Patent Application
20050278823
Every winter, drivers get stuck on roads, run the engines of their vehicles until they run out of gas or other vehicle fuel, and then are hurt by hypothermia while they wait for assistance at a location to which they have not brought sufficiently insulating clothing. Skiiers may similarly dress for a short run, but fall or become caught by unexpected conditions that lead to exposure to cold sufficient to produce hypothermia. Still others may find themselves in such conditions with insufficient clothing insulation.
An emergency anti-hypothermia system for such conditions provides a thermally insulating vest that is sufficiently portable to be carried for emergency use in a pocket, purse, backpack, compartment of a vehicle, ski pole or other location. A high degree of portability is desirable for this.
For this system, an inflatable vest is provided. The vest provides thermal insulation by being made with air impervious material that also provides for its inflation. The inflating air also provides insulation as, preferably, does thermal radiation reflective material on inwardly facing surfaces of the vest, preferably inwardly facing surfaces of outer layers of inflated chambers about the vest, the multiplicity of the chambers about the vest reducing convection heat transfer therewithin. The vest thus preferably provides thermal insulation by anti-conduction, anti-radiation and anti-convection in a highly portable system.
The thermal insulation is achieved with high portability by inflation. The portability achieved by inflation is preferably augmented by thin material.
Preferred embodiments will now be described with respect to a drawing that illustrates but does not limit the invention, and in which:
A highly portable, inflatable emergency vest is preferably made from a high tensile-strength polyester film, similar to the aluminized Mylar® used in novelty balloons (which aren't actually Mylar, but rather nylon sheet, coated on one side with polyethylene and metalized on the other). The material is electrically resistant, chemically stable, noncombustible (94VTM-2), and comes in thicknesses ranging from 0.001″ to 0.014″. It's a thermoplastic polymer, and is thermally and ultrasonically fusible.
The cells in the vest (see illustrations) are cross-connected and inflated through a simple one-way mouthpiece, for example a flap valve, for example of the film material of the vest on the garment's collar. Inflating the vest creates a layer of trapped, still air in much the same way as goose down, while conforming to the shape of the wearer—insulating the wearer's body core while allowing moist air to circulate through the shoulders and arm holes. The outside layer is offset printed using traditional methods and can be any color or design one desires, while the inside is nearly 100% reflective, preventing most radiant heat loss.
The manufacturing process looks very much like printing, and I suspect we'll need 3 sizes. The only additional line work required is the attachment of the adhesive strip on the vest's storm flap, and roll and insertion into a container, for example a box or, preferably, tube container. The container is small, because of the material and valve of the vest, preferably like the plastic, self-lidded can of M&M Mini's, e.g. a tube about 5-6 in. long by 1-1.5 in. in diameter. Just compare a handful of those to a stack of Red Cross blankets.
The Human Factors
The biggest danger posed to an exposed individual is hypothermia. This is true at a Red Cross station, huddled with other survivors after a natural disaster, or simply changing a tire on a roadside in winter night.
Hypothermia is defined as the unintentional lowering of the deep body (core) temperature below 95.0° F. (35.0° C.). Hypothermia can be mild, moderate, or severe. During 1979-1998, approximately 700 persons died annually in the United States from hypothermia, with approximately half of these deaths attributed to extremely cold weather.
Since 1999, CDC's National Center for Health Statistics (NCHS) has used information from death certificates categorized with International Classification of Diseases codes to estimate national mortality trends. During 1999, exposure to excessive natural cold (ICD-10code X31) was listed as the underlying cause of death for 598 persons in the United States, and hypothermia (ICD-10 code T68) was listed as a nature of injury in 1,139 deaths. Of the 598 hypothermia-related deaths, 380 (64%) occurred among males, and 359 (60%) of the 597 persons who died of hypothermia and whose age was known were aged>65 years. During 1999, Pennsylvania and New York had the greatest number of hypothermia-related deaths (36 each) (2), and Alaska had the highest crude death rate (1.9 per 100,000 population), approximately twice that of Montana, which had second-highest rate (0.9).
Hypothermia during cold weather is the result of decreased heat production, increased heat loss, or impaired thermoregulation. Older persons, who have a decreased basal metabolic rate, might be at further risk for hypothermia because of impaired physical exertion, which produces heat to keep the body warm. Inactivity limits heat production through physical exertion, but overexertion can increase evaporation from the respiratory tract and cause fatigue. Shivering also can cause enough lactate generation eventually to produce acidosis and fatigue. Exposure to high winds can further increase heat loss. As body temperature decreases, the hypothalamus fails to compensate body temperature, and the central nervous system follows the progressive systemic depression of metabolism. Finally, metabolic impairment from alcoholism, malnutrition, hypothyroidism, or advanced age can cause poor endurance to cold.
Hypothermia-related morbidity is not exclusive to cold northern climates either. Hypothermia can occur in cold and warm climates alike. In fact, a survey of 12 medical centers found that the greatest number of cases of accidental hypothermia occurred in warmer states. Hypothermia has been reported in tropical countries as well. Persons from regions with warmer winters might be at greater risk from the indirect effects of cold weather than persons from regions with colder and longer winters. However, geographic distributions might represent not only seasonal temperature variations but also socioeconomic status (which can limit access to controlled indoor temperature), cultural backgrounds (which can influence behavior toward individual protection from cold as well as outdoor activity), or populations with a higher proportion of elderly persons.
Additional Applications
For safety/visibility applications, I'm planning to use 3M's Series 8000 reflective ink for textiles, instead of the bulky Scotchlite reflective strips. The Inks are composed of a water-based (latex) ink base combined with the familiar retro-reflective microlenses. This process is used for direct screen printing onto fabric or plastics, and the end result with respect to visibility is the same. 3M also makes a stabilizing coating, but since this is a one-use item, it's hardly necessary for this application. I may just choose to use another medium like PolySol, instead of the latex base if I need greater adhesion stability. I also need to learn a bit more about ANSI Class II certification before I finalize the placement of the reflectors. It should be noted that in this application, unless the vest is sealed in front and/or inflated, it can be used again and again.
The Market
Naturally, there's retail sales to individuals (perhaps bundled in branded, home and car emergency kits), but I think there's a much larger market as a custom-printed OEM product to automobile manufacturers, airlines, commercial transportation networks, national parks, sports stadiums and other outdoor entertainment venues; as well as emergency-response and relief organizations like the Red Cross, FEMA, The United Nations, U.S. and international police and fire services, EMS, hospitals, military, etc. It's a virtually endless list.
Combinations, permutations and variations as will occur to those of ordinary skill are contemplated within the scope of the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 60547918 | Feb 2004 | US |
