Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
Oxygen masks have been known and used for some time
as efficient means for delivering oxygen to a patient during
inhalation or respirator therapy. More recently, these ~ ~
masks have been made of relatively soft and flexible plastic ~ `
thereby making them disposable for single patient use. The ~
modern and efficient masks have also been constructed so as ~ -
to have a peripheral edge surface for fitting entirely
around the patient's nose and cheeks, with the shorter
masks passing beneath the patient's mouth along the chin and
the longer masks extending under the patient's chin, but all
in substantial sealing engagement so as to prevent loss of
the oxygen containing gas delivered through the mask.
Although such masks deliver the oxygen containing gas
with desirable efficiency, since they are in substantial
sealing engagement with the patient's face substantially
entirely around the mask periphery, they offer some
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disadvantages. For example, the masks may become un-
comfortable to the patient because of the extensive
contact with the patient's face and also because of
heat build up within the entirely enclosed mask area.
In addition, C02 build up is often a problem in masks
of this type which results in significant limitations
of the upper end of oxygen delivery concentrations
possible. Further, because such a mask encloses the
patient's lower face area, in order for the patient to
speak or to take in food through the mouth, the mask
must be removed or at least temporarily lifted which
causes further discomfort and possible patient aggrevation
or anxiety. Obviously during the time that the mask is
removed, oxygen delivery to the patient is interrupted. ;
Of further concern is the possibility of a
patient choking where fluids such as vomitus are aspirated
from the enclosed mask area. Moreover, because tihe
state of the art oxygen delivery masks require close
fit about and around the patient's face in order to ~`
prevent leakage and achieve the intended and desired ~;
oxygen concentrations, the positioning of the mask ;;
and maintaining that position on the patient is quite
important. If the mask becomes loosened or significantly
moved, the sealing engagement of the mask edge with
the patient's face will be disturbed thereby allowing
undesirable venting of exterior ambient air into the
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mask as well as loss of oxygen and concomitant oxygen concentra-
tion change delivered to the patient, which may not be monitored.
It is to the elimination and obviation of these disadvantages
of state of the art masks that the device of the present invention
is directed.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided
a device for deliverying gas to a patient during respiratory
therapy comprising: a unitary, shape retaining shell member
adapted to overlie a patient's nose and mouth, having an upper
peripheral surface adapted to provide a substantially gas tight
seal with the patient's nose bridge and cheeks having a lower
edge spaced outwardly from the patient's face, and a gas
delivery member extending along the shell member interior, and
having at least one gas delivery orifice therealong.
The gas delivering face shield device of the present
invention offers a number of advantages over known oxygen
delivery masks. For example, although the device is in sealing
engagement around the patient's nose and cheeks 50 as to prevent ;
2a oxygen from being directed upwardly into the patient's eyes
resulting in discomfort or eye injury, the bottom of the shield
around the patient's mouth is entirely open thereby preventing
heat build up, presenting fewer pressure points or contact of ;
the mask with the patient's facial skin, allowing the patient
to talk more freely than an entirely enclosed mask, and also
providing for the patient to take food or at least to be straw
fed through the mouth without removing the shield or otherwise
interrupting the desired oxygen delivery and concentrations.
The device of the invention is relati~ely simple, comprising
a unitary face shLeld in the preferred form of an arched shell
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and ;ncoxporating an oxygen delivery tube or pipe having a
pl~lral;t~ of gas deIivery orifices and which pipe is extended
along the
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interior shield surface, preferably below the patient's nares. The
features and characteristics of the device as well as additional
advantages will be evident from the following detailed descrïption.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure l is a perspective view of the oxygen delivering face
shield of the invention showing it in place on a patient;
Figure 2 is a front view of the face shield shown in Figure l;
Figure 3 is a sectional elevation of the face shield taken along
lines 3-3 of Figure 2;
Figure 4 is a top view of the gas delivery pipe utilized in the
face shield; and
Figure 5 is a partial sectional view illustrating another
embodiment of the face shield and gas delivery orifices.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 illustrates the face shield 10 which comprises a ~-
unitary shield member 16 and a gas delivery member 20. As illustrated,
the shield member is a shell, arched outwardly away from the patient's
face and is divided into an upper portion 14 and lower portion 12
between which is located the gas delivery pipe 20. It should be
appreciated that the shield member 16 is a unitary component, preferably
molded of a single plastic sheet. However, in the preferred embodiment
shown, the upper and lower shield portions are shaped somewhat differently
and are separated by the gas delivery pipe.
Figures 2 and 3 illustrate the device in more detail, Figure 2
illustrating the upper portion 14 having a peripheral edge surface which
lies against the patient's face, particularly over the nose bridge and ``
down the cheeks on both sides of the nose. The arched shell is formed
between peripheral side edges and is bowed or arched away from the face
and defines an interior cavity 31 into which gas from the delivery pipe
is discharged for patient inhalation. The lower portion 12 forms a sort
of shield or skirt which overlies the patient's mouth and chin and is
outwardly from the patient's face so that there is no contact of this
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low0r portion with the patient. Instead, as seen in Figures 1 and 39 the
lower portion extends outwardly from the patient's mouth and chin area to
also form an interior space or cavity 37. Such a space offers one of the
specific and important advantages of the invention in allowing the
patient to comfortably exhale and to speak and be easily heard without
the mask entirely closing the nose and mouth area. Moreover, because the
peripheral edge 33 of the lower portion is also arched or bowed away from
the patient, an enlarged port or opening 25 is provided between the
patient and the shield, which port communicates directly with the interior
shield cavities. Accordingly, the inside of the device is open to the
environment so that C02 and heat build up are minimized as well as allowing
the patient to be fed at least through a straw without having to remove
the mask or otherwise disturb the delivery of oxygen.
Figure 3 also illustrates the preferred attachment of the oxygen gas
delivery pipe 20. The pipe is preferably received in a channel 30 defined
between a pair of ribs 32 and 34 extending arcuately along the interior
shield surface. These ribs are integrally formed as part of the shield
member and the gas delivery pipe is simply urged into the channel at the
time of assembly. The ribs are preferably formed apart enough so that
the pipe is forced therebetween with the ribs acting as support walls.
Further, the ribs channel and pipe are conveniently located between the
upper and lower shell portions.
The gas delivery pipe 20 is shown in more detail in Figure 4. Pre-
ferably the pipe is molded from a more rigid material than that used to
prepare the shield portion. One end of the gas delivery pipe is provided
with a inlet member 18, having a length sufficient to adequately attach a
gas supply tube 35. At the other pipe end is a button 22 of similar
member for assisting in securing the pipe to the shield member. Accord-
ingly, the shield member preferably has a pair of openings or holes,
oppositely disposed and on each side, one for receiving the gas inlet
member 18 and the other the button 22. Since the shield member is
prepared from a softer, resilient and flexible plastic such as PVC or
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the like, button 22 may be oversized relative to the orifice through which -~
it extends and have a groove or slot formed along the button so that the
smaller orifice edges can fit into the slot once the button has been
pushed through. This or any similar or equivalent means for securing ~-
the gas delivery pipe may be used. Again, channel 30 further assists in
supporting and fixing the gas delivery pipe within the shield interior
surface, with the pipe being pressed or otherwise urged between the -two
ribs forming and defining the channel. Although gas inlet member 18 is
shown positioned at OnQ end of pipe 20, it may be instead located anywhere
along the pipe, for example, in the middle of the shield. In addition,
the ends of the pipe may be inset somewhat from the side shield edges
to avoid any patient discomfort. An alternative means for supplying oxygen
to the pipe comprises using a gas inlet member at both ends of pipe 20,
with a gas supply tube connected to each inlet member. Such supply tubes
may be extended over the patient's ears to assist in keeping the shield
in place on the patient, or may be drawn together under the patient's chin. .-
The gas delivery pipe is provided with a plurality of openings or
orifices 36 through which oxygen containing gas is delîvered within the
shield for patient therapy. Figures 1 and 3 further illustrate the
disposition of pipe 20 relative to the patient's nostrils and mouth.
Since the pipe is arched or arcuate shaped to conform to the arched
shield interior surface, it is disposed below or lower than the patient's
nares throughout most of its length. Accordingly, it is preferred that
the orifices 36 be positioned so as to direct oxygen containing gas toward ;
the patient and at least somewhat upwardly toward the nares. Moreover, in
a preferred embodiment, oxygen delivery pipe 20 is also provided with a
plurality of gas delivery orifices 42 which direct a portion of the
oxygen containing gas toward the patient's mouth or lower part of the
shield. The purpose for such downwardly gas directing orifices is to
insure that a sufficient supply of oxygen containing gas will be delivered
to the patient even if the person is breathing from his or her mouth. For
; example, if the patient's nasal passageway is occluded or the patient is
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otherwise breathing from the mouth, with all of the oxygen containing gas
being directed upwardly, the desired concentrations of oxygen may not be
inhaled by the patient because the shield is open at the bottom. The
specific number of orifices may be varied widely depending on orifice
sizes used, oxygen flow rates, etc. Normally, it is more desirable to
incorporate more upwardly directing orifices, preferably between about
4 and 20, with downwardly directing orifices numbering between about 2
and 8.
Figure 3 illustrates another important feature of the invention,
specifically the gas sealing engagement of the shield member at the
patient's nose and cheek area. The upper shield end 26 is arch shaped
to comfortably overlie the patient's nose bridge. Optionally, and -
preferably, a flexible metal strip 44 is also secured to the exterior ~ -
mask surface which can be easily bent to further assist the mask in
forming to the general contour of a patient's face. The metal is
preferably soft such as aluminum so that it can be easily bent and formed
by hand once the shield is placed on the patient. Protuberances or tabs
47 are formed on each side of the shield for securing the metal strip 44
as shown in Figure 2. The upper peripheral edge surface 24 is also
formed to provide a gently rounded or curved surface where it is compressed
against the patient's face $o form the proper seal. Although an outward
curved surface 26 is shown, i.e., where the outer edge is directed away
from the shield interior or center opposite curve such as is used in some
state of the art oxygen masks where the shield edge is curled inwardly.
Either shape may be used, so long as sealing engagement is provided to
prevent the oxygen containing gas directed upwardly in the shield from
passing to the patient's eyes, which could cause undesirable drying or
other eye injury or discomfort.
On the other hand, the lower portion of the shield need not be so
formed since there is no engagement of the peripheral lower portion edge
with the patient's face. Although inner edge 38 may lightly touch the
patient's face in the lower part of the cheeks adjacent the mouth, the
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lower outwardly extending peripheral surface 33 does not make contact, and
indeed, is designed to provide an opening as previously described. In
any event, it is understood that there is no problem of any gas sealing
engagement of the lower portion of the shield member, below the gas
delivery tube, since it is intended and specifically provided that the lower
- mask portion be open as described. The face shield according to the
invention provides delivered patient oxygen concentrations of between 22
and 65% at flow-rates between 1 and 10 liters per minute. Thus, accurate
deliveries throughout the low and medium concentration ranges can be
achieved. Moreover, because of the open bottom feature, there is no
problem with C02 accumulation in the shield due to constant oxygen flow
~, flushing exhaled gas into the atmosphere.
! A further optional embodiment is an inwardly directing curl
illustrated in Figure 5 which provides or forms a sort of pocket 45 to
assist in increasing oxygen concentration within the shield. In this -~
embodiment, the bottom edge 40 of the lower shield portion is curved inward ;
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and slightly upward toward the shield interior to form the pocket 45,
~-~ which feature has been found to increase oxygen concentration within the
shield withou~ otherwise increasing the concentration or volume of oxygen `~
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delivered. `~
As previously noted, the face shield is preferably made of a soft,
resilient, and flexible materials such as PVC (polyvinyl chloride~ or other
suitable and equivalent material. The gas delivery pipe is produced from a
more rigid material such as rigid PVC or rigid polyethylene, polypropylene -
or the like. When these components are separately formed, they are
assembled in a simple manner as previously described, utilizing the formed
channel shown. Alternatively, it may be desirable to mold the device from
a single mold in which the gas delivery pipe is integrally formed with the
shield member. Accordingly, any method of preparing the shield member
having the sealing engagement with the face along the upper portion, and
the open lower portion and otherwise delivering oxygen through a plurality
of orifices within the device, may be utilized.
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Any suitable means for securing the shield to the patient' 5 head
such as an elastic band 49 secured through openings 51 as shown in
` Figures 1 and 2, or any other equivalent means may be used. It will be
understood, because of the advantages of the invention, that the placement
of the device is not so critical since a gas tight seal around the
- patient's lower face area is not required. Moreover, because of the
open bottom feature, patient comfort is maximized as is drainage from
~ the patient's mouth area without danger of aspiration of liquids. These
-' as well as other advantages and modifications within the purview of the
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