Method and arrangement for detecting changes of a magnetic response in magnetic particles

US6825655B2 · kind B2 · utility

Assignee

• Imego AB · SE

Inventors

• Ana Minchole · Zaragoza, ES
• Andrea Astalan · Gothenburg, SE
• Christer Johansson · Gothenburg, SE
• Kerstin Lagerwall-Larsson · Gothenburg, SE
• Anatol Krozer · Gothenburg, SE

Key dates

• Filing date: Dec 30, 2002
• Grant date: Nov 30, 2004
• Expiry date: Dec 30, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/16
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for detecting changes of magnetic response of at least one magnetic particle provided with a external layer in a carrier fluid, comprising measuring the characteristic rotation time of the magnetic particle with respect to the external layer, and measuring Brownian relaxation in the carrier fluid under the influence of an external alternating magnetic field. The method implies that upon modification of the effective volume of the particle or its interaction with the carrier fluid, a hydrodynamic volume of the particle changes, which implies a change of the frequency (ƒmax) at which an out of phase component of the magnetic susceptibility has its maximum.