Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: OXYGEN DELIVERY APPARATUS
BACKGROUND OF THE IN~ENTION
The invention set forth in the specification pertains to a new
5 and improved oxygen delivery apparatus. It also pertains to a new
and improved method of delivering oxygen which is practiced
utilizing this apparatus.
Virtually everyone is aware of the fact that it is frequently
10 necessary or advisable to deliver oxygen enriched air or other gases
or gas mixtures to patients during various different types of therapy.
It is not considered that an understanding of the present invention
requires an understanding of or a detailed discussion of all of the
various different types of apparatus which have previously been
15 developed for the purpose of administering oxygen or oxygen enriched
gaseous mixtures in connection with various different types of
therapy. It is, however, considered important to note that it is
generally believed that none of the various different apparatuses
developed for administering oxygen is as acceptable as normally
20 desired for any one of a variety of different reasons.
Amongst these reasons are various items concerning factors
such as cost and reliability. Another particularly important factor in
connection with the acceptability of prior oxygen delivery apparatus
"s concerns whether or not such apparatus results in the use of a
minimal amount of oxygen reasonably approaching only the amount of
oxygen actually required or needed in connection with the treatment
of a patient. This is particularly important because of the relatively
high cost of oxygen of a purity normally required in connection with
30 the treatment of a human body.
SUMMARY OF THE INVENTION
It is believed that it will be apparent from the preceding that
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there is a need for new and improved apparatus for delivering oxygen to a
patient. There is also considered to be a related need for a new and improved
method of delivering oxygen to a patient which overcomes certain of the
limitations of prior methods for delivering oxygen to a patient. Broadly, the
present invention is intended to provide both a new and improved apparatus and
a new and improved method which are intended to fulfill these closely related
needs.
More specifically, the present invention is intended to provide an
apparatus which can be easily and conveniently constructed at a comparatively
nominal cost, which is very simple to utilize and which will operate in an
intended manner over a very prolonged period with substantially no
maintenance. The invention is also intended to provide a method as indicated
in the preceding which can be easily and conveniently practiced. Both the
apparatus and process objectivss of the present invention are also directed to
the delivery of oxygen to a patient in such a manner as to minimize the amount
of oxygen used and, hence, so as to minimize the cost to the patient of the
oxygen used. This latter and the simple, effective character of the apparatus
of the present invention are considered to be quite important.
In accordance with this invention, those various objectives indicated in
the preceding pertainin~ to an apparatus and achieved by providin~ an oxygen
delivery apparatus cannula means for use in conveying gases into and out of
the human body through the nostrils, oxygen supply line means for conveying
oxygen to said apparatus and inhalation and exhalation responsive flow control
means connected to said cannula means and said supply line means for
controlling the flow of oxygen to said cannula means as said apparatus is used
in which the improvement comprises:
said cannula means being sufficiently small so that they will not close
off air flow through the nostrils of the human body,
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said flow control means including an elon~ated receptacle with first and
second opposite ends and definin~ an open sided elon~ated chamber extending
therebetween, said supply line means connected into the interior of said
chamber and said cannula means connected to the interior of the chamber, said
receptacle further having an elongated diaphragm means formed of flexible
material and mounted on said receptacle over said open side thereby enclosing
said chamber, said diaphra~m means bein~ mounted transversely to said cannula
means to move forward and away from said cannula means, said supply line means
and said cannula means spaced from one another by said chamber a sufficient
distance so that gas flow from said supply line means will be throu~h said
enclosed chamber and will be capable of forcing gas from within said chamber
out through said cannula means,
ssid supply line means bein~ connected to said cannula only through the
interior of said chamber, said diaphra~m means having a side opposite the side
ad~acent said enclosed chamber communicatin~ with the surrounding atmosphere,
sald aiaphrs~m means belng sufficiently elexible and responsive to
pressures that are developed durin~ inhalation and exhalation so as to receive
8as in saia chamber durln~ exhalation and to substantially close off the flow
of gas between said supply line means and cannula means through said chamber
in response to inhalation.
BRIeF DeSCRIPTIO~ OF THe DRAWING
Because of the nature of this invention, it is best more fully explained
with reference to the accompanying drawing in which:
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Fig. 1 ls a top plan view of a presently preferred apparatus in accordance
with this invention;
Fig. 2 is a side elevational view of the apparatus as it appears in claim
l;
Flg. 3 is a view of the apparatu~ shown in Fig. 1 in which various parts
are shown in elevation after two tubes, illustrated in Fig. 1 have been bent
so that the parts appear as they are shown in this figure;
Fig. 4 is a partlal cross-sectional view taXen at the curved line 4-4 in .
Fig. 3;
Pi~. 5 is a partial cross sectional view taken at line 5-5 of Fig. 4;
Fig. 6 is an enlar~ed fragmentary view of a part of Fi~. 5; and
Fig. 7 is an enlar~ed cross-sectional view taXen at line 7-7 of Fi~. 3.
The specific apparatus illustrated in the drawing is constructed so as to
utilize the principles or concepts of the pre~ent invention verbally expressed
in the appended claims. Those sXilled in the field of the desi~n and
construction of various different types of apparatus for administering oxygen
to a patient will realize that these concepts and principles can be employed
in 8 vsriety of somewhat differently appearing apparatuses through the use or
exercise of routine engineering skill in their field on the basis of the
disclosure embodied within the specification. For this reason, this inventiGn
is to be considered as being limited solely by the appended claims.
DETAILED DESCRIPTIOU
In the drawing there is shown an apparatus 10 of the present invention
which is constructed so as to include an elongated, imperforate receptacle 12
more or less having a shape of an inverted trough. This receptacle 12 is
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preferably formed out of a reasonably self-supporting, pliable, somewhat
resilient, somewhat flexible material such as rubber or rubber like material
so that it may be distorted from its normal confi~uration to fit adjscent to
the face of a patient and so that it will not be uncomfortable to the patient
when in contact with a patient's skin. It may, however, be formed of other
materials. This receptacle 12 is shaped so as to include somewhat bulbo~s
extremities 14 connected by an elongated, necked down section 16. This
section 16 preferably is slightly longer than the distance across the base of
the nostrils of an individual (not shown).
Small tubular nipples 18 are provided on the extremities 14 remote from
the center section 16. The6e nlpples 18 are adapted to contain the ends 20 of
small tubes 22 used for the purpose of conveying oxygen to the remainder of
the apparatus 10. Preferably, these tubes 22 are joined by a common Y fitting
24 to a common line 26 ~oing to a pressure re~ulator ~not shown) and supply
tank for deliverin~ oxy~en ~not shown). The individual tubes 22 are
preferably of such a size that they can be easily snapped or popped into
~rooves 28 in small holders 30 shaped so as to fit behind the ears of a
pat~ent in the manner of which the bows of glasses fit behind a patient's ears.
The receptacle 12 is also provided with integrally formed tubes or cannula
32 which are shapet and spaced from one another in such a manner as to be
capable of bein~ fitted within the nostrils of a patient ~not shown) without
causin~ the patient any si~nificant or material discomfort. These cannula 32
are located 80 as to extend off of the section 16 generally midway between the
two nipples 18. These cannula 32 must be sufficiently small in diameter so
that they will not effectively close off or block the nostrils of a patient.
Thus, the cannula 32 are of such a dimension that when they are used air will
f low around the exterior of these cannula 32.
In order to avoid any possibility of the cannula 32 fitting inside the
nostrils 80 as to block air flow around them it is possible to form them so
that they include small radially pro~ectin~ fins 34 which will
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serve to space them more or less in the center areas of nostrl2s.
When such fins 34 are used it is also considered preferable to extend
them to a limited extent along the section 16 as shown in Figs. 1 and
4 so as to avoid any possibility of the section 16 fitting against the
5 face of the user in such a manner as to effectively block or impede
air flow generally around or passed it as the apparat~s 10 is used in
the intended mnnner. When the receptacle 12 is formed of a plielble
rubbcr or rubbcr like material as indicuted in tlle preceeding, the;e
fins 34 will normally be small enough in dimension as to be capable
10 of adequate flexure so as to minimize any discomfort to a patient.
The receptacle 12 has an open side (not separately numbered)
defined by a side edge 36. This edge 36 supports and is secured to
a flange like edge 38 of an elongated dinphragm 40 by any convel ient
15 means such as, for example, vulcanization. This diaphragm 40 is
preferably formed of a flexible material such as rubber or a rubber
like composition which is cflpablc of chunging in configuration as
hereinafter indicated during the use of the apparatus 10 in response
to pressures as are dcveloped by a patient during inhalation and
20 during exhalation and as are apparent at the cannula 32. This
diaphragm 40 is essentially of a loose, "floppy", pliable character and
is capable of being moved between positions as are discussed in this
specification as the apparatus 10 is used.
This diaphragm 40 is covered by a retainer 42 manufactured out
of a rubber or rubber-like material such n~ is uscd in manufacturing
the receptacle 12 having an edge 44 which ovcrlies the edge 38 and
which is attached to it by any convcnient method such as, for
example, through vulcanization to the edge 38 and to the edge 36.
This retainer 42 can also be formed of a much harder material
inasmuch as this retainer 42 does not normally come in contact with
a patient as the apparatus 10 is used. When the retainer 12 is
formed of such a hurder n~aterial, it may be curvcd or bowed slightly
so as to serve to hold the rcccptucle 12 in a configuration clo~ely
35 conforming to the shape of a face with the cannul~ ~2 in place in th~
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nostrils. ~t is to be noted that the ed~es 36, 33 and 44 need not be sealed
to~ether but can be secured together in any convenlent manner such as for
example through the use of conventional flange connections (not shown).
In the apparatus 10 the retalner 42 is used for the purpose of protecting
the diaphra~m 40 and for the purpose of limiting the amount that the diaphragm
40 can expand outwar~ly generally away from the receptacle 12. In order for
the retainer 42 to effectively serve this latter purpose, lt is provided with
a plurality of different vent openings 46 which prevent air from bein~ trapped
between the diaphragm 40 an~ this retasner 42. Preferably the interior 48 of
the retainer 42 is substantially a mirror image of the interior of the
receptacle 12 80 as to avoid the the diaphragm 40 havin~ to be capable of
stretchin~ in order to be capable of being supported by either the interior 48
or the interlor 50 a~ the apparstus 10 is used. As a consequence of this, it
is possible to use material~ in forming the diaphra~m 40 which are not
"stretchy" in character but are of such a nature as to be capable of being
forced or of being pushed to either of two locations - against the interior 48
or against the lnterior 50 - as a result of the pressure of the breath as the
apparatu~ 10 i8 used.
The use of thi~ apparatus 10 i8 quite simple. To be used it must be
located upon the face of a patient with the cannula 32 in the patient's
nostrils ant preferably with the holders 32 supporting the remainder of the
device by being posltlonea over the ears of the patient. Either before or
sfte~ the apparatus 18 located in this manner oxygen will be supplied to the
line 26 in a compsratlvely low volume at a pressure as subsequently
indicated. As soon as both the oxygen is supplied as noted and the apparatus
10 is in place, the patient should commence breathing in a normal manner.
As the patient starts to exhale if the diaphragm 40 is a~ainst the
retainer 42 the gas within the receptacle 12 and the oxy~en being supplied to
this receptacle 12 will normally exert a sufficient back pressure so that
exhaled ~as will flow between the nostrils of the patient and the cannula 32
to the ambient. Then as the patient starts inhalin~ the gas from the volume
within the receptacle 12 enclosed by the diaphragm 40 will be drawn in through
the cannula 32 and into the lun~s of the patient. ~uring the initial
inhalation gas will be drawn from within the interior of the receptacle 12
because of the position of the cannula 32 generally within the center re~ion
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of the nostr~ls of a patSent normally there will be some limited gas flow from
the amb~ent around the exterior of the cannula 32. Such resistance is a
result of the normal considerations relstive to fluid control. Nevertheless,
there w~ll be some minor amounts of flow around the cannula 32 until the ~as
within the receptacle 12 becomes exhausted.
As this occurs, the diaphragm 40 will change its orientation from a~ainst
the interior 48 to against the interior 50. Normally, this change in
orientation will not result in any ~as beinB trapped within the interior of
the receptacle 12. In case a problem should be encountered with such
entrapment because of a particular desi~n of an apparatus 10 it is considered
preferable to use small flow channels 52 in the section 16 leadin~ to the
extremltle~ 14 which will not be blocked or filled by the diaphra~m 40 as it
moves in this manne~.
At the point that the 8as mixture within the receptacle 12 is exhausted
amblent alr is drawn in to the body of an lndividual throu~h the space around
the cannula 32 until at the end of the inhalation cycle expiration starts.
Then, preferentially, the initial exhaled 8a8 will flow through the cannula 32
for sub8tantially the same reasons that there were preferential flow throu~h
the cannula 32 on ~nhalation. There will be some minor amount of exhaled
8aseg that will be vented around the cannula 32 during the initial part of
this exhalation. As the initial exhalation occurs, the diaphra~m 40 will
"flop" up against the surface 48 and the receptacle 12 will become filled.
After this occurs because of the build up of pressure within the receptacle
12, the remainin8 exhaled gas will be vented directly to the ambient around
the cannula 32. At the end of the exhalation cycle the inhalation cycle as
described in the precedins will be resumed.
~ uring these cycles oxygen will be continuously entering the receptacle
12. The quantity or bolus of expired ~as used to fill the receptacle 12 on
exhalation will consist of expired gas which only reached the upper part of
the respiratory tract of an individual and which, as a result of this will not
contain the same quantity of gases normally given off by the body through the
lungs as the 8as which is exhaled during the last part of an exhalation
cycle. The quantity or bolus of 8as inhaled using the apparatus at the start
of the inhalation cycle from the receptacle 12 will be the first gas to enter
the lungs on inhalation ana, hence, will be the gas which is most important in
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connection with oxygen therapy.
These factors are important in connection with another matter - the
pre~surs of t~e oxygen suppl~e~ to the receptacle 12 through the tube 22.
Normally, the oxygen flowing through the tubes 22 will be at a pressure which
i8 high enough to displace any expired air trapped within the receptacle 12
and will be at a volume which is such that at least 50% of the exhaled gas
caught within the receptacle 12 will be purged or displaced from within the
interior of the receptacle 12 prior to the start of an inhalation cycle.
Preferredly the pressure and volume of oxygen used are su~h that an amount of
oxygen is supplied corresponding to about from 80 to about 120~ of the volume
of the expired 8as trapped within the receptacle 12. Any oxygen supplied in
excess of the amount necessary to displace sub6tantially all the expired gas
from within the receptacle 12 will move through the cannula 32 and will be
entralned within expired gas moving to the ambient. Any oxygen moved in this
manner will be moved toward the end of the exhalation cycle and at least some
of it will normally be in a position relative to the nose of a person such
that some of this oxyKen will tend to be inhaled at the start of the
inhalation cycle.
At the start of an inhalation cycle the volume of gas inhaled from within
the receptacle 12 as well as a partial vacuum caused by the inhalation will
tend to move the diaphragm 40 against the interior 50. Such movement can be
roughly compared to the movement of a metastable diaphragm such as a common
bowed oil can bottom from one of its two positions to the other. This will
have the effect of retarding oxygen flow from the lines 22 through the
receptacle 12 for a brief time interval. During this time period the oxygen
flow through the lines 22 will, to a degree, move and open up the diaphragm 40
to a sufficient extent 80 that some oxygen will be retained by the diaphragm
40 within the receptacle 12 in areas remote from the cannula 32. If, for any
reason, the inhalation cycle is undesirably long or if the oxygen pressure is
higher than is indicated, the only effect of this will be that the diaphragm
40 will be displaced to a sufficient extent so as to permit some limited
direct flow through the receptacle 12 to the cannula 32 from the lines 22.
On the start of an exhalation cycle the pressure of the exhaled gas will
be sufficient so as to completely move the diaphragm 40 as previously
described more or less in the manner in which a mestastable diaphragm goes
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from one of its positions to another. ~f course, at this point the sequence
of operations described will recommence.
By makin~ the internal capacity of the receptacle 12 comparatively limited
it is possible to utilize this sequence of operations as described in the
preceedlng in order to supply an amount of oxygen such as is normally required
in connect~on with most forms of oxygen therapy while concurrently holdin~
down the amount of oxygen used to an extent that it is quite si~nificant from
a financial standpoint. It is presently considered that satisfactory oxygen
therapy along with concurrent minimization of oxygen usage are achieved when
the volume within the receptacle 12 which can be contained within this
receptacle and the tiaphragm is from about 3 to about 20% of the tidal volume
of an anticipated user of the apparatus 10. Preferred results are achieved
when this range is from about 5 to about 10qo. On occasion it is possible to
obtain satisfactory results with a few patients when the volume of the
receptacle 12 is less than this amount. This is particularly the case when
the amount of oxygen required auring therapy is limited. The use of a
receptacle having a larger volume is considered to be primarily detrimental
because when such a larger volume is used, the user cannot effectively exhaust
the entire contents of the volume. As a consequence of this, a desired de~ree
of oxygen concentration is not normally achieved when a larger volume is used.
It is to be noted that the apparatus 10 need not be utilized only in the
manner described in the preceeding. On occasion a patient may not have normal
use of his or her nasal passages. In these circumstances the cannula 32 can
be held in the mouth of the individual in such a manner that air flow around
the cannula is not restricted to any significant extent. If it is desired to
provide an apparatus corresponding to the apparatus 10 which is only suitable
for use by individuals having impaired nasal passages a single cannula 32 can
be substituted for the two cannula 32 illustrated. It is considered that
whenever reasonably possible the use of an apparatus in accordance with this
invention in the mouth of the patient should be avoided so as to Xeep the
mouth of the patient free.
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