Biomedical Simulations Resource (BMSR)

LYSIS (the Greek word for "solution") is an interactive software of a set of modular programs (each performing a specific task) that provide an integrated computing environment for data analysis and system modeling. Unique capabilities of LYSIS include nonlinear system modeling and its relation to Artificial Neural Networks, as well as the novel methodology of "principal dynamic modes". This package has expanded through time to incorporate emerging methodologies developed by the Biomedical Simulations Resource (BMSR) at USC, under the supervision of Prof. V.Z. Marmarelis.

LYSIS 7.1 is currently available to run on Windows 95/98/NT/2000/XP. It is also available for UNIX, distributed as source code to be compiled for each UNIX implementation (e.g., Solaris, HPUX, Linux, etc).

LYSIS 7 (Window 9x/NT/2000/XP) comes bundled with the pgplot library and fonts (PGPLOT.LIB,GRFONT.DAT, and RGB.TXT), which are necessary for the graphics programs to operate. The pgplot library is installed in the same folder as LYSIS 7.1.

LYSIS 7.1 is packed with all the necessary files to make all necessary modifications to the Windows 9x/NT/2000/XP environment. It requires minimal changes in environment (setting a few variables). This installation creates the LYSIS 7.1 Group (as well as ten subgroups) off the Programs group at the Start button.

The development of LYSIS is funded by Grant RRO1861 from the National Center for Research Resources of the National Institutes of Health. LYSIS is made available to the biomedical community at large free of charge in order to promote research in this area and enhance the computational capabilities of biomedical investigators nationwide. The BMSR holds the copyright of LYSIS and its use must be acknowledged by individual investigators in their research publications.

*Key relevant publications

Marmarelis, V.Z. Identification of nonlinear biological systems using Laguerre expansions of kernels. Annals of Biomedical Engineering, 21: 573-589; 1993.

Marmarelis, V.Z. Modeling methodology for nonlinear physiological systems. Annals of Biomedical Engineering, 25: 239-251; 1997.

Marmarelis, V.Z. and X. Zhao. Volterra models and three-layer perceptrons. IEEE Transactions on Neural Networks, 8(6): 1421-1433; 1997.

Features in Version 7.1

These specific features cannot be found in other commercially available packages. For instance, efficient kernel estimation using Laguerre expansions or modeling of nonlinear dynamic systems using artificial neural networks with polynomial activation functions are unique to LYSIS. Along with the basic programs (including graphics), they constitute a powerful toolset for time-series data analysis and system modeling indispensable to cutting-edge research.

Accurate estimation of Volterra kernals from short date-records and associated model predictions for nonlinear systems
Combined use of Volterra kernels and artificial neural networks for nonlinear system modeling
Estimation and simulation of parametri NARMAX models
Principal Dynamic Mode analysis of nonlinear systems

Requirements

PC/486, Pentium
        Operating Systems
                Windows 95/98/NT/2000/XP
Sun/Unix
       Operating Systems
                Solaris 2.x

Minimum system requirements to run LYSIS 7.1:

Intel P5 (or better) based computer
256 Mbytes of RAM or more
MS-Windows 95/98/NT/2000/XP
Disk space of atleast 35 Mbytes
1 GB pagefile
video card capable of 256 colors or better