Low oxygen flow alarm for anesthesia systems
US4191952A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1978 |
| Grant date | Mar 4, 1980 |
| Priority date | — |
| Expiry date | Aug 25, 1998 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2016/0027
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
In anesthesia apparatus for supplying oxygen and an anesthesia gas through respective flow control valves to a patient breathing circuit a low oxygen flow alarm system is provided. The alarm system includes a restrictor in the pipeline of the oxygen flow control valve and a restrictor in the pipeline of the anesthesia gas flow control valve. A differential pressure sensing unit including a diaphragm assembly responsive to the pressure in the oxygen pipeline and another diaphragm assembly responsive to the pressure in the anesthesia gas pipeline is coupled to the restrictor pipelines. The diaphragm assemblies are opposed to each other and coupled together by a displaceable linkage. Electrical switch means are provided coupled to the linkage to provide an alarm signal when the linkage has been moved to a predetermined position indicating that the oxygen concentration has dropped below a predetermined value. The differential pressure sensing unit includes spring biasing means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.