Method and apparatus for monitoring lung compliance
First Claim
1. A device for deriving an indication of the compliance of a patient'"'"'s lungs while a respirator provides a supply of gas to the patient and with the use of a pressure sensor operatively coupled to the patient'"'"'s airway to produce a pressure signal represenatative of the patient'"'"'s airway pressure as a function of time during the inspiratory phase of the breathing cycle and wherein a slope of the pressure signal during the inspiratory phase is representative of the compliance of the patient'"'"'s lungs, comprising:
- means responsive to the pressure signal for periodically effectively measuring said slope for respectively different breathing cycles and generating pressure wave index signals representative thereof as indicative of the compliance of the patient'"'"'s lungs; and
means responsive to said pressure wave index signals to register an indication thereof.
1 Assignment
0 Petitions
Accused Products
Abstract
Respirator techniques are described for measuring the linear slope of the inspiratory phase to monitor lung compliance. The measurements of the slope characterize a pressure wave index which is recorded at regular intervals to provide a clear record from which a warning of the patient'"'"'s pulmonary condition such as lung compliance can be derived. Several techniques are shown and described. In one, the pressure wave index is determined by sensing the times when the pressure-time signal reaches predetermined pressure levels above a base line. In another technique, the linear slope segment is searched for and its slope then measured.
-
Citations
19 Claims
-
1. A device for deriving an indication of the compliance of a patient'"'"'s lungs while a respirator provides a supply of gas to the patient and with the use of a pressure sensor operatively coupled to the patient'"'"'s airway to produce a pressure signal represenatative of the patient'"'"'s airway pressure as a function of time during the inspiratory phase of the breathing cycle and wherein a slope of the pressure signal during the inspiratory phase is representative of the compliance of the patient'"'"'s lungs, comprising:
-
means responsive to the pressure signal for periodically effectively measuring said slope for respectively different breathing cycles and generating pressure wave index signals representative thereof as indicative of the compliance of the patient'"'"'s lungs; and means responsive to said pressure wave index signals to register an indication thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for deriving an indication of the compliance of a patient'"'"'s lungs while providing a supply of air to the patient with a respirator having a pressure sensor used to produce a pressure signal representative of the patient'"'"'s airway pressure as a function of time during the inspiratory and expiratory phases of the patient'"'"'s breathing cycle and wherein the slope of a linear portion of the pressure signal during the inspiratory phase is representative of the compliance of the patient'"'"'s lungs, comprising the steps of:
-
periodically effectively measuring the slopes of the linear portions of the inspiratory phases of the pressure signals as they are generated by the pressure sensor while a patient is connected to the respirator, and generating pressure wave index signals representative of the magnitude of said slopes; and recording the pressure wave index signals to form a warning record of the patient'"'"'s lung compliance. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A device for deriving an indication of the compliance of a patient'"'"'s lungs with a respirator for providing a supply of air to a patient with the use of a pressure sensor operatively coupled to the patient'"'"'s airway to produce a pressure signal representative of the patient'"'"'s airway pressure as a function of time during the inspiratory phase of the breathing cycle and wherein the slope of a linear portion of the pressure signal during the inspiration phase is representative of the compliance of the patient'"'"'s lungs, comprising:
-
means responsive to the pressure signal for periodically effectively measuring the slopes of said linear portion of the inspiratory phases of the patient'"'"'s breathing cycles and generating pressure wave index signals respectively representative of said measured slopes and the compliance of the patient'"'"'s lungs during respective breathing cycles; means for detecting when a said pressure wave index signal represents a lung compliance measurement indicative of a significant alteration of the compliance of the patient'"'"'s lungs and generating a warning signal indicative thereof; and means for registering said warning signal to indicate said significant alteration in the patient'"'"'s lung compliance. - View Dependent Claims (17, 18)
-
-
19. In a respirator for providing a supply of air to a patient with the use of a pressure sensor to produce a pressure signal representative of the patient'"'"'s airway pressure as a function of time during the inspiratory phase of the patient'"'"'s breathing cycle and wherein the slope of a linear portion of the pressure signal during the inspiratory phase is representative of the compliance of the patient'"'"'s lungs, the improvement comprising:
-
means responsive to the pressure signal for effectively measuring the slope of said linear portion of the inspiratory phase of the patient'"'"'s breathing cycle and generating pressure wave index signals respectively representative of said measured slopes and the compliance of the patient'"'"'s lungs during respective breathing cycles; means responsive to the pressure wave index signal during a selected time period for generating a reference level thereof; means for comparing pressure wave index signals measured subsequently to said selected time period with the reference level for producing a warning signal when pressure wave index signals deviate from said reference level by a predetermined amount; and means for registering said warning signal to indicate a significant alteration in the patient'"'"'s lung compliance.
-
Specification