Note: Descriptions are shown in the official language in which they were submitted.
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
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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. ' ,"'
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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
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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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Brief Summary of the invention
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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
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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
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assist valve which is operable, if the patient attemPtS to
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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
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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
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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
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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. .
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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
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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
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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
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Features as described 7 but comprehends all such variation~
thereof as come within the scope of the appended claims.
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