gradual increase in that person’s stress level. How does a less-fit person’s heart
performance compare to that of a fitter person? What about a display of the effects
of heart disease?
17.2 Heart Beat Model Equations
Left_Atrium(t) ¼ Left_Atrium(t À dt) + (Pulmonary_veins À Tricuspid__Valve) * dt
INIT Left_Atrium ¼ 40
INFLOWS:
Pulmonary_veins ¼ smth1(Pulmonary_art,Medulla * .1)
OUTFLOWS:
Tricuspid__Valve ¼ smth1(Pacemaker_1 * Fitness,Medulla * .1)
Left_Ventricle(t) ¼ Left_Ventricle(t À dt) + (Tricuspid__Valve À Aorta) * dt
INIT Left_Ventricle ¼ 40
INFLOWS:
Tricuspid__Valve ¼ smth1(Pacemaker_1 * Fitness,Medulla * .1)
OUTFLOWS:
Aorta ¼ delay(AV_Node_1,1)
Right_Atrium(t) ¼ Right_Atrium(t À dt) + (Vena_Cava À Bicuspid_Valve) * dt
INIT Right_Atrium ¼ 40
INFLOWS:
Vena_Cava ¼ Aorta
OUTFLOWS:
Bicuspid_Valve ¼ smth1(Pacemaker_2 * Fitness,Medulla * .1) {Ventricle fills passively until halfway through the cardiac cycle.}
Right_Ventricle(t) ¼ Right_Ventricle(t À dt) + (Bicuspid_Valve À Pulmonary_art) * dt
INIT Right_Ventricle ¼ 40
INFLOWS:
Bicuspid_Valve ¼ smth1(Pacemaker_2 * Fitness,Medulla * .1) {Ventricle fills passively until halfway through the cardiac cycle.}
OUTFLOWS:
Pulmonary_art ¼ delay(AV_Node_2,1)
Activity ¼ 1 {1 represents a person at rest, values less than 1 represent activity}
AV_Node_1 ¼ pulse(Left_Ventricle,Transmitance,Medulla)
AV_Node_2 ¼ pulse(Right_Ventricle,Transmitance,Medulla)
Fitness ¼ 1.4
Infarction__factor ¼ 1.1
Medulla ¼ 8 * Activity
Pacemaker_1 ¼ PULSE(Left_Atrium,1,Medulla)
Pacemaker_2 ¼ pulse(Right_Atrium,1,Medulla)
Pressure ¼ GRAPH(Left_Ventricle)
(0.00, 113), (12.0, 116), (24.0, 119), (36.0, 119), (48.0, 118), (60.0, 115), (72.0,
107), (84.0, 93.6), (96.0, 69.0), (108, 42.0), (120, 5.00)
Transmitance ¼ 2 * Infarction__factor
146
17 Heart Beat