Coordinating the Einthoven Body Impedance Model for ECG Signals with IEC 60479-1:2018 Electrocution Heart Current Factors: Invited Lecture - Extended Summary

The Einthoven electrical circuit for ECG measurement has been modeled as a 2.5-mA impulse current source at the heart, feeding a 13-resistor network. This model can be inverted to establish heart threat currents from electrocution potentials applied at extremities. Using designation of R (right), L (left), H (hand) and L (leg), electrical safety standard IEC 60479-1:2018 defines risk factors for LH-RH and LL-RL paths compared to reference LH-LL path. Heart current reduction factors can be fitted by adjusting some resistor values and by adding a cross-hip resistance to make nodes at each hip. This suggests an approach to validate IEC heart current factors by comparing ECG signal magnitudes for different contacts. Hypothetically, the LH-RH ECG signal should be 10x larger than the LL-RL signal. In-vivo tests suggest that some electrocution heart current factors can be verified using two-lead or three-lead ECG monitor results.