AUTOMATIC NON-REBREATHING VALVE CIRCUITS: SOME PRINCIPLES AND MODIFICATIONS

Automatic non-rebreathing valve.

EFFICIENT ventilation of the anaesthetized patient, without carbon dioxide absorption, can be carried out using the valve to be described. It is simple, reliable, efficient and silent. In figure 1 A and E are low resistance valves. P, and P2 form a bypass opening into the balloon B, which lies free in the exit tube X. The balloon is made of very thin rubber and is of such a size that when infla...

The Advantages of a Combined T-piece and Non-rebreathing Valve: a Simple Device.

Ayre's T-piece. The Ayre's T-piece (Ayre, 1937) has a very low resistance, is simple, and almost trouble-free. Intermittent positive pressure respiration (IPPR) can be induced by occluding the exhalation reservoir tube intermittently with one finger. However, the pressure, volume, and riming of lung inflation depends on the flow of gases from the anaesthetic machine and the duration of finger o...

Isoflurane leakage from non-rebreathing rodent anaesthesia circuits: comparison of emissions from conventional and modified ports.

Chronic exposure to low levels of fluorocarbon-based waste anaesthetic gas (WAG) has been linked to a multitude of human health problems. We have shown that isoflurane exhaust from passive gas-scavenging canisters is often quite high when using conventional rodent anaesthesia protocols and equipment. Another likely source of WAG build-up in rodent procedure rooms is leakage at the interface bet...

Design principles of biological circuits

Some Programming Principles: People

This is the fourth and last in a series of columns about programming principles. The earlier columns discussed the principles that relate to programming requirements, software products, and the projects for developing these products. This column deals with people and the human aspects of the software process. While this is an enormous subject and no brief column could possibly do justice to the...