Clark R E, Goldstein A H, Pacella J J, Walters R A, Moeller F W, Cattivera G R, Davis S, Magovern G J
Cardiovascular and Pulmonary Research Center, Allegheny-Singer Research Institute, Pittsburgh, Pennsylvania 15212, USA.
Ann Thorac Surg. 1996 Jan;61(1):452-6. doi: 10.1016/0003-4975(95)01018-1.
In 1991, Allegheny General Hospital and Allegheny-Singer Research Institute purchased a centrifugal pump, then a 2-year-old technology, from Medtronic Bio-Medicus, as part of its research program for novel treatments of acute and chronic heart failure. During a 4-year development program, we then established and met goals of durability, performance, thromboresistance, and low cost.
In vitro testing involved extensive hydraulic characterizations using Penn State mock loops. Calorimetry was used to determine efficiency. Durability studies used heated (37 degrees C) seawater for 28 to 45 days. In vivo studies used 46 sheep to test performance and engineering changes and to determine myocardial oxygen consumption, thromboresistance, and long-term durability. A left atrium-to-aorta circuit was used in all.
Hydraulic testing showed no preload sensitivity but moderate afterload sensitivity at all impeller speeds (2,000 to 6,000 rpm). The heat load was low, and overall efficiency was 13% to 15%. Bench durability studies showed no electrical malfunction of the stator or console without degradation of the biomaterials used. Acute in vitro studies showed a near-linear relationship of myocardial oxygen consumption and left ventricular stroke work, pump flow, and pump speed. At speeds of 2 to 3 L/min (50% bypass), left ventricular stroke work and myocardial oxygen consumption were decreased approximately 50%. Additionally, 5 animals have had implants for 28 to 154 days with no macroemboli or microemboli detected in any animal. Hematologic and biochemical studies became normal 3 to 7 days after implantation. Hemolysis was low at less than 10 mg/dL. Clinical costs of the device are estimated to be 80% less than those of currently available devices.
We conclude that an old technology has been made into new technology by application of sound engineering design principles, microchips, and new biomaterials. Qualifying trails for a Food and Drug Agency investigational device exemption application are in progress.
1991年，阿勒格尼综合医院和阿勒格尼 - 辛格研究所从美敦力生物医学公司购买了一台当时已有两年历史的离心泵，作为其急性和慢性心力衰竭新疗法研究项目的一部分。在为期4年的开发项目中，我们确立并实现了耐久性、性能、抗血栓性和低成本等目标。
体外测试包括使用宾夕法尼亚州立大学模拟循环进行广泛的水力特性分析。量热法用于确定效率。耐久性研究使用加热至37摄氏度的海水，持续28至45天。体内研究使用46只绵羊来测试性能和工程变更，并确定心肌耗氧量、抗血栓性和长期耐久性。均采用左心房至主动脉回路。
水力测试表明，在所有叶轮速度（2000至6000转/分钟）下，该泵无预负荷敏感性，但有适度的后负荷敏感性。热负荷较低，总效率为13%至15%。台架耐久性研究表明，在未使用的生物材料未降解的情况下，定子或控制台无电气故障。急性体外研究表明，心肌耗氧量与左心室每搏功、泵流量和泵速呈近似线性关系。在2至3升/分钟（50%旁路）的速度下，左心室每搏功和心肌耗氧量降低了约50%。此外，5只动物植入该装置28至154天，未在任何动物中检测到宏观或微观栓子。血液学和生化研究在植入后3至7天恢复正常。溶血率较低，低于10毫克/分升。该装置的临床成本估计比现有装置低80%。
我们得出结论，通过应用合理的工程设计原则、微芯片和新型生物材料，旧技术已转化为新技术。食品药品监督管理局研究器械豁免申请的资格试验正在进行中。
