CA2079359A1 - Breathing apparatus - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A breathing apparatus for supplying breathable gas to a patient, having a housing which can be hand held by one hand, over the face of the patient and which incorporates a gas inlet on the housing, a gas outlet on the housing, a gas circuit within the housing, a switch on the housing by which gas can be either automatically supplied by the gas circuit to the gas outlet on a cyclic basis, or can be supplied continuously to a manually operable valve in the housing, and a trigger on the housing for controlling the supply of gas to the outlet through the manually operable valve. An attachment for a face mask, so that the face mask can be held in place, and the controls operated, by one hand, leaving the other hand free.

Description

Fi,eld,,"o,f,_t,b"e"",I,,nv,en,~t"i"on This invention relates to breathing apparatus for supplyin~
breathable gas to a patient~ Such apparatus can be used for smergency resuscitation and also as a lung ventilator for non breathin~ Patients being transported. The apparatus is adapted to be hand held~ and operated simultaneously, by one hand, leaving the other hand free.
Back~ ound_of_the_Inv,ent,i~on Breathing apparatus in general are known. Known apparatus includes a control module having a gas circuit means incorporating various valvss and throttles whereby pulses of ,. .
breathable gas can be supplied to the patient on a continuous ,-basis. However, in this known system the gas control and gas circuit means comprised a separate modular portion of the apparatus. The fac~ mask itself was connected to the control module by a flexible hose, thus an operator would have to use one '~
hand to hold the face mask in position and would have to use the ' ~', other hand to operate the controls on the separate module.
When working on a patient lying on the ground or on a stretchor, the working position of the operator would require him to kneel beside the patient without any other support. This working position is fatiguing and awkward. In some cases it maY
actually require two operators to perform the two separate fu~nctions. '-In known breathing apparatus of the type in question, ths ,~
gas~control~circuitry is usually embodied as a control module. ' ,"' . ~

A separate hand piece is connected to the control module by a length of flexible tubing. All adjustments must be effected at the control module. This requires the user to free at least one hand from the face mask and hand piece which has to be hand held to seal around the patient's mouth and nose~ so as to reach and operate the controls.
The controls on the control module usually permitted either automatic cyclic suPply of gas to the hose and face mask~ but also provided for a manual switch which bypassed the automatic control. In this bypass condition, gas was supplied to a manual valve. The operator with then have to operate a manual operation lever on the control module so as to manuallY supply gas to the face mask. This module may also have a control for varying the -breathing parameters to suit the individual patient~
ClearlyJ this system was clumsy and disadvantageous. It was either extremely tiresome and difficult for a single operator, or else required two operators.
The present invention provides improved breathing apparatus for supplying breathable gas to a patient, which can be held by . . .
one hand on the face, and on which the controls can also be operated by the same handJ leaving the other hand free~

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~ ccording to one aspect of the inv0ntion, there is provided breathing apparatus for supplying air or gas to a patient, comprising a housing adapted to be hand held, over the face of the patient and which incorporates a gas inlet on the housing, a gas outlet on the housing J gas circuit means all within the housing, a switch on the housing whereby gas can be either automatically supplied by the circuit means to the gas outlet on a cyclic basis or is supplied continuously to a manually operable valve in the housing, and a trigger on the housing for controlling the supply of gas to the outlet through the manually op~rable valve and means for attaching a face mask.
The invention further comprises a face mask which in use is attached to the gas outlet on the housing, and on which all adjustments and operations of the apparatus can be carried out with the fingers of one hand substantially without relaxing the hand holding the face mask in position. In particular, the trigger can be operated to cause cycling of the gas supply under manual control, for example in sympathy with manual cardiac massage.
The invention further comprises an apparatus in accordance -with the first aspect of the invention can be made relativelY
small and light7 for example having dimensions suitable to fit the hand7 and this is made possible by improvements in the gas control circuitry.

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The invention further comprises a breathing apparatus for supplying air or gas to a patient comprising a mask inlet, a gas outlet J and gas circuit means operable to supply gas to the gas outlet on a cyclic basis, wherein the gas flow rate to the patient is controlled by a first adiustable throttle and the periodicity of the cycle is controlled by a second adjustable throttle~ the two throttles being combined into a coaxial assembly of inner and outer throttle elements of which the inner throttle element is carried by the outer throttle elsment.
The invention further comprises throttle elements which preferably comprise inner and outer throttle needles adjustable with a fixed sleeve. The outer throttle needle, which is hollow, and preferably controls the gas flow to the patient, is adjustable within the fixed sleeve by means of cooperating screwthreads, whilst the inner throttle needle is in screwthreaded engagement with the outer needle to control tha cycle periodicity~ Thus, while the cycle periodicity is independently adjustable for calibration purposes, adjustment of i~ the gas flow rate to the patient also automatically adjusts cycle timing. This is convenient to enable the provision of an adult/child control on the instrument~ Adjustment of the control (~ towards the child setting reduces the gas flow rate to the '~ patient and simultaneously increases the cycle periodicity.
The invention further comprises the gas circuit means preferably includes a main valve which produces the gas cycling -effect. This main valve has a main gas inlet and a gas outlet ~ 4 ~

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from which gas passes to the flow rate/timing throttle means, a secondary gas inlet receiving from the throttle means a proportion of the gas flowing to the Patient which is dependent on the setting of the timing needle, and a spring loaded valve member which is gradually driven by build-up of gas pressure at the secondary inlet to a position in which it occludes the main gas inlet, whereupon flow of g~s to the throttle means ceases, gas bleeds back from ths secondary inlet towards the throttle ; means, and the valve member is restored eventually to re-open the main inlet.
Z~nother advantage of this arrangement of the main valve, is that it can dispense with the need for a gas reservoir.
The invention further comprises, in a preferred instrument, the two aspects of the invention combined~ In this case, gas Z enters the inlet to the housing and passes to a manual/auto switch, preferably after passing through an adiustable pressure I regulator 7 the manual/auto switch directing the gas either to the IZ trigger operable manual valve or to the main inlet of the above-fl described main valve of the gas cycling circuit.
In addition to a pressure relief valve at the gas flow outlet to the patient designed with a spring biased silicon disc acting against a raised seat to ensure clean lift and exhaust of excess gas at a set pressure and also to provide audible warning of the release of gas by the vibration of the silicon disc ~ against the seat, the apparatus preferably includes a respiratory ',:
assist valve which is operable, if the patient attemPtS to _ 5 _ ~ , .. . . . . . . . ..... . .

relieve pressure at the secondary inlet of the main valve thereby at once to initiate a gas-on phase.
The various features of novelty which characterize the invention are pointed out with more particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
IN THE DR~WINGS
3 Figurs 1 shows embodiment of the breathing apparatus incorporating the invention in perspective view, with a face mask attached partially cut awaY to reveal the interior, and, Figure 2 shows the gas control circuit contained within the housing of the breathing apparatus.
D ~ _~e~ m d ment Referring first to Figure 1, the preferred apparatus or instrument embodying the invention comprises a housing 10 convenient for hand holding in a single hand, and having a gas outlet 12 to which has been attached a face mask 14 for the purposes of illustration~
The housing has a manual/auto switch 16 J a pressure relief or blow-off valve 18 associated with the gas outlet, a control 20 fully adjustable between adult and child settin~s, and a manual trigger 22. Q gas inlet 23 supplies gas to the housing.
The Hou~s_ing The gas inlet 2~, (Figure 1~ supplies breathable gas from a storage cylinder or a pipeline ~not shown) of a type well known in the art.
~ s will be described in detail later, within the housing the instrument has gas control circuitry (Figure 2) wherebY
breathable gas can either be supplied automatically as pulses on a cyclic basis, i.e. when the switch ~6 is on the auto setting, or may be supplied to a manually operable valve controllable by the trigger 22, i.e. when the switch 16 is on the manual setting.
When gas is delivered on a cyclic basis, the gas flow rate and cycle timing are adiustable by means of the control 20 (as described below~
While both hands can be used, if desired, to hold the instrument, with attached face mas~, to ensure a good seal of the mask around the mouth and nose of the patient, it is also possible, by using only one hand to operate all the instrument controls, and especially the trigger 22, can readily be operated ~ with ths fingers of one hand, without relaxing hold of that one ; hand on the instrument and face mask. In the manual mode, for example, the trigger 22 can readily be operated to deliver pulses of gas in sympathy with manual cardiac massage~ This leaves the other hand free for providing cardiac massage and other 7 - . ' functions, without impairing the operation of the unit and face mask themselves.
The gas control circuitry within the housing is shown in Figure 2. Gas enters the body 28 at an inlet 30 through a sintered bronze filter 32 to a pressure regulator 33. Screw 34 adjusts the pressure of spring 35. Spring 35 bears on plate 36.
Plate 36 is mounted on stem 38. .~ore 40 permits gas to pass around valve 38, to chamber 42. Chamber 42 is connected via port 44 to the manual auto switch indicated generally as 16.
Manual Oe~ation The manual auto switch comPrises a body 44 mounted, rotatively in body 28. Body 44 has a central bore 46, and two outlets namely a manual outlet 48, and an auto oulet 50.
By rotation of the valve, gas can be supplied either to the manual port 48 or to the auto port 50.
The manual port 48 is connected by pipe 52 to a manual flow control valve indicated generally as 54. Valve 54 consists of a cylindrical body 56 containing a spring 58. Spring 58 bears on a valve plate 60, which in turn seats on a seal 62. Stem 64 connects with the trigger 22 by any suitable means J SO that operation of the trigger 22 causes the stem 64 to riss upwardly '~ against the spring 58.
~ Gas thsn passes from pipe 52 into the interior of body 56, :, around valve plate 60, and out through outlet 66. When the trigger is depressed, gas is delivered from outlet 66 to outlst ' 12 and then to the mask and thus to the patient.
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f~u,.t. .,om,,a,t,i,c,,""O,.p,,e,",r~a,t,,i,,,o,, .,n,,, In the auto setting of the switch 16~ gas passes through pipe 70 to the main inlet 72 of a main valve 74, having an outlet 76 from which gas passes to a throttle unit 80 Main valve 74 comprises a cylindrical body 82, containins a spring 84. Spring 84 bears on a compensating piston 86.
Compensating piston 86 is itself a generally cylindrical structure, containing a spring 88, and having seals 90 bearing on the inside of bodY 82.
Within compensating cylinder 86, a plate 92 is biased by spring 88. Plate 92 is connected by stem 94, to~a main valve closure member 96. Closure member 96 is slideable in maln valve chamber 98 between lower seal 100 and upper seal 102. Inlet 72 ~ :
; connects with chamber 98 between the lower and upper seals.
Thus when main valve closure 96 is in its lower position bearing on seal 100 gas can pass directly from inlet 72 to outlet 76~
' However, when in a manner described below main valve 96 : rises upwardly against seal 102, no further gas can pass to . .
outlet 76.

The operation of the main valve 74 will be described below. , For purposes of permitting movement of piston 86, an air vent opening 104 is provided in body 82.
Throttle valve 80 will be seen to comprise a main body 110, defining an interior flow chamber 112~ Chamber 112 connects to , , ~ . . . . . ......

pipe 78 via inlet 114, and gas can pass outwardly therefrom through outlet 116.
~; The purpose of throttle valve 80 is to both control the flow of gas to the mask, and also to cycle the pulses flow, so as to ` optimize the resuscitation effect of the breathing apparatus, in the automatic mode, so as to sequence the pulses in time with the breathing of the patient~
In order to do this, an outer throttle sleeve 120 is threadedly received within body 110~ The lower end of outer sleeve 120 has a tapering formation adapted to gradually open and close the top end of the chamber 112 so as to regulate the gas flow there through.
Within the outer sleeve 120, a feed back throttle rod 122 is threadedly received the inner throttle member 112 has a stem 124 extending through chamber 112. Stem 124 extends through passage ~: 126 into chamber 128. Within chamber 128 a valve 130 is mounted l~ on ths lower end of stem 124. A compensating spring 132 urges ~.
~ stem 124 upwardly, to take up any slack in the threads between ,~ rods 122 and 120. A compensating opening 134 communicates with ~ 20 tube 136 to inlet 138 at the lower end of chamber 82. .
1, In the position as shown in figure 2 gas from gas inlet 114 can bleed downwardly through 126 into chamber 128 and through tubes~l34 and 136 into the lower end of chamber 182. This . -~
compensating pressure will then urge piston 86 to rise upwardly agai:nst spring 84.

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When valve ~6 reaches seal 102, and shuts off further passage, any further increase in pressure, will merely cause piston 86 to move against the influence of spring 88, without causing damage similarly, by effectively balancing the forces of the two springs 84 and 88, the compensating piston 86 can be permitted to move a short distance, or even to move up and down slightly without moving the valve stem 94 and valve 96, so that only when a certain specified pressure is reached, will the valve stem 94 actuallY move. Thus the compensating piston 86 can perform in effect two functions.
Both the outer sleeve 120, and the inner shaft 122 can be controlled from the exterior of the housing 10 if desired, the control 20 being connected to the both inner shaft 122 so that both the outer shaft 120 can be moved simultaneously. The ;i . .
cycling rate and the flow of gas can thus be regulated, while the ~ operator is actually holding the unit in one hand simply by 3i operating his thumb against the operating lever 20.

From outlet 116 of body 110, gas passes dirsctly to the main outlet ~12, and then to the mask. In the event of an unusual overpressure occurring, a pressure relief valve 130 is provided.

Pressure relief valve 130 comprises a generally cylindrical ` chamber 132 having openings 134 for discharge of gas to the atmosphere.

Chamber 132 is connected to outlet 12 by means of a branch .
I pipe 136.
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~ valve plate and flexible silicon disc 138 bia~ed by a spring 1~0 is provided in chamber 132. Disc 138 is somswhat domed (as shown in phantom) so as to make a good seal~ The spring is preset in the factorY so that the blow off pressure cannot be adjusted by an operator.
further component of the unit is the patient assist valve 142, connected to outlet 12 by means of piPe 144. Valve 142 comprises a generally cylindrical body 146, opened to atmosphere at 148 for purposes to be described.
10A lower valve chamber 150 connects with main chamber 146, chamber 150 is connected by pipe 152 to pipe 136.
~ valve member 154 is located in chamber 150, mounted on a stem 156 which in turn extends into main chamber 146 and connects with a diaphram 158 contained by the cap 159 at its edges. A
; spring 160 biases diaphram 158 the operation of the valve is such if the patient tries to inhale during a gas-off phase of the gas cycle, a negative pressure is created in branch line 144 leading to the valve 142, causin~ the valve element 154 to open.
Immediately, therefore, pressure at the secondary inlet 138 of the main valve 74 is relieved, allowing the valve slement 96 to open communication between the main valve inlet 72 and the outlet 76. This will produce a gas-on phase of the gas cycle to be initiated.
; The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific - ~ .

Features as described 7 but comprehends all such variation~
thereof as come within the scope of the appended claims.

Claims (9)

1. A breathing apparatus for supplying air or oxygen to a patient, comprising a housing adapted to be hand held over the face of the patient and which incorporates a gas inlet and a gas outlet gas circuit means within said housing;
a switch on the housing whereby gas can be either automatically supplied by the circuit means to the gas outlet on a cyclic basis or may be supplied continuously to manually operable valve means in the housing;
a trigger on the housing for controlling the supply of gas to the outlet through the manually operable valve means, and means for attaching a face mask to said gas outlet.

2. Breathing apparatus as claimed in claim 1 wherein, in use, with a face mask attached to said gas outlet on said housing, all adjustments and operations of the breathing apparatus can be carried out with the fingers of one hand substantially without relaxing the hold of said face mask in position.

3. A breathing apparatus as claimed in claim 1 trigger can be operated to cause cycling of the gas supply under manual control, for example in sympathy with manual cardiac massage.

4. A breathing apparatus as claimed in claim 1 for supplying air or gas to a patient and comprising;

a gas inlet;
a gas outlet;
gas circuit means operable to supply gas to said gas outlet on a cyclic basis;
first throttle means wherein gas flow rate to the patient is controlled by said first adjustable throttle;
second throttle means whereby the periodicity of the cycle is controlled by said second adjustable throttle means, said two throttle means being combined into a coaxial assembly of inner and outer throttle elements of which said inner throttle element is carried by said outer throttle element.

5. A breathing apparatus as claimed in claim 4 wherein said throttle elements preferably comprise inner and outer throttle needles adjustable with a fixed sleeve, and wherein said outer throttle needle is hollow, and preferably controls the gas flow to the patient, is adjustable within said fixed sleeve by means of cooperating screwthreads, and wherein said inner throttle needle is in screwthreaded engagement with said outer needle to control the cycle periodicity, whereby the cycle periodicity is independently adjustable, for calibration, but during use adjustment of the gas flow rate to the patient by means of the external control also automatically adjusts cycle timing.

6. A breathing apparatus as claimed in claim 5 wherein adjustment of the control towards the setting for a child reduces the gas flow rate to the patient and simultaneously increases the cyclic rate and conversely adjustment of the control towards the adult setting increases the gas flowrate and simultaneously decreases the cyclic rate.

7. A breathing apparatus as claimed in claim 4 and wherein said gas circuit means preferably includes a main valve which produces the gas cycling effect, said main valve having a main gas inlet and a gas outlet from which gas passes to said throttle means, a secondary gas inlet receiving from said throttle means a proportion of said gas flowing to the patient which is dependent on said setting of the timing needle, and including a spring loaded valve member which is gradually driven by build-up of gas pressure at said secondary inlet to a position in which it occludes said main gas inlet, whereupon flow of gas to said throttle means ceases, gas bleeds back from said secondary inlet towards said throttle means, and said valve member is restored eventually to re-open said main inlet.

8. A breathing apparatus comprising;
a hand-held holdable housing means;
gas inlet means for said housing means;
a manual/auto switch means;
an adjustable pressure regulator;
said manual/auto switch means being operator to direct gas either to trigger operable manual value means or to the inlet of automatic main control valve operable for automatic cycling of said gas, all being contained within said housing means.

9. A breathing apparatus as claimed in claim 8 including a respiratory assist valve means operable, if the patient attempts to relieve pressure at the main valve means thereby at once to initiate a gas-on phase.