This model simulates a closed loop resistor-capacitor circulatory network driven by a pressure generator (PV).
This model simulates a closed loop resistor-capacitor network driven by a pressure generator (Pv). Volumes flow through a varying-elastance pressure generator component (simulating a contracting ventricle) and two compliant vessels in series. The simulated ventricle has two one-way valves: one at either opening, but only one (Rv) offers resitance.
The governing equations are:
where VV, V1 and V2 are the volumes of the ventricle, vessel 1 and vessel 2 and FV, F1 and F2 are the volumetric flow rates in the ventricle, vessel 1 and vessel 2. The volumetric flows are determined from the fluid analog of Ohm's law:
where Pv, P1, P2, Rv, R1 and R2 are pressures and resistances of the ventricle, vessel 1 and vessel 2 respectively. To keep flow in one direction through the ventricle, if Pv is less than P1 then Fv is zero and if P2 is less than Pv then F2 is zero. The pressures at P1 and P2 are derived from the definition of compliance:
so we have:
where V1,rest and V2,rest are the resting volumes of vessel 1 and vessel 2 respectively and Pext is the external pressure of the system. The volumes of vessel 1 and vessel 2 are not allowed to become negative in these equations as enforced by condition statements given in the JSim code.
The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.
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Ohm GS. Die galvanische Kette, mathematisch bearbeitet, 1827
Please cite https://www.imagwiki.nibib.nih.gov/physiome in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.
Model development and archiving support at https://www.imagwiki.nibib.nih.gov/physiome provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.