摘要
采用特殊设计的扭曲叶轮,研制成脉动流叶轮血泵,当叶轮转速周期性改变时,产生出符合生理要求的脉动血流。由于血细胞的速度变化达极小,泵内紊流切应力也达极小,所以血泵达最佳的溶血性能。血泵输出的平均流量和压力,由输入电机的方波电压的平均值决定,与脉动频率基本无关。为了达到40mmHg的压力脉动又不产生返流,需要40％的收缩期和5V的电压脉动。脉动流叶轮血泵同时在收缩期排血和充盈,跟隔膜血泵不一样。在实验室作溶血比较时,脉动流叶轮泵的溶血约为自制隔膜泵的1/6和丹麦产Polystan脉动泵的1/13;动物试验中,脉动流叶轮泵工作20小时,试验动物体内血细胞计数,血色素和红细胞容积均下降得不明显,血浆游离血红蛋白保持在50mg％以下。
<ABSTRACT>
A pulsatile implantable impeller pump with low hemolysis has been
developed, without markedly increasing complexity of the system as comp-
ared with nonpulsatile pump. The impeller was designed specially to have
minimal velocity variation of blood cells and thus minimize turbulent she-
ar in the pump by changing RPM periodically. The mean pressure and
mean volume are controlled by adjusting the mean voltage just as in non-
pulsatile pump. The pulse of the pressure is determined by square voltage
pulse and systole ratio. In order to vanish the regurgitation of the pump,
40% systole period is desirable for 40 mmHg pressure pulse (80 to 120
mmHg ). The pulsatile frequency has no effect on pump output. The pu-
mp ejects and fills simultaneously at systole, because there is no flexible
chamber in the pump. In hemolysis tests with fresh citrated porcine blood,
the pump delivers blood flow of 4 1/min at 100 mmHg mean pressuro. Ev-
ery half hour the free hemoglobin is tested. The pump was also compared
with self-made diaphragm Fump and POLYSTAN Fulsatile pump. Resulta-
ntly,the pulsatile impeller pump has only an index of hemolysis of 0,020,
being about 1/6 of the diaphragm pump and 1/13 of POLYSTAN. In anim-
al experiments of LVAD for up to 20 hours, the blood counts, hematocrit
and hemoglobin were found reduced sllghtly with Flasma hemoglobin of
below 50 mg%.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
1990年第2期113-119,共7页
Chinese Journal of Biomedical Engineering
基金
中科院科学基金资助课题
