Towards surface analysis on diabetic feet soles to predict ulcerations using photometric stereo

Abstract

Diabetic foot ulceration is a major complication for patients with diabetes mellitus. Approximately 15% to 25% of patients with Type I and Type II diabetes eventually develop feet ulcers. If not adequately treated, these ulcers may lead to foot infection, and ultimately to total (or partial) lower extremity amputation, which means a great loss in health-related quality of life. The incidence of foot ulcers may be prevented by early identification and subsequent treatment of pre-signs of ulceration, such as callus formation, redness, fissures, and blisters. Therefore, frequent examination of the feet is necessary, preferably on a daily basis. However, self-examination is difficult or impossible due to consequences of the diabetes. Moreover, frequent examination by health care professionals is costly and not feasible. The objective of our project is to develop an intelligent telemedicine monitoring system that can be deployed at the patients' home environment for frequent examination of patients feet, to timely detect pre-signs of ulceration. The current paper reports the preliminary results of an implementation of a photometric stereo imaging system to detect 3D geometric abnormalities of the skin surfaces of foot soles. Using a flexible experimental setup, the system parameters such as number and positions of the illuminators have been selected so as to optimize the performance with respect to reconstructed surface. The system has been applied to a dummy foot sole. Finally, the curvature on the resulting 3D topography of the foot sole is implemented to show the feasibility of detecting the pre-signs of ulceration using photometric stereo imaging. The obtained results indicate clinical potential of this technology for detecting the pre-signs of ulceration on diabetic feet soles.

Automatic detection of diabetic foot complications with infrared thermography by asymmetric analysis

“…(c) Combining the thermography technology with other modalities, such as photometric stereo imaging 24 and multispectral imaging, 25 in the experimental setup to predict the development or healing of diabetic foot complications. Future research objectives are: (a) Both the left and right feet may be restored to a general and unbiased foot contour template to reduce the asymmetry in the foot registration.…”

An intelligent telemedicine system for detection of diabetic foot complications

“…b) Thermal image analysis of the ipsilateral foot to detect diabetic foot complications without the need to image the contralateral foot. c) Combining the thermography technology with other modalities, such as photometric stereo imaging [83] and multispectral imaging [40], in the experimental setup to predict the development or healing of diabetic foot complications. d) Comparing the effectiveness and efficiency of predicting diabetic foot complications using different modalities; e) Developing and investigating an intelligent telemedicine system with the most cost-effective modality or modalities to monitor diabetic foot status in daily clinical practice.…”

“…The PSI modality in this experimental setup conducts the image acquisition by the corporation of one commercial digital RGB camera, Canon EOS 40D, and eight power LED light sources [83] as shown in Fig. 2.5 and Fig.…”

“…An experimental setup, consisting of one commercial digital RGB camera, the Canon EOS 40D, and eight power LED light sources [83], has been developed for measurements on patients as shown in Figure 6.1. The digital camera was placed at a distance of 860mm from the measurement plane, covering a field of view 420 × 280 mm 2 with resolution 3888 × 2592 pixels (pixel size ≈ 0.1mm).…”