Impedance measurement circuit and method

US8831898B2 · kind B2 · utility

Assignee

• KONINIKLIJKE PHILIPS N.V. · NL

Inventors

• Robert Pinter · Wulfen, DE
• Ralf Schmidt · Nuremberg, DE

Key dates

• Filing date: Oct 8, 2009
• Grant date: Sep 9, 2014
• Expiry date: Oct 17, 2030

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B5/053
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

An impedance measurement circuit comprises a current source arrangement, a voltage measurement arrangement and a processor. The circuit is operable in a two-point measurement mode and a four-point measurement mode and the processor is adapted to derive the impedance to be measured by combining the measurement voltages from the two-point and the four-point measurement modes. This combines the results of both two-point and four-point measurement techniques to provide improved accuracy. In particular, the two results enable the effect of the electrode resistance to be cancelled.