Estimation of Active Tension in Cardiac Microtissues by Solving a PDE‐Constrained Optimization Problem

Microphysiological systems (MPS) provide a highly controlled environment for the development and testing of human‐induced pluripotent stem cell‐based cardiac microtissues, with promising applications in disease modeling and drug development. Through optical measurements in such systems, we can quantify mechanical features such as motion and velocity during contraction. While these are useful for evaluating relative changes in muscle twitch, it remains challenging to quantify and characterize the actual active tension driving the contraction. Here, we aimed to quantify the active tension over time and space by solving an inverse problem in cardiac mechanics expressed by partial differential equations (PDEs). We formulated this as a PDE‐constrained optimization problem based on a mechanical model defined for two‐dimensional representations of the microtissues. Our optimization predicts active …