In Vivo Evaluation of a Novel Control Algorithm for Left Ventricular Assist Devices Based Upon Ventricular Stroke...

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Devices

Background:

• Patients with terminal heart failure often require left ventricular assist devices (LVADs) to improve physical fitness.
• Optimizing LVAD function through advanced control strategies is crucial for enhancing patient outcomes.

Purpose of the Study:

• To compare the efficacy of three distinct LVAD control strategies: constant stroke work (CSW), work ratio (WR), and constant speed (CS).
• To evaluate the impact of these control strategies on LVAD responsiveness under various physiological load conditions.

Main Methods:

• The study involved eight pigs with induced biventricular heart insufficiency.
• Three LVAD control strategies (CSW, WR, CS) were tested during alterations in preload, afterload, and contractility.
• LVAD speed changes and systemic flow were measured to assess controller performance.

Main Results:

• The CSW control strategy demonstrated significantly more pronounced LVAD speed adjustments across all tested load interventions compared to CS and WR strategies.
• A significant difference in systemic flow was observed specifically during afterload increase, favoring the CSW strategy.
• LVAD speed changes were significantly more pronounced with CSW control during preload, afterload, and contractility alterations.

Conclusions:

• The constant stroke work (CSW) control strategy exhibits superior adaptability to changing physiological conditions in LVADs.
• An evolved CSW strategy, potentially avoiding invasive measurements, could be clinically feasible for improving patient physical fitness.
• Load-adaptive LVAD control holds promise for enhancing the management of advanced heart failure.