WO2010128519A1

WO2010128519A1 - A method for detecting neuropathy and predicting foot ulcer development in human beings with health conditions like diabetes mellitus

Info

Publication number: WO2010128519A1
Application number: PCT/IN2009/000720
Authority: WO
Inventors: C. Jairaj Kumar
Original assignee: Kumar C Jairaj
Priority date: 2009-05-04
Filing date: 2009-12-15
Publication date: 2010-11-11
Also published as: WO2010128519A4

Abstract

A method for detecting neuropathy and predicting foot ulcer development in human beings with health conditions like diabetes mellitus, by providing a an arrangement for recording the image of the feet of patient comprising a transparent mounting stand (2), a camera (3) connected to computer (5) equipped with Video to Image converter, Data analyzer and report generator. Once the patient stands on the mounting stand; images are displayed on computer, markings on the displayed images allow the prediction of development in the diabetic patient.

Description

Title Of The Invention:

A Method For Detecting Neuropathy And Predicting Foot Ulcer Development In Human Beings With Health Conditions Like Diabetes Mellitus Field Of Invention:

This present invention relates to development of a new device using the revolutionary chaos theory to diagnose conditions like neuropathy and predict possibility of ulcer development in various health conditions especially like diabetes etc.

State Of The Art In The Field And Description Of Prior Art:

It is believed that the high pressure point areas on the foot are at a higher risk for developing plantar ulcers. Therefore it is believed that development of foot ulcers in diabetes is related to amount of pressure exerted on a given point of the feet and accordingly medicines are prescribed and treatments are given by the Doctors all over the world. If one goes by this belief it is surprising as all the athletes and actively playing young adults should develop pressure ulcers as they are exerting themselves while playing and develop higher amount of plantar pressure than any other normal diabetic patient.

Therefore, there is a flaw in the present system of diagnosing a diabetic patient particularly or planter ulcers. So for no research has been conducted to detect cause for foot ulcer and the present invention is aimed to develop a successful method to detect the same scientifically and accurately without any flaw.

Object of the Invention (problem and solution): The object of the invention is to prove that foot ulceration is linked to the sustenance of pressure rather than the degree plantar pressure, since very little pressure is required to cause capillary blanching. Tissue anoxia thus should occur if the pressure continues to cause blanching rather than a large pressure that disappears occasionally and does not cause sustained tissue anoxia. The further object of the invention is to show the effect that there is a continuous temporal plantar weight bearing foci in healthy individuals, which ensures that high pressure is exerted on the feet which do not hinder the capillary circulation of blood to any part of the feet continuously for extended periods even while standing. It is also believed that this physiological temporal variation and shift of weight bearing foci which ensures circulation to every part of feet disappears in a person suffering from diabetics there by leading to continuous deprivation of blood supply to some parts of the feet bearing weight continuously, which leads to development of diabetic ulcers. Another object of the invention is development of method to quantify the amount of temporal variations to diagnose diabetic neuropathy and predict the probable ulcer development areas in the feet of diabetics and to initiate preventive measures to delay or totally stop the path physiological processes responsible for formation of diabetic ulcers. Statement of the invention:

Accordingly the invention provides a method for detecting neuropathy and predicting foot ulcer development in human beings with health conditions like diabetes mellitus, consisting of glass slab, mounting stand, a camera, led light and computer equipped with CGN Data analyzer and report generator software.

Characterized in that, the principles of chaos theory is used to explain the cause of development of pathology, wavelets and fractal deviations and nonlinear methods are adopted to predict ulcer development and generates reports.

The present invention also quantifies the amount of temporal, variation and shift of plantar pressure bearing points by using skin capillary colour change

(which clearly indicates circulation to the skin without any ambiguity) over the from blanching to pink. Whereas in earlier inventions mainly quantifies the amount of pressure.

Detailed description of the drawings: Hardware Part

Figure 1 represents the overall assembly of Glass Slab (1), measuring 12 mm thick and 40 cm length and 40 cm breadth. The glass with tolerance of weight up to 200 Kg, mounting stand (2) made of metal, plastic or wood with dimensions 45cm in breadth and 45cm length and 50cm in height, capable bearing of upto 300kg, camera (3) placed beneath the glass slab. The camera should be of 5 megapixels or above. The camera should be positioned to record the video of both feet when a patient stands on the glass slab (1). The camera should view from the operator's computer and the person standing on the glass slab should be instructed to expose their feet to the camera. Light emitting diode (LED) lights (4) are placed below the mounting stand to supply light for camera recording. Usually 10 LED lights on right and 10 LED lights on left are sufficient are enough to allow camera recording and computer (5) for analization of graph.

Software Figure 2 Figure 2 illustrates the computer ( 5) equipped with CGN Video to Image converter & CGN Data analyzer and report generator, where the image of the feet of patient is displayed (6).

Figure 3 Figure 3 illustrate the graph (8) obtained when normal healthy person stand on the arrangement referred in figure 1, graph (9) obtained when diabetic patient stand on the same.

Figure4. Figure 4 Illustrate the mean distances of the centre of these points with reference to Mayer's line in controls (4a) and diabetic individuals (4b.) The DI (diabetic individual), time series has fewer fluctuations and lower magnitude that that of controls.

Detailed description of the invention with reference to the drawings: The patient is made to stand on the glass slab (1), mounted on a mounting stand (2), the camera (3) fixed beneath the glass slab, connected to the computer (5). The camera after recording the video of the patient feet transfers the images to the computer at specific intervals of time. Once the images are displayed on computer, at least ten markings (points) are made (7) . After analysis, comparison a graph (9) is displayed on all nonlinear of all the selected points, predicting the nerve condition of the possibility of the ulcer development in the diabetic patient.

Diabetic foot syndrome is perhaps one of the most important complications of diabetes mellitus. The prevalence of diabetic foot ulcers ranges between 4- 10%, while the lifetime incidence rates may be as high as 25% (Ref-1). A number of factors like the peripheral vascular disease, changes in foot architecture, peripheral sensory neuropathy and the plantar pressure are considered to be the prime etiological factors for the development of ulcers

(Ref -2, 3). Studies in the past have demonstrated that, the capillary flow is increased rather than decreased in the diabetic neuropathic foot and the high pressure areas are presumed to be associated with increased basal skin blood flow as compared to low pressure areas (Ref-4-6)). Currency it is believed that the development of plantar pressure ulcers is associated with high amount of pressure exerted on certain regions of the foot (Ref-7-9). Considering the minimal amount of pressure (<30 mm Hg) required to occlude the capillary flow, any pressure greater than this is likely to cause an ulcer. It would be more appropriate to suspect the prolonged sustenance of pressure at particular points causing unremitting tissue anoxia at these points rather than its magnitude as the prime cause for plantar ulcers. In our previous study we had demonstrated the role of redistribution of the pressure points or the weight bearing points in preventing the development of pressure ulcers in healthy individuals (Ref-10). The possible disruption of this bio-mechanism in diabetics owing to peripheral neuropathy may lead to the development of pressure ulcers in susceptible individuals. As sub-clinical neuropathy is may exist for long periods in diabetic individuals (DI)

(Ref :11) we hypothesize that the loss of redistribution of pressure points may precede evidence of clinical neuropathy. The present invention is of the aim to compare and quantify temporal redistribution of plantar pressure points (areas of capillary blanching) between normal subjects and DI with no clinical signs of neuropathy.

Methods This study was conducted at a premiere university teaching hospital in South India. The protocol of the study was approved by the Institute ethics committee. Written informed consent was obtained from each subject. Three adult male and 1 female diagnosed to have Type-2 Diabetes as per the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus criteria were selected (Ref 12). Patients underwent routine outpatient neurological examination. None of the patients were found to have any abnormalities in sensation or muscle weakness or any evidence of claudication pain. Age matched healthy male individuals were included as controls. The subjects were asked to stand on a transparent plexiglass slab of thickness 12mm. A digital video camera (5 megapixel camera) was placed 42cm below the glass slab and a 10 minute video recordings of the plantar area was done for each of the study participants. Offline analysis of the images at every 10 second intervals was done. Ten pressure points (areas of capillary blanching) were selected from the right foot of all subjects. These pressure points were chosen from our previous study, analyzing pressure point changes in normal subjects. The measured points are detailed below.

The points were: a) The lowest point of the pale area on the 2^nd toe. b) The lowest point of the pale area on the 3^rd toe. c) The lowest point of the pale area on the 4^th toe. d) The lowest point of the pale area on the 5^th toe. e) A point to the left of the mid-point of the Meyer's lines (an anatomical line passing through the middle of the great toe and the heel). f) A point to the right of the mid-point of the Meyer's line. g) A point 2 cm above the base of heel, to the left of Meyer's line. h) A point 2cm above the base of heel, to the right of Meyer's line. i) A point on the Meyer's line corresponding to the lower limit of the pale area on the foot. j) A point on the Meyer's line corresponding to 5 the upper limit of the pale area on the foot

Measurement of perpendicular distances of the first eight points with reference to Mayer's line and of the last 2 points with reference to the lowest point on the heel (also the lowest 10 point on the Meyer's line) was done at every

10 seconds. A total of 60 measurements were obtained per point per subject.

For each point the following parameters were calculated:

15 a) Standard deviation of difference between consecutive redistribution of centre of the pressure point (SDPP) in cm. SDPP was used rattier than raw distances since it is invariant to foot size.

20 b) Fractal dimension (FD) as described by Katz,

1988 (13) FD = log (N-l)÷ [log (N-I) + log (d/L)] N = Number of samples (Le. 60), d = Maximum & L = Total 'distance' on waveform. FD (range 1-2) itself has no units. Statistical Analysis

All statistical analysis were done using SPSS version 11. Continuous variables were expressed as mean ± standard deviation. Comparison of parameters between patients and controls was performed using Mann-Whitney U test for exact significance values.

Results :

Demographics of the subjects are shown in Table 1. The age range for DI was 41-51 years and 38-47 years for controls. Duration of illness for DI at diagnosis ranged from 132-192 months. (25.1+0.98 kg/m²) (23.6±0.49 kg/m²) Figure 4 depicts the mean distances of the centre of these points with reference to Mayer's line DI and control subjects Overall variability is higher in normal individuals when compared to diabetics.

Comparison of combined points show SDPP (DI =0.013 ± 0.008 cm, controls= 0.196+0.233 cm, P <0.001) and FD (DI =1.000 ± 0.000, controls= 1.010+0.017, P <0.001) of diabetic patients to be significantly lower than controls. On examination of individual pressure points, (Table 2) two pressure points on the plantar aspect of the foot in diabetics (point 3,8) (pressure point at base of 4^th toe ,right of the midpoint of Meyer's line appear to have similar SDPP and FD in both patients and controls and do not reach significance levels. The FD of point 1 (base of second toe) is comparable between diabetics and controls.

Table 1: Demographic data of controls and diabetic patients.

DI: Diabetic individuals

Table2: Statistical and Fractal Dimensional comparison between Diabetic individuals and controls

SDPP: Standard deviation of difference between consecutive pressure points in cms.;FD: Fractal dimension; DI: Diabetic individuals. Pressure points (1: The lowest point of the pale area on the 2^nd toe. 2: The lowest point of the pale area on the 3^rd toe. 3: The lowest point of the pale area on the 4^th toe. 4: The lowest point of the pale area on the 5^th toe. 5: A pressure point to the left of the mid-point of the Meyer's line (an anatomical line passing through the middle of the great toe and the heel).6: A pressure point to the right of the mid-point of the Meyer's line. 7: A point 2 cms above the base of heel, to the left of Meyer's line. 8: A point 2 cms above the base of heel, to the right of Meyer's line. 9: A point on the Meyer's line corresponding to the lower limit of the pale area on the foot. 10: A point on the Meyer's line corresponding to the upper limit of the pale area on the foot)

The present study shows that . even in a single individual there is variability in the magnitude of redistribution of weight bearing points (Figure 4). Redistribution appears to form a complex time series in normal individuals. In DI this is lost giving rise to a monotonous time series. The resultant waveforms of DI has less fluctuations and lower magnitude that that of controls. The SDPP is a useful measure at it minimizes the affect of foot size and shape. The results suggest that point 3 and 8 (pressure point at base of 4^th toe, right of the midpoint of Meyer's line, have the least variability of redistribution in both controls and diabetics. These points thus can be presumed to be the points through which maximum weight channelized and thus balance is obtained. These points lie along the lateral osseous ridge and give rise to the observation that pressure ulcers occur under osseous pressure points (7-9). Pressure changes appear chaotic in nature and do not follow any set pattern. The overall frequency and magnitude of the redistribution of these points is significantly less in diabetics as compared to healthy individuals, demonstrated by both fractal dimension and statistical measures. As fractal dimension is related to other nonlinear measures of chaos like correlation dimension, maximal Liapunov exponent, we expect that these measures too would be lower in diabetic individuals (DI). It would a much larger time series to calculate these measures and may require image processing tools to extract higher frequency changes. It may be concluded that the causation of diabetic ulcers or pressure ulcers may be the result of loss of mechanisms leading to generation of chaos in the pressure distribution in feet.

This in contrast to the popular belief that the development of foot ulcers is related to the amount of pressure at a given point (8,9). We suggest a more intuitively plausible causality for foot ulceration. Ulceration may be linked to the sustenance of pressure rather than the degree as evidenced that very little pressure is required to cause capillary blanching. Tissue anoxia thus should occur if the pressure continues to cause blanching rather than a large pressure that disappears occasionally and does not cause sustained tissue anoxia.

The variation in the frequency of redistribution in different areas of the foot may pose a higher risk of ulcer formation in some specific parts of the foot.

These pressure points in the diabetics which display a low frequency of redistribution may be at a higher risk for development of plantar ulcers as compared to other parts of the foot. Points over the heel and third toe seem especially vulnerable with lower frequency of re distribution.

Earlier theories, proposing high pressure point areas on the foot to be at a higher risk for developing plantar ulcers have led to several expensive diagnostic instruments for the recognition of such point (6,7). However, all such futuristic diagnostic technology may not be accessible to low income group patients in the in remote and economically challenged areas especially in the developing countries. Our method of analysis of such high risk points on the foot of diabetics is simple and inexpensive. Conclusion:

Our analysis of 10 selected points shows that the sites of low to minimal frequency of chaotic redistribution of these points is specific for an individual and may vary from person to person. There is impaired redistribution of plantar pressure points in individuals with diabetes without signs of clinical neuropathy. This can be attributed to loss of chaos generating mechanisms in DI. Redistribution of pressure points may be essential in the prevention of trophic ulcers in susceptible individuals. The recognition of such points through such simple techniques may even help low-end shoe manufacturers to design comfortable footwear for sensory neuropathy patients specific to their need which shall provide them protection against the development of pressure ulcers. Scope of the invention:

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed, embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined. The flexibility of choosing as may be as many as 25,000 points in the feet.

References:

1. Singh N, Armstrong DG, Lipsky BA (2005). Preventing foot ulcers in patients with diabetes.JAMA. Jan 12;293(2):217-28

2. Richard JL, Schuldiner S. (2008

). Epidemiology of diabetic foot problems.Rev Med Interne Sep;29 2:S222-30 3. Boulton AJ (1992). The risk of foot ulceration in diabetic patients with high foot pressure: a prospective study. Diabetologia._^ Jul;35(7):660-3.

5 4. Netten PM, Wollersheim H, Thien T,

Lutterman JA. (1996) Skin microcirculation of the foot in diabetic neuropathy. CHn Sci.;91:559-565.

5. Flynn MD, Edmonds ME, Tooke JE, Watkins 10 PJ. (1988) Direct measurement of capillary blood flow in the diabetic neuropathic foot. Diabetologia.;31 :652-656

6. Newton D J, Bennett S P , Fraser J, Khan F, Belch JJF , Griffiths G and Leese GP (2005).

15 Pilot study of the effects of local pressure on microvascular function in the diabetic foot. Diabetic Medicine 22; 11,1487 - 1491.

7. Mueller MJ, Zou D, Bohnert KL, Turtle LJ, Sinacore DR. (2008) Plantar stresses on the

20 neuropathic foot during barefoot walking.Phys Ther. Nov;88(ll):1375-84.

8. Armstrong DG, Lavery LA, Vela SA, Quebedeaux TL, Fleischli JG. (1998) Choosing a practical screening instrument to identify patients at risk for diabetic foot ulceration. Arch Intern Med; 158:289-92

"5 9. Stess RM, Jensen SR, Mirmiran R. (1997) The role of dynamic plantar pressures in diabetic foot ulcers. Diabetes Care; 20:855-8.

10. Oberoi D V, Kumar C J, D'souza S, Kumar A, Hegde B M. (2007). Does non chaotic weight

10 bearing foci cause foot ulceration in diabetics?

Medical Hypotheses. 68(2), 468-9.

11. Hendriksen PH, Oey PL, Wieneke GH, Bravenboer B, and van Huffelen AC. (1993). Subclinical diabetic polyneuropathy: early

15 detection of involvement of different nerve fibre types. J Neurol Neurosurg Psychiatry. May; 56(5): 509-514.

12. Gavin JR, Alberti KGMM, Davidson MB, DeFronzo RA, Drash A, Gabbe SG, et al.

20 (2002) Report of the Expert Committee on the

Diagnosis and Classification of DiabetesMellitus. Diabetes Care,;25 Suppl l:S5-S20. 13. Katz MZ.(1988) Fractals and analysis of waveforms. Comp Biol Med;18:145-156.

10

15

20

25

Claims

I Claim:

1. A method for detecting neuropathy and predicting foot ulcer development in human beings with health conditions like diabetes mellitus, comprising steps of:

(a) providing a an arrangement ( fig 1 & 2) for recording the image of the feet of patient comprising of Glass Slab (1), mounting stand (2) camera (3), connected to computer (5) equipped with CGN Video to Image converter & CGN Data analyzer and report generator, wherein the image of the feet of patient is displayed at specific intervals of time, once the patient stands on the mounting stand;

(b) at least ten markings (points) are made (7) (fig-3) on the images are displayed on computer, analyzing , comparing the graph (9) between diabetic patient and normal individual, displayed on all nonlinear of all the selected points, predicting the nerve condition of the possibility of the ulcer development in the diabetic patient.

2. A method as claimed in claim 1, wherein the Glass Slab (1), measuring 12 mm thick and 40 cm length and- 40 cm breadth with tolerance of weight up to 200 Kg, mounting stand (2) made of metal, plastic or wood with dimensions 45cm in breadth and 45cm length and 50cm in height, capable bearing of up to 300kg, camera (3) of 5 megapixels or above, computer (5) equipped with CGN Video to Image converter & CGN

Data analyzer and report generator.

3 The method as claimed in preceding claims, wherein said electronic image comprises a color photocopy of the feet.

4. The method as claimed in preceding claims quantifies the progression of Diabetic Neuropathy, enabling the physician or the person authorized to perform this procedure and analyze the readings.

5. The method as claimed claim 4, wherein in the quantification in progression in diabetic neuropathy aids the physician to decide on the efficacy of a diabetic medication on a patient and decide appropriately on the treatment to ensue.

6. A method for detecting neuropathy and predicting foot ulcer development in human beings with health conditions like diabetes mellitus, Substantially herein described with reference to drawings.