Respiration monitor
First Claim
1. Apparatus for monitoring the respiration activity of a patient and for suppressing disturbing and spurious signals comprising:
- respiration detector means connectable to a patient for providing a variable respiration signal corresponding to the patient'"'"'s respiration activity;
first threshold circuit means coupled to said respiration detector means for producing an amplitude threshold decreasing at most to a given minimum value in response to a decreasing amplitude of said variable respiration signal;
first comparator means coupled to receive said variable respiration signal and a fixed amplitude threshold for suppressing said variable respiration signal below said fixed amplitude threshold;
second threshold circuit means receiving the output of said first comparator means and coupled to raise said amplitude threshold if the frequency of said variable respiration signal decreases below a predetermined frequency limit; and
second comparator means coupled to said respiration detector means and said first and second threshold circuit means for producing a valid respiration indication in response to said variable respiration signal only if said variable respiration signal exceeds said amplitude threshold produced, in combination, by said first and second threshold circuit means.
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Accused Products
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.
20 Citations
9 Claims
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1. Apparatus for monitoring the respiration activity of a patient and for suppressing disturbing and spurious signals comprising:
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respiration detector means connectable to a patient for providing a variable respiration signal corresponding to the patient'"'"'s respiration activity; first threshold circuit means coupled to said respiration detector means for producing an amplitude threshold decreasing at most to a given minimum value in response to a decreasing amplitude of said variable respiration signal; first comparator means coupled to receive said variable respiration signal and a fixed amplitude threshold for suppressing said variable respiration signal below said fixed amplitude threshold; second threshold circuit means receiving the output of said first comparator means and coupled to raise said amplitude threshold if the frequency of said variable respiration signal decreases below a predetermined frequency limit; and second comparator means coupled to said respiration detector means and said first and second threshold circuit means for producing a valid respiration indication in response to said variable respiration signal only if said variable respiration signal exceeds said amplitude threshold produced, in combination, by said first and second threshold circuit means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification