Heat generation and hemolysis at the shaft seal in centrifugal blood pumps.
The heat and hemolysis around a shaft seal were investigated. Materials were original pumps (Nikkiso HMS-15:N-original, and 3M Delphin:D-original), vane-removed pumps (Nvane(-), Dvane(-)), and a small chamber with a shaft coiled by nichrome wire (mock pump). The original pumps were driven at 500 mmHg and 5 L/min, and vane-removed pumps were driven at the same rotation number. An electrical powers of 0, 0.5, 2, and 10 W was supplied to the mock pumps. In vitro hemolytic testing showed that hemolytic indices were 0.027 g/100 L in N-original, 0.013 in Nvane(-), 0.061 in D-original, and 0.012 in Dvane(-). Measurement of heat with a thermally insulated water chamber showed total heat within the pump of 8.62 and 10.85 W, and heat at the shaft seal of 0.87 and 0.62 W in the Nikkiso and Delphin pumps, respectively. Hemolysis and heat generation of mock pumps remained low. The results indicate that the heat generated around the shaft seal was minimal. Hemolysis at the shaft-seal was considerable but not major. Local heat did not affect hemolysis. It was concluded that the shaft-seal affected hemolysis, not by local heat but friction itself.
Araki
K
K
Department of Artificial Organs, National Cardiovascular Center Research Institute, Miyazaki Medical College, Japan.
Taenaka
Y
Y
Wakisaka
Y
Y
Masuzawa
T
T
Tatsumi
E
E
Nakatani
T
T
Baba
Y
Y
Yagura
A
A
Eya
K
K
Toda
K
K
D000818:Animals; D001698:Biomedical Engineering; D002498:Centrifugation / Q000009:adverse effects / Q000295:instrumentation; D006041:Goats; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006461:Hemolysis; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D066298:In Vitro Techniques