The present developments are directed generally to cooling apparatuses for lessening physical body trauma such as bead and neck trauma typically after injury. In some examples, this may include lowering tympanic temperature. Current methods and apparatuses have some limitations such as suffering from ineffective cooling, or contrarily overcooling of the neck or head. Other limitations may include time period efficacy, as in how long and effectively an apparatus may cool the neck before warming to a point of less or non effectiveness. A cold therapy apparatus or device hereof could lower tympanic temperature effectively and result in similar outcomes to experiments performed with ice/water mixtures.
Thus, it may be found desirable to provide cold therapy devices, apparatuses, and/or methods, that apply cold to lower body temperature, such as tympanic or other body temperature in a cost-efficient, time effective and compact manner, and in some implementations providing safeguards that may effect cooling while minimising the risk of further injury to a patient through exposure to excessive localised cooling.
The present developments may be directed to cold therapy apparatuses, systems, and/or methods, but more particularly, in some implementations, to cold therapy apparatuses of the type used to cool human body temperatures to lessen injury and/or trauma. In some implementations, such an apparatus may be for application to the head and/or neck to lessen or reduce trauma to the head or neck after injury or illness, e.g., but not limbed to, after traumatic brain or spinal injury or in the early stages of acute ischemic stroke. The present disclosure thus relates to a cold therapy apparatus and/or system and/or method by which the cold therapy may be employed.
A cold therapy apparatus or device hereof may provide at least two compartments comprising a water compartment and a discrete cooling chemical mixture compartment. In such an example, the water compartment may be disposed in use adjacent to and preferably held in contact with a portion of the body which may benefit from cold therapy, e.g., the head, neck, joints, feet, hands, arms, legs, torso, ribs, stomach, elbow, ankle, wrist, shoulder, knee, buttocks, hips, pelvis, and the like. For example, the neck or head can be used (e.g., next the back, sides, or front of the neck or head, and/or e.g., adjacent to a carotid artery or jugular vein). The cooling chemical mixture can then be disposed adjacent the water compartment and may optionally use one or more of ammonium nitrate, sodium acetate trihydrate, and water. In addition, further compartments or baffles can be used within a device hereof to protect the patient's skin from direct contact with the chemical mixture compartment and thereby reduce the likelihood that the skin contact temperature will drop below 0 degrees Celsius. Outcomes may be similar to or better than outcomes in experiments performed with an ice and water mixture.
In the drawings:
As discussed in further detail below, experimental results show that ice applied to the body can provide therapeutic benefit, as for example as applied to a neck which may thus provide an effective means for lowering, a sustained and measurable amount, body temperature, such as or as evidenced by tympanic temperature. The result, measured as drop in temperature from, a baseline level, can be improved by applying ice to the head in addition to the neck. Contributing factors to tympanic temperature drop are believed to be heat conduction through neck and head, resulting in a cooling of the carotid and tissue surrounding the ear. In addition, counter-current heat exchange occurs between the carotid and jugular vein. This effect, may he increased when one or more regions of the head are iced in addition to the neck.
The developments hereof relate to a cold therapy apparatus or system typically configured to achieve one or more of easy and rapid transportation, use, application, and/or removal, and a method of use thereof. In many implementations, the cold therapy apparatus may have a water barrier and a chemical cold pack contained within a single structure, though in separate but adjacent compartments, adapted for use in a cold therapy apparatus to be applied to a subject and/or patient.
The respective compartments, e.g., 11 and 14, can be continuous or separated into 1, 2, 3, 4, 5 or more compartments, for each of the chemical or water compartments.
An attachment device 16 can also be provided on a cold therapy apparatus 10 to attach the apparatus 10 onto a subject 20. The attachment device 16 can include any suitable attaching mechanism, e.g., but not limited to a clasp, a button, a zipper, VELCRO™ or like hook and loop fasteners, a tie, or the like or alternative connection devices or means.
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Cooling or endothermic chemical mixtures (e.g., as known in the art or described herein) can be provided as associated with compartment 11. The cooling or endothermic mixture can be provided as separated or mixed with the water component of the chemical mixture 12. The separated mixture can be provided in mixable components or containers, such as activated or that can be activated, e.g., but not limited to, breakable, operable, releasable, or mixable chemical mixture containing containers, packaging, packets, mechanisms, or the like, to mechanically, physically, or chemically add the chemical mixture to the water to provide the cooling or endothermic chemical mixture further comprising water as chemical mixture 12. The cooling or chemical mixture can comprise any suitable cooling or endothermic chemical that can be activated when mixed with water. Non-limiting examples can include one or more of urea, ammonium nitrate, sodium acetate, sodium hydrate, and/or sodium acetate trihydrate. Such components can be provided in various forms and/or mechanisms to provide chemical mixture 12 for compartment 11. Typically, this may include a device or container within compartment 11, compartment 11 otherwise filled with water or the like. Then, such a device or mechanism may hold the chemicals, e.g., in solid or liquid form; typically in solid salts form; and, this may device or mechanism may be activated as by rupturing or breaking open the device or mechanism to release the chemical salts into the water with in compartment 11, mix and/or react with the water and thereby create a cold mixture within the chemically-driven cold compartment. The amounts of salts relative to the water may be chosen to provide the appropriate level of temperature relative to the water barrier 14 to provide desirable heat transfer therefrom and from the patient as well (see
The present developments also provide in some implementations, a method comprising: activating the cold therapy apparatus by causing the chemical mixture to interact with water provided in the chemical pack compartment; and applying the activated cold therapy apparatus to subject within an application time period after trauma (e.g., within minutes in preferred implementations, or perhaps within longer periods, 10, 15, 20, 30, 60 or even more time in some other implementations), injury or stroke to provide cold therapy to the subject for a cooling time period of at least 25-35 minutes; again, other periods, shorter or longer, may be desired and effected as well.
Results of some examples of such mixtures relative to water to determine effectiveness of cooling, particularly as these may approach cooling of an ice water mixture directly on the skin are set forth below. The results indicate that a chemical pack and water barrier that is approximately 1.5 inches thick, e.g., about or substantially 1-2, 1.2-1.8, 1.3-1.7, 1.4-1.6, e.g., 1.0. 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, inches, or any range or value therein, is suitable to provide the desired results according to the present developments. Additionally a chemical mixture used for cooling the adjacent water compartment maintains the water temperature close to freezing (e.g., but not limited to −1, −0.5, −0.4, −0.3, −0.2, −0.1, −0.2, −0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9. 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 3, 4, 5, 6, 7, degrees Celsius, or any range or value therein).
A baseline value for understanding how much heat can be removed from the water barrier is established by determining how much ice (starting at 0 Deg C.) direct skin contact can melt over a 30 minute period. Suitable volumes include 100-500 ml of the water and/or chemical mixture compartments and/or volumes. As a non-limiting example, a volume of 325 ml of liquid water is frozen and placed in contact with 25 square inches of skin on the neck. After a period of 30 minutes, 120 ml of water is melted. This number provides a baseline for which to design the remaining experiments around. Calculations below show the amount of heat removed item the neck during this particular non-limiting test:
Q=ΔHfus*W=333.55 J/g*120 g=40 kJ
where Q=Heat Removed (Joules), ΔHfus=Enthalpy of Fusion for Water (Joules/Gram), and W=Weight of Ice Melted (Grams).
The 40 kJ removed from the neck represents the maximum amount of heat that can be removed given it is unlikely the barrier will remain at 0 degrees Celsius during the entire time of application.
Note that the amount of energy required to freeze a gram of water is equivalent to the amount of energy needed to drop one gram of water from 79.8 Deg C. to 0 Deg C.
ΔHfus/C=(333.55 J/g)/(4.1813 J/g*K)=79.8 Celsius,
where ΔHfus=Enthalpy of Fusion for Water (Joules/Gram) and C=Specific Heat of Water.
In the experiments below, see particularly
Understanding the dynamics above allows for an iterative design process in which the amount of water and the amount of cooling or endothermic chemical mixture in compartment 11 can be provided for optimum performance, as well as the amount of water in the barrier layer (compartment 14), which alone or together can be designed to allow for maximum cooling, cooling in the shortest period, cooling for the longest duration, and other possible scenarios. There may be a design tradeoff that occurs as the water barrier volume is decreased. By decreasing the volume and thickness of the water barrier the cooling effect on the skin will be achieved more quickly. However, it must be considered that a thinner water barrier provides less protection from sub-zero temperatures and results in cooling for a shorter period of time. In the experimental setups below, a water barrier (representative of compartment 14) and a chemical pack (representative of compartment 11) were placed in contact with one another in an adiabatic environment (heat transfer is substantially only allowed to occur between the chemical pack and the water layer). For the following three sets of results,
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It would appear to be possible to continue this iterative process until nearly all of the water barrier freezes when the device temperature starts at 0 Deg C. Based on the results shown in experimental setups 1 through 3,
The chemical pack and water barrier design shown in experimental setup 3 allow for a 1.5 inch thick device assuming contact area of 25 square inches between layers of the device. This number was found by measuring the density of each chemical and calculating the necessary volume. Calculations for such a non-limiting example are summarized below;
Weight of Chemicals and Water Barrier:
Volume of Chemicals and Water Barrier:
Densities:
Total Volume:
Thickness:
A cold therapy device of the present developments effectively lowers body temperature and results in similar outcomes to experiments performed with ice/water mixtures. A cold therapy device of the present developments applied to the neck and/or head is an effective way to lower tympanic temperature a sustained and measurable amount. Non-limiting examples may include the use of a chemical mixture of ammonium nitrate, sodium acetate trihydrate, and water. In addition, one or more water compartments are provided to protect the subject's skin from direct or near contact with the chemical mixture compartment and reduce the likelihood that the skin contact temperature will drop below 0 degrees Celsius.
In some further examples; subjects were measured for a baseline temperature and a cold therapy device of the present developments applied to the neck, back of the head or forehead to promote cooling, such as tympanic vasculature cooling, which can include counter current heat exchange between the carotid artery and jugular vein. Ice was left on all subjects for at least 28 minutes, with data collection during and after removal of a cold therapy device of the present developments. All data was analyzed using a five-point linear fit, moving average, in an effort to display trends. The data was plotted as a temperature change, and data points are shifted down by the average of the five measurements prior to application of the ice. See
The average maximum drop in temperature while icing the neck and then the neck and head was 0.8 degrees C. and 1.13 degrees C. respectively. These values were calculated by first establishing a baseline temperature for each trial, calculated as the average of the five temperature measurements prior to application of the ice. The maximum drop was calculated as the difference between the baseline temperature and the lowest temperature point in the moving average data set. The maximum drop for each of the subjects was then averaged for that experimental setup. In some cases, the lowest temperature measurement was after removal of the ice. The average drop in temperature after 28.5 minutes of icing was 0.43 degrees C. while icing just the neck and 0.87 degrees C. while icing both the neck and head. These values were calculated by averaging all of the subjects' temperature measurements at one and half minute intervals for each experimental setup. The results suggest that icing the forehead and back of head, in addition to the neck, results in a measureable amount of additional cooling. Alternative implementations of one or more devices hereof may thus include forehead in addition or in alternative to carotid and/or neck and/or to target neck alone or the carotid alone or to target the head in addition to the carotid, or in other possible combinations.
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Tests were also conducted to determine whether or not an ice pack composed of Ammonium Nitrate, Sodium Acetate, and Water, along with a water barrier on a subject's skin, can safely provide effective cooling that approaches the cooling scenario of an ice water mixture directly on the skin. Other known cooling components or chemicals can also be used according to the present developments.
A cold therapy mockup prior to assembly along with premeasured amounts of ammonium chloride, sodium acetate trihydrate, and water were also tested. The mockup was divided into three isolated compartments called the “small side pouch”, “center pouch”, and “large side pouch”. These were not unlike that shown in
Table 1 displays the amount of chemical in this non-limiting example for each compartment of the cold therapy device. Note that the chemical amounts may be partially restricted by the size and shape of the device.
As in previous trials, tympanic temperature was measured at one and half minute intervals throughout the experiment. The subject for the experiment was the same as the 24 year old male used for the ice and water testing. The subject lies on the floor for a period of ten minutes while a baseline temperature is established. The mockup chemicals were activated by injecting water into the compartments containing the ammonium nitrate and sodium acetate trihydrate. The starting temperature of the water for both the baffles and the chemical pouch is 10 degrees C. The mockup was then placed on the subject for a period of forty minutes.
The data was filtered using a five-point, linear fit, moving average to be consistent with the previous trials. The drop in temperature from placing the mockup on the subject's neck was similar to the data collected from previous experiments using ice and water.
The drop in temperature from placing the mockup on the subject's neck is similar to the data collected from previous experiments using ice and water.
In
An apparatus such as any of the cold therapy apparatuses as described above may thus provide convenient and safe ways to effect cold therapy in such a manner as to make it highly advantageous to the operator. Ease and/or quickness of assembly and/or the ready availability of the materials to be used for the connective structures can be attractive features to an operator desiring a cost-efficient and space-efficient means of obtaining a cold therapy apparatus, system and/or method. Thus, it would not be necessary to carry any expensive, specialized cooling apparatus. Markets for use hereof may include places where a cold therapy apparatus is frequently used, such as sporting events or at the scene of a medical emergency such as a car accident. Then, easy use of the apparatus as described above may be achieved.
Apparatuses hereof may be made by any of a variety of methods and/or of a variety of materials. Shapes and sizes are not limited to those shown and described here either, as sizes and shapes may be selected to adapt to any of many alternative structures.
Although the present developments have been described with reference to preferred implementations, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the development described herein.
This application relates to and claims the benefit and priority to U.S. Provisional Application No. 61/438,884, filed Feb. 2, 2011.
Number | Date | Country | |
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Parent | 13365011 | Feb 2012 | US |
Child | 14032526 | US |