How to produce a pulsatile flow with low haemolysis?

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Hemodynamics

Background:

• Pulsatile blood flow is crucial for reducing peripheral vascular resistance.
• Producing pulsatile flow with impeller pumps is challenging due to blood damage caused by turbulence shear.
• Turbulence shear can lyse red blood cells, leading to hemolysis.

Purpose of the Study:

• To develop impeller blood pumps capable of generating pulsatile flow with minimal hemolysis.
• To investigate methods for reducing turbulence shear in pulsatile impeller pumps.

Main Methods:

• Developed a pulsatile axial pump with simultaneous axial reciprocation and rotation of the impeller.
• Engineered a pulsatile centrifugal pump where impeller rotation speed is periodically varied.
• Designed centrifugal pump impellers with twisted vanes to minimize turbulence during speed changes.

Main Results:

• The axial pump achieved 40 mm Hg pulsatility with a reduced 2 mm impeller reciprocation amplitude.
• The centrifugal pump successfully produced pulsatile flow with minimized turbulence.
• The centrifugal pulsatile pump demonstrated no harm to blood elements or organ function in calf circulation experiments.

Conclusions:

• Pulsatile impeller blood pumps can be designed to minimize hemolysis.
• The centrifugal pulsatile pump offers advantages in terms of driver requirements and application potential.
• Pulsatile impeller pumps are efficient for heart recovery support, mimicking diaphragm pumps and improving coronary perfusion.