Method and apparatus for indicating the absence of a pulmonary embolism in a patient
US8479731B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2005 |
| Grant date | Jul 9, 2013 |
| Priority date | — |
| Expiry date | Feb 4, 2031 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/0836
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the presence or absence of a pulmonary embolism (PE) in a patient. The breathing gas CO2 partial pressure (PCO2) during the expiration of breathing gases by the patient, the end tidal (EtCO2), CO2 partial pressure, and the CO2 partial pressure (PaCO2) of the blood are measured. The volume (V) of breathing gases expired during the expiration of breathing gases by the patient is also measured and a relationship between changes in breathing gas CO2 partial pressure (PCO2) and changes in breathing gas volume (V) in an alveolar expiration phase of patient expiration is determined. The difference between the blood CO2 partial pressure (PaCO2) and the end expiration CO2 partial pressure is divided by the relationship between PCO2 and V produce a quantity which is compared to a threshold value. If the quantity is below the threshold value, the absence of a pulmonary embolism is indicated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.