Automatic Analysis of Plantar Foot Thermal Images in at-Risk Type II Diabetes by Using an Infrared Camera

Abstract

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.

Diabetic foot ulcer mobile detection system using smart phone thermal camera: a feasibility study

“…Heating a coin and placing it near the surface of the foot increased the temperature values of the region by around +2.2 °C higher than the normal plantar feet temperature. As previously discussed, Hyperthermia occurs if there is a temperature increase of more than 2.2 °C in some regions within the foot compared to other regions [ 14 , 19 ].

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“…After segmenting the plantar feet image, further processing was performed to identify any possible ulcers or occurrence of hyperthermia (a 2.2 °C difference) [ 12 , 18 , 19 ]. Two techniques were used for this purpose, Otsu thresholding technique (discussed in the previous section) and point-to-point difference technique.…”

“…Another technique was applied for the detection of any possible ulcer, which is called the point-to-point mean difference shown in Fig. 8 [ 19 ]. In this technique, the pixel-to-pixel temperature difference between both feet was calculated.…”

“…A 1 °C temperature increase within the foot over the normal foot mean temperature requires an accurate assessment in order to decide whether it is a normal increase or an occurrence of foot ulcers [ 12 , 18 , 19 ]. Moreover, temperature differences of more than 2.2 °C between a region on one foot and the same region on the contra-lateral foot are considered Hyperthermia [ 14 , 19 ]. Monitoring such differences through thermal images proved to be an efficient way of detecting diabetic foot ulceration.…”

Design of Flexible Antenna Array for Early Diabetic Foot Detection

“…These entire technique steps are carried out by computational Smartphone.The advantage is that we can check whenever we want as smartphone is a portable one and the disadvantage is the oversegmentation problem which cause insignificant boundaries.In [3] the authors proposed an automatic way to analyze these temperature variation by using infrared camera as in type II diabetes abnormal temperature variations is the early sign of foot ulcer.Though it is the easy method to detect the problem. The polyurethane foam makes positioning a patient for the image acquisition a long and difficult process especially for old people which is a greater disadvantage.In [5] the authors proposed a specific application of the antenna in microwave thermography in S-Band [2][3][4] GHz for breast cancer detection .Though it provides a bandwidth of 550MHz around 3GHz with a total gain of about 1dB its Implementation cost is more.In [7] the authors proposed the delectability of vesicoureteral reflux using microwave radiometry whereComputed tomography (CT) images are taken using microwave radiometry.It has higher resolution but its cost is higher.In [6] the authors proposeda flexible miniaturized UWB CPW Π-shaped slot antenna designed for wireless body area network .Though return loss, voltage standing wave ratio, radiation pattern, and current distribution have been improved but the disadvantage is that gain of the antenna is not considered.…”