Respiratory exchange ratio sensor
US7390304B2 · kind B2 · utility
25Cited by
5References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2005 |
| Grant date | Jun 24, 2008 |
| Priority date | — |
| Expiry date | Mar 1, 2027 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2230/435
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A device for directly measuring a person's respiratory exchange ratio (RER) utilizes a Zn-air battery cell and a constant current load circuit as an O2 pump capable of drawing oxygen from expired air. A thermistor located in the flow path forms a leg of a bridge circuit whose output is proportional to oxygen concentration in the expired air and, therefore, to oxygen uptake. The thermistor flowmeter circuit utilizes the thermal conductivity differences between O2 and CO2 to provide a measure at the relative ratio of the two gases present.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.