The device of the present application relates generally to active wear clothing. More specifically, the device of the present application relates to active wear clothing capable of modifying the thermal environment of the wearer.
The cardiovascular system is the primary means by which the body distributes biological heat, i.e. bioheat. Heat production and heat loss are controlled in two ways. First, the transfer of heat to the body skin surface from the central core establishes an internal thermal gradient. Second, heat is dissipated from the skin surface to the surrounding environment. This balance is critical to normal thermoregulatory function. Body temperature regulation is controlled almost exclusively by intricate nervous system feedback mechanisms located in the hypothalamus. Heat-sensitive neurons located in the pre-optic area of the hypothalamus are the body's most influential temperature receptors. These receptors respond to rising temperature by increasing their impulse output and to falling temperature by decreasing their output.
Additional temperature receptors found in the skin consist of both warmth and cold receptors. There are 4 to 10 times as many cold as warmth receptors. These receptors convey nerve impulses to the hypothalamus, where the information is used to regulate body temperature. Receptors in the spinal cord itself, the abdomen, and other internal body structures also transmit signals, primarily cold signals, to the CNS to help in temperature control. Peripheral thermoreceptors dispatch signals to the posterior hypothalamus, where they are integrated to control heat loss and heat production. This “hypothalamic thermostat” is the primary temperature control mechanism in the body.
The blood serves as a heat transfer fluid regulating core body temperature by increasing blood flow to the extremities for cooling and by diverting blood from the extremities to conserve heat and to better maintain core body temperature in frigid conditions. Core body temperature depends on many variables such as the temperatures to which the extremities are exposed and the duration of that exposure, temperature difference between extremities and core, volume of blood which deviates from core temperature, and the rate of blood perfusion. Human blood has a thermal conductivity similar to that of water, but is somewhat dependent upon hematocrit values.
An increase in the body core temperature (hyperthermia) from approximately 36.5 to 39 degrees Celsius is known to cause a doubling of the cardiac output. In connection with vasoconstriction in the splanchnic circulation and in skeletal muscle this results in large increases of skin blood flow. The underlying vasodilatation is evoked by reflex regulation of the efferent sympathetic system. While there is a reduction of alpha-adrenergic vasoconstriction, there is also evidence for active sympathetic cholinergic and nitric oxide-dependent vasodilatation. In the presence of risk factors, e.g. age and diabetes, the circulatory adaptation to heat stress may be compromised.
Overexposure to cold can result in abnormal CNS responses and varies with the degree of hypothermia. Mild to moderate hypothermia is known to produce confusion and behavioral changes, even paradoxical shedding of clothes which exacerbates the problem of overexposure. Adverse cardiological effects are also prevalent in hypothermia cases. During the phase of shivering thermogenesis, there is a decrease in cardiac conductivity and automaticity and an increase in the refractory period.
This application relates to active wear which incorporates a temperature modification device, e.g. chemical hot pack or cold pack, positioned over and oriented along a major circulatory system artery or vein so as to optimize the overlap of the temperature modification device with the major artery or vein. Optimizing the overlap of the temperature modification device with a major artery or vein permits the wearer of the garment to use the blood flowing through the affected vessel as a heat transfer fluid to either increase or decrease core body temperature and appendage temperature more effectively, resulting in improved tolerance of heat and cold. Incremental changes in the temperature of blood flowing to the extremities by the use of supplemental heat or cold is believed by the applicant to improve comfort and performance. The residence time of blood flowing within a vessel is a critical dependent variable, therefore extending the area affected by the heating or cooling properties of the clothing along the length of a vessel can improve the efficiency of the thermal modification of the blood while minimizing the impact on surrounding tissue.
The garment of the present application can be formed as a shirt, body suit, shorts, pants, or similar garments. The garment includes at least one means to retain a thermal device 10, e.g. a pocket 10, which is preferably a chemical pack 50 which can be actuated to generate heat through an exothermic reaction or absorb heat through an endothermic reaction. Common thermal devices 50 include, but are not limited to, plastic packs having a plurality of compartments separated by an internal seal to segregate the active components wherein the seal can be ruptured through the application of sufficient pressure. Pressure applied to a pack compartment by squeezing the compartment with the hand or otherwise compressing the compartment causes the internal seal between the compartments to rupture and the components to mix, thus initiating the thermal event from the chemical reaction.
As depicted in
As depicted in
The garment 100 of the present application permits the user to more effectively regulate body temperature by wearing the garment 100 and actuating thermal packs 50 to heat or alternatively cool the blood as needed. In cold climates, outdoor workers and enthusiasts would use actuate heat packs 50 inserted into the pockets 10 to add some heat to the blood to avoid the rapid cooling taking place at the extremities which would permit extended exposure while delaying the onset of hypothermia and frostbite thus delaying symptoms such as the loss of dexterity and poor decision making. Conversely, cooling packs 50 could be actuated in the pockets 10 for use in hot weather conditions to help regulate core body temperature.
The present application relates to U.S. Provisional Patent Application 61/676,331 filed Jul. 27, 2012. The Applicant hereby incorporates U.S. Provisional Patent Application 61/676,331 as if fully set forth herein.