VOLUMETRIC RESPIRATOR

• US 3,633,576 A
• Filed: 10/24/1969
• Issued: 01/11/1972
• Est. Priority Date: 10/24/1969
• Status: Expired due to Term

• Current Assignee: Bear Medical Systems Inc. (Becton, Dickinson & Co)
• Original Assignee: Reynolds G. Gorsuch
• Inventors: Gorsuch, Reynolds G.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Mitchell, J. B.
• Application Number:
  US04/869,098
• Time in Patent Office: 809 Days
• Field of Search: 128/145.8,145,145.5-145.7,191,194,202,203,188,DIG.17
• 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 volumetric respirator which may utilize, as its source of air or life-sustaining gas, a conventional pressure-limited respirator. One or more flow meters, depending upon the selected pressure-limited respirator, are interposed between the respirator and the patient. An adjustable volume control, sensitive to the flow meters, shuts off the supply of air or gas after a selected tidal volume of air has passed. A timer reestablishes flow after a preselected period to permit the patient to exhale. At preselected intervals, the volume control causes a predetermined excess or sigh volume of air or gas to pass.

Claims

1. A respirator for converting a positive pressure respirator to a volumetric respirator to permit volumetric control of gas supplied to a patient, said respirator comprising:

first means, including a positive pressure respirator comprising means for supplying a life-sustaining gas to a patient via a breather head;

second means, connected to said first means, including means for sensing and measuring the rate of flow of gas supplied and time-integrating the same to provide a measure of the volume of gas being supplied;

third means, connected to said second means and including means responsive to the said sensing and measuring means for terminating the supplying of gas after a predetermined volume of gas has been supplied to the breather head; and

fourth means, connected to said third means and including time delay means for reestablishing the flow of gas to the breather head after a predetermined interval, thereby to permit the exhalation of the previously delivered volume of gas.

2. A respirator as defined in claim 1, wherein said sensing and measuring means includes a flow meter which produces an electrical signal of magnitude proportional to the rate of flow of gas therethrough and integrating means effective to integrate said electrical signal to produce a signal representing the volume of gas passing through the flow meter.

3. A respirator as defined in claim 2 wherein said means for supplying gas include a shutoff handle;

and said means for terminating supplying of gas includes an actuator engageable with the shutoff handle when supplying of gas is to be terminated.

4. A respirator as defined in claim 1, wherein said means for supplying gas includes a main supply line and an auxiliary supply line and said sensing and measuring means senses and measures the total volume of gas passing through both of said lines.

5. A respirator as defined in claim 4 wherein said sensing and measuring means includes a respective flow meter for each of said main and auxiliary supply lines, each flow meter producing an electrical signal of magnitude proportional to flow in its respective line;

a means connected to said sensing and measuring means and responsive to the signals from both flow meters to produce a signal proportional to total rate of gas flow; and

means for integrating the latter signal over a period of time to produce a signal representing the total volume of gas passing through the flow meters during that period of time.

6. A respirator as defined in claim 1, including means connected to said first and second means and operable at preselected intervals to provide a predetermined increase in the volume of gas supplied to said breather head, said latter means further including means operable to increase the next following period of the said time delay means thereby to permit exhalation of the previously delivered increased volume of gas.

7. The combination with a pressure-limited respirator including a pressure-regulating means and a source of life-sustaining gas connected thereto;

a breather head having means for connection to a patient and an exhalation valve;

a low-pressure and a high-pressure line connecting the pressure-regulating means and breather head, the high-pressure line being operable, during supply of gas to a patient, to close the exhalation valve;

said pressure-regulating means being responsive to back pressure in the low-pressure line exceeding a predetermined value to shut off the pressure-regulating means;

of apparatus for converting the pressure-limited regulator to a volume-limited respirator, said apparatus comprising;

first means, connected to said respirator, for sensing the volume of gas being supplied through the low-pressure line;

a first valve connected to said first means and responsive to the sensing means for closing the low-pressure line intermediate the pressure-regulating means and the breather head;

c. a second valve, connected to said first means and responsive to the sensing means for diverting gas from the high-pressure line into the low-pressure line between the first valve and the pressure-regulating means to raise the back pressure at the pressure-regulating means to a shutoff valve; and

second means, including time-delay means, connected to said respirator, for delaying resumption of flow of gas to the breather head for an interval predetermined to permit complete exhalation of gas supplied to the breather head.