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Publication numberUS1778716 A
Publication typeGrant
Publication dateOct 21, 1930
Filing dateJun 16, 1927
Priority dateJun 16, 1927
Publication numberUS 1778716 A, US 1778716A, US-A-1778716, US1778716 A, US1778716A
InventorsRichard Foregger
Original AssigneeRichard Foregger
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Inhalation apparatus for anzesthetic and other purposes
US 1778716 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Oct. 21, 1930. R. FOREGGER 1,778,716


My invention relates to apparatus for administering gas or gases for anaesthetic and other analogous purposes.

The object of my invention is to improve such apparatus, particularly in connection with the meters or devices that show the rate of flow of the gases. More especially, I so arrange the apparatus as to permit an ether bottle or other obstruction to be interposed in the path of the gas at any time without affecting the accuracy of the flow meter or meters; also I so arrange the apparatus as to permit gas flows in excess of the capacities of the flow; meters when necessary, and any gases that may pass certain types of meters inadvertently and heretofore wasted to the atmosphere, are now sent on to the patient; and in connection with such apparatus I have provided a scale which permits the samemeter, without any adjustment, to be used for substantially any gas suitable for the case in hand although the different available gases have Widely different flow characteristics.

The accompanying drawings illustrate an anaesthetic apparatus'embodying my invention. Figure l is a diagrammatic elevation of the gas machine, with certain representative attachments added thereto. Figure 2 is a sectional elevation of the cap portion of the flow meters shown in Figure 1. Figure 3 is an elevation of one of these flow meters, without the cap, drawn to a larger scale. Figure 4 illustrates a scale for such flow Ineters suitable for use with gases of different flow characteristics. Figure 5 is a slightly modified form of cap for the type of flow meter illustrated in igure 1.

In Figure 1, the base or table 10f the apparatus (which may be provided with a leg 2 or supports to elevate it if desired) is provided with yokes 3 of ordinary, form for holding cylinders of the desired gases such as 4. A machine can be arranged for as many cylinders and gases as may be desired; the machine shown in Fig.- 1 is arranged for four different gases. The usual shut off valves in the necks of the cylinders are shown, in one instance, at 5. Each yoke 3 is perforated with a horizontal passage to Illustrative of 1927. Serial No. 199,224.

receive gas from the outlet in the side of the neck of the respective cylinder when the valves 5 are open, from whence the gas passes by the pipes 6, one for each gas, to the flow meter or meters 8. In these passages 6 are interposed,ordinarily, individual control mechanism to reduce the pressure of the gases from that within the cylinders 4: to a pressure only slightly above atmosphere, and to control the rate of flow; ordinarily the valves 5 are opened wide when the machine is in use, the. gasflow being controlled by. these control devices of the machine. Preferably I use for these control devices thosevalves '7 which are described and claimed in my Patent No. 1,433,104, dated October 24, 1922, but it will be apparent that my invention is not limited to the use of such valves. At or from the meter or meters 8 the different gases join and flow through a single passage 10 toward the patient. As is well known, ether bot tles, whennsed, are preferably or necessarily'inserted in the common passage 10.

such attachments which somewhat obstruct the flow of the gas or gases when inuse and permit a freer flow of the gases when taken out of service, I have shown an ether bottle at 11. As usualthis ether bottle is provided with a valve 11, by means of which the gas or gases can be passed directly through the cap of the bottle or can be madeito pass down through the tube 12 and," bubbling out at the bottom of the tube, pass upward through the ether and thence "on to the patient. At 13 is indicated a so-called sight feed that is frequently used in apparatus of this type, in order that the anaesthesist may observe visually that'the gas or mixed gases are actually flowing to the patient. The device illustrated for this apparatus comprises a glass bottle partly filled with water and provided with a tube 1 1 perforated longitudinally. The gas coming from'the common passageway 10 passes down this tube and bubbles out of one or more of the perforations, depending on'the quantity being supplied to the patient. From abovethe waterlevel the gases'pass directly to the gas bag 15 ordinarily used, and from thence to the face mask 16.

Because of the relatively small volume of gas handled per minute and the necessity of making the machine as small and simple as possible, it is prefrable to measure the rate of gas flow (usually the rate of flow of each gas individually), by means of a device or devices directly responsive to pressure. Since however attachments such as the ether bottle 11 which ofi'er some obstruction to the gas flow, are usually used only more or less temporarily and occasionally, they afford a variable obstruction, changing the back pressure on the gases as the attachments are put into and taken out of service, and this ren ders such flow meters inaccurate from time to time. I avoid this and maintain the accuracy of the flow meters by connectin the opposite sides of each pressure instrument to two points along the gas passageway both in advance of the obstructions (ether bottle 11), so that the pressure instriunent or instruments responds to the difference between the pressures at these two points in the pa.- sageway. This causes the instrument or instruments to give an indication accurately proportional to the rate of gas flow regardless of the presence or absence of obstructions tothe gas flow farther along. Preferably the passageway of the gas or mixture of gases) to be measured is locally restrcted, and the pressure instrument is connected to the two sides of the restriction; small changes in the gas flow then cause easily noticeable changes in the reading of the instrument. Each or mixture of gases to be measured is provided with such a restriction and pressure responsive mechan sm, but where a. number of gases are to be measured, certain of the passageways may be common to all, and the meters may be more or less combined in the general manner described with reference to the deviceillustrated. Thus in the machine of Fig. 1, which, as before stated, is arranged for handling four different gases, for convenience the flow meters are combined into two dev ces 8, each indicating the rate of flow of two These meters 8 are in the form I regard as preferable. Each of these flow meters shown comprises a transparent glass) container 21 for liquid (usually water) as more clearly illustrated in 3, and a pierced block in the form of a. special cap indicated at and in F g. 2. Each cap is pierced with an inlet passage 2 for each individual gas (see Fig. 2) to which a passage 6 leads. Each of these inlet passages opens freely to the interior of the container 21 as through the passages 25. At- 26 an annular mir space is provided having an outlet at 23 going to the common passage 10 leading toward. the tient: at 9 the gases from the two meters join. Passages 27 and 28 connecting the inlet passages 24 and the outlet 2623 pro- Vicle respectively the localized restrictions. The outlet passage 2-23 leading on toward the patient, is also connected by an ample passage or passages 29 with the interior of the container 21, near the top thereof. Connected to the branches 25 leading oil from the respective inlet passages 2d, are individual transparent (glass) tubes 32 and 33 ex:- tending downwardly into the liquid within the container 21 as indicated in Fig. 3, and open at their bottoms. The normal liquid level (no pressure in the tubes 32 and 33 is at the point marked Water on the scale.

It will now be seen that the gases from the individual cylinders 4-, subject to individual control by the valves 7 or other devices for the purpose, are forced to traverse the respective localized restrict-ions 2?, 28 on their way to the patient, and that the pressure of each gas at one side of its re spective restriction, for example, the restriction 27, is transmitted by the passage to the interior of the respective glass tube, i. e. the tube 32, wh le the pressure at the opposite side of the restrictions, in this case the pressure Within the mixing space and outlet 2623, is impres ,d on the larger surface of the liquid within the container 21, but outside the tubes. Accordingly the surface of the l quid within each tube is de pressed below the surface of the liquid outside the t-ube, a distance proportional to the pressure required to force the respective gas through the respective localized restriction 27 or 28; It will be observed therefore that the device will indicate the quantity of each gas flowing per unit of t me, and since the ind cation depends entirely on the conditions existing at the localized restrictions, the indication is independent of an obstructions to flow that may ex st bet veen the flow meter and the patient, for example at the ether bottle 11. It Will be observed that the localized restrictions 27 and 28 may be diiieretn diameters or different lengths, or both, depending on the flow characteris tics of the respective gases and the quantities respectivel required. Of certain the quantit es required may be measured in cubic centimeters per minute, while a number of liters per minute will be required of other gases. Furthermore the rate of flow of any certain through any certain restriction. under a civen pressure, depends on its molecular weight or specific gravi thus a certain pressure will pass much less nitrous oxide through a certain hole or restriction than ethylene, and less oxygen than ethylene, but more oxygen than nitrous oxide. The rate of How or quantity per unit time is dependent upon the molecular weight, i. e. specific gravity, as these ex amples indicate.

1 may use with the container 21 and tubes 32 and 33, a scaleor scales of the kind indicated in Fig. 3, that is to say, a scale individual to each tube and calibrated ,for a single particular gas; such a scale will be accurate for the single gas for Whichit was calibrated and other gases of the same molecular weight. Furthermore the scale for one tube may; be calibrated in cubic centimeters per minute and the other in liters per minute, as indicated. By comparing the position of the surfaces of the liquids in the respective tubes with respect to these'scales, one may observe the flow rate of the respective gases going on to the patient. As an alternative for the scales of Fig. 3, I may use a scale of the type illustrated in Fig. 4:, which adapts a single restriction and pressure responsive device (e. g. tube 32) for use with gases of different molecular weights. Certain commonly used gases are marked at the top of the scale, and the scale can be marked with vertical lines 36 below each gas or group of gases of ubstantially the same molecular weight. Joining those points on these ver tical lines which represent the flow of equal volumes in equal times of the respective gases, are marked lines 37, 38, 39, etc. each representing the flow of a certain quantity' of gas per unit of time... Thus the line indicated by the reference character 38 indi cates a flow rate of three liters per minute; when the gas is oxygen, the depression of the liquid surface .within the tube tothe point where line 38 crosses the middle ver tical line, indicates that three liters of that gas per minute are flowing; when the gas is nitrous oxide, the surface of the liquid must be depressed to the point where line 38 reac 18S the right hand vertical line to assure a flow rate ofthree liters per minute.

In rectangular scales, such as are suitable for straight vertical liquid columns such. as shown in Fig. 3, these equal-flow-rate lines 37, 38, 39, etc. are generally sloped from one side of the scale to the other. 'By interpolation, such a scale as illustrated in Fig. 4 can be used not only for the particular gases marked on the scale, but for other gases as well, provided only that the molecular weight or specific gravity of the desired gas is known as well as the molecular weight or specific gravity of the gases marked on the scale- Thus a gas, the molecular weight of which is midway between the molecular weight of nitrogen and the-molecular weight of oxygen, if employed with thescale'Figi 4, has its flow rate measured by points on the cross lines 37, 38, 39, etc. midway between the vertical lines 36 respectively directly under the oxygen and nitrogen markings.

In. Figure 5, I have illustrated a slightly different form of cap for the flow meter. The inlet passage is at 42 and the outlet at 44. As before, the inlet 42 leads to the tube 32 intended to be suspendedwithin a container cap of Fig. 2. The outlet a l opens from the top of the container as before. Although only one tube 32 appears in the drawing of Fig. 5, it will be apparent that a plurality of tubes may be used with a cap perforated in the-manner indicated in that figure.

With my invention as thus applied to flow meters of the liquid type shown, it will be observed also that should any gas be fur nished inadvertently to the meters 8 at a greaterpressure than can be sustained by the liquid in the tubes 32 or 33, the excess will escape from the bottom of the tube, bubble up through the liquid, and pass to considerable excesses more quickly than the controllers at 7 can be operated, or. excesses furnished temporarily without, disturbing the setting of the controllers 7 Forthis purpose ,I provide another orother-by-passes 46.

lhese have respective quick-openingshut-ofl' valvest'l' which take their gases froma point between the controllers 7 and the'cylinders 4, and. they deliver the gas or gases to'the patient side of the restriction or restrictions.

By opening any valve 47, an excess of the respective gas can be sent onto the patient momentarily both quickly and without requiring that the settingof the controller 'Zbe disturbed. In order that the surface of the liquid-within the tubes 32, 33, and the like may be found quickly by theeyeJafloat 45 can be placed in each tube,-thatis'-to=say, a body, light enoughto float at the surface of the liquid and then follow this surface' up and down. Furthermore, the sight feed,at 13 may constitute a flow meter: for the mixed gases; by making the highest perforation in 14' suitable for passing, say, one liter of the mixed gases per minute and each other hole suitable for passing another literolfthe mixture per ininutefat'least the approximate total flow. rate can be observled noting the number of holes through which thegases emerge from thetube 14; thus active emergence of gas from three holes simultaneously indicatesthat the flowQra te of the mixed gases isthree liters per minute. Ianticipate that knowledgeiofboth the flow, rates ofthe the patient, instead of being Wasted to the atmosphere as heretofore with meters of this liquid type'on analogous apparatus.

tain instances. As will thus be observed, my apparatus can afford such knowledge.

lVhile I have illustrated and described certain embodiments of my invention, in detail, it will be understood that my invention is not limited to these details except as appears in the following claims.


1. Apparatus of the kind described comprising means for holding a cylinder of gas, a liquid container, a cap for the container pierced with a gas passage connected to the gas cylinder and opening into the container, an outlet passage opening from said container, and a passage providing a restricted passageway through which gas flows from the first mentioned passage on its way to the outlet passage, a sight tube Within the container connected to said first mentioned passage and having an opening near its bottom, and means for fastening to said outlet passage an attachment through which the gas may flow on its way to the patient.

2. Apparatus of the kind described comprising means for holding a plurality of cylinders of gas and individual means for controlling the flows therefrom, a liquid container, a cap for said container pierced with passages for conducting the gases unmixed to the container, sight tubes within the container, open near their bottoms, and respectively receiving gas from said passages and a common outletineans for conducting the gases toward the patient, said cap being pierced with individual restricted passages through which the gases flow on their way from the first mentioned passages to said outlet means and said outlet means being connected to said container to receive gas from above the liquid therein.

3. Apparatus of the kind described comprising a liquid container, cap means therefor pierc'e'd with a plurality of inlet passages opening into the container, a gas mixing space and outlet, a passage connecting the top portion of the container to the mixing space, and a restricted passage connecting each inlet passage to said mixing space, a sight tube connected to the opening from each inlet passage into the container, said sight tubes extending downwardly into the container and having openings near their bottoms, means for holding a plurality oi gas cylinders, and means for connecting the gas cylinders to the respective inlet passages of said cap means including means for regu lating the flows of gas therethrough. 7

4. Apparatus of the kind described comprising means for holding a cylinder of gas, a liquid container, means providing a gas passage connected to the gas cylinder and opening into the container, an outlet passage opening from said container, and a passage providing a restricted passageway for gas Hem-the first mentioned passage to the out specification.



Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2870764 *Jan 28, 1957Jan 27, 1959E & J Mfg CompanyAnesthetic gas machine
US2890696 *Dec 17, 1957Jun 16, 1959Morris Lucien EAnesthesia apparatus
US4581945 *Dec 24, 1984Apr 15, 1986Tibor RuszPressure to voltage converter for measuring gas glow rates
US6474132Jul 30, 1998Nov 5, 2002Tuthill CorporationPrecalibrated flow meter
US6581458Jun 18, 2001Jun 24, 2003Tuthill CorporationPrecalibrated flow meter with airflow compensator
U.S. Classification128/203.25, 73/196, 73/198
International ClassificationA61M16/10
Cooperative ClassificationA61M16/104
European ClassificationA61M16/10B