I have simbiology 2019a. I am trying to fit ka using a one compartment PK model (I have Vd and Cl fixed).
I had previously scanned my model for ka and found that ka should be approximate 0.5. When I compared simulations to observed data, 0.5 allowed for the model to fit the data well.
I next tried fitting the data using the same concentrations in the model simulations. The ka's were much larger than expected. Upon further expection, the generated simulated concentration vs time profile doesn't produce a curve. It appears as if the model fittings are not generating a concentration profile. I checked if I was making a mistake in the dosing information or response information, but my fitting screen is similar to the example (https://www.mathworks.com/help/simbio/gs/fit-data.html)
Any input or additional references to compare would be greatly appreciated.