Spirography is a standard neurological test that has been commonly used for essential tremor diagnosis and its severity assessment for years. Spirography requires simple hardware and software for data recording, which perfectly suits for clinical applications by its easy accessibility and useful and rich-information-contained outcomes. However, current spirography analysis is handled by Fourier Transformation (FT) on acquired data only. Further analysis on spirography is limited due to the loss and restraint of information during digitization, and the lack of valid processing procedures. ...