Diagnostic apparatus for measuring changes of arterial and venous blood volumes in brain with respiration signal modulation
US5253646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1992 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | Mar 18, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/14553
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A diagnostic apparatus includes light sources which emit near infrared light rays of different wavelengths. The light rays are introduced into human brain to be subjected to diagnosis and the light rays transmitted through the brain are picked up. There are provided a first detector which detects occurrences of respirations of the subject and outputs a respiration signal, and a second detector which detects occurrences of heartbeats of the subject and outputs a heartbeat signal. The light transmitted through the brain is derived in synchronism with both the respiration signal and the heartbeat signal and first and second modulated light transmission signals are produced which are respectively modulated by the respiration signal and the heartbeat signal. The first and second modulated light transmission signals are separately analyzed to provide variations in concentration of oxygenated media .DELTA.X.sub.02 and disoxygenated media .DELTA.X contained in venous and arterial blood of the brain, respectively. Based thereon, oxygen saturations of both venous and arterial blood flowing in the brain are separately computed and displayed in a monitor screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.