Hemolysis in an electromechanical driven pulsatile total artificial heart.

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Hemodynamics

Background:

• Electromechanically-driven pulsatile total artificial hearts (TAH) are crucial for end-stage heart failure.
• Motor rotation dynamics can impact blood cell integrity, specifically causing hemolysis.
• Optimizing TAH motor operation is essential for minimizing adverse hemocompatibility issues.

Purpose of the Study:

• To evaluate the effect of different motor rotational conditions on hemolysis in a pulsatile TAH.
• To identify the optimal motor speed profile for reducing blood damage.
• To compare hemolysis and pressure changes between constant and gradually increasing motor speed modes.

Main Methods:

• The study utilized an in vitro testing loop with a pulsatile TAH.
• Two motor rotational modes were tested: constant speed (Mode A) and gradually increasing speed (Mode B).
• Hemolysis (NIH value) and maximum pressure change rate (dP/dt) were measured at a fixed pumping rate (100 bpm), preload (15 mm Hg), and afterload (100 mm Hg).

Main Results:

• Mode B (gradually increasing rpm) resulted in significantly lower maximum dP/dt (2953 mm Hg/s) compared to Mode A (5914 mm Hg/s).
• Hemolysis, measured by the NIH value, was substantially reduced in Mode B (0.026 g/100 L) versus Mode A (0.063 g/100 L).
• The gradually increasing rpm mode demonstrated superior hemocompatibility.

Conclusions:

• Driving a TAH with a gradually increasing motor speed is an effective strategy to minimize hemolysis.
• This operational mode also reduces peak pressure gradients, potentially improving device safety and longevity.
• The findings suggest that optimizing motor speed profiles is critical for enhancing the hemocompatibility of artificial heart devices.