We introduce a new algorithm for "Least Squares Approximation of ECG Signals with Rational Functions". There are no Figures in the MS01v100.rtf ("Project milestone") description below. Figures are contained in [1r] and [2r], referred to in the description as FEX3-ECG/Charts01 and FEX3-ECG/Charts02. The reason for this is that they contain — among other things — 50 large-sized (~1800×800 pixels) gif images. Therefore, we recommend downloading and extracting the 2 zip files into 2 directories. In the future, we also plan to upload the programs and their descriptions. References: [1r] Kobzos, Laszlo. (2022). FEX3-ECG/Charts01: Least Squares Approximation of ECG Signals with Rational Functions. Zenodo. https://doi.org/10.5281/zenodo.6479410 [2r] Kobzos, Laszlo. (2022). FEX3-ECG/Charts02: Least Squares Approximation of ECG Signals with Rational Functions. Zenodo. https://doi.org/10.5281/zenodo.7365661 Kobzos, Laszlo Location: HU (Budapest) email: zehu.kola.ci@gmail.com