Title of Invention

A NOVEL DIABETIC FOOTWEAR FOR HEALING OF FOOT SOLE ULCERS

Abstract This invention relates to novel footwear for healing diabetic foot sole ulcers The new footwear, namely, sandals and shoes used for healing of foot sole ulcers are designed based on important engineering principle of unloading the foot sole. The design geometry of the insole and outer sole, heel insert or flat bottomed rocker with extended shoulders and their axis of fixation on the outer sole of the new footwear, ( sandals and shoes) used for healing of foot sole ulcers , hardness, density and the selection of type of materials to be used for the above components of the new footwear, are determined by three dimensional finite element stress analysis of foot-footwear composite models, which give the least foot sole stresses, thus helping in very fast healing of even long duration non-healing foot sole ulcers in any part of foot sole of diabetic patients. Some of the footwear of the present invention for healing of foot sole ulcers in the heel and mid-foot region of the foot sole are new and unique (since such footwear does not exist anywhere in the world); the other new footwear for healing of foot sole ulcers in the fore-foot, are more efficient in faster healing, more comfortable, durable, lighter, and much cheaper, than the existing footwear.
Full Text

A Novel Diabetic Footwear for Healing of Foot Sole Ulcers
Field of Invention
This invention in general relates to the Biomedical Engineering field. In particular this invention relates to an unique category of footwear, for those who have already foot sole ulcers in different parts of the foot sole, to be used by them for faster healing of foot sole ulcers and thereby prevent amputation of foot.
Prior Art
Diabetes mellitus is increasing globally. Foot ulceration is a common sequel to diabetes mellitus. Foot ulceration in the diabetic patient is the most common single precursor to amputation having been identified in 85% of lower extremity amputations. Foot sole ulcers occur in feet that are either insensate or ischemic or both or subject to high foot pressures. Therefore, it becomes important to prevent high pressures in the early stage itself by providing appropriate footwear to the diabetic subjects to reduce the foot pressure thus prevent ulcers and be suitable to be worn by them depending upon their work requirement and weather conditions. There are some diabetic subjects (with complete loss of foot sole sensation) having already foot sole ulcers in different parts of the foot sole, which do not heal for a long time due to high foot pressures. These diabetic subjects have to be given appropriate foot wear to reduce the foot sole pressures to heal the ulcers quickly and be suitable to be worn by them depending upon their work requirement and weather conditions.
The footwear for healing of foot sole ulcers, of diabetic subjects offered in the westem world, is a shoe for healing of ulcers in the fore foot (metatarsal and toe) regions, is shown in Figure 1 (Dahmen et al 2001, Diabetic Care, Vol. 24, 705-709). This is a shoe with a hard outer sole (1), medium hard thin insole and a slightly thicker insole in the medial arch region to have contact with the foot sole (2), leather upper with lace (3) and a hard triangular projection (4) fitted to the bottom front portion of the outer sole. This design is not based on stress analysis of the foot sole, but based only on experience and trial and error method of design. This design is not efficient and therefore reduces the foot pressure inside the shoe to a small extent and the it takes 4 to 6 months time to heal the foot sole ulcers (Chentlelau et al 1993, Diabetic Medicine, Vol. 10, 267- 270, Sinacore et al 1996, Phys. Ther,, Vol. 76, 296- 301, Armstrong et al, 1998, J. Rehab. Research & Dev., Vol. 35,1-5, Patil et al 2002, International Journal of Lower Extremity Wounds, Vol.1,93-103).
There is no footwear (sandals or shoes) available in the Indian market for healing of foot sole ulcers.

The Limitations of Prior Art
Limitations of Existing Footwear for Healing of Foot Sole Ulcers:
1. Foot wear both in India or in the western world is not designed by stress analysis of foot-footwear composite model for minimizing the foot sole stresses which are necessary to unload the foot sole and reduce the foot sole pressure. Therefore, the thickness, hardness, type of material and its density vised for the footwear insole and outer sole are not appropriate to reduce the diabetic foot sole pressures to the required extent and thus, to heal the foot sole ulcers in diabetic foot
2. The footwear insole is very thin less than appropriate for reduction of foot sole stresses.
3. The existing footwear available m the Indian market (sandal type) for relief of pressure with thin micro-cellular plastic insole (MCP) absorbs water, not suitable for wash and wear, has low durability.
4. The footwear insole is not of appropriate thickness and harder than required hardness and therefore not able to reduce foot sole pressure to the required level and thus inefficient in healing of foot sole ulcers and it is also heavy.
5. The footwear outer sole is thicker and made of material harder than required hardness and therefore is not able to reduce foot sole stresses below necessary level to heal foot sole ulcers.
6. The footwear is heavier than required and therefore uncomfortable.
7. There is no soft inner lining attached to the straps of the sandal or to the inner part of shoe upper and thus it gives rise to high frictional forces between the footwear upper and the foot upper part which results in ulcers in diabetic subjects with complete loss of foot sole sensation.
8. In diabetic patients with complete loss of foot sole sensation, it is essential to constrain the foot within the footwear to avoid injury to foot by hitting against outside objects. Both the sandals available in the Indian market are not able to take care of this aspect.
9. The existing footwear is very costly cannot be afforded by most of the diabetic patients.
10. There is no footwear available in the Indian market for healing of foot sole ulcers.
11. One model of the shoe available in the westem world is meant for healing of foot sole ulcers in the fore foot areas only and that design is not efficient since it is not designed by the stress analysis of the foot-shoe composite model. Therefore, it is not able to unload and reduce the foot sole stresses around the ulcer region to the required extent and thus it takes considerable time (4 to 6 months) for healing of ulcers.
12. There are no footwear (sandals or shoes) available in India or in the westem world for healing of foot sole ulcers in the heel as well as the in the mid-foot region of the diabetic foot.
Because of the limitations listed above, it has become very essential and urgent to develop appropriate footwear (sandals to be used in southem India for tropical weather and shoes for use in cold weather or as per the need of the profession) for use by the diabetic patients for healing of foot sole ulcers in all parts of the foot sole area.

This invention "A Novel Diabetic Footwear for Healing of Foot Sole Ulcers" has many improvements as compared to earlier used footwear.
1. The new footwear (different designs of sandals and shoes) for diabetic subjects are unique, have new features and many improvements are made as compared to the existing devices. They are designed based on engineering principles of unloading the foot sole to reduce the foot sole stresses or pressures to prevent the foot sole ulcers or healing them (if they already exist) quickly. This is done by stress analysis of three dimensional foot-footwear composite model by using finite element method so as to select dimensions of footwear such as thickness, hardness and materials of footwear insole, outer sole and rocker bottom and its location (wherever it is lised) to minimize the foot sole stresses appropriately for prevention and healing of foot sole ulcers, in all regions of the foot sole, within a short time (within 3 to 4 weeks time).
2. The new footwear is able to constrain the diabetic foot within the footwear by appropriate adjustable straps to prevent external injuries,
3. It is able to take care of any swelling in the diabetic foot and also have an appropriate grip on the foot by adjustable straps provided with buckle and Velcro straps.
4. The straps in the footwear or shoe uppers are provided with soft inner linings to avoid or minimize friction between foot and footwear, thus prevent foot ulcers.
5. The new footwear for healing of diabetic foot sole ulcers is provided with novel aesthetic design of rocker with its axis appropriately located in different parts of the outer sole to reduce the foot sole stresses in the ulcer and other regions to speed up the process of healing,
6. The new footwear is light, comfortable and will be made available at low cost (3 to 10 times less than the commercially available footwear depending upon the type of footwear used by the diabetic patients).
7. The new footwear will be made available in all foot sizes, for ladies and men and in 3 colours, depending on the choice of the diabetic subject.
8. The insoles and outer soles of the new footwear are of appropriate thickness, hardness and weight to minimize foot sole stress or pressure (about 3 times less than the commercially available footwear).
9. The new footwear is comfortable, can heal foot sole ulcers in all regions of the foot sole in 3 - 4 weeks time which is 5 - 6 times faster than the healing time needed for footwear available in the westem world.
10. The new footwear (sandal as well as shoe type) has insole made of micro-cellular rubber (MCR) of appropriate quality, hardness, thickness, and washable insole which does not absorb water, and has high durability.
It is to be noted that the prior art description gives in detail information of the technology, method, process and system known in the prior art. It explains the deficiency in the related art and the object of the invention being to overcome or surmount the problem associated with the prior art. This forms the essential feature and object of the invention.

SUMMARY OF INVENTION
The inventors have made great effort to provide new footwear which meet the requirements of the diabetic patients and also the industry and to overcome the problems associated in the prior art.
To achieve the above object according to first aspect and feature of the present mvention there is provided with different types of footwear healing of foot sole ulcers to improve, efficiency.
According to second aspect and feature of the invention in addition to first feature the invention comprises footwear which is unique, light weight, comfortable, more efficient in faster healing of ulcers and economical than existing footwear.
At the outset of the description which follows, it is to be understood that ensuing description only illustrate particular forms of this invention. However, such particular forms are only an exemplary embodiment without intending to imply any limitation on the scope of this invention. Accordingly, the description is to be understood as an exemplary embodiment and reading of the invention is not intended to be taken restrictively.
The above and other objects features will be clear from the following description of preferred embodiment taken in conjunction with accompanying drawings.
The foregoing description is outlined rather broadly preferred and alternative feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis of for manufacturing by way of and modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should realize such equivalent conception do not depart fi-om the spirit and scope of the invention in its broadest form.
The present invention pertains to new footwear for use by diabetic subjects, for healing of foot sole ulcers. Again, there are two types of footwear m each category, namely sandals and shoes. The sandals are meant to be used in tropical weather and to suit habits of the diabetic population. The shoes are to be used in mostly colder weather and to suit the habits and professional requirements of the diabetic subjects.
The new footwear, namely, sandals and shoes used for prevention and healing of foot sole ulcers are designed based on engineering principle of unloading the foot sole. The design geometry of the footwear (insole, outer sole, rocker bottom attached to outer sole for healing footwear), material hardness, density and material to be used are determined by three dimensional finite element stress analysis of foot-footwear composite model, which gives the least normal and shear stresses at the foot sole, thus preventing foot sole ulcers as well as healing of ulcers in any part of the foot sole and healing 5 to 6 times faster than by existing footwear xised by diabetic patients.

statement of invention:
1. A novel diabetic footwear for healing of foot sole ulcer(s) comprising
a) an outer sole having the Shore hardness between 35 degree and 70 degree,
b) an inner sole having the Shore hardness between 10 degree and 30 degree,
c) a flat bottom rocker, preferably made out of the material used for the
preparation of the outer sole.
1. The new sandal , for healing of diabetic foot sole ulcer in the heel region
shown in Fig. 2, is the modification of new type of sandal shown in Fig. 4 (used for prevention of foot sole ulcers) by adding a heel insert of appropriate thickness, shape and hardness, between the inner sole and outer sole to unload the heel region and thus to reduce the stresses in the heel region as well as in all other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men,
2. The new sandal, for healing of diabetic foot sole ulcer in the mid-foot region
of the foot sole shown in Fig. 3, is the modification of new type of sandal shown in Fig. 4 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the heel region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to unload the mid-foot region by reducing the foot sole stresses in the mid-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men,
3. The new sandal, for healing of diabetic foot sole ulcers in the fore-foot region (metatarsals and toes) of the foot sole shown in Fig. 4, is the modification of of new type of sandal shown in Fig. 4 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the mid-foot region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to unload the fore-foot region by reducing the foot sole stresses in the fore-foot ulcer regions as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men,
4. The new shoe, for healing of diabetic foot sole ulcer in the heel region of
shown in Fig, 5, is the modification of new type of shoe shown in Fig. 5 (used for prevention of foot sole ulcers) by adding a heel insert of appropriate thickness, shape and hardness, between the inner sole and outer sole to unload the heel region and thus to reduce the stresses in the heel region as well as in all other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men,
5. The new shoe, for healing of diabetic foot sole ulcer in the mid-foot region of
the foot sole shown in Fig. 6, is the modification of new type of shoe shown in Fig, 5
(used for prevention of foot sole ulcers) by adding an aesthetically designed flat
bottom rocker of appropriate material and hardness, of appropriate thickness and
width and with appropriate dimension shoulders on both sides; the axis of the rocker

being placed in the heel region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to unload the mid-foot region by reducing the foot sole stresses in the mid-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men,
6. The new shoe, for healing of diabetic foot sole ulcer in the fore-foot region of the foot sole (metatarsals and toes) shown in Fig. 7, is the modification of of new type of shoe shown in Fig. 5 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the mid-foot region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to unload the fore-foot region by reducing the foot sole stresses in the fore-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings are intended to provide further understanding of the invention and is incorporated in and constitute a part of the invention. The drawings illustrate an embodiment of invention and together with the description illustrate principle of invention.
The drawings should not be taken as implying any necessary limitation on the essential scope of invention.
The drawings are given by way of non-limitative example to explain the nature of the invention.
For more complete understanding of the instant invention reference is now made to the following description taken in conjunction with accompanying drawings.
The various features of novelty which characterize the invention are pointed out specifically in the claims which forms part of the description. For a better understanding of the invention, its operatmg advantage, specific objects obtained by its use, reference should be made to the dmwings and descriptive matter in which these are illustrated and described as preferred embodiments of invention.
Referring now to drawings, where like numerals designate identical or corresponding parts throughout the referred views.
Figure 1 of the drawings shows prior art shoe for healing of ulcers only in the forefoot region (available in the western market only)
Figure 2 of the drawings shows new type of sandal for healing of ulcers in the heel region with modification made on new type of sandal, used for prevention of ulcers

Figure 3 of the drawings shows new type of sandal for healing of ulcers in the midfoot region with modification made on new type of sandal, used for prevention of
ulcers
Figure 4 of the drawings shows new type of sandal for healing of ulcers in the forefoot region with modification made on new type of sandal, used for prevention of ulcers
Figure 5 of the drawings shows new type of shoe for healing of ulcers in the heel region with modification made on new type of shoe, used for prevention of ulcers
Figure 6 of the drawings shows new type of shoe for healing of ulcers in the mid-foot region with modification made on new type of shoe, used for prevention of ulcers
Figure 7 of the drawings shows new type of shoe for healing of ulcers in the fore-foot region with modification made on new type of shoe, used for prevention of ulcers.
Figure 1 of the drawings shows prior art shoe (available in the west; to be made individually) with a hard outer sole (1), medium hard thin insole and a slightly thicker insole in the medial arch region (2), leather upper with lace (3), and a hard triangular projection (4) fitted to the bottom front portion of the outer sole, to be used by diabetic patients for healing of foot sole ulcers in the fore-foot region only, according to prior art.
Figure 2 of the drawings shows new type of sandal with modification made on new type of sandal shown in Fig. 5 (used for prevention of foot sole ulcers) by adding a heel insert (8) of appropriate thickness, shape and hardness, between the inner sole and outer sole to imload the heel region and thus to reduce the stresses in the heel region as well as in all other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the heel region, according to the present invention.
Figure 3 of the drawings shows new type of sandal with modification made on new type of sandal shown in Fig. 4 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker (8) of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the heel region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to imload the mid-foot region by reducing the foot sole stresses in the mid-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the mid-foot region , according to the present invention.
Figure 4 of the drawings shows new type of sandal with modification made on new type of sandal shown in Fig. 4 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker (8) of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both

sides; the axis of the rocker being placed in the mid-foot region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to unload the fore-foot region by reducing the foot sole stresses in the fore-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the fore-foot region (metatarsals and toes) , according to the present invention,
Figure 5 of the drawings shows new type of shoe with modification made on new type of shoe shown in Fig. 5 (used for prevention of foot sole ulcers) by adding a heel insert (4) of appropriate thickness, shape and hardness, between the inner sole and outer sole to imload the heel region and thus to reduce the stresses in the heel region as well as in all other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the heel region, according to the present invention,
Figure 6 of the drawings shows new type of shoe with modification made on new type of shoe shown in Fig. 5 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker (4) of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the heel region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to imload the mid-foot region by reducing the foot sole stresses in the mid-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the mid-foot region of the foot sole, according to the present invention,
Figure 7 of the drawings shows new type of shoe vnih modification made on new type of shoe shown in Fig. 5 (used for prevention of foot sole ulcers) by adding an aesthetically designed flat bottom rocker (4) of appropriate material and hardness, of appropriate thickness and width and with appropriate dimension shoulders on both sides; the axis of the rocker being placed in the mid-foot region of the outer sole at an appropriate distance ( a percentage of the foot length) from the back of the heel to imload the fore-foot region by reducing the foot sole stresses in the fore-foot ulcer region as well as other regions of the foot sole, available in appropriate colours, sizes for ladies as well as for men, for the use of healing of diabetic foot sole ulcer in the fore-foot region of the foot sole (metatarsals and toes), according to the present invention.






The inventions have been explained in relation to specific embodiment. It is inferred that the foregoing description is only illustrative of the present inventions and the it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modifications of the present inventions which come within the scope of the following claims are to which the present inventions are readily susceptible without departing from the spirit of the invention.
The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.
The applicants have made another application for patent being a co-pending application in respect of invention relating to a novel diabetic footwear for prevention of foot sole ulcers.





We claim
1) A novel diabetic footwear for healing of foot sole ulcer(s) comprising of,
a) An outer sole having the Shore hardness between 35 degree and 70 degree.
b) An inner sole having the Shore hardness between 10 degree and 30 degree.
c) A flat bottom rocker, preferably made out of the material used for the preparation of the outer sole.

2) The novel footwear as claimed in claim 1 wherein the flat bottom rocker protrudes from the outer sole.
3) The novel diabetic footwear as claimed in preceding claims wherein

a) The most preferable design of the flat bottom rocker is a flattened base having inclined sides.
b) The length of the flattened base is equal to the width of the footwear at a position decided to have the said flat bottom rocker.
c) The total width of the flat bottom rocker is equal to the width of the flattened base of the flat bottom rocker plus at least one and half of the width of the said flattened base on either side.
d) The position of the flat bottom rocker is variable.

4) The novel footwear as claimed in the preceding claims wherein the shape, thickness, hardness of the flat bottom rocker is decided on the position of ulcer(s) on the foot sole.
5) The novel footwear as claimed in any of the preceding claims 1 to 3 wherein the distance between the edge of the heel and the axis of the flat bottom rocker is placed as a function of the percentage of the footwear length.
6) The novel footwear as claimed in any of the preceding claims wherein the position of the rocker is placed, depending on the area of the ulcer in the foot sole. Wherein the Healing footwear is of three types namely Heel raise rocker for the ulcers in Heel region, Hind foot rocker for the ulcers in Mid foot region and Mid foot rocker for the ulcers in Fore foot region respectively.
7) The novel footwear as claimed in claim 1 is a sandal or a shoe.
8) The novel footwear as claimed in any of the preceding claims wherein the said footwear has conventional gripping means.
9) The novel footwear as claimed in any of the preceding claims wherein the inner sole and outer sole are optionally adhered by using an adhesive.
10) The novel footwear as claimed in the claims 1 to 9 wherein the inner sole is made to
fit exactly in the welt/groove of the outer sole.

11) A novel diabetic footwear as described in the description and illustrated by way of figures 2 to 7 of drawings accompanying the complete specification.
Dated this 18th day of November 2004.


Documents:

1213-che-2004-abstract.pdf

1213-che-2004-claims.pdf

1213-che-2004-correspondnece-po.pdf

1213-che-2004-description(complete).pdf

1213-che-2004-drawings.pdf

1213-che-2004-form 1.pdf

1213-che-2004-form 19.pdf

1213-che-2004-form 3.pdf


Patent Number 220156
Indian Patent Application Number 1213/CHE/2004
PG Journal Number 27/2008
Publication Date 04-Jul-2008
Grant Date 16-May-2008
Date of Filing 18-Nov-2004
Name of Patentee SUNDARAM MEDICAL FOUNDATION
Applicant Address
Inventors:
# Inventor's Name Inventor's Address
1 PROF. KEELANJE MOTHIRAM PATIL
2 DR. VENGESANA BALAKRISHNARAJA NARAYANA MURTHY
PCT International Classification Number A43B 7/22
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA