Abstract-Temperature of the plantar foot surface is an important feature in type II diabetes as abnormal temperature variations can be an early sign of foot diseases. In this paper, automatic way to analyze these temperature variations is presented by using an infrared camera. A robust acquisition protocol is proposed and an image processing software is developed. Three types of analysis are performed. First, the mean plantar foot temperature of both feet results from a segmentation procedure based on the Chan and Vese active contour method. Second, the point-to-point absolute mean difference between the 2 feet is assessed by using a rigid registration method. Third, significant hyperthermia regions such that the point-to-point absolute difference is greater than 2.2°C are highlighted. All these measures are fully automatic and do not need manual intervention. 82 type II diabetic subjects in a preulcerative state were recruited in the Dos de Mayo hospital (HNDM) in Lima, Peru. These persons were classified in two risk groups of developing an ulcer based on a medical exam: a medium risk group, and a high risk group. Results show that the mean temperature of the plantar foot surface is higher of 1ºC in the high risk group compared to the medium risk group. The mean point-to-point absolute difference shows identical values in the 2 groups. Finally, 9 subjects out of the 82 ones show significant hyperthermia of one foot compared to the other (6 in the medium risk group and 3 in the high risk group). It is expected that the new opportunity to automatically analyze foot temperature in hospitals or in diabetic health centers will help in reducing foot ulcer occurrence for type II diabetic persons.

In diabetic foot, the occurrence of an ulcer is often associated with hyperthermia. Hyperthermia is defined as a temperature greater than 2.2°C in a given region of one of the foot compared to the temperature of the same region of the contralateral foot. Unfortunately, hyperthermia is not yet assessed in current diabetic foot therapy. In this paper, we propose an easy way to detect a possible hyperthermia by using an infrared camera. A specific acquisition protocol of the thermal images is proposed. A dedicated image analysis is developed: it is composed of a contour detection of the 2 feet using the Chan and Vese active contour method associated to the ICP rigid registration technique. Among 85 type II diabetes persons recruited in the Dos de Mayo hospital in Lima, Peru, 9 individuals show significant hyperthermia. It is expected that the new possibility of detecting hyperthermia in hospitals or in diabetic health centers which is now available, thanks to the proposed method, will help in reducing foot ulcer occurrence for diabetic persons.

The changes in diameter of retinal vessels are an important sign of diseases such as hypertension, arteriosclerosis and diabetes. Obtaining precise measurements of vascular widths is a critical and demanding process in automated retinal image analysis. This paper presents the development of a prototype for measuring the vessel diameters to calculate the arteriovenous ratio (AVR) by using different techniques including Gabor wavelet, gradients, morphological operations and Niblack. The diameter measurement is based on the image skeleton and the perpendicular segment of the vessel. An executable tool is developed using MATLAB and the results are evaluated.

It has been well documented that subjects with peripheral neuropathy resulting from diabetes mellitus are at high risk of developing foot ulceration. Decreased sensation, in combination with high underfoot pressures, have been identified as prime etiology factors in the cause of plantar naturopathic ulceration [1]. This study presents the effect of four orthotic treatment techniques in reducing metatarsal head, heel and toes pressure during walking. A pressure measurement study was carried out on a diabetic patients group wearing four insoles, including the insole designed by the computer model proposed in this project. The aim of this study was to evaluate the effect on plantar pressure in diverse insoles prescribed and manufactured with various techniques on a random group of patients with diabetes mellitus in the early stages of the disease. Four types of insoles were designed and manufactured by methods available in the market; the computer model proposed on this project was used in order to design and manufacture the insole. The results show that every patient requires an individual assessment and often a personalized insole.

For an effective prevention of foot sole ulcers in diabetic patients, the Bioengineering and Signal processing group of the Electronics Department of the Pontificia Universidad Javeriana developed a novel method for the computer assisted design and production of therapeutic insoles, integrating several technologies, such as: CAD/CAM registration of pressure on the foot sole, Podoscopy, and an expert system based on knowledge. The afore mentioned method allows topographical modeling of the insoles starting by the digitization in 3D of a cast of the foot sole surface of the patient and its computer assisted design taking into account the recommendations of the knowledge based system. The aim of this study was to evaluate the effect on plantar pressure distribution of different insoles prescribed and manufactured with various techniques on a random group of patients with diabetes mellitus in the early stages of the disease. Four different types of insoles were manufactured by methods available in the market and by the computer model system proposed on a previous research, which was used in order to design and manufacture one of the insoles evaluated. The differences between the four types of insoles were established by comparing their effectiveness in plantar pressure reduction.