Patent Publication Number: US-2022219795-A1

Title: Using illuminable dyes to facilitate search and rescue

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with government support under FA 8652-19-P-WI13 awarded by the Department of Defense (Department of the Air Force, Air Force Materiel Command). The government has certain rights in the invention. 
    
    
     BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates generally to search and rescue. More particularly, the present disclosure relates to maritime search and rescue. 
     Description of Related Art 
     Many hazards face individuals that are lost at sea or in other open water. The chances of survival diminish rapidly with time and, thus, there is a need to quickly find and rescue those that are in open water. 
     SUMMARY 
     An apparatus that facilitates search and rescue, for example, in open water. The apparatus comprises a substrate with a particular geometry and a perimeter. The apparatus further comprises a cover positioned atop the substrate with the cover also having a particular geometry and perimeter, which correspond to the geometry and perimeter of the substrate. An air-tight seal seals the substrate perimeter to the cover perimeter and creates a sealed internal region. A liquid-releasable vessel holding an illuminable dye located in the sealed internal region, along with an activator that is also located in the sealed internal region. When the liquid-releasable vessel releases the illuminable dye, the illuminable dye reacts with the activator, thereby resulting in illumination of the illuminable dye. The liquid-releasable vessel comprises an opening with a release mechanism (e.g., clamp, etc.). 
     Other systems, devices, methods, features, and advantages will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a diagram showing an individual with one embodiment of an apparatus that facilitates search and rescue in open water. 
         FIG. 2A  is a diagram showing a top view of another embodiment of an apparatus that facilitates search and rescue. 
         FIG. 2B  is a diagram showing a side cut-away view of the apparatus of  FIG. 2A  upon deployment of the apparatus. 
         FIG. 3A  is a diagram showing a liquid-releasable vessel with a closed release mechanism. 
         FIG. 3B  is a diagram showing the liquid-releasable vessel of  FIG. 3B  with an open release mechanism. 
         FIG. 4A  is a diagram showing a top view of another embodiment of an apparatus that facilitates search and rescue. 
         FIG. 4B  is a diagram showing a side cut-away view of the apparatus of  FIG. 4A  prior to deployment of the apparatus. 
         FIG. 4C  is a diagram showing a side cut-away view of the apparatus of  FIG. 4A  upon deployment of the apparatus. 
         FIG. 4D  is a diagram showing a focusing behavior of light in the apparatus of  FIG. 4A . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Search and rescue operations take place in many different environments, with each environment presenting its own challenges. For those that are lost in open water (e.g., large lakes, seas, oceans, etc.), the hazards include hostile temperatures, dangerous marine animals, and tumultuous waves. Thus, it is not surprising that the chances of survival diminish rapidly over time. Because of this, there is a need to quickly find and rescue those that are in open water. 
     To facilitate maritime search and rescue operations (or other open-water-based search and rescue operations), the present disclosure provides an illuminable dye and an activator. The activator is positioned at select locations. The illuminable dye is contained in a liquid-releasable vessel (e.g., pouch, bag, etc.). The liquid-releasable vessel comprises an opening and a release mechanism (e.g., releasable clamp, etc.) that controllably releases the illuminable dye through the opening. When the release mechanism is opened, the illuminable dye is released and, when activated by the activator, begins to luminesce. A liquid-releasable vessel with a releasable clamp operates under a different principle than a breakable vessel. This is because, unlike a breakable vessel, the releasable clamp can controllably release the contents of the vessel, can be closed, and can also be re-used. Conversely, once a breakable vessel is broken, then the release of the vessel&#39;s contents is automatic. Also, unlike a releasable clamp, the breakable vessel cannot be un-broken and, also, cannot easily be re-used. 
     For some embodiments, the apparatus has a geometry that, when released in open water, allows the apparatus to spread to a sufficiently large area, such that the apparatus becomes visible from a distance of at least six hundred meters (400 m) and, more preferably, at least 1.5 kilometers (km). The activator is placed at select locations in the apparatus so as to maximize visibility during search and rescue operations. For some embodiments, once the apparatus begins to luminesce, it becomes detectable using drones, space-based assets (e.g., satellites), or other un-manned vehicles. 
     Having provided a broad technical solution to a technical problem, reference is now made in detail to the description of the embodiments as illustrated in the drawings. While several embodiments are described in connection with these drawings, there is no intent to limit the disclosure to the embodiment or embodiments disclosed herein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents. 
     To illustrate potential hazards in open waters,  FIG. 1  shows an individual  110  that is lost in open water  120 . The individual  110  is exposed to risks of hypothermia (if the water is cold) or drowning (if the waters are choppy or tumultuous). In addition to hypothermia and drowning, the individual  110  can be exposed to other hazards, such as, for example, flailing injuries to limbs and internal injuries from impacts (e.g., ejection from an aircraft, crash-related impacts, etc.). Additionally, the individual  110  can sometimes be surrounded by dangerous marine animals, such as, for example, stinging jellyfish or sharks. Furthermore, if the individual  110  is in an area that is teeming with fish, then the fish can also attract other predatory animals. Thus, a speedy rescue increases the chances of survival for an individual  110  in open water  120 . 
     Turning now to  FIGS. 2A and 2B , shown are both a top view ( FIG. 2A ) and a side view ( FIG. 2B ) of one embodiment of an environmentally isolated apparatus  200  that facilitates search and rescue (also designated herein as a sealed balloon  200 ). As shown in  FIGS. 2A and 2B  (collectively,  FIG. 2 ), the sealed balloon  200  comprises a bottom substrate  210  that is substantially impermeable to water. Some embodiments of the bottom substrate  210  comprise reflective material. Also, for some embodiments, the bottom substrate  210  is substantially circular and has a diameter of between approximately fifty (50) centimeters and approximately two (2) meters. It should be appreciated that the bottom substrate  210  can be any geometric shape with a substantially equivalent surface area to that of a circular embodiment. 
     Next, several activators  220  are adhered to the surface of the bottom substrate  210 . The activator can be an oxidant, such as, for example, sodium percarbonate, hydrogen peroxide, bromine, bromates, chlorinated isocyanurates, chlorates, chromates, dichromates, hydroperoxides, hypochlorites, inorganic peroxides, ketone peroxides, nitrates, nitric acid, nitrites, perborates, perchlorates, perchloric acid, periodates, permanganates, peroxides, peroxyacids, persulphates, or other oxidizers. Preferably, the activators  220  are arranged in a pattern that is readily distinguishable from patterns that occur naturally in open waters (meaning, a non-naturally occurring pattern). Consequently, the pattern allows for potentially faster and easier detection in open waters because it is less likely that the pattern will be mistaken for a naturally occurring reflection or naturally occurring luminescence. 
     The sealed balloon  200  also comprises a liquid-releasable vessel  230 , which releases an illuminable dye that is contained therein. It should be appreciated that the activators  220  can also be arranged in a pattern that maximizes saturation or activation when the illuminable dye is released from the liquid-releasable vessel  230 . Preferably, the arrangement pattern of the activators  220  in the sealed balloon strikes a balance between optimized saturation and optimized visibility. By way of example, the illuminable dye can be an oil-based dye or a dye comprising an organic solvent, such as, for example, dibutyl phthalate, dimethyl phthalate, dioctyl phthalate, butyl benzoate, ethyl benzoate, tert-butyl alcohol, tributyl citrate, triethyl citrate, dioctyl adipate, didecyl adipate, or ditridecyl adipate. 
     The bottom substrate  210  is covered with a transparent water-impermeable top  240  and a seal  250  provides an air-tight seal  250  around a periphery of the sealed balloon  200 , thereby isolating the contents of the sealed balloon  200  from external elements. To the extent that industrial sealing processes (such as those used in mylar balloons), only a truncated discussion of the air-tight seal  250  is provided herein. Prior to activation, the sealed balloon  200  is substantially flat and can be folded or rolled to occupy a smaller space. 
     Turning to  FIGS. 3A and 3B , shown are a closed liquid-releasable vessel  230   a  and an open liquid-releasable vessel  230   b , respectively. For the embodiment of  FIG. 3A , the liquid-releasable vessel is a polyvinyl chloride (PVC) bag  310  that contains the illuminable dye  320 . The PVC bag  310  comprises an opening  330 , which is shown in  FIG. 3A  as a hose that extends from the PVC bag  310 . The liquid-releasable vessel  230   a  further comprises a release mechanism  340  that selectively opens and closes the opening  330 . In the embodiment of  FIG. 3A , the release mechanism  340  is shown as a clamp  340 , which when closed creates an occlusion  350  (or a pinch) that prevents the illuminable dye  320  from escaping the PVC bag  310 . The open liquid-releasable vessel  230   b  in  FIG. 3B  shows the release mechanism  340  being open, thereby releasing the illuminable dye  320  through the opening  330 . 
     Thus, returning to  FIGS. 2A and 2B  to continue discussing the operation of the sealed balloon  200 , the illuminable dye is activated by opening the liquid-releasable vessel  230 . A cross-section of the sealed balloon along the broken line A-A is shown in  FIG. 2B . The illuminable dye reacts chemically with the activators  220 . For some embodiments, some of the activators  220  can be coated with a dissolvable coating, thereby allowing different activators  220  to be activated at different times after the release of the illuminable dye. In other words, by applying different time-release coatings to certain activators  220 , it is possible to cascade in time the luminescence from one set of activators  220  to another set of activators  220 , and so on, based on the rates at which the coatings dissolve. 
     Continuing, the chemical reaction produces two (2) results. First, the chemical reaction creates a luminescence at a given wavelength. Preferably, the wavelength is in the range of ultraviolet (UV) light, but it should be appreciated that the chemicals can be customized to emit at different wavelengths and for different durations. Second, the chemical reaction releases a gas, which inflates the sealed balloon  200 . As noted above, both the activators  220  and the liquid-releasable vessel  230  are enclosed in the apparatus and sealed from external elements using an air-tight seal  250 . Thus, if a gas is released from the chemical reaction, then the released gas inflates the sealed balloon  200  because the gas cannot escape through the seal  250 . By way of example, if the sealed balloon  200  has a sixty-centimeter (60 cm) diameter, then the liquid-releasable vessel  230  contains approximately one hundred milliliters (100 mL) of illuminable dye. Correspondingly, if the sealed balloon  200  has a 1.5-meter (m) diameter, then approximately 200 mL of dye should suffice. Those having skill in the art can readily calculate the amount of illuminable dye that will be sufficient to react with the pattern of activators  220 . 
     By way of example, if the illuminable dye is an oil-based dye (e.g., dibutyl phthalate, dimethyl phthalate, dioctyl phthalate, butyl benzoate, ethyl benzoate, tert-butyl alcohol, tributyl citrate, triethyl citrate, dioctyl adipate, didecyl adipate, or ditridecyl adipate), and the activator  220  is a hydrogen-containing oxidant (e.g., sodium percarbonate, hydrogen peroxide, bromine, bromates, chlorinated isocyanurates, chlorates, chromates, dichromates, hydroperoxides, hypochlorites, inorganic peroxides, ketone peroxides, nitrates, nitric acid, nitrites, perborates, perchlorates, perchloric acid, periodates, permanganates, peroxides, peroxyacids, persulphates, or other oxidizers), then hydrogen gas is released from the reaction and fills the sealed balloon  200 . 
     Because the sealed balloon  200  has an air-tight seal  250 , the illuminable dye continues to wash over the activators  220  as the isolated apparatus undulates or jolts with the waves in the water. The continued washing of the activators  220  allows for unreacted activators  220  to be activated by the illuminable dye. In other words, continued movement of the illuminable dye within the sealed balloon  200  results in a more complete reaction between the illuminable dye and all of the activators  220 . The air-tight seal  250  also prevents dissipation of the illuminable dye or the activators  220  in open water because neither the dye nor the activator  220  can escape the sealed balloon  200 . Thus, the sealed balloon  200  is visible for a longer period than devices that release dyes into open waters. Preferably, the sealed balloon  200  provides visibility (at a twenty degree (20°) cone of view) from a distance of up to (or greater than) approximately 400 m for some embodiments and up to (or greater than) approximately 1.5 kilometers (km) for other embodiments, depending on the luminescent intensity. For some embodiments, once the sealed balloon  200  begins to luminesce, it becomes detectable using drones, space-based assets (e.g., satellites), or other un-manned vehicles. 
     The sealed balloon  200  can be securely attached to an individual or, alternatively, the sealed balloon  200  can be securely attached to a life raft using, for example, a clip or other type of harness. For such embodiments, it should be appreciated that the sealed balloon  200  can include a tethering hole to which a tether is secured. Additionally, to prevent capsizing or overturning in turbulent waters, a weight or other know devices to keep the transparent top  240  facing upward (rather than facing toward the water). 
     In yet another embodiment, emissions from the luminescent materials can be collimated using a parabolic substrate. The parabolic geometry allows for more concentrated or focused emissions of light. The embodiment having a parabolic geometry is shown in greater detail with reference to  FIGS. 4A, 4B, 4C, and 4D  (collectively,  FIG. 4 ). 
       FIG. 4A  shows one embodiment of the apparatus  400  having a parabolic geometry (designated herein as a parabolic embodiment  400  for convenience). The parabolic embodiment  400  comprises a reflective substrate  410  with a substrate perimeter (shown in  FIG. 4A  as having a substrate geometry that is substantially square). When the parabolic embodiment  400  is deployed, the reflective substrate  410  forms a reflective parabolic surface or a reflective parabolic geometry with a focal point. 
     As shown in  FIG. 4A , the number of parabolic surfaces can be increased by sub-dividing the reflective substrate  410  (e.g., four (4) separate parabolic surfaces are shown in  FIG. 4A ). Unlike the sealed balloon  200  of  FIG. 2 , the parabolic embodiment  400  comprises activators  420   a ,  420   b ,  420   c ,  420   d  (collectively,  420 ) that are placed at the center of each sub-divided parabolic reflective surface  410 , with each activator  420  being operatively coupled to its respective liquid-releasable vessel  430   a ,  430   b ,  430   c ,  430   d  (collectively,  430 ), each of which contains illuminable dye. A transparent cover  440  is placed atop the reflective substrate  410 . Similar to the reflective substrate  410 , the transparent cover comprises a cover geometry (also shown as being substantially square in  FIG. 4A ) and a cover perimeter that corresponds substantially with the substrate perimeter. An air-tight seal  450  is formed to seal the substrate perimeter to the cover perimeter to create a sealed internal region. For some embodiments, an air-tight seal  450  also separates each of the parabolic reflector sub-divisions (as shown in  FIG. 4A ). 
     Continuing to  FIG. 4B , a cross section of the parabolic embodiment  400  (along the broken line B-B) prior to activation is shown. Unlike the sealed balloon  200  of  FIG. 2 , the parabolic embodiment  400  affixes the activators  420  to the transparent cover  440  (using, for example, an adhesive or tape or other appropriate means), rather than to the reflective substrate  410 . In other words, each activator  420  is located approximately at the focal point. The activators  420  are each located within its respective sealed internal region. Liquid-releasable vessels  430  (or liquid-releasable vessels) are each operatively coupled to its respective activator  420  (and, thus, also located within the corresponding sealed internal region). Unlike the sealed balloon  200 , which has a patterned array of activators  220  within the sealed area, each sealed internal region in the parabolic embodiment  400  comprises a single activator  420  that is located at the respective center of each of the sealed internal region. 
     Continuing,  FIG. 4C  shows the parabolic embodiment  400  (along B-B) upon deployment. As noted above, each liquid-releasable vessel  430  is operatively coupled to its respective activator  420 . Thus, upon opening of the liquid-releasable vessel  430 , the illuminable dye contained in each liquid-releasable vessel  430  is released and reacts promptly with its respective activator  420 . The reaction between the illuminable dye and the activator  420  releases a gas that inflates the parabolic embodiment  400 . Concurrent with the inflation, the combination of the activator  420  and the illuminable dye results in luminescence. 
     Turning to  FIG. 4D , which shows an enlarged view of one of the parabolic sub-divisions of  FIG. 4A , when the parabolic embodiment  400  is deployed, the luminescent combination of the activator  420  and the illuminable dye separates from the reflective substrate  410  approximately to a focal point. It should be appreciated that the precise location of the focal point is dependent on many factors, such as the geometric shape of the reflective substrate  410 , the geometric shape of the transparent cover  440 , the size of each parabolic sub-division, the degree to which each parabolic sub-division inflates, etc. However, how to position the activator  420  on the transparent cover  440  prior to deployment so that the activator  420  becomes affixed at the parabolic focal point after deployment is a determination that can be done readily by those having skill in the art and, thus, further discussion of the placement of the activator  420  is omitted herein. What is significant for  FIG. 4D  is that the focal point be located on or near the transparent cover  440 . 
     Continuing with  FIG. 4D , when the combination of the activator  420  with the illuminable dye luminesces approximately at the focal point, the emitted light  460   a  (whether visible or UV or otherwise) is reflected from the reflective substrate  410  and emerges as collimated light  460   b . The focused (and now collimated) light  460   b  has a greater concentrated intensity than the light from the sealed balloon  200 . Consequently, the parabolic embodiment  400  provides visibility from a greater distance than the sealed balloon  200 . 
     As shown in the embodiments of  FIGS. 1 through 6 , an individual is tethered to a deployable apparatus (through, for example, a tethering hole on the deployable apparatus). The deployable apparatus combines an illuminable dye with an activator, thereby increasing immensely the visibility of an individual in open water. The increased visibility facilitates maritime (or other open-water-based) search and rescue operations. 
     Although exemplary embodiments have been shown and described, it will be clear to those of ordinary skill in the art that a number of changes, modifications, or alterations to the disclosure as described may be made. For example, although an embodiment is shown in which the activator is located on the substrate and the illuminable dye is released from a liquid-releasable vessel, it should be appreciated that the illuminable dye can be located on the substrate, with the activator being released from the liquid-releasable vessel. Furthermore, although specific dimensions and chemical compositions are recited for clarity, it should be appreciated that the disclosed embodiments are not limited to only the recited dimensions or chemical compositions. Additionally, although the embodiments are described in the context of maritime search and rescue, those having skill in the art will understand that the increased visibility is beneficial in land-based operations or land-based environments. Also, those having skill in the art will appreciate that certain features of one embodiment can be implemented in other embodiments to realize advantages that are greater in combination than in isolation. All such changes, modifications, and alterations should therefore be seen as within the scope of the disclosure.