WO2011015821A1

WO2011015821A1 - Brain cooling device

Info

Publication number: WO2011015821A1
Application number: PCT/GB2010/001477
Authority: WO
Inventors: Julian Joshua Preston-Powers
Original assignee: Julian Joshua Preston-Powers
Priority date: 2009-08-04
Filing date: 2010-08-04
Publication date: 2011-02-10
Also published as: GB0913561D0

Abstract

Headwear incorporating an endothermic reactor, wherein each of two or more reagents is contained in the endothermic reactor, separated from other reagents with which it will react, in respective cells or reservoirs (50, 40).

Description

BRAIN COOLING DEVICE

TECHNICAL FIELD

The present invention relates to headwear comprising an endothermic reactor. Such headwear is particularly suited for use by Emergency Medical Services (EMS) on head trauma victims. Notably Traumatic Brain Injury (TBI) victims. BACKGROUND

It has long been recognised that neurological deterioration in trauma victims is dramatically reduced when a hypothermic state is induced. This phenomenon has been observed, for example, when an accident victim has fallen into cold, icy water resulting in hypothermia. A similar phenomenon was observed during the Napoleonic Wars, when wounded soldiers who were left "out in the cold" managed to survive their injuries, whilst their counterparts who had been warmed by a nearby fire perished. More recently, medical practitioners have made use of this phenomenon by deliberately inducing mild hypothermia in patients, prior to emergency treatment or during surgical operations. This causes the body's vital functions to be slowed down, thus reducing the chances of brain damage occurring in the patient. In extreme circumstances, the patient's core temperature can be reduced by submerging the patient in a bath of ice water, or by pumping cold fluids through or next to their internal organs. Cooling has also been noted to be particularly effective when applied directly to the patient's head.

The human skull has many small holes passing through it, known as emissary foramina, through which veins transport (hot) blood from the scalp into the venous sinuses. The blood transported to the surface of the head is cooled by the surrounding environment and by sweat evaporating from the surface of the skin, before re-entering the skull at a lower temperature, to help keep the brain cool. This explains how cooling the head at the surface can produce significant cooling within the human brain, even at significant depths within the skull, more quickly than would be expected to be achieved through mere thermal conduction.

Cranial cooling has been noted to reduce brain damage and increase survival rates in accident victims, and patients with head injuries are often treated in accident and emergency departments by cooling the patient's head. It is, however, often the case that victims will have suffered their injuries significantly in advance of their arrival at a hospital "Accident and Emergency" department. If the delay between receiving an injury and receiving treatment at a hospital or other medical care facility is too long, significant neurological deterioration may already have occurred in the interim, and brain damage may thereafter be unavoidable. The sooner that effective brain cooling can be applied to victims of serious injury, the more effective the cooling will be to prevent the onset of brain damage. The crews of emergency response vehicles are often the first on site with any means for treating a victim of severe injuries, but as yet paramedic teams do not widely carry head-cooling apparatus as part of their standard equipment, if at all. What is required is an easily portable means of equipment by which paramedics and other emergency medical practitioners can easily and effectively apply head cooling to victims of serious injury in danger of suffering neurological deterioration as a result of their sustained injuries.

One proposed solution is a nasal spray device, which administers a fine mist of PFCs (perfluorochemicals) into a patient's nasal cavity. The mist droplets evaporate on contact with the back of the nose to absorb heat and carry it away from the nose, which in turn cools the brain.

United States patent publication US 5 950 234 Al, to Leong et al, discloses a cooling pack head covering. The cooling pack is intended to be worn so as to cover the scalp of a patient undergoing chemotherapy treatment. It is contemplated that the cooling pack may be a chemical cold pack, in which chemicals in a container become cold when they are mixed together by breaking a barrier which otherwise separates them. The cooling pack is generally circular and has a "V" shaped notch formed therein to enable the pack to be wrapped around and secured to a patient's head, in a generally bowl shape. It is contemplated that, if an American football cap were to be used, then the cooling pack might be formed in multiple parts to fit in the cap, with the objective of cooling the wearer's scalp to a temperature which will minimise hair loss. The cooling pack must be activated before being put on, and has no means by which to activate the cooling pack whilst being worn.

United States patent publication US 5 469 579 Al, to Tremblay et al, discloses a head cooling device for mounting over a person's head, generally within headgear or a safety cap, such as the construction hats worn on building sites. The head cooling device is configured to sit within the hat or cap of a wearer, and to contain ice cubes therein. As the ice cubes melt, the head cooling device allows the melting water to pass one drop at a time onto the wearer's scalp, so as to absorb and extract heat from the wearer's head. US patent publication US 5 755 756 Al, to Freedman, Jr. et al, discloses a hypothermia- inducing resuscitation unit which includes a cap adapted to be mounted on the head of a patient. A coolant source is pumped from external of the cap into a bladder which is inflatable to achieve a tight fit over the head of a patient, and to provide cooling to the patient's head.

SUMMARY OF THE INVENTION

According to the present invention, there is provided headwear incorporating an endothermic reactor comprising two or more reagents which will react together in an endothermic reaction, when the reaction is initiated.

Each of the two or more reagents may be contained in the endothermic reactor, separated from other reagents with which it will react, in respective cells or reservoirs. At least one of the reagents may be contained in a layer arranged to encompass substantially all or a part of the head of a wearer. One or more membranes may separate the reagents from each other, a trigger being configured to initiate the endothermic reaction by opening a hole in the membrane through which the separated reagents may be brought into contact. In one form, the trigger includes a plunger for opening the hole in the membrane. In another form, the trigger includes one or more frangible regions in the membrane, configured to open to form a hole when tension in the membrane exceeds a threshold magnitude.

DETAILED DESCRIPTION OF THE INVENTION The accompanying drawings (Figures 1 to 3) illustrate examples of embodiments of the invention.

A cap 3 is for location on a person's head and, in the Figure 1 embodiment, includes outer shell 70, a thick expanded polystyrene layer 60, water pack 50, ammonium nitrate layer 40 and a fabric inner lining 30. In the Figure 2 embodiment cap 3 includes an outer padding, a water layer 50 and an ammonium nitrate layer 40.

When the endothermic reactor is triggered, the water in outer layer 50 is released into the inner layer 40, to initiate the endothermic reaction by causing the ammonium nitrate to begin to dissolve into the water. This immediately begins to produce a cooling effect within the interior of the motorcycle safety cap. The reaction between water and ammonium hydrate is able to deliver an amount of cooling corresponding to around I⁰C per minute after the reaction is initiated, resulting in noticeable cooling after around four minutes. Because the endothermic reaction is progressive, heat will be continually absorbed from the head and brain of the motorcycle cap wearer during the endothermic reaction. The progressive nature of the reaction can be enhanced by configuring the outer layer 50 containing the water to release the water into the layer containing the ammonium nitrate in a gradual fashion, such as through restricted openings or via capillary action. The ongoing release of the one reagent into the other will lead to an ongoing cooling effect for an extended period of time, although this will be determined also in part by the quantity of the reagent materials contained in the cap main body 3, in the inner layer 40 and outer layer 50.

Of course, the endothermic reaction should not be so severe as to cause any cold burning to the patient, and in this respect the inner comfort layer 30 can provide a useful heat transfer medium between the endothermic reactor (consisting of the inner layer 40 and outer layer 50) and the head of the wearer of the motorcycle cap. A dissolution reaction between water and ammonium nitrate is presently preferred, since the reagents and the products of the reaction are relatively non-toxic. It is, of course, intended for the reagents to remain contained within the endothermic reactor, and not to be released onto the wearer or into the external environment.

In the embodiment shown in Figure 3, the helmet includes an outer elasticated woven layer 1, a water reservoir 2, an ammonium nitrate layer 3 and a layer of medicated paste 4.

As well as dissolution of ammonium nitrate in water, a number of further endothermic reactions are known which could be of practical application, in accordance with the present invention. Notably, for applications where the headwear in question is not a motorcycle safety cap, there is a markedly reduced risk of the wearer of the headwear coming into contact with the reagents and reaction products in question. Other known endothermic chemical reactions, which might be utilised in place of dissolving ammonium nitrate in water, are: • reaction of barium hydroxide octahydrate crystals with dry ammonium chloride;

• dissolving ammonium chloride in water;

• reaction of thionyl chloride (SOC12) with cobalt (II) sulfate heptahydrate;

• mixing water with potassium chloride; and

• reaction of ethanoic acid with sodium carbonate.

Claims

1. Headwear incorporating an endothermic reactor, wherein each of two or more reagents is contained in the endothermic reactor, separated from other reagents with which it will react, in respective cells or reservoirs.

2. Headwear of Claim 1, wherein at least one of the reagents is contained in a layer arranged to encompass substantially all or a part of the head of a wearer.

3. Headwear of Claim 1 or 2, wherein the headwear includes as one or more membranes which separate the reagents from each other, a trigger being configured to initiate the endothermic reaction by opening a hole in the or at least one membrane through which the separated reagents may be brought into contact.

4. Headwear of Claim 3, wherein the trigger includes a plunger for opening the hole in the membrane.

5. Headwear of Claim 3, wherein the trigger includes one or more frangible regions in the membrane, configured to open to form a hole when tension in the membrane exceeds a threshold magnitude.

6. Headwear of Claim 3, wherein the membrane or trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to open a hole in the membrane in response to a change in the shape memory state to a second memorized state.

7. Headwear according to any preceding claim, wherein the trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to initiate the reaction in response to a change in the shape memory state to a second memorized state.

8. Headwear according to any preceding claim, wherein the headwear includes an outer elasticated woven layer.

9. Headwear according to any preceding claim, wherein the headwear includes an inner medicated paste layer.

10. Headwear according to any preceding claim in the form of an Emergency Medical Services cap