Compliance compensation for electronically controlled volume respirator systems

• US 3,923,056 A
• Filed: 06/19/1974
• Issued: 12/02/1975
• Est. Priority Date: 06/19/1974
• Status: Expired due to Term

• Current Assignee: Donald O'Neal Edwards, Frank J. Desiderio, Richard Bingmann
• Original Assignee: Donald O'Neal Edwards, Frank J. Desiderio, Richard Bingmann
• Inventors: Bingmann, Richard, Desiderio, Frank J., Edwards, Donald O'Neal
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/480,799
• Time in Patent Office: 531 Days
• Field of Search: 128/145.8,145.5,145.6,145.7,DIG.17 73/194F
• US Class Current: 128/204.21
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit

Abstract

A volume-cycled respirator for delivering a prescribed volume of gas to a patient utilizing pressure responsive apparatus to monitor the gas pressure developed at the patient interface. The apparatus produces a signal proportional to gas pressure and includes a variable gain amplifier to proportion the signal to volume. The signal is then used to compensate a volume cycled control signal for the volume of gas required to fill the interconnecting hoses and equipment between the volume measuring apparatus and the patient interface to assure that the prescribed volume of gas is delivered to the patient.

Claims

1. In a respirator including an interconnecting hose assembly adapted to be connected to a patient and connected to an inhalation passageway and to an exhalation passageway and further including a pressurized gas source connected to said inhalation passageway and a flow control valve and flow rate sensor connected in said inhalation passageway intermediate said source and said interconnecting hose, a flow control valve in said exhalation passageway and control means responsive to said flow rate sensor to control operation of said flow control valves, the improvement comprising:

pressure responsive means connected to said interconnecting hose assembly for developing a first signal representative of a gas pressure in said interconnecting hose assembly, means for supplying said first signal to said control means for modifying the operation of said control means in proportion to gas pressure in said interconnecting hose assembly; and

an integrating circuit means connected to said flow rate sensor for developing a second signal proportional to a volume of gas passing through said flow sensor, means for supplying said second signal to said control means for controlling the operation of said control means in response to said volume of gas flowing through said flow sensor, wherein said control means responds to said second signal by controlling the operation of said flow control valves.

2. The apparatus as defined in claim 1 wherein said pressure responsive means includes:

a pressure transducer connected to said interconnecting hose assembly for producing said first signal representative of said gas pressure in said hose assembly;

differential amplifier means for combining said first signal with said second signal representative of said volume of gas flowing into said hose assembly to produce a third signal representative of a difference therebetween; and

means for comparing said third signal to a voltage proportional to said prescribed volume of gas for controlling said flow control valves.

3. The apparatus as defined in claim 2 and including a variable gain amplifier connected intermediate said pressure transducer and said differential amplifier means for adjusting the amplitude of said first signal to proportion said first signal to a volume signal.