CUSTOMIZED SPLIT INSOLE FOR DIABETIC PATIENTS

Abstract

An inventive custom made split insole for use by diabetic patients, split into zones for normal and flat foot persons and five zones for high arch foot persons where these splits have projections which are hexagonal or oval in shape and have specific dimensions and specific spacing but are of uniform height and elasticity.

Claims

1. A custom made split foot insole, consisting of 6 zones for normal and flat foot persons and 5 zones for high arch foot persons, where the splits have projections, hexagonal or oval, of specific dimension and specific spacing but of uniform height; elasticity which varies from zone to zone.

2. An invention as in claim 1, where the zones 2 to 6 for normal and flat foot persons is placed on the first zone, which forms the bottom part of the split insole.

3. An invention as in claim 1, where the zones 2 to 5 for high arch foot persons, is placed on the first zone, which forms the bottom part of the split insole.

4. An invention as in claim 1, where the zones of split insole 2, 3, 4 and 6 for normal and flat foot persons are of uniform thickness of 4 mm and the first split insole is of uniform thickness 2 mm.

5. An invention as in claim 1, where the zones of split insole 2, 3 and 5 for high arch foot persons are of uniform thickness of 4 mm and the first split insole is of uniform thickness 2 mm.

6. An invention as in claim 1, where the projections in each split are of uniform height of 1 mm.

7. An invention as in claim 1, where the projections in zone 2 are of hexagonal pattern with distance between the hexagons perforation spacing 3 mm and angle 60 and their diameter in this zone is 2.5 mm.

8. An invention as in claim 1, where the spacing of the projections in zone 3 is located only in the middle of this zone. Around the projections there are horizontally placed oval projections of varying dimensions. This size and placement of these oval projections depends upon the peak pressure acting on the person's foot.

9. An invention as in claim 1, where the projections in split zone two are so made so that they come under the toes of the foot.

10. An invention as in claim 1, where the elasticity of the split insole in each zone, is directly proportional to the peak pressure applied at that point.

11. An invention as in claim 1, where there are two mounts of size (7 mm height, 8 mm length and 8 mm width) made on the surface of zone one, in such a manner that it can be inserted in the square socket in zone five, which is of appropriate size to take these mounts.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 is types of foot.

[0045] FIG. 2 is a split insole for normal foot and flat foot.

[0046] FIG. 3 is a split insole split into six different zones.

[0047] FIG. 4 is a split insole for high arch foot.

[0048] FIG. 5 is a pressure distribution on bare foot.

[0049] FIG. 6 is pressure distribution using custom insole.

[0050] FIG. 7 is pressure distribution of bare foot and custom split foot insole.

DESCRIPTION AND WORKING

[0051] The invention is a customized split insole for use by diabetic patients as in FIG. 2. The foot insole is made from VeroClear RGD810, TangoPlus FLX930 which is a resin. The specialty of this resin is that the shore hardness values can be modified there by changing the elasticity.

[0052] The human foot is classified into three types, namely, normal, flat and high arch foot depending on the arch in the middle inner side of the foot. This is depicted in FIG. 1. The split insole is separately designed in the form of a human foot, for all the said three types of human foot as in FIGS. 2 and 4. Further, the split insole is custom made for each person, so its size varies depending upon the foot size of the person who is to use it.

[0053] For a normal foot, the split insole is split into six different zones as in FIG. 3. Except the first zone, all the other zones have projections and varying elasticity levels. The shape of each projection is hexagonal and its diameter varies zone wise. However the height of the projections is 1 mm uniform in all the zones. Distance between the projections also varies zone wise. The fifth zone, is arched to fit in to the natural arch of the foot, there are two square mounts molded in zone one, as in FIG. 3.6, into which is fitted the fifth split. Each zone, experiences varied levels of both static and dymanic loads.

[0054] The first zone is the bottom zone of the foot insole which acts as a support structure to hold all the other five zones on its top surface, as in FIG. 3.1. This is of uniform thickness and elasticity.

[0055] The second zone is located at the head of the split insole, in the phalanges region of the foot, as in FIG. 3.2. The projections are so placed that they are below the person's toes. The projections are made of hexagonal pattern with distance between the hexagons perforation spacing 3 mm and angle 60 and their diameter in this zone is 2.5 mm. The thickness of the insole in this zone is 4 mm. The elasticity, which is the flexibility of the sole measured as the shore hardness value varies according to the requirement for this zone. Further, in this zone, depending on the persons pressure build up area, the elasticity is more if the pressure acting is more and vice versa. In this zone also primarily there is pressure distribution.

[0056] The third zone is located just below the second zone, in the metatarsal region of the foot, as in FIG. 3.3. The projections are located only in the middle of this zone. Around the projections there are horizontally placed oval projections of varying dimensions. This size and placement of these oval projections depends upon the peak pressure acting on the person's foot. In this zone also primarily there is pressure distribution.

[0057] The fourth zone is located just below the third with the fifth zone on its inner side, as in FIG. 3.4. The entire zone is filled with projection till the border of this zone. Height and diameter are even for all the projections, but vary from person to person.

[0058] The fifth zone is located on the inner curve of the foot, adjacent to the fourth zone, as in FIG. 3.5. It is curved according to the arch profile of the person's foot. Elasticity is same through out this zone. Projections are given for enhanced gripping and ventilation. The split in this zone has two square sockets in its bottom side, which are so made to fit into the square mounts in the first zone, as in FIG. 3.6.

[0059] The sixth zone is at the bottom of the foot insole in the heel region of the foot, and below the fourth zone, as in FIG. 3.7. This zone receives much more pressure from the person, than the other zones. The projections are evenly spaced and of diameter of hexagon is 3 mm, pattern layoutperforation spacing 4.5 mm and angle 60. Elasticity is high, because the pressure applied in this zone is much higher when compared to the other zones.

[0060] For a flat foot person, the split insole is split into six zones similar to the normal foot split insole as in FIG. 2. But here the height of the inner arch is comparatively lower than that in the normal arch, rest of its description is the same as that for a normal insole.

[0061] Similarly, for a high arch foot person, the split zone is split into five zones as in FIG. 4. Here the third and fifth zones of a split insole of a normal person are combined into one. Rest of the description and functionality is similar to the normal arch person.

[0062] Working:

[0063] The custom made split insole is inserted into the foot wear of the person or patient who is to use the same. He can start moving by wearing the footwear inserted with the custom made split insole. The split insole with the projections and elasticity offloads the pressure build up in certain areas to the other parts of the foot, avoiding concentrating of pressure at particular points of the foot which in due course lead to foot ulceration and in several cases to gangrene and amputation in the diabetic patients.

[0064] The distribution of peak pressure to the other parts of the foot is measured using the Plantar Pressure Measuring Device, which is a machine with a sensor pad used for pressure data collection for both static and dynamic situations. The peak pressure of the bare foot as measured by the Plantar Pressure Measuring Device is as shown in FIG. 5. The peak pressure distributed to the other parts of the foot when using the custom made split insole is as shown in FIG. 6.

Example

[0065] The distribution of peak pressure loads under bare foot and using the custom split foot insole is as illustrated in the following Table 1;

TABLE-US-00001 TABLE 1 Pressure distribution with bare foot and custom split foot insole Bare Foot Custom Insole Zone 2 3 4 5 6 2 3 4 5 6 Average 70 81 51 0 149 49 124 66 54 114 Pressure kPa Maximum 185 140 80 0 265 150 205 135 190 195 Pressure kPa Minimum 10 10 15 0 10 10 10 10 10 10 Pressure kPa Median 60 85 55 0 155 35 135 60 40 115 Mode 80 70 60 0 240 10 125 55 30 70 SD 48 33 16 0 78 39 56 26 37 55

[0066] A graphical representation of the comparison of FIG. 5 showing barefoot pressure with FIG. 6 showing the pressure distributed using the split foot insole is as shown in FIG. 7.

[0067] The pressure build up in the various areas of each zone of plantar surface is as in FIG. 5 and the pressure offload after using the inventive custom made split insole as in FIG. 6, indicated in various colours highlighting the pressure rating as depicted in Table 2 here under.

TABLE-US-00002 TABLE 2 Analysis of FIG. 5 S. No Colour Pressure Build up Pressure Rating 1 Pink 300 kPa and above Dangerously high 2 Red 220 kPa to 299 kPa Very high 3 Yellow 150 kPa to 219 kPa High 4 Green 100 kPa to 149 kPa Normal 5 Light blue 60 kPa to 99 kPa Moderate 6 Dark blue 30 kPa to 59 kPa Low 7 Black 10 kPa to 29 kPa Very low 8 White No

[0068] From the above Table 2 which is an analysis of FIG. 5 it can be seen that the areas highlighted in pink, red and yellow are more vulnerable to nerve and tissue damage and the chances of ulcer formation is very high. More is the area of pink colour, the chances of ulcer formation is highest and once formed ulcer would be very severe and chances of healing is very poor, which directly increases the chance of gangrene formation and amputation.

[0069] Therefore, pink and red colour is directly proportional to high risk ulcer formation, and poor healing and thereby leading to high possibility of gangrene formation. So the hexagonal and oval projections offload the pressure build up in the pink, red and yellow areas to the other normal, moderate or low pressure areas so as to offload the pressure build up in the said areas.

[0070] When a person is static wearing the custom made split insole, the peak pressure applied by his foot on the split insole would first be sensed in the fifth zone, then by the sixth zone, then by the third, second and fourth respectively, and then distributed to the entire foot, as shown in FIG. 6. The peak pressure is in zone 6 FIG. 5. The distributed peak pressure is in zone 3 shown in FIG. 6.

[0071] The application of peak pressure in the bare foot and its distribution in the split foot insole, is as shown in FIGS. 5 and 6 respectively. The numerically illustration of the same is as in Table 3 below;

TABLE-US-00003 TABLE 3 Zone wise pressure distribution Pressure Values Bare Foot Customized Insole kPa Pressure Zone Pressure Zone 300 and above 220-299 Zone 6 150-219 Zone 2 & 6 Zone 2, 3, 5 & 6 100-149 Zone 2, 3, & 6 Zone 2, 3, 5 & 6 60-99 Zone 2, 3, 4 & 6 Zone 2, 3, 4, 5 & 6 30-59 Zone 2, 3, 4 & 6 Zone 2, 4 & 5 10-29 Zone 2, 3, 4 & 6 Zone 2, 4 & 5 Contact Area sq.cm 135 158.5

[0072] The above Table 3 describes the pressure values in kPa, which is followed by zone wise pressure point distribution for both bare foot and during custom split insole application. From the above, it is evident that the custom split insole increases the surface area of contact between the foot and the insole, thereby leading to offloading of the peak pressure from few particular points in the feet to the entire feet, thereby reducing stress concentration to the soft foot tissue and the nerve at those particular points, which is the major cause for foot ulceration in diabetic patients, whose, foot is already affected by peripheral neuropathy and tissue damage, due to concentration of peak pressure at a few particular points in the foot.

Advantages of the Present Invention

[0073] 1. Replace-ability of the individual splits which are worn out is possible, rather than replacing the entire insole. This reduces cost of replacement and longer usage of the un-worn out splits. [0074] 2. Comfortability of use as the entire custom split insole is custom made, to the size of the user. [0075] 3. The deformation potential of VeroClear RGD810, TangoPlus FLX930 resin from which the split insoles are made is much less than the other insoles that are available for sports and other orthotic applications, so the life of these split insoles made from this resin is much more, when compared to that of others. [0076] 4. Inventory holding cost of raw material is drastically reduced, [0077] 5. Wastage of raw material is negligible in the present invention whereas it is quite high in conventional manufacturing processes. [0078] 6. Life of insole is high as only worn out parts need to be replaced and not the entire insole. [0079] 7. Effective distribution of plantar pressure is achieved.