Air bag

A manually operable resuscitator bag of one-piece construction having a generally elongated football shape, an inlet at one said end, and an outlet at the other end, fold-rings in each end portion having walls of reduced thickness, whereby the ends may be telescoped, ridges of thickened wall section between the fold-rings, the center of the bag having a wall thickness equal to the thickness of said ridges in the tapering ends between the fold-rings, and longitudinal ribs formed on the outer surface of the center of the bag spaced around the circumference, providing increased resiliency and a rapid recovery for the shape of the bag.

The invention relates to a resuscitator device, for the treatment of 
persons suffering from breathing difficulties, and in particular, to a 
manually operable pressure bag, by means of which air or gas is supplied 
to such a person. 
BACKGROUND OF THE INVENTION 
Resuscitation of persons suffering from breathing difficulties is required 
in a great many different circumstances. It may be required for example, 
in a hospital or medical operating room. It is frequently required in 
emergency vehicles such as ambulances, fire appliances, rescue vehicles, 
life boats and the like. Resuscitation is frequently required in sporting 
locations, particularly, where water sports are carried on, and in many 
working environments such as mines, on hydro electrical service vehicles, 
and in many different military vehicles and installation, which are too 
numerous to mention. 
It is well known that resuscitation may be carried out initially on an 
emergency basis by mouth to mouth methods. However, it is much more 
satisfactory to supply fresh air rather than rebreathed air, and better 
still, to supply air enriched with gas or in certain circumstances, 
special gas breathing mixtures. In addition, the effort required for mouth 
to mouth resuscitation is very great, and it can leave an assistant 
exhausted after only a few minutes. 
Consequently, for all these reasons, it is highly desirable to provide some 
form of simple, manually operated resuscitation equipment, by means of 
which fresh air, or if available, some form of gas/air or gas mixture, can 
be supplied to a person suffering from breathing difficulties in an 
emergency. For reasons of economy, it is necessary that such equipment 
should be as simple as possible, and preferably manually operated so that 
it does not require to be connected to a power source. 
For this purpose, numerous forms of apparatus have been proposed which are 
based essentially on a flexible bag or bellows-like device, which may 
function as an air pump, so that it may be manually squeezed to force air 
into the lungs of a patient. 
Such air bags must however, be capable of being stored in a small space or 
compartment or in a small emergency pack. They must have a very extended 
shelf life without any requirement for inspection or testing or servicing, 
and they must be instantly ready for use as soon as the pack is open. They 
must operate in a reliable, efficient manner in this way in an emergency 
which may not occur for years after the equipment has been put in place. 
Such equipment may be subjected to extremes of weather and temperature, 
and must be resistent so that it will function even in extremes of heat 
and cold. 
It must also be resistant to moisture which might cause rust in a metal 
structure, and be resistant to other forms of decay. 
One form of air bag has been proposed, in U.S. Pat. No. 3,363,833 which is 
formed of an integral one piece construction, being molded from a 
thermoplastic material. The bag described in such patent is of such a type 
that it can be collapsed for packing, and storage, and is yet ready for 
use when unpacked. The bag is designed in such a way as to incorporate a 
wall area around the center of the bag which is of thin-wall construction, 
so that the user can more readily sense the pressure in the bag. 
Apparently, it was felt at the time that that product was being developed, 
that the ability to feel the pressure within the bag was essential to the 
safe usage of the bag. The theory was that where a person was not in fact 
breathing at all, or was breathing only with great difficulty, and where 
the bag was being used to force air into the lungs so as to actually 
dilate them, that a user of the bag might inadvertently apply excessive 
pressure to the bag thereby causing damage to the lungs. 
There is no doubt that over pressure applied to the lungs especially in the 
case of small children, can cause damage. 
In practice however, it has been found by experience that a bag designed in 
this way had certain disadvantages which caused even greater problems. 
In situations particularly where breathing is arrested or is taking place 
only with great difficulty, resuscitation is being carried out in haste, 
and often with feelings of considerable anxiety or even fear, on the part 
of the assistant or person applying the treatment. 
It is well known that unless breathing is restarted within a very short 
period of time, that irreversible brain damage will take place leading 
rapidly to death. 
Accordingly, the assistant will usually be highly agitated when using the 
bag, and will be anxiously watching for signs of breathing restarting. 
One of the disadvantageous features of the bag described in the 
above-mentioned patent is that due to its thin-wall construction, it 
tended to collapse too easily. Once collapsed, the bag then took a 
considerable length of time to recover to its normal shape. There are no 
internal springs in such bag for the reasons given above, and it must rely 
on its own inherent resiliency to recover its original shape. Until it has 
recovered its own original shape, it is not possible for the operator to 
compress it again to create a further positive pressure for the patient. 
During normal non-emergency breathing assistance, the bag will not be 
compressed more than once for each breath of the patient. Since the normal 
patient will not inhale more frequently than about thirty to forty 
inhalations per minute, and provided the recovery time for the bag is no 
longer than about 1/2 second in length, then there is no problem. However, 
during emergency resuscitation, when a person is not breathing, the best 
medical practice recommends that four or five short, sharp pulses of 
positive pressure should be applied rapidly in quick succession. These 
initial pulses may be in the order of two or three per second. The slow 
recovery rate of the bag described in such patent therefore rendered it 
difficult if not impossible to apply these initial rapid pressure pulses. 
In addition to this disadvantage, the slow recovery rate of the bag was, to 
many operators, an additional cause of stress and worry. The operator, in 
each cycle, must compress the bag gradually, with a graduated carefully 
controlled manual pressure and must then release it, waiting for the bag 
to recover. Under emergency conditions, the slow recovery rate of the bag 
tended to increase the stress level or worry of the operator so that he 
would attempt to speed up the resuscitation cycle by either applying the 
next pressure stroke too soon before the bag had completely filled or, 
alternatively, applying it too rapidly. This would in turn, produce an 
excess pressure in the lungs of the user, which was precisely what the 
design of the bag was intended to prevent. 
It has been found by experience that the great majority of operators 
greatly prefer a bag which has an almost immediate recovery rate. This 
removes a source of worry or tension, and leaves the operator free to 
concentrate on the condition of the patient. This in turn, leads to a more 
carefully controlled and relaxed application of pressure in each cycle, 
which leads to an improved resuscitation effect, on the patient. 
It is therefore, a general objective of the invention to provide a 
resuscitation bag which is of integral one piece molded construction 
formed of thermoplastic material, and which is capable of being collapsed 
and stored for extended periods of time, and which when opened up for use, 
is provided with a significant degree of inherent resiliency, causing a 
rapid recovery of the shape of the bag each time it is squeezed. 
BRIEF SUMMARY OF THE INVENTION 
With a view to providing these advantages, and overcoming the problems of 
the prior art, the invention comprises a resuscitator bag of one piece 
integral molded construction, formed of thermoplastic material, and having 
a generally elongated football shape, defining an enlarged centre portion 
of maximum diameter, and two tapering end portions of progressively 
reducing diameter, and an opening at each end, inlet means at one said 
end, and outlet means at other said end, and each said tapering end 
portions having fold-rings comprising wall portions of reduced thickness, 
defining fold lines in said tapering end portion and ridges of greater 
thickness between such fold-rings whereby said end portions may be 
telescoped, and said enlarged centre portion having a wall thickness 
substantially equal to the thickness of said ridges in the tapering end 
portions between said rings, and there being a plurality of longitudinal 
ribs formed on the outer surface of said enlarged centre portion at spaced 
intervals around the circumference thereof, providing increased resiliency 
and a rapid recovery for the shape of the bag after compressing, whereby 
the bag may be gradually compressed, and rapidly released, without 
substantial delay caused by a delayed recovery of the said shape of said 
bag. 
More particularly, the invention comprises a resuscitator bag having the 
foregoing advantages including further reinforcing ribs formed in said two 
tapering end portions, whereby to still further enhance the recovery rate 
of the bag. 
The various features of novelty which characterize the invention are 
pointed out with 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.

DESCRIPTION OF A SPECIFIC EMBODIMENT 
As shown in FIG. 1, it will be seen that the invention comprises the 
resuscitator air bag 10, which is shown here used in conjunction with a 
breathing valve 12 and a mask 14. The bag will usually have an air intake 
valve indicated generally as 16. In cases where it is used in conjunction 
with a breathing gas supply, such a gas supply can be connected by means 
such as the hose H shown in phantom. 
The gas supply may include a gas accumulator bag (not shown) of well-known 
design for collecting gas and storing it at or about atmospheric pressure. 
The bag 10 is typically of such a size that it may be held in one hand, and 
squeezed and released, or alternatively may lie on any available surface, 
so that an operator may simply press down on the bag. 
Usually, there is some form of swingable or rotatable connection between 
the bag 10 and the breathing valve 12, and if necessary, a longer piece of 
hose can be incorporated. 
As mentioned above, this type of resuscitator equipment is designed to be 
used on an emergency basis in a wide variety of different locations. It is 
frequently required to be stored for extended periods of time, and 
subjected to very wide variations in ambient conditions of temperature, 
humidity and the like, and must nonetheless be ready for instantaneous use 
as soon as it is required. 
Typically, it will be packed into a small container. This container may be 
for example a portable pouch (not shown) which may be carried on the 
person, or may be a small box which may be stored in any suitable 
emergency vehicle or at any location where an emergency is likely to 
arise. 
For this purpose, since the bag 10 is relatively bulky, it is considered 
essential that the bag shall be collapsible into as small a space as 
possible. 
It is also considered essential that the bag shall be made of a relatively 
inert substance such as a high quality thermoplastic material. In many 
cases this will be a polyvinyl plastic material, and in other cases, 
silicone-based materials are preferred as having an even longer storage 
life, and an even greater resistance to variations in ambient conditions, 
and therefore being less likely to deteriorate during extended periods of 
storage. 
In order to provide these various functions, the bag is molded as an 
integral one-piece structure, with various integral formations providing 
the various different functions. 
For the purpose of this explanation, the bag may be considered as having a 
central region 20 of maximum diameter, and two progressively tapering end 
portions 22-24, terminating in end collars 26-28. 
The end portions 22 and 24 are intended to be infolded in a telescoping 
manner within the central portion 20, for packing and storage of the bag 
10. 
In order to accommodate this function, the end portions are shown in FIG. 3 
as incorporating three reduced thickness fold rings 30, 31 and 32. The 
ring 30 is of greater diameter and the ring 32 of lesser diameter. 
Thickened ridge portions 34 extend between rings. The rings permit the end 
portions 22 and 24 to be retracted in a generally telescoping manner. When 
required for use, the end portions 22-24 may be readily snapped out simply 
by pulling on the end connectors 26 and 28, rendering the bag 10 ready for 
use. 
In order to provide the bag with a substantial degree of inherent 
resilience, the central portion 20 is made with a wall thickness shown as 
T, which is essentially equal to the wall thickness of the ridge portions 
34 of the tapered ends 22-24. In addition, a thickened reinforcing ring 36 
is provided at the transition from the central portion 20, and the first 
ring 30. 
It is found that these characteristics provide to some degree the rapid 
recovery desired by operators. However, additional longitudinal 
reinforcing spring ribs 38 are preferably provided on the exterior of the 
central portion 20 aligned with the central axis of the bag 10, and 
arranged at spaced intervals. The spring ribs 38 extend substantially from 
one of the internal reinforcing rings 36 to the other, along the full 
longitudinal extent of the central portion 20. The spring ribs 38 function 
to provide an effective outward springing action to the bag, causing it to 
rapidly recover its original shape after it has been compressed. 
In order to still further enhance this recovery rate, additional spring 
ribs 40 are provided on the tapering end portions 22-24. The spring ribs 
40 preferably extend from the larger reduced thickness ring 30, at spaced 
intervals therearound to the next adjacent ring 32 of lesser diameter. 
The spring ribs 38 and 40 are moulded integrally in one piece of 
thermoplastic material as shown, and being of the same material, 
consequently have the same extended storage life and resistance to 
deterioration. 
The usage of the bag 10 is self evident from FIG. 1. In use it will 
normally be compressed progressively to induce inhalation. After an 
inhalation stroke, the bag 10 is released and allowed to recover its 
original shape. During this phase pressure may be applied to the chest or 
abdomen of the patient, causing him to exhale. In the normal case 
exhalation takes place through suitable ports and valving (not shown) in 
the breathing valve 12. 
During the initial phases of resuscitation, particularly where an emergency 
has occurred and the patient is not breathing, four or five rapid pulses 
are usually administered. This is achieved by rapidly compressing and 
releasing the bag 10. It is found that the bag 10 as shown and described 
herein performs well during this rapid initial pulsing, and provides the 
virtually instantaneous recovery of the bag shape which is required for 
this type of treatment. 
Where the bag is used to resuscitate an infant, the breathing rate may be 
much higher, i.e., sixty breaths per minute. It is not found that there is 
any increased danger of overpressuring the lungs, when using the bag, and 
in fact, the rapid recovery rate reduces operator stress and enables him 
to concentrate on controlling the treatment. 
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, but 
comprehends all such variations thereof as come within the scope of the 
appended claims.