A Magnetic Fluid-Driven Artificial Heart

点击翻译按钮获取中文摘要

A variety of implantable artificial hearts have been studied. They, however, have a common drawback of utilizing bearings and a complicated driving mechanism. A magnetic fluid actuator, on the other hand, drives magnetic fluids directly simply by applying magnetic field and does not require a bearing. Feasibility of a magnetic fluid-driven artificial heart was studied.Two ring solenoids with an air gap of 10 mm were arranged near an acrylic tube (10 mmOD, 7.4 mmID). A small balloon (volume: 2mL) was connected to the both ends of the acrylic tube. The balloon was encased in a rigid box that had an inlet and outlet port. The acrylic tube and the balloons were filled with Fluorinert. Magnetic fluid and an iron cylinder were immersed in Fluorinert. Two solenoids were alternately activated according to control signals from a computer. Two experiments were conducted: (1) magnetic fluids alone were used. (2) A combination of magnetic fluids and the iron cylinder was used. This combination was used as a substitute for magnetic fluids with high magnetization.With the use of magnetic fluids alone, a flow of 26 mL/min was obtained at 140 beats/min. Closing pressure was 13 mmHg. With the use of magnetic fluids and the iron cylinder, a flow of 318 mL/min was obtained at 260 beats/min. Closing pressure of 300 mmHg was obtained.With the use of magnetic fluids and the iron cylinder, 90 % flow of the maximum flow was obtained. Calculation disclosed that a driving pressure over 100 mmHg is obtained with the use of magnetic fluids with a magnetization of 113 kA/m.A magnetic fluid-driven artificial heart could be feasible if magnetic fluids with a magnetization of 113 kA/m are developed.