title: An artificial heart driven by liquid gas.
abstract: An artificial heart (AH) driving system, in which a sac or diaphragm type blood pump is liquid gas driven, is designed. The working mechanism of this system is as follows: 1) liquid gas is used for the driving source; 2) a liquid gas is stored in its liquid state in the circuit; 3) a liquid gas is vaporized, and the vaporizing pressure squeezes the blood pump, causing ejection of blood; 4) vaporized gas is aspirated and compressed by a small compressor to liquefaction through the heat exchanger, then negative pressure is applied to the blood pump and blood is aspirated; and 5) the blood pump is driven in this closed cycle. To demonstrate the mechanism of this system, a prototype was developed using Freon 114 as the liquid gas. In this system, the maximum flow of the AH at a 100 pulse per minute rate, was about 6.9 L/min, using a 90 ml sac type blood pump. The advantages of this AH driving mechanism are as follows: 1) a small system is available because pressure chambers are not necessary; 2) a biventricular system is available, with a single compressor; 3) no compliance chamber is necessary if the system is small enough to be implanted.
authors: Institute of Medical Electronics, Faculty of Medicine, University of Tokyo, Japan.
authors: Y
authors: Y
authors: Abe
authors: T
authors: T
authors: Chinzei
authors: K
authors: K
authors: Imachi
authors: K
authors: K
authors: Mabuchi
authors: K
authors: K
authors: Atsumi
authors: I
authors: I
authors: Fujimasa
mesh_terms: D000641:Ammonia; D005617:Chlorofluorocarbons, Methane; D011211:Electric Power Supplies; D004867:Equipment Design; D006354:Heart, Artificial; D006801:Humans; D009330:Nebulizers and Vaporizers
chemical_list: D005617:Chlorofluorocarbons, Methane; D000641:Ammonia