An optimal control approach for blood pressure regulation during head-up tilt

Abstract

This paper presents an optimal control approach to modeling effects of cardiovascular regulation during head-up tilt (HUT). Many patients who suffer from dizziness or light-headedness are administered a head-up tilt test to explore potential deficits within the autonomic control system, which maintains the cardiovascular system at homeostasis. This system is complex and difficult to study in vivo, thus we propose to use mathematical modeling to achieve a better understanding of cardiovascular regulation during HUT. In particular, we show the feasibility of using optimal control theory to compute physiological control variables, vascular resistance and cardiac contractility, quantities that cannot be measured directly, but which are useful to assess the state of the cardiovascular system. A non-pulsatile lumped parameter model together with pseudo and clinical data are utilized in the optimal control problem formulation. Results show that the optimal control approach can predict time-varying quantities regulated by the cardiovascular control system. Our results compare favorable to our previous study using a piecewise linear spline approach, less a priori knowledge is needed and results were obtained at a significantly lower computational cost.

Postural Orthostatic Tachycardia Syndrome explained using abaroreflex response model

“…This is the first study that uses a closed-loop model of the baroreflex response to explain the oscillatory dynamics observed in POTS patients. Our results advance previous models have had success representing baroreflex responses but with the input of arterial blood pressure [21,40,63,62]. Others have used a closed-loop model but have used a more complicated baroreflex model and did not specifically consider POTS [25].…”

“…In [63] this approach was adapted to study the response to HUT. In Matzuka et al [40] parameter estimation was carried using Kalman Filtering, while the study by Williams et al [62] and Matzuka et al [40] used optimal control theory to estimate model parameters.…”

Hemodynamic Response to the Head-Up Tilt Test in Patients With Syncope as a Predictor of the Test Outcome: A Meta-Analysis Approach

“…On the other hand, Hear Rate Variability (HRV) and its dynamics during HUTT were not different in comparison between HUTT(+) and HUTT(–) groups of patients (Budrejko et al, 2018). Williams et al (2018) showed the effectiveness of optimal control method as a predictor of time-varying quantities regulated by the cardiovascular control system. Moreover, they showed that pre-syncope was correlated with muscle oxygenation elevation, decreased skin blood flow and oxygenation (Lund et al, 2017).…”

Control theory in biology and medicine

“…Optimization problems arising in the design of efficient controllers for neuronal, cardiac, and motor systems are discussed in [2,7,28,29]. Optimal feedback controls 2 intrinsic to the organism are analyzed for homeostasis of blood pressure [39] and neuronal firing rates [27]. One paper [24] discusses optimizing a new approach to regulation of blood sugar in a diabetes model.…”

“…A much-vaunted advantage of the use of models in medical applications is that it enables experimentation without many of the hurdles, in terms of feasibility, costs, and ethical considerations, that would arise from in vivo experiments. In An optimal control approach for blood pressure regulation during head-up tilt, Williams et al [39] use optimal control techniques to investigate the effect on the systemic blood flow, volume, and pressure changes in response to head-up tilt, a common test used to assess a patients ability to regulate blood pressure.…”