********** MODEL NAME
model_3cpt_linear_abs1emax

********** MODEL NOTES

PK model for simulation of drug concentration in central compartment
with following characteristics:
Compartments:  3
Elimination :  linear
Absorption  :  first order time dependent absorption Emax model (with lag time)

Unit convention
Dose: mg
Concentration: ug/mL
Time: hours

The annotation of the parameter units is consistent with the given unit convention.
Units of the inputs (dose) and outputs (concentration) in the dataset for parameter estimation need to match the unit convention.

********** MODEL STATES

d/dt(Ad) 	= -ka*Ad + Fabs1*INPUT1
d/dt(Ac) 	=  ka*Ad - Q1/Vc*Ac + Q1/Vp1*Ap1 - Q2/Vc*Ac + Q2/Vp2*Ap2 - CL/Vc*Ac
d/dt(Ap1) 	=        + Q1/Vc*Ac - Q1/Vp1*Ap1
d/dt(Ap2) 	=                                + Q2/Vc*Ac - Q2/Vp2*Ap2

Ad(0) 	 	= 0
Ac(0)    	= 0
Ap1(0)    	= 0
Ap2(0)    	= 0

********** MODEL PARAMETERS
Fabs1         = 1   # Relative bioavailability (fraction)
kafin 	      = 2   # Asymptotic value of ka (1/hour)
CL 	      = 3   # Apparent clearance (L/hour)
Vc 	      = 32  # Apparent central volume (L)
Q1	      = 1   # Apparent intercompartmental clearance to first peripheral compartment (L/hour)
Vp1	      = 10  # Apparent first peripheral volume (L)
Q2	      = 1   # Apparent intercompartmental clearance to second peripheral compartment (L/hour)
Vp2	      = 10  # Apparent second peripheral volume (L)
Tlag1         = 0   # Absorption lag time (hours)
Hill          = 1   # Hill coefficient (-)
T50           = 2   # Time at which kabs is half of kafin

********** MODEL VARIABLES
ka   = kafin*(time^Hill/(T50^Hill+time^Hill))

% Calculation of concentration in central compartment
Cc 		  = Ac/Vc

% Defining an output (only needed when interfacing with NLME
% parameter estimation tools such as NONMEM and MONOLIX)
OUTPUT1  	  = Cc  # Compound concentration (ug/mL)


********** MODEL REACTIONS


********** MODEL FUNCTIONS


********** MODEL EVENTS