The invention relates to protective clothing, and more particularly to garments providing protection against lightning-caused cardiopulmonary arrest.
Though a rare cause of death, lightning is reported to be responsible for more fatalities each year in this country than any other type of natural disaster. Lightning injuries differ significantly from other high voltage electrical injuries because of the high current flow, but extremely short duration of the lightning strike.
Lightning can affect all organ systems, especially the cardiovascular system. The primary cause of death following a lighting strike is cardiopulmonary arrest. The current in a lightning bolt is as high as 30,000 Amperes at 1,000,000 or more Volts. The short duration of about 1-100 milliseconds limits, but does not prevent serious injury. There are several types of outdoors lightning injury. The most severe is a direct strike, either on the victim or on some object the victim is holding such as a golf club, tripod or umbrella. A “side flash” occurs when lightning hits a nearby object and jumps to the victim. Ground current injuries occur when lightning strikes the ground nearby and spreads to a victim.
Avoidance and prevention are the best means of lightning safety. The risk of a lightning related injury can be minimized with some simple safety measures but not eliminated completely. Just as remaining in a metal vehicle during lightning activity can provide protection, a protective garment that includes an electrically conductive shield can benefit someone who finds himself exposed to a potential lightning strike. What is needed is a protective garment that reduces deaths related to cardiopulmonary arrest following a lightning strike.
Applicant has found no patent nor non-patent literature expressly describing such a Garment, however, U.S. Pat. No. 7,712,149 issued to Baldwin in 2010 for a “Protective Article of Outer Clothing” discloses a garment intended for protection against attack by Taser (an electrical stun gun), and suggests (at col. 4, lines 8-12) that such garment might be useful as protection against a lightning strike. The Baldwin garment provides an electrically conductive shield, but lacks any other feature that will benefit the victim of a lightning strike.
Several U.S. patents, in addition to that by Baldwin, disclose electrically conductive textiles of varying types, potentially useful for making electrically protective garments, e.g., U.S. Pat. Nos. 7,947,773, 7,832,983, 7,817,401, 7,284,280, 6,272,781, and 5,906,004. Medical information related to lightning-caused injury and death has been reported in two publications, limited portions of which are paraphrased above: (1) a publication of the Center for Disease Control, “Lightning-Associated Deaths—United States, 1980-1995”, MMWR 47 (19), at pages 391-394, May 22, 1998; and (2) a paper titled “Deaths Caused by Lightning”, by Lifschultz et al., Journal of Forensic Sciences 38 (2), at pages 353-358, March 1993.
An interesting medical study published in 1986 [“Lightning injury caused by discharges accompanying flashovers—a clinical and experimental study of death and survival”, Ohashi M., et al., in Burns Incl Therm Inj 1986 October; 12 (7): 496-501, Abstract] reported that “[d]uring the 17 years preceding March 1985, 140 patients sustained lightning injuries caused by 44 thunderbolts. Fifty patients showed evidence of current flow through their bodies. These 50 victims were classified into two groups, the first consisting of 9 victims who showed rupture of their clothes or lineal superficial dermal burns along their whole bodies from head to feet, indicating the occurrence of surface flashovers. The remaining 41 patients showed no evidence of this flash effect. It is noteworthy that in the first group 5 of the 9 survived, whereas in the second group only 6 among 41 survived. The result indicates that when a flashover occurs along the whole body, the probability of survival is higher than 50 percent. The conditions which determine death or survival were investigated experimentally, imposing artificial lightning voltage impulses on rats and developing flashovers on them. The rats survived when the voltage drop caused by flashover occurred immediately after the peak point, and the current waveform exhibited a sharp peak. In contrast, the rats were killed when the voltage drop caused by flashover was delayed by more than 20 microseconds, and the current waveform showed a blunt cone shape. It has been concluded that a fast flashover appreciably diminishes the energy dissipation within the body and consequently results in survival.”
No garment that is both practical and wearable can prevent most serious injuries resulting from a lightning strike. A victim will be severely injured. What is needed is a protective garment that can reduce the number of deaths resulting each year from cardiopulmonary arrest following a lightning strike.
It is an object of the present invention to provide a garment that can reduce the number of lightning caused deaths by effectively protecting the user's cardiopulmonary system.
The above object is achieved by a cardiopulmonary lightning protection garment including a fast flashover facilitating, electrically conductive shield covering at least an upper portion of the body and having a region of limited conductivity for directing electrical charge away from the heart. The garment includes a grounding member providing a movable connection between the garment's conductive shield and a local ground plane, such as the Earth.
The principle of operation of the invention is to shield the body while facilitating fast flashover to reduce electrical potential, conduct the electricity across the garment body, away from the heart, then down the grounding member to the ground plane—or in a reverse direction for a lightning strike that jumps from Earth to sky.
Various configurations of the basic garment are contemplated, including a hooded jacket, hooded raincoat, padded vest, rain poncho, and the like. In various embodiments, the grounding member is a strap-like tail attached to the electrically conductive body shield at an upper end, and falling to the ground at a lower end. A ball or sliding weight is attached to the lower end of the tail to maintain a movable contact between the conductive tail and the ground, and both ball and tail can be stuffed into a garment pocket for carrying when not in use.
With reference to
In a specific embodiment, garment 100 is manufactured out of cloth so that it appears to be normal clothing, specifically, a hooded jacket as shown in
Various forms of conductive layer 202 are contemplated including enclosure between cloth layers, as shown in
In various other embodiments, the garment is manufactured from a sandwiched construction such as illustrated in
In various embodiments, the body shield 302 is made of the electrically conductive layer 202 of
One variation in the regions of low-conductivity is that they are of different size and shape. In particular, the region 612 in
In other embodiments of the protective shield (e.g.,
Use of a material of low conductivity in the region near the heart helps direct the charge away from the heart. In various embodiments that use a low-conductivity material in the heart region, the low-conductivity material is electrically connected at its edges to the higher-conductivity of the surrounding regions (not illustrated). In other embodiments, the low-conductivity region is created as a conductive void in the material of the protective shield. The phrase “conductive void” as used here refers to a hole—an absence of conductive material in the body shield. The cloth, of course, remains covering the heart region so that the garment appears natural. In another variation (not illustrated) the body shield does not include a region of reduced conductivity near the heart; instead, the protective body shield also covers the heart region with high conductivity material, and relies instead upon facilitating a fast flashover and electrical body shielding for protection.
While the invention has been described in relation to the embodiments shown in the accompanying Drawing figures, other embodiments, alternatives and modifications will be apparent to those skilled in the art. It is intended that the Specification be exemplary only, and that the true scope and spirit of the invention be indicated by the following Claims.
This application is a continuation of U.S. patent application Ser. No. 13/468,069 filed, May 10, 2012 and entitled CARDIOPULMONARY LIGHTNING PROTECTION GARMENT, the contents of which are hereby incorporated by reference in their entirety.
Number | Date | Country | |
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Parent | 13468069 | May 2012 | US |
Child | 15055927 | US |