Two-Compartment Linear System

"If the rates of change of all the state variables of a system can be written as sums of processes none of which is of higher than first order, the system is a linear system and is described by a set of linear differential equations."

x1 = Concentration of tracer in compartment 1

x2 = Concentration of tracer in compartment 2

Units of concentration = mass/volume (i.e. g/ml)

V1 = volume of compartment 1

V2 = volume of compartment 2

q1 = mass of tracer in compartment 1

q2 = mass of tracer in compartment 2


Conservation of Mass

d/dt(q1) = (mass entering in) - (mass exiting out)

d/dt(q1) = k12(q2) - k21(q1)

d/dt(q2) = k21(q1) - k12(q2);

where k12 and k21 are rate constants. The first subscript for k denotes the destination and the latter the origin of the directional flow .

How should we solve for q1 and q2?


B.3-a