Abstract:
A disposable device for monitoring exposure to ultraviolet radiation (UVR) over a single period of time and a cumulative period of time. The device includes a base upon which is applied a UVR sensitive material that irreversibly changes after exposure to UVR. A protective covering is applied over the UVR sensitive material and includes segments that are individually removable to reveal a portion of the UVR sensitive material thereunder. A UVR exposure scale and first and second keys are provided on the base. A first segment of the covering is removed and the base is placed in an appropriate location. After a period of time, the change in the UVR sensitive material is compared to the scale and first key to determine if the level of exposure is safe for that time period. The procedure may be repeated over a number of time periods with a new segment of the protective covering being removed for each time period. The cumulative UVR exposure is determined by comparing the change in the first time period&#39;s UVR sensitive material to the scale and a second key associated therewith.

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention generally relates to health products. More particularly, the invention relates to a monitoring device. Specifically, the invention relates to a device that aids in monitoring exposure to ultraviolet radiation (UVR) which includes a UVR sensitive material and a cover tape that are progressively removed to reveal the UVR sensitive material over a period of time. 
   2. Background Information 
   Over the past several decades, there has been a growing awareness of the dangers of overexposure of the skin to ultraviolet radiation from the sun. The climbing rates of skin cancers, awareness of problems with the ozone layer and media attention to these and other issues have made the general population more aware of the need to take preventive steps to protect their skin from potential damage. Some of these measures have included using specially manufactured UV blocking clothing, wearing of hats and sunglasses, and the application of sunblocks and sunscreens that contain protective chemicals. 
   All of these measures restrict the amount of UV radiation a person is exposed to. They do not, however, provide any real information about the actual quantity of UV radiation a person is receiving and whether or not that exposure level is safe. 
   There are several products available today that may be used to monitor a person&#39;s exposure to UVR. An example of such a device is found in U.S. Pat. No. 5,117,116 issued to Bannard et al, discloses a UV radiation detection device that is applied to the skin by way of an adhesive. The device comprises a housing having a UV sensitive material applied to an inner surface thereof. The top of the housing shields the UV sensitive material from direct exposure to UV radiation. When the UV sensitive material is exposed to indirect UV radiation that has been reflected off the individual&#39;s skin, the material irreversibly changes color. The color change is compared to a graduated scale to determine if the level of exposure is harmful. The device is designed for single day use and is disposable. One of the issues with this type of device is that attaching the device on the skin may leave a shaped area that has not been as exposed to the sun as the surrounding region. This leaves a less tanned shaped region on the body which some individuals find aesthetically displeasing. Furthermore, the device is intended as a single use device and consequently is of no assistance for monitoring cumulative exposure to UVR over a period of time. 
   Yet another device is disclosed in U.S. Pat. No. 6,132,681 issued to Faran et al. The device is contemplated to be in the form of a sticker or badge that is attachable to the individual or to their clothing, for example. The device is manufactured to indicate when a specific quantity of exposure has occurred, namely 1 MED. The patent defines a MED as “the radiant exposure of the UV radiation that produces a just noticeable erythema (i.e., sunburn) on previously unexposed skin.” (Clarification added by the applicant). The device includes photochromic compounds which irreversibly change their color after exposure to this 1 MED dose of UVR and once this irreversible change has occurred, the individual is supposed to get out of the sun and throw away the device. The device takes into account the fact that individuals have differently pigmented skin and a 1 MED dose of UVR for a fair skinned individual differs greatly from a 1 MED does for a darker skinned individual. Consequently a number of differently graduated devices would be made available and the individual will purchase the device most appropriate for their skin color. The device does not include a graduated scale that indicates a range of possible exposures to UV radiation—just a single color change when the full dose of radiation has been received. This device again may leave a less tanned region on the person&#39;s body and is only meant for single use and is therefore of little assistance in monitoring UVR exposure over several days. 
   Finally, Hovorka discloses in U.S. Pat. No. 6,060,321 a disposable UV dosimeter that has a test zone that changes color when exposed to UVR over a period of time. The test zone is surrounded by a color panel which includes at least three areas that indicate whether the individual has been exposed to a low, moderate or high dose of UVR. The user compares the test zone with the color panel to determine the level of UVR to which they have been exposed. 
   These and numerous other devices have been developed for determining the level of an individual&#39;s exposure to UVR. However, these devices have been designed for single day use. Most vacationers tend to go to sunny destinations for an average a length of about a week. The daily exposure to the human skin is cumulative over this length of time. Each day can have varying amounts of sun intensity and the user may or may not be exposing themselves to the sun each day or part of the day. 
   A number of other UV monitoring devices which include complex electronic circuits, display panels and the like, have been proposed for monitoring exposure to UVR over a period of time. These devices are not contemplated to be disposable, would typically be relatively expensive and may be prone to failure because of all their component parts. 
   Accurate monitoring of the sun&#39;s intensity on humans is problematic as humans are three-dimensional in nature. They therefore tend to have different parts of their body exposed to the sun at different times and at different rates. The angle of the sun to the monitoring device has a large effect on how much exposure the card will record. There are also two different types of possible users of UVR monitoring devices. A responsible adult will use the device to monitor their personal exposure and will likely place the device correctly for exposure to the sun. When they are in the sun, they will monitor the device throughout the period and decide if the exposure is excessive. The other type of user would be a person who is taken care of a group of children in a common area such as a park or swimming pool. Each of these applications requires a different device for monitoring UVR exposure. 
   It would be therefore be desirable to have a UV monitoring device that would last the duration of a typical vacation, i.e., one week, and which would provide both daily and weekly readings of UVR exposure. The daily reading is important so that the individual can ensure they are not being exposed to too much UVR from the sun in one single day. The weekly cumulative readings are important so as to monitor the total sun exposure received during a week&#39;s vacation. 
   SUMMARY OF THE INVENTION 
   The present invention comprises a disposable device for monitoring exposure to UVR (UVR) over a single period of time and a cumulative period of time and a method of monitoring UVR exposure. The device includes a base upon which is applied a UVR sensitive material that irreversibly changes after exposure to UVR. A protective covering is applied over the UVR sensitive material and includes tape segments that are individually removable to reveal a portion of the UVR sensitive material thereunder. A UVR exposure scale and key are provided on the base. A first segment of the covering is removed and the base is placed in an appropriate location. After a period of time, the change in the UVR sensitive material is compared to the scale and first part of the key to determine if the level of exposure is safe for that time period. The procedure may be repeated over a number of time periods with a new segment of the protective covering being removed for each time period. The cumulative UVR exposure is determined by comparing the change in the first time period&#39;s UVR sensitive material to the scale and a second part of the key. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred embodiments of the invention, illustrative of the best mode in which applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims. 
       FIG. 1  is a front view of an ultraviolet radiation monitoring device in accordance with the present invention shown in an unused state; 
       FIG. 1A  is a cross-sectional view of the ultraviolet radiation monitoring device taken through line  1 A- 1 A of  FIG. 1 ; 
       FIG. 1B  is a front perspective view of the monitoring device with the protective strip removed to show the UVR sensitive material and the adhesive bands that secure the protective strip to the device; 
       FIG. 2  is a front perspective view of the monitoring device of  FIG. 1 , with the protective strip for day 1 removed therefrom; 
       FIG. 3  is a rear view of the monitoring device of  FIG. 1  showing a first manner of securing the device to an appropriate surface; 
       FIG. 3A  is a rear view of the monitoring device showing an alternative manner of securing the device to an appropriate surface; 
       FIG. 3B  is a rear view of the monitoring device showing a second alternative manner of securing the device to an appropriate surface; 
       FIG. 4  is a rear perspective view of the monitoring device of  FIG. 3 ; 
       FIG. 5  is a perspective view of the monitoring device shown after a period of three days use; 
       FIG. 6  is a perspective view of the monitoring device shown after a period of six days use; 
       FIG. 7  is a front view of a second embodiment of an ultraviolet radiation monitoring device in accordance with the present invention shown in an unused stated; 
       FIG. 8  is a front perspective view of the monitoring device of  FIG. 7  with the protective strip for day 1 removed; 
       FIG. 9  is a perspective view of the monitoring device of  FIG. 7  being positioned for use on a user&#39;s wrist; and 
       FIG. 10  is a perspective view of the monitoring device of  FIG. 7  in use on a user&#39;s wrist. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1-6 , there is shown an ultraviolet radiation (UVR) monitoring device in accordance with the present invention, and generally indicated at  10 . Monitoring device  10  comprises a card  12  that is of the shape and size of a credit card so that it may be easily and conveniently carried in a wallet or purse. Card  12  has a front surface  12   a  and a rear surface  12   b.    
   In accordance with a specific feature of the present invention, a strip  14  of an ultraviolet sensitive material is secured to card  12  by an adhesive layer  21 . The ultraviolet sensitive material may be of any suitable type known in the art that will react to UVR and will change color accordingly. The type of UV sensitive material used in strip  14  preferably changes color cumulatively and irreversibly. Strip  14  preferably is of a fairly substantial length extending from proximate a first side edge  16  of card  12  to proximate a second side edge  18  thereof. 
   In accordance with another specific feature of the present invention, a cover tape  20  is applied over the UV sensitive strip  14  to initially entirely prevent strip  14  from being exposed to UVR. Cover tape  20  preferably is made from a single length of paper. Cover tape  20  is provided with a plurality of lines of perforations  22  that effectively divide strip  20  into a plurality of individual segments  24 , such as segments  24   a ,  24   b - 24   g . An adhesive  23  is applied to an inner surface of cover tape  20  in such a manner that each segment  24  of strip  20  is individually secured to card  12 . Segments  24  are also each provided with a tab  26  that enables it to be individually detached from strip  20  and removed from card  12 . Tab  26  does not have an adhesive applied to an inner surface thereof and is therefor easy to grasp. When one segment, such as segment  24   a  is detached from cover tape  20 , then segments  24   b - 24   g  remain fully secured to card  12  and prevent the portion of strip  14  disposed thereunder from being exposed to UVR. Segments  24  are also preferably marked with indicators  28  which identify the individual time segments represented by segments  24 . So, for example, segment  24   a  is marked with an indicator  28  which reads “Day 1”; segment  24   b  is marked with an indicator  28  which reads “Day 2”, and so on. Furthermore, card  12  preferably is also marked with indicators  30  that correspond to the indicators  28  on the individual segments. So, for example, the indicator  30  positioned on card  12  that is disposed underneath segment  24   a  is marked with an indicator  30  reading “1”; and the area under segment  24   b  is marked with the indicator  30  reading “2”. 
   In accordance with yet another feature of the present invention, card  12  is also provided with an exposure scale  32 . Scale  32  includes a plurality of permanently marked exposure indicators  34 , such as indicators  34   a ,  34   b  through  34   g . These indicators  34  are graduated to show increasing increments of UVR exposure. Indicator  34   a  is substantially clear showing little to no UVR exposure. Indicator  34   b  is hatched to show a smaller quantity of UVR exposure and finally indicator  34   g  is a solid color indicating maximum UVR exposure. Indicator scale  32  may be produced as a printed color scale that reflects the potential color changes that can occur in the ultraviolet sensitive strip  14  upon exposure to UVR. Alternatively, each individual indicator  34  of scale  32  may be produced using an ultraviolet sensitive material, such as the material used for strip  14 . These individual pieces of UV sensitive material are exposed to a predetermined amount of UVR so that the irreversible color change occurs and then the scale  32  is produced by mounting the changed pieces of UV sensitive material on card  12 . 
   Scale  32  is also provided with a first key  36  and a second key  38  for interpreting the level of exposure indicated by the single scale  32 . First key  36  includes a plurality of first characters which indicate the safety of a daily level of UVR. So, for instance character  36   a  represents a low or “Safe” daily UVR exposure level to UVR, character  36   b  represents a “Moderate” daily exposure level and character  36   c  represents a high or daily exposure level to UVR and thus is indicated by the word “Danger”. 
   Second key  38  is also used in conjunction with scale  32  and includes a second plurality of characters which represent cumulative exposure to UVR over a period of several days, and typically one week. So, for instance, character  38   a  represents a low or “Safe” cumulative weekly exposure level to UVR, character  38   b  represents a “Moderate” cumulative weekly exposure level and character  38   c , “Danger”, represents a high cumulative weekly exposure level. 
   Referring to  FIGS. 3 &amp; 4 , card  12  includes an adhesive layer  40  on back surface  12   b  thereof. Adhesive layer  40  is covered with a paper strip  42  that is similarly manufactured to cover  20  on front  12   a  of card  12 . Paper strip  42  includes a plurality of lines of perforations  44  that separate strip  42  into a plurality of individual sections  46 . Each section  46  includes a tab  48  that is not in contact with adhesive layer  40  and that therefore may be easily grasped to remove the relevant section  46 , such as  46   a , from back  12   b  of card  12 . 
   Referring to  FIGS. 1-6 , monitoring device  10  is used in the following manner. Device  10  is designed for monitoring an individual or group of individuals in an area where people are in the sun such as a group of children at a beach or pool party. The monitoring individual removes a first section  46   a  of the paper strip  42  from back surface  12   b  of card  12 . This exposes a first region  40   a  of adhesive layer  40 . Card  12  is then secured to an appropriate surface such as a beach umbrella, chair arm or any other convenient and properly exposed surface using adhesive region  40   a . The monitoring individual also removes the first segment  24   a  of cover tape  20  on front surface  12   a  of card  12 . This exposes a first region  14   a  of the UVR sensitive strip  14  on front surface  12   a . The monitoring individual will check card  12  periodically and will compare the color change in region  14   a  with the indicators  34  on graduated scale  32 . Region  14   a  represents the UVR exposure for the first day of that group or individual to the sun. Consequently, the monitoring individual will compare the color change in region  14   a  with the indicators  34  on scale  32 , in conjunction with the first characters of first key  36 , to determine whether the color change in region  14   a  is low, moderate or high. If the color change in region  14   a  is found to be low, the group can remain outdoors for a longer time period. If the color change in region  14   a  is found to be moderate, the group of children can be warned that their time outdoors is coming to an end. If the color change in region  14   a  is found to be high, then the monitoring individual knows it is time for the group to head indoors. 
   So, as shown in  FIG. 2 , the color change on day 1 as indicated by region  14   a , when compared with indicators  34  on scale  32 , most closely represents indicator  34   b . When reference is made to the first key  36 , it will be seen that indicator  34   b  falls within a zone between the “Safe” and “Moderate” first characters of key  36 . Consequently, the monitoring individual knows that they are still within a safe range of UVR exposure for that day but should make plans to go indoors shortly. 
   One will appreciate that while an individual may be exposed to a moderate amount of UVR in a single day, over the course of a period of several days that exposure is cumulative and may be higher than desired. It is another specific feature of the present invention to provide a means for measuring cumulative exposure to UVR over a period of several days, in this instance one week. This is accomplished by progressively removing segments  24  of the cover tape  20  to expose additional regions of the UVR strip  14  as illustrated in  FIGS. 2 ,  5  and  6 . It will be understood that the UVR sensitive material used in strip  14  is of a type that maintains the change in color that occurred over the first day and does not revert back to its original state if removed from exposure to sunlight overnight, for example. The UVR sensitive material, however, does continue to change color when exposed for an additional period of time, such as if card  12  is exposed to the sun on day 2. So, if the group of individuals from day 1 (as represented by card  12  of  FIG. 2 ) returns to the beach on day 2, the monitoring individual will remove section  46   b  ( FIG. 4 ) of paper strip  42  to expose a second region  40   b  of adhesive layer  40 . This second region  40   b , in conjunction with any adhesive properties remaining from first region  40   a , is used to secure card  12  to an appropriately positioned and exposed surface. The monitoring individual also removes second segment  24   b  of cover tape  20  to expose a second region  14   b  of UVR sensitive strip  14 . At this stage, both the first and second regions  14   a ,  14   b  of strip  14  are exposed to UVR. Although not illustrated in these figures, it will be understood that the color change in first region  14   a  indicates the cumulative exposure to UVR over both day 1 and day 2. The color change in second region  14   b  indicates the exposure to UVR for day 2 only. 
   Similarly, as represented by  FIG. 4 , when the group returns to play in the sun on day 3, the monitoring individual will remove section  46   c  of paper strip  42  to expose a third region of adhesive layer  40 . The third segment  24   c  of cover tape  20  is removed to expose a third region  14   c  of strip  14 . The color change in first region  14   a  indicates the cumulative exposure to UVR over day 1, day 2 and day 3. The color change in second region  14   b  represents the cumulative exposure to UVR for day 1 and day 2, and the color change in third region  14   c  indicates the UVR exposure for day 3 only. The monitoring individual will then compare the color change in region  14   c  with scale  32  and first characters of first key  36  to determine if the UVR exposure for day 3 is low, moderate or high. As illustrated in  FIG. 5 , the color change in  14   c  most closely resembles indicator  34   b . When indicator  34   b  is compared to first characters of first key  36 , the region falls between the “Safe” and “Moderate” zones. The monitoring individual therefore knows their exposure to UVR for that day, day 3, is not too high and is safe. The monitoring individual also compares first region  14   a  with scale  32  and second characters of second key  38 . It will be seen that region  14   a  most closely resembles indicator  34   d  and when this indicator  34   d  compared with second key  38  it falls in the range of the “Moderate” second character. The monitoring individual therefore knows that their weekly exposure is satisfactory and they can safely continue to be in the sun over the next few days. 
     FIG. 6  represents the monitoring device  10  after six days exposure to the sun. The color change in region  14   a  represents the cumulative exposure to UVR over days 1 to 6, and the color change in region  14   f  represents the exposure to UVR on day 6 only. When region  14   f  is compared with scale  32  and first characters of first key  36 , it will be seen that the region  14   f  most closely resembles region  34   b . Using the daily first key  36 , the monitoring individual will see that their exposure for day 6 is between “Safe” and “Moderate”. Region  14   a  is then compared to scale  32  and second characters of second key  38 . Region  14   a  most closely resembles indicator  34   g  of scale  32 . When indicator  34   g  is compared with second key  38 , it will be seen that the region is in the “Danger” zone. Consequently, the monitoring individual is able to determine that too much exposure to UVR has occurred over the six day period and that the group or individual should not go out into the sun on the seventh day of that week. 
   Once all of the segments  24   a - 24   g  of cover tape  20  have been removed or maximum exposure to UVR as indicated by card  12  has been reached, card  12  may be disposed of. If the vacation extends for a period longer than one week, a second card can be utilized for monitoring exposure to UVR for the second week. The monitoring individual can retain the first card  12  and use both cards for the second week so that the first exposed section  14   a  of strip  14  continues to monitor total UVR exposure over the entire vacation. If the maximum recorded level of UVR exposure on scale  32  is reached prior to the end of the vacation, the monitoring individual would be advised to take steps to avoid outdoor activities for the remainder of the vacation. 
     FIGS. 7-10  show a second embodiment of a monitoring device in accordance with the present invention and generally indicated at  110 . Monitoring device  110  comprises a snap bracelet  112  that is designed to be snap-fittingly engaged around the wrist  113  of an individual. Snap bracelet  112  is made from a narrow thin piece of spring steel and is coiled during manufacture so that it has a memory. During manufacture, a small radius is formed across the bracelet&#39;s width that can keep the strip from coiling until the radius is compromised (i.e., flattened) and allows the curling to start around the individual&#39;s wrist. Bracelet  112  is also easy to remove if the individual is going to take part in an activity and can be left wrapped around the arm of a beach chair to keep its exposure correct. It is easily placed around the wrist once again when the individual is finished with their activity. 
   Bracelet  112  includes a strip  114  of an adhesive-backed ultraviolet sensitive material that is applied to a central region of bracelet  112 . A cover tape  120  is applied over the UV sensitive strip  114  and is provided with a plurality of lines of perforations  122  that effectively divide strip  120  into a plurality of individual segments  124 , such as segments  124   a ,  124   b - 124   g . As with the previous embodiment, an adhesive is applied to an inner surface of cover tape  120  in such a manner that each segment  124  is individually secured to bracelet  112 . Segments  124  are also each provided with a non-adhesive tab  126  that enables it to be individually detached from strip  120 . and removed from card  12 . Segments  124  are also preferably marked with indicators  128  which identify the individual time periods represented by segments  124 . Bracelet  112  preferably is also marked with indicators  130  that correspond to the indicators  128  on the individual segments. As with the previous embodiment, bracelet  112  is also provided with a graduated exposure scale  132  that includes individual indicators  134  that indicate a color change commensurate with the differing levels of UVR exposure. A first set of characters  136  represent daily exposure levels and a second set of characters  138  represent cumulative exposure levels. 
   The monitoring device  112  is used in essentially the same manner as card  12 , except that the monitoring individual snap fits bracelet  112  onto their wrist  113  ( FIGS. 9 and 10 ). The individual also needs to take care that adhesive strip  114  continually faces the sun, so the bracelet&#39;s orientation on the wrist  113  may need to be adjusted a number of times during outdoor activities to correct its orientation. Once again, segments  124  of cover tape  120  are progressively removed over the course of a week and the exposure level indicated by the first section  114   a  is used to determine cumulative exposure to UVR using second characters  138  and scale  132 . 
   It will be understood that while the UVR sensitive material  14  has been shown in the attached figures as a strip of material, the UVR sensitive material may be applied to either card  12  or bracelet  112  as discrete dots or other shaped members, without departing from the spirit of the present invention. Similarly, the perforated segments  24 ,  124  of strip  20 ,  120  may be discrete and separate paper cover segments that are not attached to each other and are individually applied over discrete pieces of UVR sensitive materials, without departing from the spirit of the present invention. It will further be understood that instead of a single continuous strip  14  of UVR material being applied to card  12 , a first substantially continuous strip may be applied in a first region of card  12  or bracelet  112  for tracking exposure on a daily basis in the same manner shown in  FIG. 1 . However, a second and separate strip of UVR sensitive material may be applied in a different region of card  12  or bracelet  112 , such as adjacent the high exposure end of scale  32  to make it easier to determine if the individual has been exposed to maximum level of UVR indicated on the scale. 
   Furthermore, card  12  may be otherwise attached to a surface, such as by a lanyard  50  ( FIG. 3A ) received through an aperture  52  in card  12  or by a magnetic strip  54  ( FIG. 3B ) applied to back surface  12   b  thereof. 
   It will further be understood that the card  12  and bracelet  112  are merely representations of a possible medium or base upon which the UVR sensitive strip  14  and related components may be applied. Any other suitable base or medium, such as a container for sunscreen, can be used without departing from the spirit of the present invention. 
   It will also be understood that the UVR sensitive strip  114  used in this monitoring device  10  may be of any type, including UVR sensitive materials that can have sunscreen applied over them and materials that are manufactured to record UVR exposure for different skin tones. 
   It will further be understood that each of the characters  28  marked upon segments  24  represents a period of time, that time period may be one hour, several hours, a day or any other predetermined period. The characters marked across all of the segments  24  of tape  20  represent incremental increases in a period of time over which the device  10  is designed to be used. 
   In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
   Moreover, the description and illustration of the invention are an example and the invention is not limited to the exact details shown or described.