Computational Modeling of Individual Differences in Cardiovascular Response during Parabolic Flight

Abstract

Future human aerospace systems will consist of a complex integration of multiple technologies, including Artificial Intelligence (AI) driven autonomy. We expect autonomous systems to support and augment human performance, especially when humans are experiencing physiological or cognitive decrements in operational scenarios. To accomplish this, we need the ability to identify these human performance decrements in different individuals and in different mission contexts (e.g., varying g-levels, acceleration profiles). Factors such as sex, weight, and height can alter physiological response to various stressors. Therefore, accounting for these differences is essential to build effective autonomous systems in these operational contexts. Computational models and algorithms that drive our human assessment systems are rooted in theory but also need realistic data for testing and evaluation. While there is a basic understanding of expected changes in physiology under varying stressors, available data are largely lab-based and sparse. However, experimentally determining the response of each individual in a large variety of mission contexts is prohibitively expensive and time-consuming. Thus, future human assessment algorithm development efforts would substantially benefit from simulated, representative datasets created through configurable human models. We will build on prior cardiovascular, metabolic, and other modeling work to create a physiological model tailorable to specific operational mission contexts and personalized input parameters. In particular, we have implemented a 21-compartment lumped-parameter model to simulate physiological responses of a 50 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> percentile female and a 50 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> percentile male during a parabolic flight maneuver. The modeled individuals were differentiated by anthropometric and total blood volume data based on U.S. Army personnel. Results of the simulations highlight and quantify the differences in physiological responses between the two individuals when exposed to the same parabolic fight maneuver. Differences between the male and female models were greatest during hypergravity for almost all parameters except for Stroke Volume (SV), which presented the greatest differences between the two individuals during the transition between hypergravity and 1g. Our preliminary modeling effort demonstrates that differences exist in the cardiovascular response between two simulated, anthropometrically different individuals during a parabolic flight maneuver. In addition, those physiological differences are dependent on the magnitude of the gravity level. These results support and further justify the need for individualized modeling.