US3463151A

US3463151A - Dual venturi anesthetic gas circulating device

Info

Publication number: US3463151A
Application number: US485417A
Authority: US
Inventors: William B Neff
Original assignee: WILLIAM B NEFF
Current assignee: WILLIAM B NEFF
Priority date: 1965-09-07
Filing date: 1965-09-07
Publication date: 1969-08-26
Anticipated expiration: 1986-08-26

Description

Aug. 26, 1969 w. B. NEFF 3,463,151

DUAL VENTURI ANESTl-IETIC GAS CIRCULATING DEVICE Filed Sept. 7, 1965 I N V EN TOR. I Are. MLLMMBMFF'.

- BY I ,q-rfpauly United States Patent 3,463,151 DUAL VENTURI ANESTHETIC GAS CIRCULATIN G DEVICE William B. Neif, 11 Granite Court, San Carlos, Calif. 94070 Filed Sept. 7, 1965, Ser. No. 485,417 Int. Cl. A61m 17/00; F04b 39/10 US. Cl. 128188 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to apparatus for the administration of anesthetic gases and more particularly to a device for maintaining a continuous circulation of anesthetic atmospheres within the carbon dioxide absorbing circuit of an anesthetic gas administrating machine.

An object of the invention is to provide a circulation inducing means of an improved character for the breathing system of anesthetic gas administrating machines and similar apparatus.

A further object of the invention is to provide a gas circulating means for anesthetic gas administrating apparatus that requires no moving parts and which will enable a patient to breathe with a minimum of eifort.

Another object of the invention is to provide a gas circulating means for anesthetic gas administrating and similar apparatus in which the gas is circulated by a dual Venturi means embodying improved features of construction.

A further object of the invention is to provide a Venturi tube circulating means for a continuous flow closed circuit anesthetic gas administrating system in which the circulation of the anesthetic gas is maintained directly from the feed tube of a gas administrating machine rather than by an external source of power and in which any excess in the flow of gases required to power the Venturi is automatically relieved into the breathing system.

Other objects and advantages of the invention will be in part evident to those skilled in the art and in part pointed out hereinafter in the following description taken in connection with the accompanying drawing wherein there is shown by way of illustration and not of limitation a preferred embodiment of the invention.

In the drawing wherein like numerals refer to like parts throughout the several views:

FIGURE 1 is a sectional view taken along a vertical plane at the center of my gas circulating means,

FIGURE 2 is a transverse sectional view taken along line 2-2 of FIGURE 1, looking in direction of arrows,

FIGURE 3 is a similar sectional view taken along line 3-3 of FIGURE 1, looking in direction of arrows,

FIGURE 4 is a similar sectional view taken along line 4--4 of FIGURE 1, looking in direction of arrows, and

FIGURE 5 is a diagrammatic illustration showing my invention as employed in a continuous flow anesthetic gas circulating system.

Reference is now made to FIGURE 1 of the drawing wherein my device is shown as consisting of a main body member, designated by the numeral 10, which may be of metal, a plastic or of ceramic material having two Venturi throats or passageways 11 that operate in conjunction with associated jet producing nozzles 12 to maintain a circulation of gas through the breathing system. At the discharge end of the body member 10 there is a reducing coupling 13 which is threaded thereupon and sealed by a gasket 14. At its other end, the body member 10 has a gas atomizing chamber forming shell 15 that is secured thereupon by suitable means such as screws 16 and is sealed by means of a gasket 17. The shell 15 has an outer auxiliary chamber 18 having a threaded coupling 19 with a nipple 20 by which a connection is made to a source of anesthetizing gas under pressure. In addition to the Venturi throats, the main body member 10 also has a chamber 21 within which there is mounted a pressure relief or by-pass valve 22 that is associated with an extending conduit 23 that is disposed within a reduced cylindrical bore 24 communicating with the chamber 21 of the body member 10. This conduit 23 forms a direct connection with the auxiliary chamber 18 into which the anesthetizing gases are initially introduced when the device is in operation. The by-pass or pressure relief valve 22, as here shown, has a stem 25 that extends through a threaded bushing 26 having a plurality of spaced openings 27 through which gases may flow when the valve 33 is in its open position. In this arrangement, the bushing 26 is threaded into the chamber 21 and provides a means for adjusting the effectiveness of a coiled compression spring 28 that serves to maintain the by-pass valve 22 in its normally closed position. In addition to the reducing coupling 13 at the discharged end of the body member 10, the shell 15 is shown as having a downwardly extending inlet conduit 29 through which the returned anesthetizing gases, after passing through a C0 absorber or canister may reenter the breath circulating system as will be pointed out in more detail hereinafter.

Before proceeding further with reference to the remaining figures of the drawing, it should be pointed out that the Venturi throat 11 of the member 10, to simplify the drawing, is shown as located along the central plane of the body member 10. However, in actual construction, the dual Venturi throats 11 of the body member 10 are, as shown in FIGURES 2 and 3 of the drawing, disposed in equally spaced relation at opposite sides of the central vertical plane of the device, and the jet producing nozzles 12 are likewise arranged at the sides of the central vertical plane and in line with the Venturi throats 11 as shown in FIGURE 4 of the drawing.

In FIGURE 5 of the drawing, there is schematically shown a closed anesthetic breathing system in which my Venturi circulator powered from a source of anesthetic gas is connected through a flexible inhale breathing tube 30 to a fitting 31 at one side of a face mask 32. Opposite the fitting 31, the face mask 32 has a second fitting 33 which carries a flexible exhale breathing tube 34. The tube 34 leads to a breathing bag 35 that is interposed in a connection with a C0 absorbing canister 36. As here shown, the canister 36 is connected at its upper end to the inlet conduit 29 of the circulator which communicates with the interior of the chamber forming shell 15 where the two jet producing nozzles 12 of the Venturi are located. With this arrangement, when a source of anesthetic gas is introduced at the nipple 20, the gas will enter the auxiliary chamber 18 and then to nozzle 12. This will establish a continuous circulation of anesthetic atmospheres within the CO absorbing circuit of any standard anesthetic gas machine. The anesthetic gases and vapors will be projected through the jet producing nozzles 12 and this will power the two parallel Venturis so that the entire anesthetic atmospheres will pass through the throats of the Venturi in a unidirectional manner and thus eliminate any need for flow direction controlling valves. The throats of the Venturi will preferably have a total crosssectional area at least equal to if not greater than the cross-sectional area of the most restricted portion of the breath circulating system. In practice, it has been found that 3 litre/minute flow of the anesthetic gas is sufiicient to power the Venturis and maintain a circulation of 30 litre/ minute flow of gas in the breathing system. Should it be desired to quickly fill the breathing bag with emergency oxygen or anesthetic gas, the gases greater than the flow required to power the dual Venturis will then enter the general circulation of the anesthetic atmosphere through the by-pass valve 22. This, therefore, makes it possible to more quickly fill the breathing bag than would be the case if this excess gas had to be projected through the Venturi throats of the circulator. The system here disclosed and schematically shown, will perform optimally without the use of flow direction controlling valves. However, any such valves in a standard CO absorbing circuit may be left in the system as an indicator of the soundness of the anesthesia machine when powered by my dual Venturi circulating device. To eliminate the undermask dead-space, I have shown the face mask 32 as having an inhalation port at one side and an oppositely disposed exhalation port which will put the undermask space in the circuit of the anesthetic atmosphere breathed in by the patient. A conventional face mask with a By-Y coupling may also be used with my circulator. By assisting the patient in this manner, the anesthetic gas, after passing through the CO absorber circuit, will keep the undermask atmosphere sweet and permit the patient to breathe with less effort.

While I have, for the sake of cleamess and in order to disclose my invention so that the same can be readily understood, described and illustrated a specific form and arrangement, I desire to have it understood that this invention is not limited to the specific form disclosed, but may be embodied in other ways that will suggest themselves to persons skilled in the art.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an anesthetic gas administering system, the combination of a gas circulating means having an elongated body member, a coupling at one end of said body member connected with the inhalation conduit of a face mask, a face mask having an inhalation and an exhalation conduit extending therefrom, a C0 gas absorbing canister and a breathing sack connected in the exhalation conduit of said face mask, an atomizing chamber forming shell at the oher end of said body member having an open port through which the exhaled gases after pasing through the CO gas absorbing canister will flow from the face mask, an auxiliary chamber carried by said shell into which anesthetizing gas under pressure is first introduced from a suitable source of supply, said elongated body member having spaced Venturi passageways extending from said atomizing chamber and exhausting into the coupling at the end of said body member, atomizing jet producing nozzles disposed within said chamber forming shell in cooperating relation with the Venturi passageways of said body member and extending from said auxiliary chamber for projecting jets of gas under pressure from said auxiliary chamber through said Venturi passageways, whereby a substantially constant flow of refreshed anesthetizing atmosphere wil be maintained in the breathing circuit of the face mask when the circulating means is in operation, said body member also having a normally closed by-pass conduit leading from said auxiliary chamher and extending in parallel relation with the Venturi passageways of said body member, and a pressure responsive valve means in said by-pass conduit operating to admit anesthetizing gas from the auxiliary chamber and into a breathing circuit of the system when anesthetizing gas is required in excess of that provided for by the Venturi passageways in said body member.

2. The invention as set forth in claim 1, characterized by the fact that the by-pass in said body member is of two different axially related diameters, said pressure responsive valve means in the larger diameter of said bypass biased into closing relation with the smaller diameter of the by-pass, a spring means biasing said valve means, and a threaded and apertured plug at the open end of said conduit for varying the response of said valve means to pressure exerted thereupon.

3. The invention as set forth in claim 2, characterized by the fact that the normally cosed by-pass conduit of said body member is of two differing coaxial dimensions forming a shoulder intermediate the ends thereof, a valve means engaging the shoulder in said passageway for closing said by-pass conduit, and a nipple extending from said auxiliary chamber in sealed contact with the smaller diameter end of said by-pass through which anesthetizing gas may flow directly from said auxiliary chamber independently of said Venturi passageways when said valve member is in its open position.

4. A gas circulating device for an anesthetizing gas administering system, comprising a main body member having a Venturi passageway therethrough with a by-pass conduit extending parallel with said Venturi passageway, means carried by said main body member forming a gas atomizing chamber at the smaller end of the Venturi pasageway of said body member, an atomizing jet producing nozzle disposed within said chamber in alignment with said Venturi passageway adapted to be connected with a source of gas under pressure, said chamber also having an inlet opening through which exhaled atmosphere may enter said chamber, coupling means at the other end of said body member adapted to be connected with the inhalation side of a face mask, characterized by the fact that a nipple connects said by-pass directly with the pressurized source of anesthetizing gas, and a pressure responsive valve means located in the by-pass of said body member adapted and arranged to open when the required volume of anesthetizing gas is greater than that circulating through said Venturi passageways when the circulating means is in operation.

References Cited UNITED STATES PATENTS 1,737,575 12/1929 Driiger 128-191 XR 1,804,569 5/1931 Taddiken 230103 2,057,218 10/ 1936 Timpson. 2,525,256 10/1950 Byram 103-271 XR 2,891,542 6/1959 Pentecost 128-188 WILLIAM E. KAMM, Primary Examiner US. Cl. X.R. 230-103