Here is the BIOKMODWEB site. It can be used for solving yourself compartmental models or to make use of the ICRP biokinetic models (including the new ICRP 130/134/137 models). It can be applied in internal dosimetry, bioassay evaluations, nuclear medicine, pharmacokinetic, and more. It have been developed using the Wolfram Languaje Mathematica, webMathematica
powered by Wolfram webMathematica
and Java.

BIOKMODWEB uses the Mathematica toolbox: BIOKMOD. The most usual features of BIOKMOD are available here (use the left side menu). It runs entirely within your web browser.

What things you can do with BIOKMOD?
It can be used to solve systems of differential equations, to fit coefficients, convolution, and more, with application for modeling Linear and Nonlinear Biokinetic Systems. Most of the ICRP biokinetic models are included and they can be applied in internal dosimetry and bioassay evaluations.
(i) The user can build and solve its own compartmental model (constant and variable coefficients can be used).
(ii) All ICRP30/66/78 are solved for most isotopes (including some specific options for Lung and Respiratory Tract)
obtaining the Intake Retention Fractions (IRF), their analytical expressions (intake retention functions), the compartmental contents and the graphic representations. Acute, constant -chronic, continuous (variable in the time) and multi-inputs, even random, intakes can be used. One can accept the default parameters or introduce specific values. They can be used for bioassay evaluations and for research and education purposes.
(iii) (New) The new ICRP 130/134/137 models for Co, I, Cs and U have been added in an addional package, which can be applied for bioassay evaluations.
(iv) An optimal design function is included. It can be used to establish the best moment for experimental sample or bioassay.
(v) Fitting functions for non linear fitting.
vi) A function for evaluating uncertainties analytically.

If you have any comment send me an e-mail: guillermo2046(at)

Some papers have been published where BIOKMOD has been used (below are referenced some of them). For additional information visit: BIOKMOD.

Rodríguez-Díaz Juan M. ; Sánchez-León Guillermo; “Efficient parameter estimation in mulltiresponse models measuring radioactivity retention” Radiation and Environmental Biophysics 2019.
Lopez-Fidalgo J, Sánchez-León Guillermo. "Optimal bioassay time allocations for multiple accidental chronic intakes of radioactive particles". Stochastic Environmental Research and Risk Assessment.
Sánchez G; “Fitting bioassay data and performing uncertainty analysis with BIOKMOD” Health Physics. 92(1):64-72. 2007. ISSN/ISBN: 0017-9078
Sánchez G;. Rodríguez-Díaz J. M. Optimal design and mathematical model applied to establish bioassay programs”: Radiation Protection Dosimetry. doi:10.1093/rpd/ncl499. 2007. ISSN/ISBN: ISSN 1742-3406
Lopez-Fidalgo J Rodriiguez-Díaz J.M.,Sánchez G; G., Santos-Martín M.T. Optimal designs for compartmental models with correlated observations”
Journal of Applied Statistic. 32, 2006 ISSN/ISBN: 0266-4763
Sánchez G; Biokmod: A Mathematica toolbox for modeling Biokinetic Systems”. Mathematica in Education and Research: 10 (2) 2005. ISSN/ISBN: 1096-3324
Sánchez G; Lopez-Fidalgo J “Mathematical Techniques for Solving Analytically Large Compartmental Systems” Health Physics..: 85 (2): 2003. ISSN/ISBN: 0017-9078
Lopez-Fidalgo J; Sánchez G; Statistical Criteria to Establish Bioassay Programs. Health Physics. 89 (4). 2005. ISSN/ISBN: 0017-9078.