US 4,308,872 A · Method and apparatus for monitoring respiration

Abstract

A method and apparatus are shown for monitoring respiration volumes by continuously measuring, while the patient breathes, variations in the patient's chest cross sectional area, or preferably, variations in both chest and abdomen areas. Each area is measured by measuring the inductance of an extensible electrical conductor closely looped around the body, by connecting the loop as the inductance in a variable frequency LC oscillator followed by a frequency-to-voltage converter and a voltage display. Calibration is made by measuring the area variations for a few breaths while directly measuring corresponding volumes of breath, preferably while the patient assumes at least two body positions, for example sitting and supine. The method and apparatus may also be used to monitor changes in area of any non-magnetic object.

Claims20

Dependent claims

Apparatus for monitoring volumetric respiration comprising:

elastically deformable means for disposition about a torso in elastically deformed condition for self-biasing said means into close encircling relation with said torso;
a first extensible electrical conductor mounted on said elastically deformable means and extending circumferentially about a first portion of said torso comprising the rib cage;
a second extensible electrical conductor mounted on said elastically deformable means and extending circumferentially about a second portion of said torso comprising the abdomen;
means for separately and simultaneously measuring the inductances of each of said conductors;
means for weighting said measured inductances to reflect the different contributions from said first and second torso portions to said respiration volume;
and
means for summing said weighted measured inductances and for providing a signal indicative thereof, whereby said signal is substantially proportional to said respiration volume.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for monitoring respiration

Life of this patent

Method and apparatus for monitoring respiration

Life of this patent

Abstract

Claims20