Respirator

• US 3,972,327 A
• Filed: 11/07/1974
• Issued: 08/03/1976
• Est. Priority Date: 03/22/1973
• Status: Expired due to Term

• Current Assignee: Kontron Inc (Roche Holding AG)
• Original Assignee: Hoffmann-La Roche Incorporated (Roche Holding AG)
• Inventors: Guenin, Albert, Ernst, Heini
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/521,801
• Time in Patent Office: 635 Days
• Field of Search: 128/145, 128/145.5, 128/145.6, 128/145.7, 128/145.8, 128/188, 128/142, 128/142.2, 128/1 B, 137/486, 137/487.5, 73/194 E, 73/205 D, 73/205 C
• US Class Current: 128/204.21
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0009 with sub-atmospheric pressure, e.g. during expiration
• CPC Class Codes: A61M 16/0075 Bellows-type
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

A respirator used to replace or assist the respiratory function and automatically regulate the respiration gas flow and pressure during the inspiration phase and expiration phase comprising means for measuring the flow and pressure of respiration gas and providing electrical output signals, valve means including an adjustable valve for controlling the flow and pressure of respiration gas past the measuring means, and electronic regulating means connected with the measuring means and valve means for comparing the electrical signals with predetermined values including standard values and for generating a regulating signal for adjusting the valve means.

Claims

1. A respirator for automatic regulation of flow and pressure of respiration gas during an inspiration and expiration phase by way of a single conduction path between a source of respiration gas and a patient, comprising:

a. a single conduction path having a first end adapted to be connected to a source of respiration gas and a second end adapted to be connected to a patient and, in serial arrangement, measuring means forming part of said conduction path for determining the flow and pressure of respiration gas at a single measuring location proximate the said second end and converting the same into electrical signals;

single first valve means forming part of said conduction path and coupled to the source of respiration gas and adapted to be adjustable between inspiration and expiration positions and for controllably varying the flow and the pressure of the respiration gas during the inspiration phase and expiration phase; and

single second valve means forming part of said conduction path for separating inspiratory and expiratory flow, said single second valve means being coupled between said single first valve means and said measuring means said second valve means including an outlet, and means between said first and second valve means for providing fluidic connection of the first valve means to the patient during the inspiration phase when said first valve means is in said inspiratory position and for fluidic connection from the patient to said outlet during the expiration phase when said first valve means is in said expiratory position; and

b. electronic regulating means connected with the measuring means and said first valve means for comparing said electrical signals with selected values including standard values of inspiratory and expiratory flows and pressures and for generating a regulating signal indicative of a difference between said selected valves and said electrical signals and thereby controllably adjusting said first valve means for flows and pressures of respiration gas during the inspiratory and expiratory phases.

2. A respirator according to claim 1 wherein the separation between inspiratory and expiratory paths takes place in said conducting line between said first valve means and said single measuring location.

3. A respirator according to claim 1 wherein said measuring means includes

a curved channel having a first end defining a first axis and a second end defining a second axis, said curved channel being connected via one end thereof to said second valve means and the other end leading to the patient, said curved channel having an outside wall relative to the curve defining a pair of concave bends meeting each other at a center point of the curve,

at least two auxiliary channels, designated first and second auxiliary channels, in communication with said curved channel and connected with a pressure gas source for introduction of at least one gas stream into said curved channel, whereby each said auxiliary channel opens into a respective one of said concave bends of said curved channel in the region where an extension of the axis of one of said ends intersects said respective one of said concave bends, and

said measuring means further includes thermistor means disposed in each of said auxiliary channels and being electrically coupled to said electronic regulating means.

4. A respirator according to claim 3 wherein said measuring means further includes:

at least third and fourth auxiliary channels disposed for coupling the first and second auxiliary channels and the pressure gas source; and

pneumatic resistor means arranged in the third and fourth auxiliary channels.

5. A respirator according to claim 3 wherein said measuring means further includes pneumatic orifice means disposed in said first and second auxiliary channels relative to said thermistor means such that with each of said first and second auxiliary channels said thermistor means is arranged between the respective end of said curved channel and said pneumatic orifice means.

6. A respirator according to claim 3 wherein said measuring means further includes at least third and fourth auxiliary channels, said third and fourth auxiliary channels opening in the region of the inside wall of the curved channel at locations which are laterally displaced from the curve center in a symmetrical manner and proximate the inside wall, said third and fourth auxiliary channels being connected with said first and second auxiliary channels.

7. A respirator according to claim 6 wherein said measuring means further includes a fifth auxiliary channel connecting the auxiliary channel(s) opening in the region of the inside wall of the curved channel with the atmosphere, said fifth auxiliary channel having at least one thermistor means connected electrically to said regulating means and means for providing a zero adjustment of the measured pressure signal, said fifth auxiliary channel being connected with the pressure gas source.

8. A respirator according to claim 3 wherein said measuring means further includes at least a third auxiliary channel connecting with the atmosphere and said first and second auxiliary channels, said third auxiliary channel including for the purpose of pressure measurement first thermistor means proximate the end thereof opening to the atmosphere and second thermistor means proximate the other end thereof and means for connection with the pressure gas source, said first and second thermistor means being connected with said regulating means.

9. A respirator according to claim 8 wherein said third auxiliary channel includes first pneumatic resistor means arranged between the pressure gas source line and the second thermistor means.

10. A respirator according to claim 9 further including second pneumatic resistor means provided in the line to the pressure gas source.

11. A respirator according to claim 1 wherein said second valve means includes first and second inlet connections and wherein said first valve means comprises a rotary slide valve arrangement which includes:

fixed cylindrical means having first and second borings, leading respectively to said first and second inlet connections of said second valve means, each said boring having an axis lying in a plane perpendicular to the axis of said cylindrical means; and

cylinder means, operatively connected to said regulating means, said cylinder means being supported for rotation within said fixed cylindrical means and having an aperture adapted for selective movement into alignment with said first or second borings.

12. A respirator according to claim 11 wherein said first valve means further includes servo-motor means, connected to said regulating means, for providing rotation of said rotatable cylinder means.

13. A respirator according to claim 12 wherein said first valve means further includes means connected to said servo-motor means for adjusting the angular position of the rotatable cylinder means.

14. A respirator according to claim 13 wherein said adjustment means includes rotating plate condenser means.

15. A respirator according to claim 11 further including housing means connected with and enclosing said fixed cylindrical means, and having channels aligned with said first and second borings of said fixed cylindrical means, the channels being coupled to the inlet connections of the second valve means.

16. A respirator according to claim 15 wherein said housing means contains the second valve means and at least a portion of said measuring means.

17. A respirator according to claim 8 wherein said housing means is fabricated of plastic and is disposable.

18. A respirator according to claim 1 wherein said regulating means includes:

circuit means connected with said measuring means and including means for selectively comparing the measured flow and pressure with a respective standard; and

switching means connected with said comparing means and said first valve means for controlling said first valve means for flow regulation and pressure regulation in response to said comparing means.

19. A respirator according to claim 18 wherein said comparing means includes:

flow curve generator means, operatively connected to said switching means, for producing a standard curve for the flow variation; and

pressure curve generator means, operatively connected to said switching means, for producing a standard curve for the pressure variation.

20. A respirator according to claim 19 wherein said regulating means further includes:

time generator means responsive to the inspiration-expiration time ratio, the respiration frequency and disturbances detected by said measuring means;

a source of normal flow values; and

a source of standard minute volume, and wherein said flow curve generator means is connected to said time generator means, said source of normal flow values and said source of standard minute volume.

21. A respirator according to claim 19 wherein said regulating means further includes:

a source of normal pressure values;

time generator means responsive to the inspiration-expiration time ratio, the respiration frequency and disturbances detected by said measuring means; and

means for detecting the preceeding final inspiratory pressure, and wherein said pressure curve generator is connected to said source of normal pressure values, said time generator means, and said means for detecting the preceeding final inspiratory pressure.

22. A respirator according to claim 18 wherein said measuring means includes means for automatic zero adjustment of the measured signal output of said measuring means.

23. A respirator for automatic regulation of the flow and pressure of respiration gas during an inspiration phase and expiration phase and including a connection to a source of respiration gas comprising:

measuring means for determining the flow and pressure of respiration gas and converting the same into electrical signals;

first valve means adjustable for controlling the flow and pressure of respiration gas past said measuring means during inspiration and expiration;

second valve means for separating inspiratory and expiratory flow, and adapted for connection of said first valve means to a patient during the inspiration phase and for connection from the patient to an outlet during the expiration phase, and including a first and second perpendicularly intersecting channels each connected to said first valve means whereby the first channel is also connected to said measuring means and said second channel has an outlet and;

circumfluous body means disposed in said second valve means with the first channel in the region of the intersection; and

electronic regulation means connected with the measuring means and first valve means, for comparing the electrical signals with standard values and for generating a regulating signal for adjusting said first valve means.

24. A respirator according to claim 23 wherein said circumfluous means includes:

conical part means adjacent each side of the cylindrical means and a boring leading from the end of the circumfluous body connected to the measuring means to the exterior surface portion of the circumfluous means opposite the intersection.

25. A respirator according to claim 24 whereby said second valve means includes tube means disposed concentrically to an axis defined by the second channel and opening therein and for connection to said first valve means.

26. A respirator according to claim 24 whereby said circumfluous means includes radial guide vane means on the conical means facing the inlet and twisted with respect to planes intersecting through an axis defined by the first channel.

27. A respirator according to claim 24 whereby the circumfluous body central cylindrical means extends in the direction of the inlet from a plane perpendicular to the first channel, set through an axis defined by the second channel.

28. A respirator according to claim 24 whereby the second channel is broadened toward said outlet and serving as a diffuser.

29. A respirator according to claim 24 whereby said second valve means is composed of plastic.

30. A respirator according to claim 29 including:

housing means composed of plastic including said second valve means, and part of the first valve means as well as part of the measuring means.