Dynamic pumping characteristics of the Hemopump

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Fluid Dynamics

Background:

• The Hemopump is a medical device used for blood circulation.
• Accurate prediction of blood flow is essential for effective medical device operation.
• Understanding Hemopump performance characteristics is vital for its clinical application.

Purpose of the Study:

• To investigate the predictability of instantaneous Hemopump flow using pressure difference and pump parameters.
• To characterize the Hemopump's performance when pumping blood in sheep.
• To establish a model for estimating Hemopump flow rate.

Main Methods:

• Experimental investigation of Hemopump performance in sheep.
• Measurement of pressure difference across the pump system.
• Characterization of pump parameters including maximum flow (QO(n)), internal resistance (R(n)), and inertia (Lc) at varying rotational speeds (n).

Main Results:

• Identified maximum pump flow (QO(n)), internal pump resistance (R(n)), and inertia parameter (Lc) as key characterization parameters.
• Developed a model to predict instantaneous pump flow with approximately 1.0 [ml/s] accuracy.
• Quantified the pump source parameters (Lc, QO(n), R(n)) and their relationships with rotational speed, comparing values to those obtained when pumping water.

Conclusions:

• The Hemopump's instantaneous flow can be accurately predicted using pressure difference and characterized pump parameters.
• Established quantitative relationships between pump parameters and rotational speed for blood pumping in sheep.
• The findings provide a basis for optimizing Hemopump control and performance in clinical settings.