Suppose we want to measure the electro-physiological signal of a muscle, the so called electromyogram (EMG). There are two main types of EMG: surface EMG and intramuscular (needle and fine-wire) EMG.
Most applications of EMG only require the surface EMG, which has the advantage that it is non-invasive. For measuring EMG we must place some surface electrodes on the skin above the muscle, to collect the signals that are generated by the large amount of muscle fibers. Typical EMG potentials range between less than 50 µV up to 20 or 30 mV in amplitude.
To measure the EMG of a certain muscle, two electrodes are necessary to get a bipolar montage. With our systems this can be done by using a bipolar input channel of one of our devices. Another possibility is to use two unipolar input channels with one unipolar electrode each and then do the montage (electrode1-electrode2) in software (e.g. TMSi Polybench). Of course, in both cases a patient ground electrode is also needed.
We also offer the possibility to measure High Density (HD) EMG, with multiple electrodes covering one muscle (see relevant accessories below).
For more information, please contact us:
Contact us Tel: +31 (0) 541 534603