A Control-Oriented Model of Blood Volume Response to Hemorrhage and Fluid Resuscitation

This paper presents a control-oriented model of blood volume response to hemorrhage and fluid resuscitation that can be potentially utilized in closed-loop control of fluid resuscitation. A unique characteristic of the proposed model is that it is built to ensure structural parsimony while retaining physiological transparency. To accomplish this characteristic, blood volume regulation in the body to external perturbations of hemorrhage and fluid resuscitation was modeled as a low-order control system in which the fluid transfer between blood and interstitial fluid is governed by a proportional-integral controller. This in essence resulted in a minimal model with four parameters to be adapted to each individual. The validity of the proposed model was tested using data available in the literature. The results indicated that the proposed model was able to reproduce the blood volume response to hemorrhage and fluid resuscitation with high fidelity: on the average, the prediction error was only 1.53 ± 11.5 %, thus strongly supporting our claim that it can be used as viable basis for the design of closed-loop fluid resuscitation controllers.