Modeling Blood Alcohol Concentration Using Fractional Differential Equations Based on the $ψ$-Caputo Derivative
Om Kalthoum Wanassi, Delfim F. M. Torres
TL;DR
The paper tackles modeling blood alcohol concentration (BAL) by deploying a fractional calculus framework based on the $\psi$-Caputo derivative to capture memory effects in gastric absorption and distribution to the blood. By applying a generalized Laplace transform, it derives explicit analytic solutions for BAL dynamics and demonstrates that the $\psi$-Caputo model encompasses classical and Caputo cases as specializations. Empirical fitting to BAL data shows substantial improvements: the best $\psi$-Caputo setup with an affine kernel $\psi(t)=a_1+a_2 t$ achieves BAL error below $202$ $(\mathrm{mg/L})^2$, a $59\%$ gain over the previous best, with even further gains using non-affine kernels like $\psi(t)=(t+0.5)^{0.97}$. These results underscore the value of kernel choice in fractional models for physiological data and point to broader applications of generalized $\psi$-Caputo operators in biomedical dynamics.
Abstract
We propose a novel dynamical model for blood alcohol concentration that incorporates $ψ$-Caputo fractional derivatives. Using the generalized Laplace transform technique, we successfully derive an analytic solution for both the alcohol concentration in the stomach and the alcohol concentration in the blood of an individual. These analytical formulas provide us a straightforward numerical scheme, which demonstrates the efficacy of the $ψ$-Caputo derivative operator in achieving a better fit to real experimental data on blood alcohol levels available in the literature. In comparison to existing classical and fractional models found in the literature, our model outperforms them significantly. Indeed, by employing a simple yet non-standard kernel function $ψ(t)$, we are able to reduce the error by more than half, resulting in an impressive gain improvement of 59 percent.
