The Einthoven leads I,II,III

The Einthoven leads measure the ECG in a truly bipolar fashion between two limbs:

I = left arm - right arm
II = left leg - right arm
III = left leg - left arm

In modern ECG machines Einthoven III is usually not measured but calculated from I and II: III = II – I.

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Disclaimer: Use the information shown on this page and the other related pages at your own risk. See the disclaimer in the CC Attribution-Noncommercial-Share Alike 3.0 Unported license. Safety first: always use an electrically isolated A/D converter for all signal- and power-connections when conducting experiments with subjects. If you measure biosignals from other people you might need to apply for ethical approval. Make sure that the subject is electrically isolated from the mains at all times!

Author: Bernd Porr Except where otherwise noted. Content is licensed under the following license: CC Attribution-Noncommercial-Share Alike 4.0 International