Apparatus for measuring xenon concentration in xenon cerebral blood-flow studies
US4535780A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1984 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | Nov 7, 2004 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B6/507
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Apparatus for measuring xenon concentration in xenon cerebral blood-flow studies operates under the control of a microprocessor which is used to monitor the patient's breathing cycle and to control a sampling pump in order to assure that only end-tidal gas is sampled. A xenon gas mixture is delivered to a patient by means of a mask assembly. At the end of each exhale cycle, the patient's end-tidal gas is held in a chamber on the exhale side of the mask assembly. At the start of the next inhale cycle, the microprocessor activates the sampling pump which draws end-tidal gas into a thermal conductivity detector. The output of the detector is transmitted through an A/D converter and the resultant value stored in the microprocessor memory along with the time of the sample. At the completion of a CT scan series, the accumulated data in the microprocessor is transferred to the CT-system-housed computer to be used in the reconstruction of cerebral blood-flow images using conventional techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.