A Protocol for Coupling Volumetrically Dynamic In-Vitro Experiments to Numerical Physiology Simulation for a Hybrid...

Area of Science:

• Physiology
• Biomedical Engineering
• Computational Modeling

Background:

• The Physiology Simulation Coupled Experiment (PSCOPE) framework integrates physical experiments with computational simulations of cardiovascular physiology.
• Existing PSCOPE methods are limited to rigid experiments and cannot accommodate volumetrically dynamic systems with periodic fluid volume variations.
• This limitation hinders the study of medical devices and anatomies exhibiting dynamic volume changes.

Purpose of the Study:

• To develop a novel PSCOPE method for coupling multi-branch and volumetrically dynamic in-vitro experiments with lumped parameter networks (LPNs).
• To enable the simulation of physiological systems where fluid volume changes periodically.
• To expand the applicability of the PSCOPE hybrid modeling framework.

Main Methods:

• An iterative weighted-averaging algorithm was developed to determine unique solution waveforms for PSCOPE models.
• Mathematical surrogates of in-vitro experiments were integrated into the LPN to generate reference solutions for validation.
• The proposed method was validated by coupling mathematical surrogates to the LPN and comparing results to reference solutions.
• A practical application involved coupling an in-vitro renal circulation experiment to the LPN.

Main Results:

• The coupling method demonstrated high accuracy, with normalized root mean square errors for flow and pressure waveforms ranging from 0.001% to 0.55% compared to reference solutions.
• The successful coupling of an in-vitro experiment to the LPN confirmed the method's real-world performance.
• The framework operated effectively within the limitations of physical experiment sensors and actuators.

Conclusions:

• A new PSCOPE method has been successfully developed and validated for coupling volumetrically dynamic in-vitro experiments with LPNs.
• This advancement significantly enhances the PSCOPE framework's utility for investigating medical devices and anatomies with periodic volume changes.
• The study demonstrates the framework's capability to accurately simulate complex physiological dynamics.