| 摘要 |
835,154. Respiratory apparatus. LEWIS, M. A. Oct. 17, 1958 [Sept. 17, 1957], No. 29189/57. Class 81 (2). Artificial respiration and anµsthesia apparatus has a bellows a operated by a lever b which is moved by a motor-driven cam f. The bellows a connected with the respiratory circuit is alternately expanded and contracted by the lever b rocked about a fulcrum c by the cam assembly f which is rotated by a variable speed electric motor n. The end of the lever b remote from the bellows a is loaded by a spring g the tension in which may be adjusted to vary the negative pressure applied to the lungs on expansion of the bellows. The fulcrum c is adjustable along the length of the lever b to vary the respiratory volume. The cam assembly comprises several cams of different shapes mounted on a core l which is slidable on the cam-shaft e so that any one cam may be used to rock the lever. The shape of the cam chain determines the relationship between exhalation and inhalation phases of the respiratory cycle and the respiratory pattern produced in each phase. |
