MEDICAL DEVICE

Abstract

The present invention relates to a medical device for treating, preventing or ameliorating an eye condition. The device comprises a cover, at least a portion of which comprises an antimicrobial agent and is at least partially filled with temperature control means. In use, the cover is arranged to contact a subject's eye and/or a surrounding area thereof, and the temperature control means is configured to modulate the temperature of the cover to thereby treat, prevent or ameliorate the eye condition.

Claims

1. A medical device for treating, preventing or ameliorating an eye condition, the device comprising a cover, at least a portion of which comprises an antimicrobial agent, comprising a silver salt and an oxide, and is at least partially filled with temperature control means, wherein, during use, the cover is arranged to contact a subject's eye and/or a surrounding area thereof, and wherein the temperature control means is configured to modulate the temperature of the cover to thereby treat, prevent or ameliorate the eye condition.

2. The medical device according to claim 1, wherein the antimicrobial agent is configured to contact a person's eye without causing damage or irritation thereto.

3. The medical device according to either claim 1, wherein the antimicrobial agent further comprises a cationic surfactant or a polymer.

4. (canceled)

5. (canceled)

6. The medical device according to claim 1, wherein the silver salt is selected from the group consisting of silver sulphate, silver nitrate, silver chloride, silver sodium zirconium hydrogen phosphate and silver sulfadiazine.

7. The medical device according to claim 1, wherein the oxide is selected from the group consisting of copper oxide, iron oxide, zinc oxide, titanium dioxide and silica dioxide.

8. The medical device according to claim 7, wherein the oxide is titanium dioxide.

9. The medical device according to claim 1, wherein an external surface of the first side of the cover comprises the antimicrobial agent.

10. The medical device according to claim 1, wherein an internal surface of the first side of the cover comprises the antimicrobial agent.

11. The medical device according to claim 1, wherein the concentration of the antimicrobial agent is at least 110.sup.11 mol/cm.sup.2, or at least 110.sup.10 mol/cm.sup.2, or at least 510.sup.10 mol/cm.sup.2, or at least 110.sup.9 mol/cm.sup.2, or at least 210.sup.9 mol/cm.sup.2, or at least 310.sup.9 mol/cm.sup.2.

12. The medical device according to claim 1, wherein a first side of the cover is made of a first material, which dissipates heat when the device is in use, at a greater rate than that of a second side of the cover made of a second material comprising a phase change material (PCM).

13. (canceled)

14. The medical device according to claim 12, wherein the second material comprises a fabric with a layer of the PCM disposed thereon.

15. The medical device according to claim 14, wherein the layer of the PCM is disposed on an internal surface of the fabric.

16. The medical device according to claim 12, wherein the PCM has a transition temperature between 30 and 70 C., or between 40 and 60 C., or between 42 and 47 C.

17. The medical device according to claim 1, wherein the device comprises a pouch disposed within the cover and at least partially filled with the temperature control means, wherein the cover is removable such that the pouch is removably disposed therein.

18. The medical device according to claim 1, wherein the temperature control means comprises grain, seed, tourmaline beads, silica beads or silica gel.

19. (canceled)

20. A method of manufacturing a medical device, the method comprising: contacting at least a portion of a cover with a solution comprising an antimicrobial agent, comprising a silver salt and an oxide; and allowing the cover to dry; wherein the cover is at least partially filled, or adapted to be at least partially filed, with temperature control means, and, in use, the cover is arranged to contact a subject's eye and/or a surrounding area thereof, and wherein the temperature control means is configured to modulate the temperature of the cover to thereby treat, prevent or ameliorate the eye condition.

21. The method according to claim 20, wherein allowing the cover to dry comprises heating the cover to between 30 C. and 150 C., or between 40 C. and 100 C., or between 50 C. and 80 C., or between 55 C. and 65 C. for a pre-determined time.

22. The method according to claim 21, wherein the pre-determined time is at least 5 minutes, or at least 30 or 60 minutes, or at least 1 hour 30 minutes.

23. A kit to make a medical device, the kit comprising: a device comprising a cover which is at least partially filled with temperature control means; and a solution comprising an antimicrobial agent, comprising a silver salt and an oxide, configured to be applied to the cover; wherein, in use, the cover is arranged to contact a subject's eye and/or a surrounding area thereof, and wherein the temperature control means is configured to modulate the temperature of the cover to thereby treat, prevent or ameliorate an eye condition.

24. (canceled)

25. The medical device according to claim 1, wherein a weight ratio of the silver salt to the oxide is between 5:1 and 1:20.

Description

[0079] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

[0080] FIG. 1 is a plan view from above of an outer cover of a medical device of the invention, which is used for treating eye conditions;

[0081] FIG. 2 is a plan view from below of the outer cover medical device shown in FIG. 1;

[0082] FIG. 3 is a plan view of an inner pouch of the medical device;

[0083] FIG. 4 shows the complete medical device in use, when worn by a patient; and

[0084] FIG. 5 is a plan view from above of an outer cover of a further medical device of the invention, which is used for treating eye conditions.

EXAMPLES

[0085] The inventors asked volunteers to wear prior art eye-masks. Testing of the eye-masks identified that bacteria was transferred to all of the eye masks tested, and in some instances mould was also transferred. The inventors have found that it is not possible to kill these microbes using a microwave.

[0086] The inventors work seeks to overcome this problem.

Example 1

The Medical Device

[0087] Referring to the Figures, there is shown a medical device 2, which consists of an outer cover 3 and an inner pouch 38 disposed therein. FIGS. 1 and 2 illustrate various views of the cover 3, FIG. 3 shows the pouch 38, and FIG. 4 shows the device 2 in position on a subject 32. In use, the device 2 is either heated by a conventional microwave, or cooled in a conventional fridge/freezer, and is effectively used to treat or even prevent a very wide range of eye conditions, such as styes and cysts, inflammation, dry eye disease, grittiness and irritation, itchy eyes (e.g. caused by hay fever), Meibomian Gland Dysfunction (MGD), chalazion, blepharitis and conjunctivitis, and so on, depending on whether heating or cooling of the eyes and the associated areas is desired. It will be appreciated however that this list of eye conditions is not exhaustive and that the device 2 can be used to treat or prevent any kind of eye pain or condition, or to soothe a headache, which may have been caused by eye strain. Use of the medical device 2 is the first step in eye/eyelid hygiene followed by the application of eyedrops etc to treat an eye condition. Effective use of the device 2 improves eye hygiene such that the chances of many eye conditions occurring are significantly reduced or prevented.

[0088] Referring first to FIG. 1, the back of the outer cover 3 of the device 2 is shown, and is composed of a single piece of material 4, for example soft cotton or silk. The rear piece of material 4 is generally light blue or white in colour, and so will not emit heat to the same extent as a black piece of material would. As described in more detail in example 3, below, the rear piece of material also comprises an antimicrobial agent.

[0089] Referring to FIG. 2, the front of the outer cover 3 of the device 2 is shown, and is composed of two pieces of material 6a, 6b, for example soft cotton or silk. In the embodiment illustrated, the two pieces of material 6a, 6b comprise a phase change material (PCM) which is configured to absorb, store and release heat. Suitable PCMs are sold under the trade mark Outlast and are described in a variety of patent applications, for instance see EP2558504, EP2501846, EP2264231 and EP2392712. The PCM helps to thermally regulate the temperature of the device 2, ensuring a roughly consistent temperature is delivered through the rear piece of material 4 for an extended period of time.

[0090] The perimeter of the front piece of material 4 is stitched to the two rear pieces of material 6a, 6b by a line of stitching 8, and rear pieces 6a, 6b are stitched to each other only at their peripheral edges, as shown in FIG. 2.

[0091] As can be seen in FIGS. 1 and 2, an adjustable comfort strap 14 is secured to each side of the cover 3. Each strap 14 is approximately 20 cm in length, and is stitched 16 to each side of the rear piece of material 4. As can be seen in FIG. 1, each end of the straps 14 distal from the stitching 16 is covered with an area of Velcro 18. In use, the subject 18 can easily adjust the tightness of the outer cover 3 around the head and over the eyes 36 by varying the combined length of the straps 14 via the respective positioning of the Velcro regions 18.

[0092] As shown in FIG. 4, the shape of the cover 3 is such that it fits comfortably around the subject's head and over their eyes 36. The cover 3 has a narrow central section 10 which is arranged, in use, to overlie the subject's nose 34, and two wide side sections 12 disposed either side of the central section 10, which are arranged, in use, to overlie the subject's eyes 36. The width of the central section 10 is about8 cm across and is therefore narrower than the width of each side section 12, which is about 10 cm across. The length of the entire cover 3 (excluding the straps 14) is approximately 25 cm across.

[0093] As shown in FIG. 2, the front piece of material 6a forming the outer cover 3 extends across about 75% of the width of the rear of the cover 3, and over a small section of the front piece of material 6b, thereby creating a small overlap. The pieces 6a, 6b are not stitched together at the overlap, and so an opening 20 is created, which leads to a pocket 21 that is disposed between the rear piece of material 4 and the two front pieces of material 6a, 6b. The opening 20 extends diagonally across the front surface 6 of the cover 3, generally along a side region 12 thereof. The opening 20 is suitably sized to enable the insertion of the inner pouch 38, which is shown in detail in FIG. 3, and described below.

[0094] Referring now to FIG. 3, the inner pouch 38 consists of two pieces of thin material, such as cotton, which are stitched together to create a flexible sack or bag. The material of the pouch 38 may also comprise an antimicrobial agent. The shape of the pouch 38 resembles that of the front 4 and rear 6 surfaces of the outer cover 3, although the dimensions are slightly less so that the pouch 38 can be easily removed and inserted though the opening 20 in the cover 3. Thus, as can be seen in the Figure, the pouch 38 has a narrow central region 24, which corresponds to the narrow central region 10 of the outer cover 3, and wider side regions 26, which correspond to the wider side regions 12 of the cover 3. Stitched to one of the side regions 26 of the pouch 38, there is provided a label 28 on which instructions 30 for use are clearly printed.

[0095] In a first embodiment of the device 2, the pouch 38 contains a plurality of microwaveable grains or seeds 40. For instance, the grains may be a special mix of natural seeds (e.g. 33.3% canary seed, 33.3% rapeseed, and 33.3% millet seed), which has been developed to ensure that the device 2 warms to the correct temperatures in the least amount of time, and then retains the heat for as long as possible, and at a comfortable level when worn by the subject 32. Other grains that may be used are flax seed or wheat, either alone or in combination with the other grains described herein. Alternatively, silica beads can also be used, and are described in more detail in WO 2015/011455 A1. This embodiment is used for microwaving and transferring heat to the subject 32, as will be described below.

[0096] The embodiment of the device 2 described above may also be used to apply a cooling effect to a subject's eyes. Alternatively, in a second embodiment of the device 2, where the subject's eyes 36 require a cooling effect, instead of being filled with microwaveable grains, seeds and/or beads 40, the pouch 38 contains a cooling gel or alternatively polymer cooling crystals, or the like (not shown). An example of a suitable cooling gel is available from Yangzhou Tianle Hot Water Bottle Factory (China). In use, when exposed to cold temperatures (i.e. from a conventional fridge or freezer), the gel cools down and retains the cool temperature. Suitable cooling crystals (available from N-rit co., ltd, #223-427, Seoknam2-Dong, Seo-gu, Incheon City, Korea 404-825), can also be used to cool down the device 2, but without the need for a freezer. To cool the device 2, it is first immersed in cold water for 3-5 minutes until the high-tech polymer crystals fully absorb the water and become activated. It may be desirable to also place the activated crystals in a fridge for 30 minutes for an even greater cooling effect. The crystals are made of a non-toxic crystal polymer, which becomes cold, and has a long-lasting cooling effect. The subject 32 can enjoy the soothing, cooling effect imparted by the crystals.

[0097] For clarity, FIG. 3 does not show a full complement of grains, seeds and/or beads 40 (or cooling gel/crystals); instead it shows, for illustrative purposes only, small groupings of grains 40 at various positions within the pouch 38. However, it should be appreciated that the pouch 38 contains enough grains, seeds and/or beads 40 (or cooling gel/crystals) to be fully dispersed throughout, such that the subject's eyes 36 and surrounding areas are fully covered when the device 2 is placed in the correct position. Conversely, the pouch 38 is not completely filled with grains, seeds and/or beads 40 (or cooling gel/ crystals) so that the subject 32 can easily move them around the inside the pouch 38 to avoid hot/cold spots. Also, the subject 32 is able to easily insert the pouch 38 through opening 20 into the pocket area 21. As a guide, the pouch 38 is filled to about 50-70% of its capacity with the grains, seeds and/or beads 40 (or cooling gel/crystals).

[0098] While not illustrated, it will be appreciated that in an alternative embodiment the grains, seeds and/or beads 40 (or cooling gel/crystals) may be disposed directly in the cover 3. Accordingly, in this embodiment, the device 2 would not comprise a pouch 38. Furthermore, the front of the cover 3 may comprise a single piece of fabric, such that the cover does not comprise an opening 20.

[0099] In use, the subject 32 must first remove the inner pouch 38 from the outer cover 3 by carefully pulling it out. The relatively sizes of the pouch 38 and cover 3 mean that it is not a very tight fit, and so there is no risk that the pouch would be ripped and lose its contents during the removal operation. The subject 32 then places the pouch 38 on a clean microwaveable plate, and heats it on full power (based on a 850-1000 Watt microwave) for approximately 30 seconds. Heating times should never be exceeded. The microwave energy is absorbed by the grains 40, which are therefore heated up to an elevated temperature of about 42-47 C. After heating, the pouch 38 is then inserted into the outer cover 3 through the opening 20 and then arranged such that it fits well within the pocket area 21, in an extended configuration therein, i.e. the positions of the central region 24 and side regions 26 of the pouch 38 correspond with the positions of the central region 10 and side regions 12 of the outer cover 3.

[0100] Alternatively, in the embodiment where the grains, seeds and/or beads 40 (or cooling gel/crystals) are disposed directly in the cover 3, the subject 32 may simply heat the cover 3 in the microwaveable.

[0101] In order to distribute the heat effectively, and to prevent any hot spots developing, the device 2 can be shaken during (e.g. about half-way) through the heating period, and again after heating, but before use. Once fully heated, the subject 32 then carefully checks the temperature of the grains 40 by touching the outer cover 3 (now containing the heated pouch 38) on to the inside of the wrist, before putting on the eyes 36. To avoid damage to the eyeball, the subject 32 must close the eyes 36 prior to gently resting the outer cover 3 of the device 2 in place, as illustrated in FIG. 4. The rear 4 of the outer cover 3 is contacted on the subject's eyes, and the front 6 is exposed to the air.

[0102] The straps 14 are then fastened together via the Velcro 18 forming a headband. The pressure that is applied by the device 2 to the subject's eyes 36 can be adjusted by tightening or loosening the straps 14 to suit personal comfort. The device 2 gently conforms and moulds to the contours of the eyes 36 and shape of the subject's face, and is left in position for 7 to 10 minutes, or longer if desired. Due to the two pieces of material 6a, 6b comprising the PCM, the inventors have found that the device is capable of maintaining the temperature between 42 C. and 47 C. in excess of ten minutes. The straps 14 provide tight support and even distribution of the grain 40 to the eyes and surrounding areas, thereby maximising pain relief.

[0103] After using the device 2, with the eyes closed, the subject 32 then gently massages the upper eyelid by smoothing a finger from the inner corner of the eye 36 to the outer corner just above the lashes. This procedure is then repeated just below the lashes on the lower lid. Debris should then be removed from the subject's eyes 36 and the surrounding area. The exercise should be repeated for about a minute on both eyes. The device can be used two or three times a day, but can be reduce to 2-3 times a week once the symptoms improve.

[0104] It is widely recognised and accepted that warmth eases pain and helps movement in muscles and joints, by increasing vasodilation and therefore blood flow to restricted areas. Accordingly, the device 2 is useful for treating a range of conditions, which would benefit from such soothing heat treatment. However, it is also possible to use the device 2 when it is cold, rather than warm (following microwaving). Applying the device 2 when cold reduces pain and swelling by causing blood vessels to vasoconstrict. It has also been demonstrated by hay fever sufferers that cooling the eyes 36, especially the corners thereof, results in a satisfying reduction in itchiness and irritation.

[0105] When wishing to cool the eyes 36, the pouch 38 is first removed from the outer cover, and then placed inside a receptacle, such as a clean plastic bag (not shown), and left in the fridge or freezer for at least an hour. The cooled pouch 38 is then inserted back into the outer cover 3, which is then gently placed over the eyes 36 and nose 34. The subject 32 then increases the pressure of the device 2 over the eyes via the straps 14, as described above, and allows the cool soothing effect to act. It is highly unlikely that the user would get ice burns from using the device 2 when chilled. However, for safety, it is preferred that the device 2 is not used for more than 10 minutes at any one time.

Example 2

Antimicrobial Properties

[0106] An antimicrobial solution comprising a biguanide polymer with a molecular weight between 13,000 and 23,000 as an antimicrobial agent was produced.

[0107] A trigger spray was used to apply the antimicrobial solution first to the internal surface of the back of the outer cover 3, then to the external surface of the outer cover 3. The devices 2 were then dried in a convection oven at 60 C. for 2 hours and were then allowed to cool to room temperature for 2 hours.

[0108] A solution comprising test species was prepared. The solution comprised:

TABLE-US-00001 Pseudomonas aeruginosa 8.3 10.sup.6 CFU/g Staphylococcus aureus 2.8 10.sup.6 CFU/g Candida albicans 3.8 10.sup.6 CFU/g Aspergillus brasiliensis 6.0 10.sup.5 CFU/g

[0109] The solution comprising the test species was then spread over the external surface of the outer cover 3. After 10 minutes the external surface of the outer cover 3 was swabbed to measure the recovery of live micro-organisms. The results are given in Table 1, below. The mass of active agent was calculated assuming that 30% of the added weight is the active agent. The concentration of the active agent was calculated assuming that the average molecular weight of the active agent was 18,000 and the surface area of the blind fold was 500 cm.sup.2 (250 cm.sup.2 for the internal surface and 250 cm.sup.2 for the external surface).

TABLE-US-00002 TABLE 1 Results of application of antimicrobial solution to the outer cover 3 of the device 2 Mass after Mass Mass drying for 2 Initial after 1st after 2nd hours at Sample mass/g spray/g spray/g 65 C./g 1 13.71 19.13 21.59 13.59 2 13.75 19.14 21.63 13.67 3 13.79 18.84 21.77 13.71 4 13.85 18.31 22.11 13.57 5 13.76 19.21 21.59 13.65 6 13.69 18.31 21.63 13.62 7 14.02 19.77 21.77 13.97 8 13.82 19.11 22.11 13.67 Number of colony Mass after Mass of forming cooling to active Concentration units/cm.sup.2 room Added agent of active agent detected temperature/ mass/ added to on cover/ on Sample g g cover/g mol/cm.sup.2 sample 1 13.8 0.09 0.027 3.00E09 0 2 13.84 0.09 0.027 3.00E09 0 3 13.89 0.1 0.03 3.33E09 0 4 13.95 0.1 0.03 3.33E09 0 5 13.88 0.12 0.036 4.00E09 0 6 13.79 0.1 0.03 3.33E09 0 7 14.14 0.12 0.036 4.00E09 0 8 13.95 0.13 0.039 4.33E09 0

[0110] It will be noted that the antimicrobial solution was effectively able to kill all of the test species.

Example 3

Toxicity Tests

[0111] An agar overlay test was designed to determine the cytotoxicity of the antimicrobial solution when applied to the outer cover 3.

[0112] Six well cell culture plates were seeded with a verified quantity of industry standard L-929 cells (ATCC CCL-1) and incubated at 371 C. with 51% CO2 until approximately 80% confluent. The agar overlay consisted of an equal mixture of 1% noble agar and 2Minimal Essential Media+10% bovine calf serum. Solid test articles were placed directly on the solidified agar overlay testing100 mm.sup.2 per test well. Positive and negative reference controls were included with each assay.

[0113] All tests were performed using three test wells per test article. After the addition of the test articles, the cell culture plates were incubated as described above for 24-26 hours. Following incubation, cells were evaluated microscopically using the evaluation criteria outline in table 2.

TABLE-US-00003 TABLE 2 Evaluation criteria to score cells Grade Description of Zone 0 No detectable zone around or under the test article 1 Some malformed or degenerate cells under the test article 2 Zone limited to area under the test article and less than 0.45 cm beyond the test article 3 Zone extends 0.45 to 1.0 cm beyond the test article. 4 Zone extends greater than 1 cm, beyond the test article

[0114] An antimicrobial solution comprising silver chloride and titanium dioxide, in a weight ratio of 1:4, as an antimicrobial agents was produced and applied to a cotton fabric. Similar, treated fabric may be obtained from Polygiene. The cotton fabric was used as the test sample. Polypropylene pellets were used as a negative control and latex natural rubber was used as a positive control.

[0115] The results from the agar overlay test are given in table 3.

TABLE-US-00004 TABLE 3 Results of agar overlay test Scores Article #1 #2 #3 Average Cotton treated with antimicrobial solution 1 1 1 1 Polypropylene pellets 0 0 0 0 Latex natural rubber 4 4 4 4

[0116] The United States Pharmacopeia & National Formulary (USP <87>) states that the test article meets the requirements if the reactivity grade is not greater than grade 2 or a mild reactivity. The ANSI/AAMI/ISO 10993-5 standard states that the achievement of a numerical grade greater than 2 is considered a cytotoxic effect.

[0117] As indicated above, the cotton treated with antimicrobial solution received a score of 1, and so is not deemed to be cytotoxic.

Example 4

Further Antimicrobial Tests

[0118] As explained in Example 3, an antimicrobial solution comprising silver chloride and titanium dioxide, in a weight ratio of 1:4, as an antimicrobial agents was produced and applied to a cotton fabric. A sample of the treated cotton fabric was washed equivalently to fifteen domestic cycles at 40 C. to determine if the treated fabric maintained its antimicrobial properties after washing.

[0119] An inoculum of Staphylococcus aureus prepared in 1:500 Nutrient Broth was prepared, and 0.2 ml samples of the inoculum were applied to replicate (3) samples of either the untreated fabric, the treated fabric or the treated and washed fabric. The number of colony forming units/cm.sup.2 was calculated at the time of inoculation and then 24 hours later. The results are shown below in Table 4.

TABLE-US-00005 TABLE 4 Antimicrobial activity of treated fabric Number of colony forming units/cm.sup.2 on sample Sample 0 hrs 24 hrs Treated fabric 9300 <6.25 Treated and washed fabric 9300 <6.25 Untreated fabric 9300 3600

[0120] The results show that the treated fabric has an antimicrobial effect reducing the bacteria to below the limit of detection over 24 hours. This equates to a >3.17 log kill of the bacteria over the 24 hours. The same effect was observed for the treated fabric which had been washed fifteen times, showing that the fabric retains its antimicrobial properties after washing.

[0121] Conversely, the untreated fabric only showed a 0.41 log kill of the bacteria over 24 hours.

Example 5

A Further Medical Device

[0122] A further medical device 100 is shown in FIG. 5. Like the medical device 2 discussed in Example 1, the medical device 100 consists of an outer cover 3 and an inner pouch 38 disposed therein. However, unlike the device 2 discussed in example 1, the outer cover 3 of the device 2 does not comprise an antimicrobial agent.

[0123] Instead, a disposable barrier 102 is provided to place over the back of the outer cover 3 before use. The disposable barrier 102 is sized and shaped to substantially correspond to the back of the outer cover 3. The disposable barrier 102 comprises a sterile cotton gauze 104 with an adhesive disposed on a first side 106 thereof, and a backing strip 107 disposed over the adhesive. The disposable barrier 102 is disposed in a sterile pouch (not shown) prior to use. Accordingly, when a user wishes to use the device 2, they may heat it as described in example 1. They can then remove the disposable barrier 102 from the pouch, remove the backing strip 108 and affix the disposable barrier 102 to the back of the outer cover 3 before placing the device against their eyes 36.

[0124] After use, the user can remove the disposable cover 102 from the outer cover 3 and dispose of it. Accordingly, the disposable cover 102 prevents microbes being transferred between the patient's eyes 36 and the outer cover 3.

CONCLUSIONS

[0125] Advantages of the device 2 reside in the antimicrobial agent being able to effectively kill bacteria and fungus, thereby preventing infection or reinfection of a subject's eyes. Furthermore, the PCM material thermally regulate the temperature of the device 2, ensuring a roughly consistent temperature is delivered to the eyes of the subject for an extended period of time.

[0126] Furthermore, the device 100 also prevents transfer of microbes between the patient's eyes 36 and the outer cover 3, also preventing infection or reinfection of a subject's eyes.