Respirator appliances

• US 4,401,115 A
• Filed: 05/22/1981
• Issued: 08/30/1983
• Est. Priority Date: 06/10/1980
• Status: Expired due to Term

• Current Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Monnier, Jean-Pierre
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Shein, Mitchell J.
• Application Number:
  US06/266,480
• Time in Patent Office: 830 Days
• Field of Search: 128/204.21, 128/204.23, 128/204.24, 128/204.25, 128/204.26, 128/205.13, 128/205.28
• US Class Current: 128/204.23
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/1015 using a gas flush valve, e.g. oxygen flush valve
• CPC Class Codes: A61M 16/1055 bacterial
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 16/206 Capsule valves, e.g. mushroom, membrane valves
• CPC Class Codes: A61M 16/208 Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 pressure meter

Abstract

This invention relates to a respirator provided with a supply circuit and a utilization circuit, with a breathable gas accumulator, a distributor and a cyclic action control device.

The respirator comprises an auxiliary make-up circuit for providing a make-up or complement of breathable gas, a discharge circuit for the breathable gas and a ventilation corrector device sensing the pressure in the utilization circuit and acting on said make-up circuit and discharge circuit to provide a complement or withdrawal of breathable gas.

The invention is applicable for treatment of respiratory inadequacies performed in hospital or domestic environments.

Claims

1. In a respirator for the artificial ventilation of the pulmonary tracts of a user in accordance with a cycle of inhalation and exhalation stages of the kind comprising supply circuit means delivering a breathable gas, utilisation circuit means including an inhalation branch and an exhalation branch provided with an exhalation valve, breathable gas accumulator means communicating with said supply and utilisation circuit means and forming a reserve buffer of said breathable gas, distributor means connected to said supply circuit means and comprising an inhalation valve in communication with said inhalation branch for selectively admitting said breathable gas thereto, an accumulator valve and a non-return valve both of which are disposed between the inhalation valve and said accumulator, a cyclic action control device which controls said inhalation valve, said exhalation valve, and said accumulator valve according to a predetermined programme and which is arranged to direct the breathable gas coming from the supply circuit means and from the accumulator means towards said inhalation branch during the inhalation stages, and to direct the breathable gas coming from said supply circuit means towards said accumulator during the exhalation stages;

the improvement comprising, in combination with the foregoing, auxiliary makeup circuit means for supplying a complement of breathable gas to the utilisation circuit means, discharge circuit means for selectively withdrawing a part of the breathable gas in advance of said utilisation circuit, and ventilation corrector circuit means sensing changes in pressure in said inhalation branch and responsive to the durations of the inhalation and exhalation stages to alter such durations accordingly, with said ventilation corrector circuit means acting on said auxiliary makeup circuit means and said discharge circuit means to cause such means to make up or to withdraw said breathable air in dependence upon said changes in pressure and changes in said durations.

2. A respirator according to claim 1, wherein said auxiliary make-up circuit means comprises a pipe connecting the supply circuit to said accumulator and provided with an electromagnetic valve and with a calibrated orifice.

3. A respirator according to claim 2, wherein said discharge circuit means comprises a venting pipe in communication with said accumulator means and provided with an electromagnetic valve.

4. A respirator according to claim 3, wherein said connecting and venting pipes are in communication with said accumulator means to cooperate with upflow and downflow, respectively, of said non-return valve for the direction of flow of the breathable gas from said accumulator means towards said inhalation branch.

5. A respirator according to claim 4, wherein said ventilation corrector circuit means comprises a pressure pickup arranged to supply electrical signals in dependance upon the pressure in said inhalation branch, an electronic calculator connected to said pickup as well as to said cyclic action control device and a controller driven by said calculator and arranged to operate the opening and closing of said electromagnetic valves.

6. A respirator according to claim 5, wherein said pressure pickup is of the piezo-resistive type and is arranged to deliver a voltage proportional to the pressure it receives from said inhalation branch.

7. A respirator according to claim 6, wherein said electronic calculator comprises comparator circuits, each having a plurality of input terminals one of which is connected to said pickup and another of which is connected to a respective control element arranged to supply a respective one of two reference valves, the one being a minimum, the other a maximum, said comparators driving said cyclic action control device so that it triggers an inhalation stage or an exhalation stage when the electrical voltage supplied by said pickup reaches the aforesaid minimum value or maximum value.

8. A respirator according to claim 7, wherein said calculator comprises memory circuits for storing inhalation and exhalation periods (I and E) each associated with the inhalation and exhalation stages and preset by its respective control element, and subtractor circuits each having a plurality of input terminals one of which is connected to an associated one of said memory circuits and another of which is connected to an associated one of said comparator circuits, which comparator circuits produce modified inhalation and exhalation periods (I_r and E_r) which are shorter than said inhalation and exhalation periods (I and E), respectively, determined in dependence upon said minimum and maximum reference values, said subtractor circuits providing difference values (I-I_r and E-E_r) driving said cyclic action control device so that it controls of opening of the respective electromagnetic valves in dependence upon the difference values (I-I_r and E-E_r).

9. A respirator according to claim 8, wherein said controller comprises amplifier means having a plurality of input terminals which are connected to said subtractor circuits and a plurality of output terminals which are connected to said electromagnetic valves.