CARDIOVASCULAR ENGINEERING Journal for Extracorporeal Circulation, Assist Devices,Transplantation and Artificial Organs
	Volume 2, 1997, No 4

The Roller Pump as a Source of Electrostatic Energy in an Extracorporeal Circuit

R. J. Elgas, J. M. Binford, N. D. Plotkin, R. F. Gremel, V. Chung, R. V. Worrell

Abstract:
It has been known for some time that roller pumps can generate interference with the electrocardiograph (ECG) signal. This interference is believed to be caused by the same phenomenon that produced a leak in the heat exchanger module of four of the new Medtronic® Maxima Forté™ oxygenators. The new Maxima Forté oxygenator is one of a new generation of oxygenators that uses plastic fibers for the heat exchange material. The benefits of the plastic fibers are improved in biocompatability and performance over the traditional metal heat exchange materials. The oxygenator underwent a rigorous series of laboratory and animal testing during its development. The manufacturing process also went through an extensive qualification and validation. During the initial period of clinical use, there were reports of four blood to water leaks. No patient complications were associated with these leaks. After a thorough evaluation, the cause of the leaks was found to be an electrostatic discharge that occurred within the heat exchanger during priming of the extracorporeal circuit. It was found that an electrostatic potential between the blood path and the water path of the heat exchanger is generated as the prime solution is recirculated. Infrequently a discharge occurs through the wall of a single heat exchange fiber. The magnitude of the potential generated was found to be a function of the type of arterial pump and pumpheader utilized. A roller pump with a polyvinyl chloride (PVC) pumpheader was found to be the worst case situation. Centrifugal blood pumps and silicone rubber pumpheaders were found to generate no significant electrostatic potential. A unique solution to this problem with roller pumps and a PVC pumpheader, a charge equalization line (CEL), has been identified and evaluated.

Keywords:
cardiac surgery, ECG interference, electrostatic discharge, oxygenator, heat exchanger, plastic heat exchanger

Address for Correspondence:

Reference:
(CVE. 1997; 2 (4): 219-227)

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