Human Biophysics as Network Weights: Conditional Generative Models for Dynamic Simulation

Simulations of biophysical systems have provided a huge contribution to our fundamental understanding of human physiology and remain a central pillar for developments in medical devices and human machine interfaces. However, despite their successes, such simulations usually rely on highly computationally expensive numerical modelling, which is often inefficient to adapt to new simulation parameters. This limits their use in simulating dynamic human behaviours, which typically proceed along a sequence of small time steps. One may painstakingly produce a few static simulations at discretised stages, but not the hundreds of simulations that are essential to capture the dynamic nature of human body. We propose that an alternative approach is to use conditional generative models, which can learn complex relationships between the underlying generative conditions and the output data whilst remaining inexpensive to sample from. As a demonstration of this concept, we present BioMime, a hybrid-structured generative model that combines elements of deep latent variable models and conditional adversarial training. We demonstrate that BioMime can learn to accurately mimic a complex numerical model of human muscle biophysics and then use this knowledge to continuously sample from a dynamically changing system in a short time. This ultimately converts a static model into a dynamic one with no effort. We argue that transfer learning approaches with conditional generative models are a viable solution for dynamic simulation with any numerical model.