Practical lesson Two models of the cardiovascular system: 1. - PDF document

Lesson 5 University of Bergamo Engineering and Management for Health FOR CHRONIC DISEASES MEDICAL SUPPORT SYSTEMS LESSON 5 Lumped parameter models of the cardiovascular system: practical lesson. Ettore Lanzarone March 25, 2020 Practical lesson Two models of the cardiovascular system: 1. Simple RLRC model 2. Accurate model with several segments (Burattini and Gnudi, 1982; Lanzarone et al., 2017)

Lesson 5 Practical lesson Simple RLRC model • Parameters according to Sharp and Dharmalingam (1999) • Swanson and Clarck input flow Practical lesson Simple RLRC model • Simnon code with only one .T file

Lesson 5 Practical lesson Accurate model with several segments • Parameters according to Burattini and Gnudi (1982) and Lanzarone et al. (2017) • Swanson and Clarck input flow • Includes the feedback controls in agreement with Lanzarone et al. (2017) Practical lesson Accurate model with several segments • Architecture of several Simnon files Centrale.T Perif***.T Segments and peripheral networks PRINCIPALE.T Macro to run the system Conness.T Exchange of variables between subsystems

Lesson 5 Practical lesson Accurate model with several segments 1. Open MTESI 2. Write MTESI in the command dialog box 3. Launch simulation with the dedicated window ( store variables of interest and use fixed step time ) 4. Write “Ashow” and “Show” to view results Practical lesson Accurate model with several segments Where to change parameters for the analysis we are conducting? File Centrale.T

Lesson 5 Practical lesson ANALYSES TO PERFORM 1. Choose a duration of the simulation to be sure that the initial transient time is over 2. Compare the two models. Which is the most accurate one and why? 3. Evaluate the pressure in the aortic segments 2 – 7 in the complete model. What do you observe? Is it in agreement with the medical literature? Practical lesson ANALYSES TO PERFORM 4. Study a pathological case: old patient with rigid vessels. All compliances reduced by a fixed percentage. What do you observe? Did you expect that? 5. Study a surgical case: insertion of an aortic prosthesis. Resistances are increased and compliances are decreased in segments 3 – 7

Lesson 5 Practical lesson POSSIBLE PROJECT ON THIS TOPIC Based on the available information on the existing prostheses, chose the best one in order to limit the impact on pressure alteration.