What methods can I use for the Patient Ground for SAGA?

The Patient Ground can be measured either via the wristband or a snap-on electrode.

Having a good location of the Patient Ground (PGND) is important to get good results for the impedance check and good quality signals. There are multiple ways to measure the PGND. One way is to connect the PGND via the wristband that is delivered together with the device. Another way to measure the PGND is via a snap-on electrode that is placed on the subject. In both cases, the orange cable that was delivered together with the device should be used. Finally, if the measurement is performed with an EEG headcap, it is possible to use the Ground (GND) electrode on the cap.

The lowest impedance for the PGND is obtained by the wristband. Therefore, it is recommended to use the wristband to measure the PGND. 


  • Wet the wristband with tap or saline water to get a low impedance for the PGND.
  • Make sure to place the snap-on electrode on a spot where no or few movement artifacts occur, for example on a part of the skin with bone directly underneath. 
  • When the GND channel of the TMSi EEG headcap is gelled, the other two methods will not work. 


Do you have further questions on this topic?

Contact ✉️ support@tmsi.com, 📞+31 (0)541 539 013 or 📄 request support.