SimBiology

Segui

Identification of model (one compartment, two compartments or three compartments) which a drug follows is an important step before population pharmacokinetic modeling. I am aware that the graph between the concentration vs time, gives an idea of the number of compartment a drug follows. But is there a standard way to explore and determine the number of compartment a drug follows in a more objective manner. This would also be helpful to determine the model in which the data needs to be fit. In addition, a note on determining the order of reaction is also welcomed and would make the discussion complete. In Simbiology, is there a standard way to identify the number of compartment a drug follows? Praveen, The model selection is often driven primarily by visualization of data (as you mentioned in your post) and accounting any prior information (if available). In many cases, it is difficult to get clear indication of whether your data follows 2-cmpartment or 1-cmpartment model etc. In these situation, one should try to evaluate both model and compate fits. You can also use AIC/BIC criteria for model selection. I am not aware of any automated tool to compare the model fits in simbiology. It may be useful to have such feature (example one that is available in Phoenix) which can allow to objective function with both model fits, covariate information and GOF plots. SimBiology has a task data comparison tool that allows you to compare different fits (make sure the fits are each saved as task results!) by AIC, BIC, loglikelihood etc., see the screenshots below. <</matlabcentral/discussions/uploaded_files/90/Task%20data%20comparison.png>> <</matlabcentral/discussions/uploaded_files/89/Capture.PNG>> Dear Sietse Braakman, Yes, I use task data comparison for selecting the compartment and for selection of optimization algorithms. Thanks for the guidance. Regards. simbiology population pharmacokinetics pharmacokinetics pharmacology compartment

Hi, I have a model in Simbiology in which cell growth is very important to the relevance of the model. As such, a compartment increases in volume according to a rate rule over time. I've now found myself unable to run a sensitivity analysis of the system because the compartment size does not remain constant. Is there any possible way to assess the sensitivity of the system in this case? Thanks Alistair

Given a Simbioloogy 'model' I can access/get a specific compartment object if I know the numerical index, e.g. model.compartments(2) shows me the 2nd compartment. I can get/set properties from this indexing. Say this compartment is named 'turtle'. Can I get this compartment object from the Name, instead of by index? Something like model.compartments('turtle'), or model.compartments('Name'=='turtle'). although clearly these won't work.

The Help file suggests that this should be possible. I am trying this with set(CompartmentName, 'Capacity', ParameterName) as the event function. The compartment, CompartmentName, has the appropriate units and is not ConstantCapacity. The parameter, ParameterName, is scoped to the model and has appropriate units. Verification fails as dimensional analysis cannot cope with set(). I can work around this in an adequate manner generating a SimBiology model object through M code but I wanted to know if this can be performed using the sbiodesktop interface.