The System for Population Kinetics (SPK)
Vicini, Paolo and the Resource Facility for Population Kinetics (RFPK)
University of Washington
The Resource Facility for Population Kinetics (RFPK, http://www.rfpk.washington.edu) at the University of Washington is a research resource funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) at the National Institutes of Health. The mission of the RFPK is to encourage and support research and development in modeling and simulation of biological systems and their application in a variety of areas, at the same time deploying novel software tools that implement useful methodological advances. The System for Population Kinetics (SPK) is a web service that facilitates the development and identification of nonlinear mixed effects models. Approximations of the likelihood function based on linearization, as well as two-stage methods and Monte Carlo likelihood integration at the optimal parameter estimate, are currently available and accessible through a common interface. SPK is being developed under a three-tiered architecture that includes a client tier and a computational tier. The client tier is the Model Design Agent (MDA), a Java program which runs on the user’s desktop, collects inputs and displays outputs, and coordinates the communication between each user and the computational servers where SPK runs. A web application server provides the middle tier. Plotting capabilities and output diagnostics are provided as well. Models, together with data and results, are stored as XML files in a searchable database. Our plans currently involve the release of SPK under an open source license, which would facilitate extensibility and maintenance of the code base. The SPK service is under development and as of now is available on a trial basis to interested users via http://spk.rfpk.washington.edu. The development of SPK is partially supported by grant NIH P41 EB001975.