Table 1 Descriptions of the functions f ₁ through f ₇, G _in (t) and I _in (t)

f ₁(G(t−τ ₁))

Insulin production and release by pancreas

f ₂(G(t))

Insulin-independent glucose utilization

f ₃(G(t))×f ₄(I(t))

Insulin-dependent glucose utilization

f ₅(I(t−τ ₂))

Hepatic glucose production

f ₆(G(t))

Inhibitor of hyperglycemia

f ₇(G(t)−330)

Inhibitor of hyperglycemia

G _in (t)

Nutritional source

I _in (t)

Exogenous insulin