An Atraumatic Mock Loop for Realistic Hemocompatibility Assessment of Blood Pumps

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Hemodynamics

Background:

• Conventional mock circulatory loops (MCLs) induce blood trauma, limiting in-vitro hemocompatibility testing.
• Static test loops fail to replicate clinical hemodynamic scenarios accurately.
• Realistic hemocompatibility assessment requires advanced simulation capabilities.

Purpose of the Study:

• To develop an atraumatic mock circulatory loop (H-MCL) using a hardware-in-the-loop concept.
• To enable realistic hemocompatibility assessment of blood pumps.
• To overcome limitations of conventional MCLs in simulating clinical conditions.

Main Methods:

• Designed an H-MCL with minimal blood-contacting components (polycarbonate, silicone/PVC tubing).
• Implemented decoupling pressure control via feedback linearization and optimized level control.
• Evaluated H-MCL accuracy with a HeartMate 3 and assessed hemolysis in bovine blood.

Main Results:

• H-MCL accurately replicated typical hemodynamic scenarios with low root mean square error (RMSE < 1.74 ± 1.37 mmHg).
• Fluid level control within ±4% of target was achieved.
• No significant hemolysis differences were observed between H-MCL modes and conventional loops.

Conclusions:

• The H-MCL provides a viable platform for in-vitro hemocompatibility testing.
• It simulates realistic hemodynamic conditions without inducing significant blood trauma.
• This technology eliminates setup-related risks associated with blood trauma in testing.