The present invention relates to an inflatable support for a cardiopulmonary resuscitation (CPR) apparatus and a CPR apparatus provided with the support as well as methods of using the support and the apparatus.
Cardiac arrest risks to be lethal or at least severely disabilitating if circulation and oxygenation of blood are not restored within a short time, that is, within a few minutes. While circulation and oxygenation can be restored by heart massage provided manually or, preferably, by means of a CPR apparatus, the restart of a normal heart beat requires defibrillation by electrical chock. Cardiac arrest may hit anybody anywhere. CPR other than by hand required access to a CPR apparatus within that time frame or at least within a time period during which circulation and oxygenation are provisionally maintained by manual heart massage. CPR apparatus used in the field by medical personnel, such as an ambulance team, or even by persons who received a basic medical training only, such as personnel on a carrier, must be rugged and simple to use. Their weight and volume should be kept as small as possible.
A preferred method of driving CPR apparatus for use in the field is by means of a compressed gas, in particular a compressed breathing gas like air or oxygen. The compressed gas drives a reciprocating apparatus provided with a piston in a cylinder. A compression pad is fixed at the free end of the plunger or piston rod, which extends from the cylinder. The compression pad is placed on the chest of the person under cardiac arrest. The reciprocating apparatus is held by a frame or support structure that comprises a back plate on which the patient rests in a recumbent position so as to be encircled by the back plate, the frame and the reciprocating apparatus. On the one hand, the frame must be strong and stiff enough to hold the apparatus at a constant distance above the patient's chest even during the administration of vigorous compressions provide with a force of several hundreds Newton. On the other hand the frame should be light-weight and easy to mount and dismount and to store. The driving gas for the apparatus is provided separately in a pressurized container, in particular a gas cylinder.
A support structure of this kind fulfilling the aforementioned requirements is known from US 2003/0181834; it is from this support structure that the present invention departs. The known support structure comprises a back plate and lateral legs mounted to a CPR apparatus at their one end and to the back plate at their other end.
It is an object of the invention to provide a support frame for a CPR apparatus that is light-weight and easy to mount and dismount and to store while fulfilling the requirement of being strong and stiff enough to hold a reciprocating CPR apparatus at a constant distance above the patient's chest even during administration of vigorous compressions.
It is another object to provide a CPR apparatus provided with the frame.
Additional objects of the invention will become apparent from the study of the following summary of the invention, the description of a number of preferred embodiments thereof illustrated in a drawing, and the appended claims.
According to the present invention is disclosed a support frame of the aforementioned kind comprising one or more inflatable elements. On inflation one or several chambers are formed in the inflatable element. If there are several chambers in the element they are in communication with each other. An inflatable element of the invention comprises a flexible but substantially not resilient wall. It is preferred for the wall to comprise one or more polymer materials or polymer layers. If the wall comprises more than one polymer material or layer it is preferred for them to form a multilayer structure in which adjacent layers are bonded to each other. The wall is preferably reinforced by fibres. Organic fibres such as carbon and/or polymer fibres of different composition than the polymer material of the wall can be used as well as fibres of vegetable origin such as cotton and cellulose acetate fibres. Useful inorganic reinforcing fibres include glass fibres, mineral fibres and metal fibres. Particularly suitable materials for manufacturing the inflatable elements of the invention include strong, close-weave mesh or net of polyester or nylon sandwiched between coatings of natural or synthetic rubber such as neoprene or polyurethane rubber or chlorosulfonated polyethylene (Hypalon®, DuPont), sheets of which cut to desired shape and size can be glued or thermobonded and additionally sewn to form an inflatable element. In this application any support element so designated is inflatable.
For its inflation the inflatable element of the invention has an opening in its wall at which gas conducting means is arranged, such as a flexible or stiff tube, which conducting means is in communication with a source of gas, preferably the same source of gas that provides the gas for driving the CPR apparatus, in particular a gas cylinder. The gas conducting means comprises or is coupled to a valve means for control of the inflation of the inflatable element. The valve means may be a one-way valve, in which case the inflatable element comprises a second wall opening at which a second valve for venting the gas in the element's chamber(s) or a conducting means in communication with a venting valve is mounted. The inflatable element of the invention should preferably withstand a pressure of at least 3 bar, more preferred at least 4 bar and even 5 bar. In general, the thickness of the flexible wall of the inflatable element is small in comparison with the diameter of the inflated element; a ratio of 1:25 or 1:30 and even up to 1:50 and more is preferred.
The CPR apparatus of the invention can be driven by a gas or by other driving means, such as electrical motor. If driven by a gas, it is preferred for the inflatable element to be arranged inflatable by the driving gas. According to a preferred aspect of the invention an inflatable element may serve as a reservoir or buffer of partially decompressed driving gas for a gas-driven CPR apparatus. The partially decompressed gas can be fed through the inflatable element to the CPR apparatus or the inflatable element can be connected by a T-junction to the gas line supplying the CPR with partially decompressed gas. A CPR apparatus of the aforementioned kind is preferably and usually driven by a compressed gas of constant or about constant pressure, the pressure being considerably lower than the pressure in the gas cylinder or other source of gas. The pressure in the gas cylinder or other source with a fixed amount of gas thus will decrease during operation of the CPR. Prior to being fed to the CPR apparatus the driving gas leaving the source is partially decompressed, that is, decompressed to the desired pressure for driving the apparatus. In contrast to the partial decompression of the gas leaving the gas cylinder to a given constant pressure gas consumption by the CPR apparatus varies considerably during a reciprocating cycle. To keep up with the varying consumption of driving gas by the CPR apparatus it is preferred to arrange a buffer volume or reservoir of partially decompressed gas, which function is advantageously carried out by the inflatable element of the invention. In such case partially decompressed gas in the inflatable element is, fed to the CPR apparatus.
According to a second preferred aspect of the invention the support frame comprises two inflatable legs and a back plate. The leg, which are preferably of about same size and form, extend from or are attached to opposite sides of the CPR apparatus, preferably in a mirroring manner. In this application the attached or extending ends are termed first ends. The other, second ends of the inflatable legs are releaseably mountable to and/or dismountable from the back plate. The back plate can be in one pieces or comprise two pieces of generally same shape, which can be easily attached to each other and dismounted.
According to a third preferred aspect of the invention the back plate comprises one or more inflatable elements, which may be inflatable separately from or in combination with the inflatable legs. It is preferred for the inflatable element(s) of the back plate to be integral with one or both legs; in such case it is preferred for the inflatable legs to be integral with and extend from opposite long sides of the inflatable back plate. It is preferred that this combination of inflatable legs and back plate is separate from the CPR apparatus to which it can be releaseably mounted by mounting means arranged at the free ends of the inflatable legs and at opposite sides of the CPR apparatus. It is also preferred for one or both of the mounting means to comprise means for establishing communication between the chambers of the inflatable elements of the frame and a source of partially decompressed driving gas via the CPR apparatus or separate from it. The material and design of the inflatable back plate of the invention allows to make it of a size capable of supporting the weight of an adult person, and thus suitable to be used as a stretcher, for which purpose outwardly facing portions of the back plate's long sides can be provided with handles.
A particular advantage of the inflatable frame and the inflatable or non-inflatable back plate of the invention is the small volume required for their storage and transport in a collapsed state. In contrast to stiff frames and back plates for CPR apparatus known in the art they can be folded or rolled up, and stored or transported in small containers.
According to a fourth preferred aspect of the invention the driving gas for driving the CPR is a breathing gas, which is adduced to the patient's lungs by a facial mask or intubation after having driven the CPR apparatus.
The present invention will now be explained in more detail by reference to preferred but not limiting embodiments illustrated in a rough drawing, in which is shown in
a-2c a transverse section through the embodiment of
The first embodiment of a CPR support frame 1 of the invention illustrated in
The second embodiment of a CPR support frame 101 of the invention illustrated in
The free ends of the legs 102, 103 are provided with fastening means by which the legs can be fastened at opposite sides of a CPR housing 119 by any suitable releaseable fastening means, for instance means of the same kind as used for fastening the free ends of the legs 2, 3 of the first embodiment to the back plate sections 4a, 4b. One of the releaseable fastening means is identified in
For inflation the lumen of the support frame 102-114 is put in communication with the source of driving gas by a high pressure hose 133 branching off from the gas supply line 127 connecting a differential pressure controller or regulator 126 fed by air from a gas cylinder 125 with the cylinder space 129 of the CPR unit 135 via a quick coupling 128 provided with a check valve (
Number | Date | Country | Kind |
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0602556-3 | Nov 2006 | SE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/SE07/01053 | 11/28/2007 | WO | 00 | 6/18/2009 |