Respiration monitor

US4449537A · kind A · utility

Assignee

• Hewlett-Packard Company, L.P. · US

Inventors

• Gerhard Pross · Holzgerlingen, DE
• Frank Rochlitzer · Edenkoben, DE

Key dates

• Filing date: Mar 8, 1982
• Grant date: May 22, 1984
• Expiry date: Mar 8, 2002

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B5/0816
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A respiration monitor for detecting effective respiration of a patient includes circuitry for suppressing the indication of unwanted signals due to heart activity, noise and flat breathing. A first threshold circuit is provided for increasing the sensitivity of the respiration monitor in response to a decreasing amplitude of the measured respiration signals. A first comparator circuit provides a fixed amplitude threshold below which detected signals are fully neglected. A second threshold circuit provides an adjustable amplitude threshold for the measured respiration signal, which threshold is raised in response to a decreasing respiration frequency below a predetermined frequency limit. Effective respiration is indicated only if all the aforementioned amplitude thresholds are exceeded.