...HRVAS can detrend and filter IBI and can perform time domain, frequency domain, time-frequency, Poincare', and nonlinear HRV analysis.
If you use this application or modify this application for your research, please reference the thesis entitled "DESIGN, EVALUATION, AND APPLICAION OF HEART RATE VARIABILITY
ANALYSIS SOFTWARE (HRVAS)". The thesis can be found here: http://iweb.dl.sourceforge.net/project/hrvas/Documents/ramshur_thesis.pdf