Baroreflex sensitivity controller by intra-aortic pump: a potential benefit for heart recovery

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Control Systems

Background:

• Left ventricular assist devices (LVADs) are crucial for managing advanced heart failure.
• Optimizing LVAD operation is essential for promoting myocardial recovery and improving patient outcomes.
• Baroreflex sensitivity (BRS) serves as a key indicator of cardiac function and autonomic regulation.

Purpose of the Study:

• To develop an automated control strategy for LVADs to identify and maintain optimal operating points.
• To enhance heart recovery by adapting LVAD function to the patient's cardiovascular state.
• To validate the proposed control strategy using a mathematical model of the cardiovascular system.

Main Methods:

• An extremum search algorithm (ESA) was designed to automatically identify the mean arterial pressure (MAP) that maximizes BRS.
• A model-free adaptive controller (MFAC) was implemented to ensure the measured MAP tracks the desired target.
• A cardiovascular system model was utilized to simulate scenarios including LV failure, physical activity, and cardiac recovery.

Main Results:

• The ESA successfully identified the maximum BRS, indicating optimal LVAD function.
• Simulations demonstrated automatic adjustments in LVAD speed: increased during simulated physical activity (6,800 to 8,000 rpm) and decreased during simulated heart recovery (8,000 to 7,200 rpm).
• The control strategy effectively adapted to changing physiological conditions without requiring pre-set control variable reference values.

Conclusions:

• The proposed automated control strategy effectively optimizes LVAD operation for improved heart recovery.
• This model-free approach offers a significant advantage by eliminating the need for setting specific control variable targets.
• The adaptive nature of the system holds promise for personalized LVAD management in heart failure patients.