Device for filtering out baseline fluctuations from physiological measurement signals

US5433208A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Lena Lundstrom · Stockholm, SE
• Peter Karlsson · Lund, SE
• Thomas Ohlsson · Sandviken, SE

Key dates

• Filing date: Dec 22, 1993
• Grant date: Jul 18, 1995
• Expiry date: Dec 22, 2013

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B5/316
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

Apparatus for filtering out baseline fluctuations from physiological measurement signals. The apparatus comprises a first nonrecursive low-pass filter with a downstream stage for the reduction of the sampling rate, a second nonrecursive filter connected thereto, a subsequent interpolation stage to increase the sampling rate and a subtraction stage, in which the baseline fluctuations retained by the low-pass filtering are subtracted from the measurement signals affected by baseline fluctuations. To reduce the number of computing operations to be performed in the course of the sampling filtering, the first low-pass filter comprises a recursive filter. a1