Tel: +31 (0) 541 534603


Help! I have 50/60 Hz noise in my signals?

50/60 Hz is the typical mains interference. TMSi amplifiers do not include (adaptive) filters for this kind of interference. The 50/60 Hz in your signal can be due to several causes: bad patient-ground contact, a broken cable or bad electrode contact. If you cannot get rid of the mains interference, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..

An electrode got loose and influenced all the measured data. What should I do?

There are two possibilities that can cause problems:

1) When an electrode gets loose from the body, the electrode goes in “overflow”. The electrode is then immediately thrown out of the reference calculation and you won’t see any effect on the signals.

2) The electrode gets partly loose and causes a bad signal. Now it seems as if all the signals are influenced by this one bad signal.  This is very simple to correct: we only have to discard the bad electrode from the reference calculation. You can read more about the reference calculation on the technology pages.

Is TMSi software compatible with 64-bit systems?

Yes, TMSi Polybench is compatible with 64-bit systems. Unfortunately the outdated Portilab1 and Portilab2 are not. Apart from the support for 64-bit systems, the new Polybench software package has many more advantages. Please contact us for more information.

On which Operating Systems does the driver work?

Windows 7, Windows 8.1 and Windows 10 are compatible with driver version 7.2. The Mobita is only compatible with Windows 7.

How can I check which version of the driver I have?

Via the Start-menu in Windows you go to the Control Panel. In the Control Panel you go to “Programs” and then “Programs and Features”. Now you can see a list with all the installed programs, including the TMSi driver with the version-number (e.g.: “Windows Driver Package – TMSi (TMSiDriverUSB) TMSiDriverUSB (DATE VERSION-NUMBER)”.

I am looking for the manual of my system, where can I find it?

Because of the flexibility of our amplifiers each amplifier configuration has its own manual. You can get one by filling in the service enquiries form or by mailing This email address is being protected from spambots. You need JavaScript enabled to view it.. It is important that you include the serial-number of your system, so we can find the correct manual for your system.

Are the systems of TMSi compatible with Matlab?

We have developed the TMSi MATLAB Interface for this purpose. The TMSi MATLAB Interface allows you to do both on- and offline data analysis! And best of all? You can download it free of charge after you have registered on our forum.

Why is the signal zero when I connect one electrode and the patient ground?

TMSi amplifiers measure with reference to the mean of all connected electrodes (the patient ground does not count). When only one electrode and the patient ground is connected the mean is calculated of only one electrode. In this case the mean is the same as the signal that is measured. Therefore you have to connect another electrode to see a signal.

Where can I place my patient ground electrode?

The function of the patient ground electrode is to keep the amplifier in range. So actually you are free to place the patient ground electrode wherever you like. You could even place it on a muscle because the electrical activity of the muscle is of no influence on the signal. You do have to keep in mind that, when you place the patient ground electrode between two normal electrodes, it is possible that a leak current flows underneath the patient ground electrode, resulting in 50 Hz noise becoming visible in your signal. We therefore advise not to place the patient ground electrode in the near vicinity of the measurement electrodes. Moreover it is very important that there is a good contact between the patient ground electrode and the skin. The better the contact the better the quality of your measurement signal.


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