According to the following paper of the group of the cardiologist Milind Y. Desai, Cleveland Clinic Ohio, a 3 lead ECG system as used in this study is required: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6732081/ or an OpenBCI 3-Lead ECG with Cyton or Ganglion boards: https://docs.openbci.com/GettingStarted/Biosensing-Setups/ECGSetup/ or one of the other 3-lead ECG systems listed in this table: