Background: There is emerging interest in the application of foot temperature monitoring as means of diabetic foot ulcer (DFU) prevention. However, the variability in temperature readings of neuropathic feet remains unknown. The aim of this study was to analyze the long-term consistency of foot thermograms of diabetic feet at the risk of DFU. Methods: A post-hoc analysis of thermal images of 15 participants who remained ulcer-free during a 12-month follow-up were unblinded at the end of the trial. Skin foot temperatures of 12 plantar, 15 dorsal, 3 lateral, and 3 medial regions of interests (ROIs) were derived on monthly thermograms. The temperature differences (∆Ts) of corresponding ROIs of both feet were calculated. Results: Over the 12-month study period, out of the total 2026 plantar data points, 20.3% ROIs were rated as abnormal (absolute ∆T ≥ 2.2°C). There was a significant between-visit variability in the proportion of plantar ROIs with ∆T ≥ 2.2°C (range 7.6%-30.8%, chi-square test, P = .001). The proportion of patients presenting with hotspots (ROIs with ∆T ≥ 2.2°C), abnormal plantar foot temperature (mean ∆T of 12 plantar ROIs ≥ 2.2°C), and abnormal whole foot temperature (mean ∆T of 33 ROIs ≥ 2.2°C) varied between visits and showed no pattern ( P > .05 for all comparisons). This variability was not related to the season of assessment. Conclusions: Despite the high rate of hotspots on monthly thermograms, all feet remained intact. This study underscores a significant between-visit inconsistency in thermal images of neuropathic feet which should be considered when planning DFU-prevention programs for self-testing and behavior modification.

Objective: People with diabetic neuropathy who have previously ulcerated are at high risk of re-ulceration. They should regularly attend podiatry clinics for surveillance and routine protective podiatric treatment. It has been suggested that inflammation prior to skin breakdown shows up as a hotspot on a thermal image even in the absence of clinical signs. The aim of this study is to quantify inter-patient and intra-patient thermal variations presented by diabetic feet at high risk of ulceration. Approach: Whole foot and spot temperatures were recorded for 96 patients who attended two successive podiatry appointments without ulceration 28 [28, 31] days apart, median [interquartile range]. This was a part of a longer study into whether thermal imaging in clinic can reduce the rate of re-ulceration. Main results: The variation in spot temperature right/left differences for single patients between visits was comparable to the variation observed between patients (0.8 [0.3, 1.5] °C compared with 0.9 [0.4, 1.7] °C). Similarly, whole foot temperature variation for a single patient between visits was comparable to the variation observed between patients (0.6 [0.2, 1.1] °C compared with 0.8 [0.2, 1.3] °C). Significance: Thresholds which depend on thermal differences from visit to visit are unlikely to have sufficient specificity to effectively target treatment designed to prevent the development of foot ulcers.

Image Segmentation has historically been a difficult part of Image Analysis in Infrared Imaging. Solutions include using a low-emissivity or cold material as a background or using a separate visual camera to perform image analysis tasks such as with the FLIR One. The proposed method utilises Stereophotogrammetry to obtain a depth map which is subsequently refined and segmented into fore- and background to give an accurate depiction of the object being imaged. The resulting 3D model can then be viewed on a computer for further analysis.

There are cooling products available for relieving the pain of minor sports injuries, in muscles, tendons, joints, strains, sprains and knocks. These products are based on ice, gel and cold patches. In order to quantify objectively the effect of each type of those products thermal imaging was used. This monitoring method is suitable to quantify quickly large regions of interest in skin areas over time through the thermal radiation perceived by thermal camera sensors. All recorded images were taken in a controlled environment and following a standard capture protocol in terms of subject, equipment and examination room preparation and procedure of conduction the examination. Two experiments were performed. The obtained results demonstrate that quantitative thermal imaging is a simple and objective tool for evaluating topical cooling treatments. However, it is important to assess the emissivity of any applied substance, which could have a significant effect on temperature measurement by remote sensing.

Thirty participants with healthy feet were imaged in the same way on two separate occasions (an average of 4 weeks apart). Overall, feet were found to be thermally symmetric although absolute temperature could vary considerably between visits. Temperature differences at specific sites on the foot sometimes exceeded the threshold of 2.2 degrees C regarded as clinically significant when looking for evidence of inflammation prior to skin breakdown in diabetes. At least one site exceeded this threshold in nine (30%) participants (the same figure for both visits). However, when looking for significant thermal asymmetry it is important to rule out transient changes by repeated imaging and to refer to baseline images.

Robotics, video games, environmental mapping and medical are some of the fields that use 3D data processing. In this paper we propose a novel optimization approach for the open source Point Cloud Library (PCL) that is frequently used for processing 3D data. Three main aspects of the PCL are discussed: point cloud creation from disparity of color image pairs; voxel grid downsample filtering to simplify point clouds; and passthrough filtering to adjust the size of the point cloud. Additionally, OpenGL shader based rendering is examined. An optimization technique based on CPU cycle measurement is proposed and applied in order to optimize those parts of the pre-processing chain where measured performance is slowest. Results show that with optimized modules the performance of the pre-processing chain has increased 69 fold.

Early identification of areas of inflammation may aid prevention of diabetic foot ulcers. A new bespoke thermal camera system has been developed to thermally image feet at risk. Hotspots (areas at least 2.2 °C hotter than the contralateral site) may indicate areas of inflammation prior to any apparent visual signs. This article describes the thermal pattern and symmetry of 103 healthy pairs of feet. 68% of participants were thermally symmetric at the 33 foot sites measured. 32% of participants had at least one hotspot, but hotspots overall only accounted for 5% of the measurements made. Refinements to the definition of hotspots are proposed when considering feet at risk of ulceration.

Medical infrared (IR) images are, like other medical images, sensitive to noise, which affects directly the temperature measurement of the subject. There are several noise removal techniques that have good performance on digital images, but may produce different temperature readings on thermal images. Hundred and twenty different noisy images were selected from a database and after being processed with several noise removal techniques, the result was statistically analyzed using the standard parameters: maximum, minimum and mean temperature, standard deviation of same region of interest, root mean square error, signal to noise ratio, cross correlation coefficient. In the end, all techniques were compared and graded according with the results. This investigation shows that all techniques produce different results, the recommended method for improving medical thermal images are the Median, Mean and Wiener filters. Results however suggest that noise filtering should only be applied when specifically needed.

OsteoArthritis is a debilitating disease throughout the developed world, causing significant loss of quality of life to individuals and damaging economies, the imaging system described in this paper has the potential to provide an objective means of measuring and reporting lesion dimensions and providing a machine readable data archive for future study. Existing imaging methodologies have been reviewed and contrasted and despite certain limitations the optical method proposed has the potential to address the issues highlighted to date. The preliminary depth measurement results with an accuracy of 200 μm±6% suggests a potential system for the objective reporting of tissue degradation. It is also envisaged that the bio tribological performance may be inferred from the tissue surface condition as image by the proposed system.

Repetitive Strain Injury (RSI) is a set of occupational syndromes that causes a loose group of conditions resulting from overuse of a tool or other activity that requires repeated movements. RSI needs an accurate quantitative and objective diagnostic test to aid clinicians in the judgment of the degree of injury and assess the adequate treatment, and to provide a permanent evidence record of the degree of injury. Medical thermography was used with a mechanical provocation test involving a computer keyboard typing exercise, which was followed by a thermal provocation of the hand. In order to assess the peripheral temperature changes of the hand, a computational model was developed and the images were standardized and analyzed. The proposed method is objective and repeatable, can provide information of the evolutionary stage of the condition. It was possible to discriminate between controls and patients (p<0.05). Medical thermal imaging can be used as complementary diagnostic tool to provide evidence of occupational condition affecting upper limbs in support to medical history in medico-legal liabilities.

Real-time 3D data processing is important in robotics, video games, environmental mapping, medical and many other fields. In this paper we propose a novel optimisation approach for the open source Point Cloud Library (PCL) that is frequently used for processing 3D data. Three aspects of the PCL are discussed: point cloud creation from disparity of colour image pairs, voxel grid downsample filtering to simplify point clouds and passthrough filtering to adjust the size of the point cloud. Additionally, rendering is examined. An optimisation technique based on CPU cycle measurement is proposed and applied in order to optimise those parts of the processing chain where measured performance is worst. The PCL modules thus optimised show on average an improvement in speed of 2.4x for point cloud creation, 91x for voxel grid filtering and 7.8x for the passthrough filter.

With the proliferation of the internet among casual users as well as businesses, the range and frequency of security threats have increased dramatically. One of these threats is a particular type of malware known as a polymorphic worm. This is a program that can mutate its appearance with each infection and spreads through the network via semantics-preserving code manipulation methods or self-encryption techniques. This paper describes the characteristics of polymorphic worms and then explains the most common forms of pattern based detection, such as Autograph.

In this paper we propose a novel method for acquiring stereo images using the Unreal Development Kit. Our method permits the creation and capture of virtual stereo scenes in a carefully controlled environment. Stereo image pairs produced by the system can subsequently be used for testing stereo matching algorithms and a large variety of computer vision techniques. Compared to a physical stereo camera setup this virtual method provides significantly finer and a better quantitative control over all variables involved in image acquisition ranging from camera parameters to specific detail of object materials such as texture, colour and reflectiveness including their behaviour under different lighting conditions. This is illustrated in this paper by comparing images produced via this method to those captured with physical stereo cameras in stereo matching tests using OpenCV algorithms.

Background/purposeThree‐dimensional (3D) imaging of the skin is a challenging technique. A new 3D digital camera system has been developed that enables 3D reconstruction of the skin and subsequently allows volumetric quantification. Herein we present validation data on calibrated phantoms and the clinical application of this technology.MethodsAbsolute and relative geometric 3D measurements were validated with a static imaging phantom manufactured by a metrology institution and a dynamic imaging phantom adjustable for different volume quantities, respectively. Consecutively, in a clinical study, 3D baseline and follow up images from 27 basal cell carcinomas under topical therapy were captured for volumetric analysis.ResultsValidation experiments have demonstrated an average accuracy for surface position of 55 μm and a precision of 8 μm, as well as excellent correlation (0.999) between injected and measured volumes. The geometric baseline analysis of 27 basal cell carcinomas exhibited a high correlation and agreement between 2D and 3D surface measurements. Under topical therapy, it was possible to gain statistically significant differences between verum‐ and vehicle‐treated basal cell carcinomas when analyzing geometric measurements of 3D volume (P = 0.01) and 3D surface (P = 0.001).ConclusionIn our study we were able to demonstrate that this newly developed 3D camera system offers a precise objective dimensional representation of the skin. This technique is easily applicable and sensitive enough to measure small differences in area and volume before and after intervention.

Infrared thermal imaging was first made available to medicine in the early 1960's. Despite a large number of research publications on the clinical application of the technique, the images have been largely qualitative. This is in part due to the imaging technology itself, and the problem of data exchange between different medical users, with different hardware. An Anglo Polish collaborative study was set up in 2001 to identify and resolve the sources of error and problems in medical thermal imaging. Standardisation of the patient preparation, imaging hardware, image capture and analysis has been studied and developed by the group. A network of specialist centres in Europe is planned to work to establish the first digital reference atlas of quantifiable images of the normal healthy human body. Further processing techniques can then be used to classify abnormalities found in disease states. The follow up of drug treatment has been successfully monitored in clinical trials with quantitative thermal imaging. The collection of normal reference images is in progress. This paper specifies the areas found to be the source of unwanted variables, and the protocols to overcome them.

As more and more wound treatment regimes and wound care products become available, clinicians nowadays face the difficult task of choosing the right approach for individual patients amongst an ever expanding array of options. They find increasingly that a conventional subjective description of wound status and management approach in the patient's notes can no longer answer question such as how effective a treatment regime is or what the efficacy a selected wound care product may be at a given stage of the healing process. The only way to answer these questions and, ultimately, to improve patient care is the objective recording and documentation of the status of the wound and treatment related parameters. This paper outlines progress in a variety of technologies that are now beginning to become available in clinical practice, enabling practitioners to produce immediate, objective and quantifiable portraits of the healing process.

Infrared thermal imaging is being increasingly utilized in the study of neurological and musculoskeletal disorders. In these conditions data on the symmetry (or the lack of it) of skin temperature provides valuable information to clinicians. A major study on thermal symmetry, however, was made in 1988, but there is an absence of studies with the current generation of higher resolution cameras. In this study skin temperature measurements have been carried out using thermograms of 39 healthy male subjects. Measurements were obtained from an infrared camera using the CTHERM application developed at the authors’ research unit. CTHERM is capable of calculating statistical data such as temperature averages and standard deviation values in corresponding areas of interest on both sides of the body. Results show that in healthy subjects the highest temperature symmetry difference was at most ​0.4oC ± 0.3oC in total body views and 0.4oC ± 0.15oC in regional views​. Total body views and regional views produced comparable results although less variation was achieved in regional views. Using a high-resolution camera the study achieved better results on thermal symmetry in normal subjects than previously reported. ​Symmetry assumptions can therefore be used with higher confidence when assessing abnormalities in specific pathologic states​.