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Simulations and model results do not get exported to the MATLAB workspace automatically. 2021b. Under Model Analyzer preferences, I checked "export results when model run is complete", but to no effect. I have to manually expert simulations after each run. Please advise. Thanks RD

Hello

I would like to pulse an input species. I read in the forums that repeated assignments can be used for this, but I am not exactly sure how to implement this. This is the MATLAB code that resembles what I would like the input pattern to be:

t = 0:1/1e3:60;
d = [10:2:30]';
x = @rectpuls;
y = pulstran(t,d,x);

plot(t,y)
hold off
xlabel('Time (s)')
ylabel('Waveform')

Thanks for any help! Aaron

Hello, We would like to share one of our QSP models with non-modeler colleagues for them to play with. Is there a simple way to generate a standalone app from a SimBiology model, with sliders allowing the user to change various parameter values?

Thank you,

Abed

Hello, Does the 'sbiofit' function have functionality implemented for likelihood=based handling of BLoQ censored data, similar to functionality in NONMEM and other softwares? If not, are there plans to implement this?

Thanks,

Abed

Hello,

I recently downloaded the GlobalSensitivityAnalysisApp. I am trying to perform a GSA using a simbiology model. I try running the App, but I get the error "No Sobol Indices Available to Plot. Configure the Sobol section and click the Compute button." I'm not sure if there is a step I'm overlooking. I'm following the instructional video for this app on the Matlab website, and I'm not sure what Configure the Sobol section is referring to. Any guidance would be greatly appreciated.

How can I add the value of the error for each estimated parameter?

Hi, all

Recently I read the book "Physiologically Based Pharmacokinetic (PBPK) Modeling and Simulations: Principles, Methods, and Applications in the Pharmaceutical Industry" and find this state,"Since the unbound concentrations in plasma and blood are expected to be the same, fub , fup , and R are related as follows: R=Cb/Cp=(Cub·fup)/(Cup·fub) and R=fup/fub". I don't know whether it is reasonable to generally assume unbound concentrations in plasma and blood to be the same since components in whole blood and plasma are not the same. Is it common to see this equality in real situation?

Thanks for comment.

Hello,

We're working with a vendor to expand one of our current models that's written in SimBiology, but that vendor doesn't have a license to SimBiology. It would be nice if there existed a "Simbiology Viewer" which can be downloaded as a free Matlab package, and which would allow one to view but not edit SimBiology models. Are there any plans for something like this in the future? Something like this would make it much easier to share our models with people who don't have a license to SimBiology.

On a similar note, does anyone have any advice on the best ways to share SimBiology models currently? I noticed there's some functionality to export the tables of reactions, parameters, species, etc., and there's also some functionality to export the model into SBML.

Thank you,

Abed

Hi, all friends,

I want to record the fraction of drug absorbed in each intestinal segment, so I define a set of parameters with rate rule like: AbFraction_Colon= ((PeffColon*2/organismRadiusColon+paracellularAbsorption*organismFluxMucosaSerosa/Colon)*Colon.DrugDissolved)*Colon/InitialDose The attached figure shows the simulation result that overall PK profile (purple) seems OK, but I don't know why the absorption fraction line (red) starts from value of 1. Does anyone know the cause?

By the way, I am using model modified from "generic PBPK model"

Thanks for comment.

Hi, all friends

I am dealing with a confusing NCA result. As this result shows, AUC_infinity=0.8537 (μg*h/mL), DM=1 (mg). CL should be equal to DM/AUC_infinity but why is the calculated result 2.4491? There is no dimension along with value so I do not know if I ignore anything.

Does any one can handle with this situation? Thanks very much. I also post my used data (i.v.).

Hi, all friends

If I define a parameter, like solubility with dimension of milligram/milliliter and I want to refer it in an reaction equation in dimension of millimole/liter, suppose I have define its molecularweight, could I input this parameter directly in equation with specified dimension?

Question: How to load a host of variants created through scripts to a sbproj file so that we can simulate and visualize them through the simbiology GUI.

Description : In a typical QSP workflow, we generate virtual patients by perturbing a set of parameters. These virtual patients are generated as variants by using "addvariant".

We end up with an array of variants saved as "variants.mat". This mat contains the list of ~3000 variants.

These variants are now to be simulated with different dose objects. This could be done with scripts but it would be ideal if we import these variants into the sbproj file and simulate via simbiology GUI for both purpose of troubleshooting and dosing.

Is there a way to do this?

Hi, all friends

I am working on building a oral model with "Generic SimBiology PBPK model" and meet some problems about intestinal transit rate. Take duodenum as example, the transit rate is defined as " (kTransportSmallIntestine*organismLengthDuodenum/organismLengthSmallInstestine)*Duodenum.DrugDissolved". I think assuming duodenum transit time is equal to SmallIntestineTransittime*organismLengthDuodenum/organismLengthSmallInstestine, the transit rate constant is the inverse of that,which result in kTransportSmallIntestine*organismLengthSmallInstestine/organismLengthDuodenum, contradicting with the equation in model. Am I wrong?

Besides that, the kTransportSmallIntestine_is defined as _0.693/organismMeanResidenceSmallIntestine in model. Isn't the mean residence time determining the time at which about 63.2% of initial amount having passed through the compartment and inverse of mean residence time determining the transit rate? Why does organismMeanResidenceSmallIntestine correlate with 0.693 which is often seen in half-life associated expression?

Thanks for any comment.

Hi, fellows,

I am a new user of MATLAB and SimBiology. When I open the "Generic SimBiology Physiologically-based Pharmacokinetic (PBPK) model" downloaded from "https://ww2.mathworks.cn/matlabcentral/fileexchange/37752-generic-simbiology-physiologically-based-pharmacokinetic-pbpk-model", I get a note of "Copyright 2012-2018 The MathWorks, Inc. ...". Does that mean I can not access to the model built-in or make any modification?

Thanks for any comment!

New Features

R2019b introduces the new SimBiology Model Analyzer which replaces Task Editor enabling you to do a lot more within the app.

For a detailed look into enhancements with Model Analyzer, we created a few short videos. Below is a list of the new features together with videos describing each feature.

• Programs: Compose SimBiology analysis programs from built-in analysis steps. Video: Simulating a model using SimBiology Model Analyzer
• Scenarios: Generate Samples to perform Monte Carlo simulations using various modeling and dosing conditions. Video: Generating Simulation Scenarios by Sampling Model Quantities Video: Sampling Parameters from Covariate Models
• Plotting and Datasheets: Plot multi-dimensional data slicing by categories such as response or scenarios. Visualize and manipulate raw external and analysis data using datasheets. Video: Stratifying Data for Visualization in SimBiology

Compatibility considerations with earlier versions of SimBiology

There are a few things that one needs to be aware of if planning to use R2019b with a SimBiology project created in older versions. If you load a project created pre-R2019b, the existing tasks are converted to equivalent programs. However, keep in mind the following for the current version of SimBiology Model Analyzer:

• Live Plots functionality of the Task Editor is not supported. If Live Plots in the Task Editor is turned on and shows a time plot of simulation results, then an equivalent time plot is added on import to the SimBiology Model Analyzer app with the main difference being that the time plot is updated and displayed after the program finishes (not while it is running).
• Previously available Calculate Conserved Cycles, Search Model(s), and Generate Report tasks are not supported.
• Any Group Simulation task is converted to a Scan program.
• Fit Data program does not support nlinfit as the estimation method. However, the command-line function sbiofit still supports nlinfit.
• To help with the transition to R2019b, when you open an existing project created in R2019a or earlier, the app creates a backup of the original file. The backup file has the release information suffixed to its name, filename_release.sbproj. For example, if you open an R2019a project named foo.sbproj in the app, the app creates a backup file called foo_R2019a.sbproj.
• Also, when you open and save a project, the app creates a backup file of the version prior to the saved version of the project. The backup file has the .bak extension (for example, foo.sbproj.bak).

See the complete list of general behavior change, compatibility considerations, and new features in the release notes.

I am fitting a generic TMDD model to date. Model fits look reasonable. Once I create a variant and simulate data for various doses to create observed vs predicted concentrations vs time profile, then simulated concentrations do not match fitted profiles. Simulated concentrations are either significantly higher or lower than the model fits. Not sure what is wrong. Fits look fine but simulated profiles using fitted parameters are all over the place.

Hello all,

I have created an arbitrary model for microtubule behavior. More or less just trying to familiarize with the software. I have created plots for multiple types of reactions that may occur and am looking to now plot the instantaneous derivative of each reaction. Would anyone have any suggestions as to how I could do this? I am familiar with how to do it with a clearly defined function with x,y,z,etc. values. However the 'sbiomodel' command doesn't seem to show me a function so I'm really lost on this.

Thanks for any and all help/suggestions.