Assessment of signs of foot infection in diabetes patients using photographic foot imaging and infrared thermography

Digital Health in Diabetes Care: A Narrative Review from Monitoring to the Management of Systemic and Neurologic Complications

Background/Objectives: Despite the recent advances in glucose-lowering therapy, achieving diabetes control remains challenging. With the advancing progress of innovative digital health technologies, management of diabetes is taking advantage from telehealth and telemedicine, which allow for remote assistance, virtual visits, and monitoring of diabetes-related parameters, and facilitate the exchange of documents and reports to support clinical decisions. We aim to provide an overview of the impact of telehealth and digital technologies on the care of people with diabetes, from therapeutic management to the assessment of complications. Methods: A comprehensive literature search was conducted using PubMed to assess the impact of digital technologies and telemedicine on diabetes care. Results: From the comprehensive PubMed search, 86 peer-reviewed studies were selected based on relevance, clinical significance, and methodological quality. The selected literature addressed digital health tools such as continuous glucose monitoring, connected insulin pens, automatic insulin delivery systems, mobile applications, and telemedicine systems. These interventions were associated with improved glycemic control (e.g., reduced HbA1c, increased time in range), better adherence to therapy, enhanced patient engagement, and more efficient management of complications such as neuropathy, retinopathy, and cardiovascular risk. Conclusions: Telehealth may offer a fully patient-centered approach to disease management through a tailored individual management plan. This may lead to an improvement in adherence to proper therapy and lifestyle, resulting in a subsequent increase in the quality of life.

Construction and validation of a deep learning-based diagnostic model for segmentation and classification of diabetic foot

Objective

This study aims to conduct an in-depth analysis of diabetic foot ulcer (DFU) images using deep learning models, achieving automated segmentation and classification of the wounds, with the goal of exploring the application of artificial intelligence in the field of diabetic foot care.

Methods

A total of 671 images of DFU were selected for manual annotation of the periwound erythema, ulcer boundaries, and various components within the wounds (granulation tissue, necrotic tissue, tendons, bone tissue, and gangrene). Three instance segmentation models (Mask2former, Deeplabv3plus, and Swin-Transformer) were constructed to identify DFU, and the segmentation and classification results of the three models were compared.

Results

Among the three models, Mask2former exhibited the best recognition performance, with a mean Intersection over Union of 65%, surpassing Deeplabv3's 62% and Swin-Transformer's 52%. The Intersection over Union value of Mask2former for wound recognition reached 85.9%, with IoU values of 80%, 78%, 62%, 61%, 47%, and 39% for granulation tissue, gangrene, bone tissue, necrotic tissue, tendons, and periwound erythema, respectively. In the wound classification task, the Mask2former model achieved an accuracy of 0.9185 and an Area Under the Curve of 0.9429 for the classification of Wagner grade 1-2, grade 3, and grade 4 wounds.

Conclusion

Among the three deep learning models, the Mask2former model demonstrated the best overall performance. This method can effectively assist clinicians in recognizing DFU and segmenting the tissues within the wounds.

Digital infrared thermography and machine learning for diabetic foot assessment: thermal patterns and classification

Objectives

Digital infrared thermography is a noninvasive tool used for assessing diseases, including the diabetic foot. This study aims to analyze thermal patterns of the foot sole in patients with type 2 diabetes mellitus using thermography and explore correlations with clinical variables. Additionally, a machine learning approach was developed for classification.

Methods

A total of 23 diabetic patients and 27 age- and sex-matched controls were included. Thermograms of the plantar foot surface were acquired and segmented into regions of interest. Mean foot temperature and temperature change index were calculated from predefined regions of interest. Pearson's correlation analysis was conducted for temperature measures, glycated hemoglobin, and body mass index. A two-layered cross-validation model using principal component analysis and support vector machines were employed for classification.

Results

Significant positive correlations were found between mean foot temperature and glycated hemoglobin (ρ = 0.44, p = 0.0015), as well as between mean foot temperature and body mass index (ρ = 0.35, p = 0.013). Temperature change index did not show significant correlations with clinical variables. The machine learning model achieved high overall accuracy (90%) and specificity (100%) with a moderate sensitivity (78.3%) for classifying diabetic and control groups based on thermal data.

Conclusions

Thermography combined with machine learning shows potential for assessing diabetic foot complications. Correlations between mean foot temperature and clinical variables suggest foot temperature changes as potential indicators. The machine learning model demonstrates promising accuracy for classification, suitable for screening purposes. Further research is needed to understand underlying mechanisms and establish clinical utility in diagnosing and managing diabetic foot complications.

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Point-of-care detection devices for wound care and monitoring

Healthcare resources are heavily burdened by infections that impede the wound-healing process. A wide range of advanced technologies have been developed for detecting and quantifying infection biomarkers. Finding a timely, accurate, non-invasive diagnostic alternative that does not require a high level of training is a critical step toward arresting common clinical patterns of wound health decline. There is growing interest in the development of innovative diagnostics utilizing a variety of emerging technologies, and new biomarkers have been investigated as potential indicators of wound infection. In this review, we summarize diagnostics available for wound infection, including those used in clinics and still under development.

Diabetic Plantar Foot Segmentation in Active Thermography Using a Two-Stage Adaptive Gamma Transform and a Deep Neural Network

Pathological conditions in diabetic feet cause surface temperature variations, which can be captured quantitatively using infrared thermography. Thermal images captured during recovery of diabetic feet after active cooling may reveal richer information than those from passive thermography, but diseased foot regions may exhibit very small temperature differences compared with the surrounding area, complicating plantar foot segmentation in such cold-stressed active thermography. In this study, we investigate new plantar foot segmentation methods for thermal images obtained via cold-stressed active thermography without the complementary information from color or depth channels. To better deal with the temporal variations in thermal image contrast when planar feet are recovering from cold immersion, we propose an image pre-processing method using a two-stage adaptive gamma transform to alleviate the impact of such contrast variations. To improve upon existing deep neural networks for segmenting planar feet from cold-stressed infrared thermograms, a new deep neural network, the Plantar Foot Segmentation Network (PFSNet), is proposed to better extract foot contours. It combines the fundamental U-shaped network structure, a multi-scale feature extraction module, and a convolutional block attention module with a feature fusion network. The PFSNet, in combination with the two-stage adaptive gamma transform, outperforms multiple existing deep neural networks in plantar foot segmentation for single-channel infrared images from cold-stressed infrared thermography, achieving an accuracy of 97.3% and 95.4% as measured by Intersection over Union (IOU) and Dice Similarity Coefficient (DSC) respectively.

IWGDF/IDSA Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Image-Based Artificial Intelligence in Wound Assessment: A Systematic Review

Significance: Accurately predicting wound healing trajectories is difficult for wound care clinicians due to the complex and dynamic processes involved in wound healing. Wound care teams capture images of wounds during clinical visits generating big datasets over time. Developing novel artificial intelligence (AI) systems can help clinicians diagnose, assess the effectiveness of therapy, and predict healing outcomes. Recent Advances: Rapid developments in computer processing have enabled the development of AI-based systems that can improve the diagnosis and effectiveness of therapy in various clinical specializations. In the past decade, we have witnessed AI revolutionizing all types of medical imaging like X-ray, ultrasound, computed tomography, magnetic resonance imaging, etc., but AI-based systems remain to be developed clinically and computationally for high-quality wound care that can result in better patient outcomes. Critical Issues: In the current standard of care, collecting wound images on every clinical visit, interpreting and archiving the data are cumbersome and time consuming. Commercial platforms are developed to capture images, perform wound measurements, and provide clinicians with a workflow for diagnosis, but AI-based systems are still in their infancy. This systematic review summarizes the breadth and depth of the most recent and relevant work in intelligent image-based data analysis and system developments for wound assessment. Future Directions: With increasing availabilities of massive data (wound images, wound-specific electronic health records, etc.) as well as powerful computing resources, AI-based digital platforms will play a significant role in delivering data-driven care to people suffering from debilitating chronic wounds.

Applications of thermal imaging with infrared thermography in Orthopaedics

BACKGROUND

Pathological conditions with ongoing inflammatory processes result in specific heat signatures at the affected body parts; infrared thermography (IRT) detects these changes and can be utilied in screening such conditions. The modern devices are advanced and their non contact, convenient and precise readings can aid in multiple medical sub fields. Orthopaedics as a broad entity has witnessed utilisation of this technology for different indications and the present scoping review was done to assess these established indications and further scope of its utility.

METHOD

ology: A Medline search was done on April 26, 2021 with specific keywords for studies of any design in English language discussing the usage of thermography in Orthopaedics. Animal studies, conference abstracts, systematic reviews, e-posters, case reports, book chapters, and studies describing the use of thermography in non-Orthopaedic patients were excluded.

RESULTS

Total number of hits were 1380. 43 studies including case series and case control studies were included in the review. The subfields or indications described were pain/arthritis, Charcot's foot/neuropathic ulcers, infections associated with diabetic feet and arthroplasties, reflex sympathetic dystrophy, carpal tunnel syndrome, sports medicine, paediatric orthopaedics, spine, ergonomics and compartment syndrome.

CONCLUSION

IRT has been described to be effective in orthopaedic conditions with specific heat signatures and this can assess the trend of the ongoing inflammatory process as well as response to a particular treatment. Additionally, it can specifically determine the exact loci of the pathology for targeted interventions.

Infrared Thermography Follow-Up After Lower Limb Revascularization

BACKGROUND

The purpose of this study was with a simple clinical setting to compare skin temperature changes in the feet before and after revascularization and to identify possible correlation between ankle brachial index (ABI) and toe pressure (TP) values and foot skin temperature patient with and without diabetes.

METHODS

Forty outpatient clinic patients were measured ABI, TP, and the skin temperature using infrared thermography (IRT) at the foot before and after revascularization. Patients in the revascularization group were divided into subgroups depending on whether they had diabetes or not and a wound or not.

RESULTS

There were clear correlation between increase of ABI and TP and increase of the mean skin temperature on the feet after revascularization. The temperature was higher and the temperature change was greater among patients with diabetes. Side-to-side temperature difference between the revascularized feet and contralateral feet decreased after treatment. The mean temperature was higher in the feet with wound whether patient had diabetes mellitus or not.

CONCLUSION

The simple, prompt, and noninvasive IRT procedure showed its potential as a follow-up tool among patients with diabetes or peripheral arterial disease and previous lower limb revascularization.

Use of Virtual Care for Glycemic Management in People With Types 1 and 2 Diabetes and Diabetes in Pregnancy: A Rapid Review

Our objective in this study was to answer the main research question: In patients with diabetes, does virtual care vs face-to-face care provide different clinical, patient and practitioner experience or quality outcomes? Articles (2012 to 2020) describing interventions using virtual care with the capability for 2-way, individualized interactions compared with usual care were included. Studies involving any patients with diabetes and outcomes of glycated hemoglobin (A1C), quality of care and/or patient or health-care practitioner experience were included. Systematic reviews, randomized controlled studies, quasi-experimental trials, implementation trials, observational studies and qualitative analyses were reviewed. MEDLINE and McMaster Health Evidence databases searched in June 2020 identified 59 articles. Virtual care, in particular telemonitoring, combined with a means of 2-way communications provided improvement in A1C similar or superior to usual care, with the strongest evidence for type 2 diabetes. Virtual care was generally acceptable to patients, who expressed satisfaction with their care. Health-care providers recognized benefits but raised issues of technical support, workflow and compensation.

Assessing Diabetic Foot Infections With the ThermoScale: A Comparative Thermometry Device Designed as a Patient Self-Screening Tool

Diabetic foot infection (DFI) is an important risk factor for amputation, and late diagnosis or referral is often incriminated for poor outcome. To enable an earlier diagnosis of DFI, comparative foot thermometry has been suggested as a self-screening method for patients in a home setting. We validated the efficacy of the ThermoScale, a weighing scale outfitted with temperature sensors that allows accurate temperature measurement in both feet. Temperature differentials in DFI patients (n = 52) were compared with a control group of similar diabetic patients (n = 45) without any foot wounds. Based on these findings, we drafted a receiver operating characteristic curve to determine an area-under-the-curve of 0.8455. This value suggests that the ThermoScale, as a diagnostic test, is reasonably accurate. A cutoff value of 2.15 °C temperature difference corresponded with a sensitivity of 88.9% and a specificity of 61.5%. As wearables, portable health electronics, and telemedicine become increasingly popular, we think that comparative temperature measurement technology is valuable in improving early diagnosis of DFIs.

Infrared thermography for monitoring severity and treatment of diabetic foot infections

Monitoring of diabetic foot infections is largely based on clinical assessment, which is limited by moderate reliability. We conducted a prospective study to explore monitoring of thermal asymmetry (difference between mean plantar temperature of the affected and unaffected foot) for the assessment of severity of diabetic foot infections. In patients with moderate or severe diabetic foot infections (International Working Group on the Diabetic Foot infection-grades 3 or 4) we measured thermal asymmetry with an advanced infrared thermography setup during the first 4-5 days of in-hospital treatment, in addition to clinical assessments and tests of serum inflammatory markers (white blood cell counts and C-reactive protein levels). We assessed the change in thermal asymmetry from baseline to final assessment, and investigated its association with infection-grades and serum inflammatory markers. In seven included patients, thermal asymmetry decreased from median 1.8°C (range: -0.6 to 8.4) at baseline to 1.5°C (range: -0.1 to 5.1) at final assessment (P = 0.515). In three patients who improved to infection-grade 2, thermal asymmetry at baseline (median 1.6°C (range: -0.6 to 1.6)) and final assessment (1.5°C (range: 0.4 to 5.1)) remained similar (P = 0.302). In four patients who did not improve to infection-grade 2, thermal asymmetry decreased from median 4.3°C (range: 1.8 to 8.4) to 1.9°C (range: -0.1 to 4.4; P = 0.221). No correlations were found between thermal asymmetry and infection-grades (r = -0.347; P = 0.445), CRP-levels (r = 0.321; P = 0.482) or WBC (r = -0.250; P = 0.589) during the first 4-5 days of hospitalization. Based on these explorative findings we suggest that infrared thermography is of no value for monitoring diabetic foot infections during in-hospital treatment.

Telehealth and telemedicine applications for the diabetic foot: A systematic review

The aim of this systematic review is to assess the peer-reviewed literature on the psychometric properties, feasibility, effectiveness, costs, and current limitations of using telehealth and telemedicine approaches for prevention and management of diabetic foot disease. MEDLINE/PubMed was searched for peer-reviewed studies on telehealth and telemedicine approaches for assessing, monitoring, preventing, or treating diabetic foot disease. Four modalities were formulated: dermal thermography, hyperspectral imaging, digital photographic imaging, and audio/video/online communication. Outcome measures were: validity, reliability, feasibility, effectiveness, and costs. Sixty-one studies were eligible for analysis. Three randomized controlled trials showed that handheld infrared dermal thermography as home-monitoring tool is effective in reducing ulcer recurrence risk, while one small trial showed no effect. Hyperspectral imaging has been tested in clinical settings to assess and monitor foot disease and conflicting results on its diagnostic use show that this method is still in an experimental stage. Digital photography is used to assess and monitor foot ulcers and pre-ulcerative lesions and was found to be a valid, reliable, and feasible method for telehealth purposes. Audio/video/online communication is mainly used for foot ulcer monitoring. Two randomized controlled trials show similar healing efficacy compared with regular outpatient clinic visits, but no benefit in costs. In conclusion, several technologies with good psychometric properties are available that may be of benefit in helping to assess, monitor, prevent, or treat diabetic foot disease, but in most cases, feasibility, effectiveness, and cost savings still need to be demonstrated to become accepted and used modalities in diabetic foot care.

Diabetic foot ulcer classifications: A critical review

Classification and scoring systems can help both clinical management and audit outcomes of routine care. The aim of this study was to assess published systems of diabetic foot ulcers (DFUs) to determine which should be recommended for a given clinical purpose. Published classifications had to have been validated in populations of > 75% people with diabetes and a foot ulcer. Each study was assessed for internal and external validity and reliability. Eight key factors associated with failure to heal were identified from large clinical series and each classification was scored on the number of these key factors included. Classifications were then arranged according to their proposed purpose into one or more of four groups: (a) aid communication between health professionals, (b) predict clinical outcome of individual ulcers, (c) aid clinical management decision making for an individual case, and (d) audit to compare outcome in different populations. Thirty-seven classification systems were identified of which 18 were excluded for not being validated in a population of >75% DFUs. The included 19 classifications had different purposes and were derived from different populations. Only six were developed in multicentre studies, just 13 were externally validated, and very few had evaluated reliability.Classifications varied in the number (4 - 30), and definition of individual items and the diagnostic tools required. Clinical outcomes were not standardized but included ulcer-free survival, ulcer healing, hospitalization, limb amputation, mortality, and cost. Despite the limitations, there was sufficient evidence to make recommendations on the use of particular classifications for the indications listed above.

Diagnosis of infection in the foot in diabetes: a systematic review

BACKGROUND

Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potentially mortality and present formidable challenges in surgical and antimicrobial treatment.

METHODS

In June 2018, we searched the literature using PuEbMed and EMBASE for published studies on the diagnosis of diabetic foot infection. On the basis of predetermined criteria, we reviewed prospective controlled, as well as noncontrolled, studies in any language, seeking translations for those not in English. We then developed evidence statements on the basis of the included papers.

RESULTS

From the 4242 records screened, we selected 35 papers that met our inclusion criteria. The quality of all but one of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot scheme correlates with the patient's likelihood of ulcer healing, of lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers are supportive, but not diagnostic, of soft tissue or bone infection. In patients with suspected diabetic foot osteomyelitis, both a positive probe-to-bone test and an elevated erythrocyte sedimentation rate are strongly associated with its presence. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Plain X-ray remains the first-line imaging examination when there is suspicion of diabetic foot osteomyelitis, but advanced imaging methods help in cases when either the diagnosis or the localization of infection is uncertain.

CONCLUSION

The results of this first reported systematic review on the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is a need for more prospective controlled studies of high quality.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

Instruments of Choice for Assessment and Monitoring Diabetic Foot: A Systematic Review

Diabetic foot is the most frequent disorder among the chronic complications of diabetes, happening in 25% of patients. Objective clinical outcome measures are tests or clinical instruments that provide objective values for result measurement. The aim of this study was to carry out a systematic review of specific objective clinical outcome measures focused on the assessment and monitoring of diabetic foot disorders. The databases used were PubMed, CINAHL, Scopus, PEDro, Cochrane, SciELO and EMBASE. Search terms used were foot, ankle, diabet*, diabetic foot, assessment, tools, instruments, objective outcome measures, valid*, reliab*. Because of the current published evidence, diabetic neuropathy assessment via sudomotor analysis, cardiovascular autonomic neuropathy and peripheral vascular disease detection by non-invasive electronic devices, wound 3D dimensional measurement, hyperspectral imaging for ulcer prediction and the probe-to-bone test for osteomyelitis diagnosis were highlighted in this study.

Infrared 3D Thermography for Inflammation Detection in Diabetic Foot Disease: A Proof of Concept

BACKGROUND

Thermal assessment of the plantar surface of the foot using spot thermometers and thermal imaging has been proven effective in diabetic foot ulcer prevention. However, with traditional cameras this is limited to single spots or a two-dimensional (2D) view of the plantar side of foot, where only 50% of the ulcers occur. To improve ulcer detection, the view has to be extended beyond 2D. Our aim is to explore for proof of concept the combination of three-dimensional (3D) models with thermal imaging for inflammation detection in diabetic foot disease.

METHOD

From eight participants with a current diabetic foot ulcer we simultaneously acquired a 3D foot model and three thermal infrared images using a high-resolution medical 3D imaging system aligned with three smartphone-based thermal infrared cameras. Using spatial transformations, we aimed to map thermal images onto the 3D model, to create the 3D visualizations. Expert clinicians assessed these for quality and face validity as +, +/-, -.

RESULTS

We could replace the texture maps (color definitions) of the 3D model with the thermal infrared images and created the first-ever 3D thermographs of the diabetic foot. We then converted these models to 3D PDF-files compatible with the hospital IT environment. Face validity was assessed as + in six and +/- in two cases.

CONCLUSIONS

We have provided a proof of concept for the creation of clinically useful 3D thermal foot images to assess the diabetic foot skin temperature in 3D in a hospital IT environment. Future developments are expected to improve the image-processing techniques to result in easier, handheld applications and driving further research.

Diagnosis of Cancer Using Hybrid Clustering and Convolution Neural Network from Breast Thermal Image

Breast cancer is a tumor caused by the excessive growth of cells in the breast tissue or near the region of the breast. Breast cancer is most commonly found among women, and it starts developing when the cell tissues from lump of the breast become abnormal or when there is a calcium deposit in the breast. These affected cells form a large lump that consequently becomes a tumor. Digital infrared images are obtained based on the metabolism of the breast and vascular circulation of the blood flow in and around the breast region, which has more visibility than the normal breast region. In this article, we diagnose breast cancer by processing a thermal image that is acquired from thermal cameras. By analyzing the information, we can implement image processing steps to predict quantitative and qualitative information. In this work, we propose a hybrid clustering algorithm with distance measurements. The clustering step includes adaptive fuzzy k-means clustering with Chebyshev distance with improved classifiers, which include neural networks. The article discusses the experimental results along with the comparison using various metrics, such as accuracy, time, and error rates.

Value of Infrared Thermography Camera Attached to a Smartphone for Evaluation and Follow-up of Patients with Graves' Ophthalmopathy

PURPOSE

Graves' ophthalmopathy (GO) is the most common extra-thyroid manifestation of Graves' disease (GD). The Clinical Activity Score (CAS) has been widely used to evaluate GO inflammation severity and response to treatment; however, it is quite subjective. Infrared thermography (IRT) is a portable and low-cost device to evaluate local temperature and assess inflammation. The aim was to evaluate ocular temperature by IRT as an instrument for measuring inflammatory activity in GO and its correlation with CAS.

METHODS

This is a cross-sectional study involving 136 consecutive GD patients (12 with CAS ≥ 3/7, 62 with CAS < 3 and 62 without apparent GO) with 62 healthy controls. Patients with active ophthalmopathy were prospectively evaluated. Exophthalmometry, CAS, and thermal images from caruncles and upper eyelids were acquired from all subjects.

RESULTS

All eye areas of thermal evaluation had higher temperatures in GD patients with active ophthalmopathy (caruncles, p<0.0001; upper eyelids, p<0.0001), and it was positively correlated with CAS (r=0.60 and p<0.0001 at caruncles; r=0.58 and p<0.0001 at upper eyelids). No difference in temperature was found between other groups. Patients with active ophthalmopathy were prospectively evaluated after 6 or 12 months of the treatment and a significant difference was found in ophthalmometry (p=0.0188), CAS (p=0.0205), temperature of caruncles (p=0.0120), and upper eyelids (p=0.0066).

CONCLUSIONS

IRT was an objective and simple tool for evaluation and follow-up of inflammation in GO, allowed evidencing patients with significant inflammatory activity, and had a good correlation with the CAS score.

Validation of low-cost smartphone-based thermal camera for diabetic foot assessment

AIMS

Infrared thermal imaging (IR) is not yet routinely implemented for early detection of diabetic foot ulcers (DFU), despite proven clinical effectiveness. Low-cost, smartphone-based IR-cameras are now available and may lower the threshold for implementation, but the quality of these cameras is unknown. We aim to validate a smartphone-based IR-camera against a high-end IR-camera for diabetic foot assessment.

METHODS

We acquired plantar IR images of feet of 32 participants with a current or recently healed DFU with the smartphone-based FLIR-One and the high-end FLIR-SC305. Contralateral temperature differences of the entire plantar foot and nine pre-specified regions were compared for validation. Intra-class correlations coefficient (ICC(3,1)) and Bland-Altman plots were used to test agreement. Clinical validity was assessed by calculating statistical measures of diagnostic performance.

RESULTS

Almost perfect agreement was found for temperature measurements in both the entire plantar foot and the combined pre-specified regions, respectively, with ICC values of 0.987 and 0.981, Bland-Altman plots' mean Δ = -0.14 and Δ = -0.06. Diagnostic accuracy showed 94% and 93% sensitivity, and 86% and 91% specificity.

CONCLUSIONS

The smartphone-based IR-camera shows excellent validity for diabetic foot assessment.

Continuous Temperature-Monitoring Socks for Home Use in Patients With Diabetes: Observational Study

BACKGROUND

Over 30 million people in the United States (over 9%) have been diagnosed with diabetes. About 25% of people with diabetes will experience a diabetic foot ulcer (DFU) in their lifetime. Unresolved DFUs may lead to sepsis and are the leading cause of lower-limb amputations. DFU rates can be reduced by screening patients with diabetes to enable risk-based interventions. Skin temperature assessment has been shown to reduce the risk of foot ulceration. While several tools have been developed to measure plantar temperatures, they only measure temperature once a day or are designed for clinic use only. In this report, wireless sensor-embedded socks designed for daily wear are introduced, which perform continuous temperature monitoring of the feet of persons with diabetes in the home environment. Combined with a mobile app, this wearable device informs the wearer about temperature increases in one foot relative to the other, to facilitate early detection of ulcers and timely intervention.

OBJECTIVE

A pilot study was conducted to assess the accuracy of sensors used in daily wear socks, obtain user feedback on how comfortable sensor-embedded socks were for home use, and examine whether observed temperatures correlated with clinical observations.

METHODS

Temperature accuracy of sensors was assessed both prior to incorporation in the socks, as well as in the completed design. The measured temperatures were compared to the reference standard, a high-precision thermostatic water bath in the range 20°C-40°C. A total of 35 patients, 18 years of age and older, with diabetic peripheral neuropathy were enrolled in a single-site study conducted under an Institutional Review Board-approved protocol. This study evaluated the usability of the sensor-embedded socks and correlated the observed temperatures with clinical findings.

RESULTS

The temperatures measured by the stand-alone sensors were within 0.2°C of the reference standard. In the sensor-embedded socks, across multiple measurements for each of the six sensors, a high agreement (R2=1) between temperatures measured and the reference standard was observed. Patients reported that the socks were easy to use and comfortable, ranking them at a median score of 9 or 10 for comfort and ease of use on a 10-point scale. Case studies are presented showing that the temperature differences observed between the feet were consistent with clinical observations.

CONCLUSIONS

We report the first use of wireless continuous temperature monitoring for daily wear and home use in patients with diabetes and neuropathy. The wearers found the socks to be no different from standard socks. The temperature studies conducted show that the sensors used in the socks are reliable and accurate at detecting temperature and the findings matched clinical observations. Continuous temperature monitoring is a promising approach as an early warning system for foot ulcers, Charcot foot, and reulceration.

Promoting Self-Care of Diabetic Foot Ulcers Through a Mobile Phone App: User-Centered Design and Evaluation

Background

Without effective self-care, people with diabetic foot ulcers (DFUs) are at risk of prolonged healing times, hospitalization, amputation, and reduced quality of life. Despite these consequences, adherence to DFU self-care remains low. New strategies are needed to engage people in the self-care of their DFUs.

Objective

This study aimed to evaluate the usability and potential usefulness of a new mobile phone app to engage people with DFUs in self-care.

Methods

We developed a new mobile phone app, MyFootCare, to engage people with DFUs through goals, progress monitoring, and reminders in self-care. Key features included novel visual analytics that automatically extract and monitor DFU size information from mobile phone photos of the foot. A functional prototype of MyFootCare was created and evaluated through a user-centered design process with 11 participants with DFUs. Data were collected through semistructured interviews discussing existing self-care practices and observations of MyFootCare with participants. Data were analyzed qualitatively through thematic analysis.

Results

Key themes were as follows: (1) participants already used mobile phone photos to monitor their DFU progress; (2) participants had limited experience with using mobile phone apps; (3) participants desired the objective DFU size data provided by the tracking feature of MyFootCare to monitor their DFU progress; (4) participants were ambivalent about the MyFootCare goal image and diary features, commenting that these features were useful but also that it was unlikely that they would use them; and (5) participants desired to share their MyFootCare data with their clinicians to demonstrate engagement in self-care and to reflect on their progress.

Conclusions

MyFootCare shows promising features to engage people in DFU self-care. Most notably, ulcer size data are useful to monitor progress and engage people. However, more work is needed to improve the usability and accuracy of MyFootCare, that is, by refining the process of taking and analyzing photos of DFUs and removing unnecessary features. These findings open the door for further work to develop a system that is easy to use and functions in everyday life conditions and to test it with people with DFUs and their carers.

Cost-effectiveness of telemonitoring screening for diabetic foot ulcer: a mathematical model

BACKGROUND

One of the most common (and costly) complications of diabetes are diabetic foot ulcers, which often result in lower-extremity amputation. Regular foot care can reduce complications; however, roughly half of Canadians with diabetes do not participate in screening. We sought to evaluate the economic effects of using telemonitoring for diabetic foot ulcer prevention using mathematical modelling.

METHODS

We used Markov modelling to compare current screening standards (standard care) to population-wide and targeted (high-risk) telemonitoring programs in a hypothetical cohort of Canadian patients aged 60 years. We varied the effectiveness (or outcome), defined as the proportion of diabetic foot ulcers prevented, to explore cost-effectiveness using model parameters from published literature and clinical experts.

RESULTS

At 20%-40% effectiveness, population-based prevention resulted in 0.00399-0.00790 quality-adjusted life years (QALYs) gained per person over 5 years and an incremental cost of $479-$402 compared to standard care. At 15%-40% effectiveness, high-risk prevention resulted in a cost decrease per person over 5 years ($1.26-$25.55), with health benefits of 0.000207-0.00058 QALYs gained.

INTERPRETATION

The use of telemonitoring in the diabetic lower extremity can offer patients better quality of life and can be cost-effective compared to current Canadian screening practices. Future work should focus on developing and validating technologies based on objective outcome measures for remote monitoring of the diabetic foot.

Mobile Application for Ulcer Detection

Purpose

The number of patients who are suffering from diabetes nowadays is increasing significantly. In some countries, the percentage of population who suffer from this disease can reach up to 20%. Diabetic patients have to deal with their medical conditions and any further complications that this disease may cause. One of the most common conditions is the Diabetic Foot Ulcer (DFU). The early detection of these ulcers can help and may save the life of diabetic patients.

Methods

This work proposes a mobile application for the detection of possible ulcers using a smart phone along with a mobile thermal camera (FLIR ONE). The proposed system captures thermal images of the feet from the thermal camera. The app that identifies ulcers was built using Android studio. The images were acquired to the Samsung S6 smart phone using the FLIR ONE SDK. Image processing techniques were deployed based on Open CV Library. The procedure of detecting possible ulcers was implemented based on analyzing the thermal distribution on the two feet. The developed application compares the difference between the temperature distribution on the two feet and checks if there is a Mean Temperature Difference (MTD) greater than 2.2^oC (the value which indicates a possible ulcer development).

Results

The system was tested under simulated conditions by heating different locations of the subjects' feet to different temperature ranges; one image with temperature less than 2.2^oC and another three images with temperature greater than 2.2^oC. The system has successfully identified possible ulcer regions along with an image showing the location of the possible ulcers.

Conclusions

This work is a very first step in developing a complete mobile thermal imaging system that can be validated clinically in the future.

Reliability of Infrared Thermography Images in the Analysis of the Plantar Surface Temperature in Diabetes Mellitus

Objective

The purpose of this study was to evaluate the intraexaminer and interexaminer reliability of image assessment of infrared thermography of the plantar surface of people with diabetes mellitus.

Methods

Fifty-one participants with diabetes were included. The interexaminer reliability (test) consisted of measuring the temperature of the plantar surface by 2 evaluators who separately performed the analysis of thermographic images. The intraexaminer reliability (retest) consisted of the revaluation of the images by a single evaluator 10 days after the first analysis.

Results

The analysis of intrareliability and interreliability indicated excellent levels of correlation (intraclass correlation coefficient >0.75, 95% confidence interval >0.70) in the plantar surface points analyzed.

Conclusion

Infrared thermography image evaluation identified intrareliability and interreliability for temperature analysis of the plantar surface of people with diabetes mellitus. However, further studies need to be conducted to assess validity and its application in health care.

Sensors and Biosensors for C-Reactive Protein, Temperature and pH, and Their Applications for Monitoring Wound Healing: A Review

Wound assessment is usually performed in hospitals or specialized labs. However, since patients spend most of their time at home, a remote real time wound monitoring would help providing a better care and improving the healing rate. This review describes the advances in sensors and biosensors for monitoring the concentration of C-reactive protein (CRP), temperature and pH in wounds. These three parameters can be used as qualitative biomarkers to assess the wound status and the effectiveness of therapy. CRP biosensors can be classified in: (a) field effect transistors, (b) optical immunosensors based on surface plasmon resonance, total internal reflection, fluorescence and chemiluminescence, (c) electrochemical sensors based on potentiometry, amperometry, and electrochemical impedance, and (d) piezoresistive sensors, such as quartz crystal microbalances and microcantilevers. The last section reports the most recent developments for wearable non-invasive temperature and pH sensors suitable for wound monitoring.

Measurement of pH, exudate composition and temperature in wound healing: a systematic review

OBJECTIVE

To assess the potential of measurements of pH, exudate composition and temperature in wounds to predict healing outcomes and to identify the methods that are employed to measure them.

METHOD

A systematic review based on the outcomes of a search strategy of quantitative primary research published in the English language was conducted. Inclusion criteria limited studies to those involving in vivo and human participants with an existing or intentionally provoked wound, defined as 'a break in the epithelial integrity of the skin', and excluded in vitro and animal studies. Data synthesis and analysis was performed using structured narrative summaries of each included study arranged by concept, pH, exudate composition and temperature. The Evidence Based Literature (EBL) Critical Appraisal Checklist was implemented to appraise the quality of the included studies.

RESULTS

A total of 23 studies, three for pH (mean quality score 54.48%), 12 for exudate composition (mean quality score 46.54%) and eight for temperature (mean quality score 36.66%), were assessed as eligible for inclusion in this review. Findings suggest that reduced pH levels in wounds, from alkaline towards acidic, are associated with improvements in wound condition. Metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP), neutrophil elastase (NE) and albumin, in descending order, were the most frequently measured analytes in wounds. MMP-9 emerged as the analyte which offers the most potential as a biomarker of wound healing, with elevated levels observed in acute or non-healing wounds and decreasing levels in wounds progressing in healing. Combined measures of different exudate components, such as MMP/TIMP ratios, also appeared to offer substantial potential to indicate wound healing. Finally, temperature measurements are highest in non-healing, worsening or acute wounds and decrease as wounds progress towards healing. Methods used to measure pH, exudate composition and temperature varied greatly and, despite noting some similarities, the studies often yielded significantly contrasting results. Furthermore, a limitation to the generalisability of the findings was the overall quality scores of the research studies, which appeared suboptimal.

CONCLUSION

Despite some promising findings, there was insufficient evidence to confidently recommend the use of any of these measures as predictors of wound healing. pH measurement appeared as the most practical method for use in clinical practice to indicate wound healing outcomes. Further research is required to increase the strength of evidence and develop a greater understanding of wound healing dynamics.

Views of Patients on Using mHealth to Monitor and Prevent Diabetic Foot Ulcers: Qualitative Study

Background

People with diabetes are at risk for diabetic foot ulcers (DFUs), which can lead to limb loss and a significant decrease in quality of life. Evidence suggests that mHealth can be an effective tool in diabetes self-management. mHealth presents an opportunity for the prevention and monitoring of DFUs. However, there is a paucity of research that explores its effectiveness in the DFU patient population, as well as the views and attitudes of these patients toward technology and mHealth.

Objective

This study aimed to explore the views, attitudes, and experiences of a diabetic patient population with or at risk of DFUs regarding technology, mHealth, and the diabetic foot.

Methods

We used a qualitative research approach using in-depth interviews with 8 patients with DFUs. Questions were structured around experience with technology, current health practices related to diabetic foot care, and thoughts on using an mHealth device that prevents and monitors DFUs. We transcribed and thematically analyzed all interviews.

Results

All patients had positive responses for an mHealth intervention aimed at preventing and monitoring DFUs. We found 4 themes in the data: diversity in use of technology, feet-checking habits, 2-way communication with health care professionals (HCPs), and functionality. There were varying levels of familiarity with and dependence on technology within this patient population. These relationships correlated with distinct generations found in North America, including baby boomers and Generation X. Furthermore, we found that most patients performed daily feet checks to monitor any changes in health. However, some did not perform feet checks prior to the development of a DFU. Patients expressed interest in 2-way communication with HCPs that would allow for easier appointment scheduling, sharing of medical data, decreased number of visits, and use of alerts for when medical attention is required. Patients also identified conditions of functionality for the mHealth intervention. These included consideration of debilitating complications because of diabetes, such as retinopathy and decreased mobility; ease of use of the intervention; and implementation of virtual communities to support continued use of the intervention.

Conclusions

Our patient population expressed an interest in mHealth for preventing and monitoring DFUs, although some participants were not frequent users of technology. mHealth continues to show potential in improving patient outcomes, and this study provides a foundation for designing interventions specific to a DFU population. Further research is needed to confirm these findings.

The validity and reliability of remote diabetic foot ulcer assessment using mobile phone images

Despite their potential for telemedicine in diabetic foot ulcer treatment, diagnostic accuracy of assessment of diabetic foot ulcers using mobile phone images is unknown. Our aim was to determine the validity and reliability of remote diabetic foot ulcer assessment using mobile phone images. Fifty diabetic foot ulcers were assessed live and photographed. Five independent observers remotely assessed the mobile phone images twice for presence of nine clinical characteristics and three treatment decisions. Positive likelihood (LLR+) and negative likelihood (LLR−) ratios were calculated for validity. Multirater Randolph’s and bi-rater Bennet kappa values were calculated for reliability. LLR+ ranged from 1.3–4.2; LLR− ranged from 0.13–0.88; the treatment decision ‘peri-wound debridement’ was the only item with ‘strong diagnostic evidence’. Inter-observer reliability kappa ranged from 0.09–0.71; test-retest reliability from 0.45–0.86; the treatment decision ‘peri-wound debridement’ was the only item with ‘adequate agreement’. In conclusion, mobile phone images had low validity and reliability for remote assessment of diabetic foot ulcers and should not be used as a stand-alone diagnostic instrument. Clinicians who use mobile phone images in clinical practice should obtain as much additional information as possible when making treatment decisions based on these images, and be cautious of the low diagnostic accuracy.

Telemedicine in dermatology: findings and experiences worldwide - a systematic literature review

Telemedicine has become an important element of health care in many countries and profited from the technological progress of the last two decades. Due to the visual character of the dermatological specialty, teledermatology in particular participated in that development and is becoming a major tool in dermatological consultation. The objective of this article was to identify the use of teledermatology across the world based on published original articles. A systematic literature search of the MEDLINE and Embase databases for eligible publications (predefined inclusion and exclusion criteria) and a cross-validation search were conducted. Search results were reviewed systematically. The search resulted in 204 publications meeting the inclusion criteria for analysis. The highest number of published studies on teledermatology was performed in the United States, followed by the United Kingdom, Spain, the Netherlands, Italy and Austria. The majority of dermatological indications for telemedical consultations were not specified or included various kinds of skin diseases, followed by skin cancer and wounds. Research questions predominantly focused on concordance, effectiveness and cost-effectiveness to determine the value. Teledermatology proved to be a reliable consultation tool in the majority of studies. If specified, telemedicine was used in daily dermatological routine for patient management purposes, to consult patients in peripheral locations, or for medical support in nursing homes or home care settings. The application of teledermatology worldwide is highest in North American and European countries, while countries with poor geographical distribution of physicians seem to be under-represented in teledermatological use, as concluded from publication output. Regarding indications, comparison with classic consultation and area of application, most studies were of general nature. For precise determination of the value, systematic studies would be needed. However, teledermatology is already accepted as a valid tool.

Role of telehealth in diabetic foot ulcer management - A systematic review

OBJECTIVES

To review the use of telehealth in subjects with diabetic foot ulcer; evaluating its clinical outcomes, diagnostic accuracy, cost-effectiveness and behavioural perceptions.

DESIGN

Systematic review.

SETTING

Selected studies were conducted in Australia, USA, the Netherlands, Denmark, Poland and UK.

PARTICIPANTS

A total of 948 identified studies were evaluated against the inclusion criteria. Eleven eligible studies were included for review. Patients with diabetic foot ulcer had to have telehealth guided management.

MAIN OUTCOME MEASURES

Telehealth systems were evaluated against at least one of the following: clinical implications on ulcer healing and disease prognosis; diagnostic accuracy; cost-effectiveness; behavioural perceptions among health professionals or patients.

RESULT

Eleven eligible studies were included for review. Studies that evaluated telehealth against clinical outcomes were underpowered by study design, sample sizes and short duration follow-up. Telehealth systems demonstrated good intra- and inter-observer reproducibility, high diagnostic accuracy and agreement with live assessments. Authors rationalised the cost-effectiveness of their respective telehealth systems, but could not support this with long-term cost analysis. Both patient and health professionals responded positively towards telehealth in surveys and face-to-face interviews.

CONCLUSION

Telehealth yields high diagnostic accuracy, reproducibility and positive behavioural perceptions. However, it is not clear if telehealth use in diabetic foot management has favourable clinical and economic outcomes. More long-term prospective controlled trials on larger populations are needed to further characterise our findings.

Regional differences in temperature course after knee arthroplasty

PURPOSE

During wound healing after surgery, physiological inflammation leads to an increase in soft tissue perfusion. This is reflected by a characteristic temperature course in the skin. Although local surgical trauma also influences soft tissue perfusion, no data have been available on the regional temperature distribution after knee arthroplasty to date. This study aims at testing the hypothesis that the greatest regional difference in the temperature course is on the site of the maximum surgical trauma (medially) after knee arthroplasty implantation. This is to our knowledge the first study to present regional differences in the temperature course after TKA which would limit the diagnostic value of thermography.

METHODS

Forty-two subjects who were to receive a surface replacement of the knee joint due to primary varus gonarthrosis were included in the study. In all cases, a medial parapatellar approach was chosen. Patients who underwent lateral release or a release of the lateral ligament structures were excluded. In all patients, a thermographic temperature determination was carried out on the operated knee joint every day up to the seventh post-operative day.

RESULTS

On the medial side, there was no significant change in temperature between day one 34.9° ± 0.2° (34.6-35.3 °C) and seven after surgery. Thereafter, the temperature remained constant here up to the seventh day after the operation. In contrast to this, on the lateral side there was an increase in skin temperature from the second 35.0 ± 0.2 °C (34.7-35.4 °C) to the fifth 34.6° ± 0.2° (34.1-34.9 °C) post-operative day (p = 0.002). Thereafter, the temperature remained constant here up to the seventh day after the operation.

CONCLUSION

This study refutes the hypothesis that the greatest regional difference in the temperature course is on the site of maximum surgical trauma (medially) after knee arthroplasty implantation. It is shown to the contrary that there is the least regional difference in the temperature course on the site of maximum surgical trauma (medially) after total knee arthroplasty implantation. It is on the site of the minimal trauma (laterally) where marked differences in the temperature course appeared. The normal temporary temperature increase typical of physiological wound healing could only be shown at a distance from the site of soft tissue preparation. This may be the result of a local compromise of perfusion. Consequently, the post-operative diagnostic application of thermography remains limited to regions distant from the surgical site. This may prevent misinterpretation of post-operative thermographic measurements for scientific or clinical reasons.

LEVEL OF EVIDENCE

II.

Challenges in diagnosing infection in the diabetic foot

Diagnosing the presence of infection in the foot of a patient with diabetes can sometimes be a difficult task. Because open wounds are always colonized with microorganisms, most agree that infection should be diagnosed by the presence of systemic or local signs of inflammation. Determining whether or not infection is present in bone can be especially difficult. Diagnosis begins with a history and physical examination in which both classic and 'secondary' findings suggesting invasion of microorganisms or a host response are sought. Serological tests may be helpful, especially measurement of the erythrocyte sedimentation rate in osteomyelitis, but all (including bone biomarkers and procalcitonin) are relatively non-specific. Cultures of properly obtained soft tissue and bone specimens can diagnose and define the causative pathogens in diabetic foot infections. Newer molecular microbial techniques, which may not only identify more organisms but also virulence factors and antibiotic resistance, look very promising. Imaging tests generally begin with plain X-rays; when these are inconclusive or when more detail of bone or soft tissue abnormalities is required, more advanced studies are needed. Among these, magnetic resonance imaging is generally superior to standard radionuclide studies, but newer hybrid imaging techniques (single-photon emission computed tomography/computed tomography, positron emission tomography/computed tomography and positron emission tomography/magnetic resonance imaging) look to be useful techniques, and new radiopharmaceuticals are on the horizon. In some cases, ultrasonography, photographic and thermographic methods may also be diagnostically useful. Improved methods developed and tested over the past decade have clearly increased our accuracy in diagnosing diabetic foot infections.

Noninvasive imaging technologies for cutaneous wound assessment: A review

The ability to phenotype wounds for the purposes of assessing severity, healing potential and treatment is an important function of evidence-based medicine. A variety of optical technologies are currently in development for noninvasive wound assessment. To varying extents, these optical technologies have the potential to supplement traditional clinical wound evaluation and research, by providing detailed information regarding skin components imperceptible to visual inspection. These assessments are achieved through quantitative optical analysis of tissue characteristics including blood flow, collagen remodeling, hemoglobin content, inflammation, temperature, vascular structure, and water content. Technologies that have, to this date, been applied to wound assessment include: near infrared imaging, thermal imaging, optical coherence tomography, orthogonal polarization spectral imaging, fluorescence imaging, laser Doppler imaging, microscopy, spatial frequency domain imaging, photoacoustic detection, and spectral/hyperspectral imaging. We present a review of the technologies in use or development for these purposes with three aims: (1) providing basic explanations of imaging technology concepts, (2) reviewing the wound imaging literature, and (3) providing insight into areas for further application and exploration. Noninvasive imaging is a promising advancement in wound assessment and all technologies require further validation.

Diagnostic values for skin temperature assessment to detect diabetes-related foot complications

BACKGROUND

Skin temperature assessment is a promising modality for early detection of diabetic foot problems, but its diagnostic value has not been studied. Our aims were to investigate the diagnostic value of different cutoff skin temperature values for detecting diabetes-related foot complications such as ulceration, infection, and Charcot foot and to determine urgency of treatment in case of diagnosed infection or a red-hot swollen foot.

MATERIALS AND METHODS

The plantar foot surfaces of 54 patients with diabetes visiting the outpatient foot clinic were imaged with an infrared camera. Nine patients had complications requiring immediate treatment, 25 patients had complications requiring non-immediate treatment, and 20 patients had no complications requiring treatment. Average pixel temperature was calculated for six predefined spots and for the whole foot. We calculated the area under the receiver operating characteristic curve for different cutoff skin temperature values using clinical assessment as reference and defined the sensitivity and specificity for the most optimal cutoff temperature value. Mean temperature difference between feet was analyzed using the Kruskal-Wallis tests.

RESULTS

The most optimal cutoff skin temperature value for detection of diabetes-related foot complications was a 2.2°C difference between contralateral spots (sensitivity, 76%; specificity, 40%). The most optimal cutoff skin temperature value for determining urgency of treatment was a 1.35°C difference between the mean temperature of the left and right foot (sensitivity, 89%; specificity, 78%).

CONCLUSIONS

Detection of diabetes-related foot complications based on local skin temperature assessment is hindered by low diagnostic values. Mean temperature difference between two feet may be an adequate marker for determining urgency of treatment.