEG display from the separate room for the subject

Maybe.  There is no way the EEG system can harm the TMS system, but there are some TMS systems that are essentially useless with some EEG systems.  You need a a suitable combination of features in each to be successful at all in using TMS with EEG.

Desirable attributes:

• Coils designed specifically for use with EEG will have a cable that exits the coil tangential to the head surface so that the coil does not pass close by EEG electrodes and cables.
• A coil to be used with EEG should be passively cooled, since active cooling by means of a fan will induce electromagnetic interference in the EEG.
• The TMS recharge mechanism should be designed to avoid inducing electromagnetic artifacts in the EEG.
• The TMS system should be shielded so that no more than 3 milligauss of electromagnetic interference from the TMS system’s power supply reaches the electrodes and cables.
• The TMS system should be able to produce a TMS pulse in response to an input trigger with a low and predictable latency.  Long, but especially unpredictable latency in responding to an input trigger will result in TMS artifacts that are difficult to impossible to remove from the EEG.

Aside from attributes of the TMS system, there are also important considerations regarding the EEG system in this relationship. See the other FAQ entry on that topic.

Electrodes and head caps can have positions derived from systems based on the International 1020 System.  When the positions are based on 1020, the labels on the caps and electrodes can either be the actual 1020 position names (such as Fp1, Cz, etc) or they can be what is called ABC, which actually means A1, A2, …A32, B1, B2,…B32, etc  Another way to refer to the ABC labeling is arbitrary alphanumeric.  The 1020 system is not arbitrary because the names are based on anatomical landmarks and the odd=left and even=right numbering is predictable and interpretable.  When you have only one type of cap in your lab, it makes sense to use 1020 labels for caps with positions based on the 1020 system.  However, if you have 32 channel caps AND 64 channel caps, then you might find it useful to be able to use the A1-32 labels for the A cable and the B1-32 labels for the B cable and complementary A1-32 labels on the 32 channel caps and A1-B32 labels on the 64 channel caps.  This way, the A cable can be used for the whole head in 32 channel studies of for just the left side of the head in 64 channel studies.  This does provide a short term savings if you don’t want to have two A cables on-hand, but using 1020 labels on everything is more convenient and at the limit it will not cost any more (because cables that are used less frequently will last longer).

If you have more than one item to be repaired, we will normally issue a separate work order number for each item.  In that case, it is not necessary to ship the items to us separately.  They can be packed together, assuming you pack carefully and include the documentation we request when we send you the work order number:

• Include the “work order number” on the package and on any documentation in the package.  If a repair is undertaken, the work order number will become the “invoice number” if the repair results in a bill for parts or services.
• Write a note describing the problem you are having with the part and include it in the package with the part you are returning.  We need to be sure that we are focusing on the same problem that you have been experiencing to do the best job of reporting back to you on the status of the product.
• Be sure that the note you include with the shipment references as many of the following as possible: the date of purchase, name of purchaser or customer account number.
• Let us know the address to which repaired parts should be shipped (must be a physical address with a phone number and person’s name).

Maybe.  There is no way the EEG system can harm the TMS system, but there are some TMS systems that are essentially useless with some EEG systems.  You need a a suitable combination of features in each to be successful at all in using TMS with EEG.

Desirable attributes:

• Coils designed specifically for use with EEG will have a cable that exits the coil tangential to the head surface so that the coil does not pass close by EEG electrodes and cables.
• A coil to be used with EEG should be passively cooled, since active cooling by means of a fan will induce electromagnetic interference in the EEG.
• The TMS recharge mechanism should be designed to avoid inducing electromagnetic artifacts in the EEG.
• The TMS system should be shielded so that no more than 3 milligauss of electromagnetic interference from the TMS system’s power supply reaches the electrodes and cables.
• The TMS system should be able to produce a TMS pulse in response to an input trigger with a low and predictable latency.  Long, but especially unpredictable latency in responding to an input trigger will result in TMS artifacts that are difficult to impossible to remove from the EEG.

Aside from attributes of the TMS system, there are also important considerations regarding the EEG system in this relationship. See the other FAQ entry on that topic.

No.  There are a few special attributes that are required and others that are desirable.

Required attributes:

• Inputs should be protected so that they are not damaged by the TMS pulse
• Frequency response on all channels should be from DC on the low end, since AC coupled inputs will “ring” when presented with a large voltage transient like the TMS artifact

Desirable attributes:

• Electrodes should have a low-profile so that the TMS coil can be placed as near the head as possible, maximizing penetration depth and current delivery
• It is important for the EEG system to be able to trigger the TMS system at precisely the same phase with respect to the EEG samples each time a stimulus is delivered.  This will improve the performance of artifact removal algorithms

Aside from these attributes of the EEG system, there are also important considerations regarding the TMS system in this relationship. See the other FAQ entry on that topic.

Maybe.  There is no way the EEG system can harm the TMS system, but there are some TMS systems that are essentially useless with some EEG systems.  You need a a suitable combination of features in each to be successful at all in using TMS with EEG.

Desirable attributes:

• Coils designed specifically for use with EEG will have a cable that exits the coil tangential to the head surface so that the coil does not pass close by EEG electrodes and cables.
• A coil to be used with EEG should be passively cooled, since active cooling by means of a fan will induce electromagnetic interference in the EEG.
• The TMS recharge mechanism should be designed to avoid inducing electromagnetic artifacts in the EEG.
• The TMS system should be shielded so that no more than 3 milligauss of electromagnetic interference from the TMS system’s power supply reaches the electrodes and cables.
• The TMS system should be able to produce a TMS pulse in response to an input trigger with a low and predictable latency.  Long, but especially unpredictable latency in responding to an input trigger will result in TMS artifacts that are difficult to impossible to remove from the EEG.

Aside from attributes of the TMS system, there are also important considerations regarding the EEG system in this relationship. See the other FAQ entry on that topic.

No.  There are a few special attributes that are required and others that are desirable.

Required attributes:

• Inputs should be protected so that they are not damaged by the TMS pulse
• Frequency response on all channels should be from DC on the low end, since AC coupled inputs will “ring” when presented with a large voltage transient like the TMS artifact

Desirable attributes:

• Electrodes should have a low-profile so that the TMS coil can be placed as near the head as possible, maximizing penetration depth and current delivery
• It is important for the EEG system to be able to trigger the TMS system at precisely the same phase with respect to the EEG samples each time a stimulus is delivered.  This will improve the performance of artifact removal algorithms

Aside from these attributes of the EEG system, there are also important considerations regarding the TMS system in this relationship. See the other FAQ entry on that topic.