Magnetic fluid detection method and magnetic fluid detection apparatus
US7680524B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2002 |
| Grant date | Mar 16, 2010 |
| Priority date | — |
| Expiry date | Jul 5, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/281
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The apparatus of the present invention comprises: an excitation device which excites the measurement site with a local direct-current or alternating-current magnetic field, and a plurality of magnetic field detection devices which are disposed in proximity to each other to measure the magnetic field component that is perpendicular to the exciting magnetic field. A magnetic fluid that possesses paramagnetism is injected from the outside into a substance in which a fluid can flow, and the local magnetic field gradient is then measured while the injected magnetic fluid is excited by the application of a direct-current or alternating-current magnetic field from the outside, thus measuring the presence or absence of distortion of the local magnetic field distribution arising from the fact that the specific magnetic permeability of the magnetic fluid injected into the substance is higher than that of the surrounding substance, so that sites where large amount of the magnetic fluid has accumulated are identified in a non-invasive manner without being affected by external magnetic noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.