Abstract:
An apparatus for manipulating the thermal regulatory status of a mammal. The apparatus includes a sealing enclosure for enclosing a portion of the mammal, a heat exchanger operable to transfer energy with the portion of the mammal, and a pumping device operably coupled with at least one of the sealing enclosure and the heat exchanger. The pumping device is actuated through ambulation or movement of the mammal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/609,806, filed on Sep. 14, 2004. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to the field of thermal therapeutic applications and, more particularly, to an ambulation actuated pump for generating pressure and/or vacuum for thermal loading.  
       BACKGROUND OF THE INVENTION  
       [0003]     Human body temperature is normally tightly controlled by an autonomic regulatory system referred to herein as the thermoregulatory system. The most important effector of this regulatory system is blood flow to specialized skin areas where heat from the deep body core can be dissipated to the environment. Normally, when body and/or environmental temperatures are high, the dilation of certain blood vessels favors high blood flow to these surfaces, and as environmental and/or body temperatures fall, vasoconstriction reduces blood flow to these surfaces and minimizes heat loss to the environment.  
         [0004]     Elevated deep body core temperature is a problem for many, including athletes, industrial workers, miners, firefighters, and soldiers, and is often associated with exertion. As the temperature of the body&#39;s core organs—heart, lungs, liver, kidneys, and brain—rises, fatigue may set in. This fatigue tends to rapidly diminish an individual&#39;s strength, endurance, and cognitive functions.  
         [0005]     Mammalian thermoregulation principles teach that all mammals have “radiators”—that is, specific regions of the body surface designed for dissipating excess heat from the deep body core to the environment, wherein examples of such include dogs&#39; tongues, rabbits&#39; ears, and the like. In humans, some of these radiator surfaces are found in the palms of the hands and soles of the feet. When an individual gets hot, blood flow naturally increases through these skin regions to dissipate the heat through specialized blood vessels called arteriovenous anastomoses (AVAs).  
         [0006]     Conventional methods of cooling the body include remedies typically applied to the skin&#39;s surface (i.e., misting fans, ice packs, cold water, etc.). While such solutions often make an individual “feel” cooler temporarily, they are generally ineffective at cooling the body&#39;s core organs. This is a result of two phenomena: first, these treatments are applied to the skin&#39;s surface, and thus have difficulty penetrating the body&#39;s insulating layers of tissue. Second, the cold temperatures of these remedies can result in a vasoconstriction of the peripheral blood vessels and actually cause a reverse of the desired effect by shutting down the natural heat dissipation mechanisms.  
         [0007]     Accordingly, there exists a need in the relevant art to provide an apparatus for transferred heat into or out of the thoracic/abdominal core body without triggering concomitant opposing reaction by the thermoregulatory system. Furthermore, there exists a need in the relevant art to provide an apparatus capable of transferring heat into or out of the thoracic/abdominal core body in response to a pumping action created through ambulation. Still further, there exists a need in the relevant art to overcome the disadvantages of the prior art.  
       SUMMARY OF THE INVENTION  
       [0008]     According to the principles of the present invention, an apparatus for manipulating the thermal regulatory status of a mammal is provided having an advantageous construction. The apparatus includes a sealing enclosure for enclosing a portion of the mammal, a heat exchanger operable to transfer energy with the portion of the mammal, and a pumping device operably coupled with at least one of the sealing enclosure and the heat exchanger. The pumping device is actuated through ambulation or movement of the mammal.  
         [0009]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a cross-sectional view illustrating a boot incorporating the ambulation actuated pump of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0013]     The present invention provides an apparatus  10  for dissipating heat from a radiator surface of a mammal in response to a pumping action created through ambulation or varying pressure application to the extremity. Apparatus  10  enhances heat extraction through these radiator surfaces by amplifying local blood flow using carefully controlled temperature settings and/or temperature control. These temperature settings are generally in a range from about 10 degrees Celsius to about 40 degrees Celsius and, more particularly, in a range from about 10 degrees Celsius to about 40 degrees Celsius. The pressure control can provide a negative pressure or an alternating positive and negative pressure. These pressures can generally be in a range of about 5 in. of water to about 35 in. of water.  
         [0014]     For individuals or mammalians of any type that are exercising, working, or moving about in extreme environments or those susceptible to heat stress, the present invention helps generally maintain the core body temperature within the zone for optimal performance. When overheated, the present invention serves to cool the body rapidly and non-invasively to reduce fatigue, increase endurance and strength, and improve cognitive function.  
         [0015]     By way of background, it should be understood that a significant amount of energy is generated through ambulating, in particular human ambulation. In such cases, when a shoe, boot, or other foot device strikes a surface while walking or moving, energy is consumed through compression and expansion of the sole of the foot device. Until now, this energy is typically lost.  
         [0016]     However, according to the present invention, it has been found that by creating or defining a void in a predetermined area(s) of the sole of the foot device, energy that would otherwise be lost during compression and expansion of the sole may be harnessed to move fluids or gas to create pressure differentials within portions of the foot device. That is, by controlling the flow of gas or fluid, a pressure differential may be created inside the shoe or boot. This pressure differential may be used to enhance blood flow to certain vasculature found in the human foot.  
         [0017]     A pressure differential created by the pump may also be used to create a temperature differential for the purpose of delivering a thermal load to the foot. Using a pump built into the sole of the shoe or boot or an insert placed in a shoe or boot and the energy generated through ambulation, gas or liquid moved by the pump may be managed for the purpose of expansion and contraction creating relative thermal change in that gas or liquid. The resulting temperature differential can then be used to deliver a thermal load to the foot via a heat exchanger located in close proximity (or in direct contact) with the foot.  
         [0018]     Therefore, according to the principles of the present invention, a device is provided having an advantageous construction. As best seen in  FIG. 1 , a device  10  is illustrated having a pump  12  coupled within a shoe, boot, or foot device  14 . It should be recognized that although foot device  14  of the present disclosure is a boot, any such foot device may be used, such as a shoe, sandal, boot, and the like. Additionally, application of the present invention is not limited to humans, but may be used in connection with any ambulatory mammal. Foot device  14  defines an interior chamber  100 , which is adapted to receive a negative pressure or vacuum, a positive pressure, or an alternating positive and negative pressure therein.  
         [0019]     Pump  12  is a dual chamber pump disposed at the rear of foot device  14  and is provided for generating differential pressures. Pump  12  includes a low vacuum portion  102  and a high vacuum portion  104  and or a low pressure portion and a high pressure portion.  
         [0020]     Low vacuum portion  102  includes a fluid conduit  106  disposed near a heal  108  of foot device  14  that is compressible under load during ambulation. A check valve (not shown) is operably coupled with fluid conduit  106 . In one case, the check valve may be operable to create a pressure during positive compression of heal  108 . Alternatively, the check valve may be operable to create a vacuum following the positive compression of heal  108 —that is, during the relaxing stage of heal  108  following a heal impact. Fluid conduit  106  of low vacuum portion  102  is further coupled to interior chamber  100  of foot device  14 . In this regard, low vacuum portion  102  can create a vacuum within interior chamber  100 . This vacuum is used to draw blood to the foot for improved cooling as is taught in the following U.S. Pat. Nos. 5,683,438, 6,602,277, 6,656,208, and 6,673,099, which are incorporated herein by reference.  
         [0021]     High vacuum portion  104  similarly includes a fluid conduit  110  disposed near heal  108  of foot device  14  that is compressive under load during ambulation. A check valve (not shown) is operably coupled with fluid conduit  110 . In one case, the check valve may be operable to create a pressure during positive compression of heal  108 . Alternatively, the check valve may be operable to create a vacuum following the positive compression of heal  108 —that is, during the relaxing stage of heal  108  following a heal impact. Device  10  may thus be used to generate hot or cold based on the required need of the user. Fluid conduit  110  of high vacuum portion  104  is further coupled to a multi-chamber insert  30 .  
         [0022]     Mechanical operation of pump  12  is actuated by the ambulation of the leg and foot of the individual and the force generated by the foot striking the ground. As a sole  16  of foot device  14  is compressed under the weight and force of striking a surface, the force generated drives pump  12 .  
         [0023]     As can be seen in the figure, multi-chamber insert  30  is provided in a position slightly forward from pump  12  and generally under the arch of the foot, which is known as a “radiator” region. Multi-chamber insert  30  includes a plurality of voids  32  and sinters  34 . Voids  32  are in fluid communication with high vacuum portion  104  and, thus, are under an extreme pressure differential (positive or negative) for the purpose of generating temperature differential. Sinters  34  are open to the interior chamber  100  of foot device  14 .  
         [0024]     A thermally conductive material  24  is provided generally above multi-chamber insert  30  to enhance delivery of the thermal load to the bottom of the foot.  
         [0025]     In a “dead loss” evaporation system, tubes carry a liquid coolant from a reservoir to the evaporation/expansion chamber of the boot. As the interior temperature of the boot increases a temperature sensitive bimetallic reed valve will open to admit a small amount of liquid. The liquid will be evaporated off to create a temperature change. The temperature change will cause the reed valve to close stopping the admission of liquid.  
         [0026]     A bi-metallic reed-valve (not shown) admits an amount of liquid proportional to temperature into a void and or a porous membrane within foot device  14  or boot. A high vacuum is pulled within void  18  causing evaporation of the liquid. This evaporation creates a temperature differential between a heat sink  24  (hot and/or cold conducting surface), which has at least intermittent contact directly or indirectly to the bottom of the foot.  
         [0027]     In a closed loop system, liquid or gas will be circulated through a traditional compression and expansion system consisting of an expansion chamber, condenser, heat exchanger and compressor.  
         [0028]     Foot device  14  will be fitted with a gas tight seal  20  that may either contact the skin of the user or contact a “mating” material  22  located on a liner or sock so as to cause a gas tight seal at their contact point. This gas tight seal helps maintain a pressure differential between the interior of foot device  14  and ambient.  
         [0029]     Furthermore, it is further anticipated that an outer shell  40  of foot device  14  may be used as a “radiator” to dissipate heat. Thus, device  10  may be sealed and operated as a no or limited fluid loss system. Construction of this “radiator” is intended to be incorporated into the actual body of foot device  14 . Thermally conductive, permeable, and/or impermeable tubing  46  is used to circulate liquid to indirectly contact ambient conditions. Heat loss or gain may be by convection or conduction.  
         [0030]     Furthermore, by allowing evacuation to ambient, device  10  may be built as a “dead loss” system. However, this would require a reservoir of appropriate liquid, generally indicated at  112  in phantom, to be housed within foot device  14  or carried on or attached to the body. Perspiration may act as a supplemental liquid coolant within interior chamber  100  of foot device  14 .  
         [0031]     It should be understood that additional features, such as solar cells for electrical generation and or micro turbines driven by gas or liquid pumped by the action of ambulation causing actuation of the embedded pump, may further be used. A complimentary device, such as a sock or glove liner that contains thermally conductive material located on the palm of the hand and or the bottom of the foot, may further be used. The sock will be constructed in such a way as to cause a gas tight seal when contacting the accompanying boot or glove.  
         [0032]     Furthermore, bifurcation of the vacuum and or pressure device will allow multiple areas of differing pressure and or vacuum within foot device  14 .  
         [0033]     A similar device may be used for the hand. Using the action of ambulation and the forces generated by the foot and foot device  14 . The pressure and vacuum pump  12  housed in foot device  14  could be connected via gas impermeable hoses to a glove that has similar heat sink material located in the palm. The glove or mitten may be housed in a rigid or flexible shell that will not collapse at vacuum&#39;s as high as 40 in. of water.  
         [0034]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.