Wound Area Measurement with Digital Planimetry: Improved Accuracy and Precision with Calibration Based on 2 Rulers

Hydrolyzed Collagen Powder Dressing Improves Wound Inflammation, Perfusion, and Breaking Strength of Repaired Tissue

Objective: Hydrolyzed collagen-based matrices are widely used as wound care dressings. Information on the mechanism of action of such dressings is scanty. The objective of this study was to test the effect of a specific hydrolyzed collagen powder (HCP), which is extensively used for wound care management in the United States. Approach: The effects of HCP on resolution of wound inflammation, perfusion, closure, and breaking strength of the repaired skin were studied in an experimental murine model. Results: In early (day 7) inflammatory phase of wound macrophages, HCP treatment boosted phagocytosis and efferocytosis of wound-site macrophages. In these cells, inducible reactive oxygen species were also higher on day (d) 7. HCP treatment potentiated the expression of anti-inflammatory interleukin (IL)-10 cytokine and proangiogenic vascular endothelial growth factor (VEGF) production. Excisional wounds dressed with HCP showed complete closure on day 21, while the control wounds remained open. HCP treatment also demonstrated improved quality of wound healing as marked by the improved breaking strength of the closed wound tissue/repaired skin. Innovation: These data represent first evidence on the mechanism of action of clinically used HCP. Conclusion: HCP dressing favorably influenced both wound inflammation and vascularization. Improved breaking strength of HCP-treated repaired skin lays the rationale for future studies testing the hypothesis that HCP-treated closed wounds would show fewer recurrences.

Identification of types of wound bed tissue as a percentage and total wound area by planimetry in neuropathic and venous ulcers

BACKGROUND

Neuropathic and venous leg ulcers are chronic wounds associated with devitalized tissue and recurrent infection. Management should be guided by accurate tissue assessment, including the use of planimetry, which provides tissue types as a percentage of the total wound bed surface area.

OBJECTIVE

This innovative study aimed to assess and identify the wound bed tissues, as a percentage, of neuropathic and venous ulcers using digital planimetry, providing support to nurses optimize the management of necrotic tissues and, consequently, to avoid wound infection.

METHODS

This cross-sectional study enrolled 24 patients with chronic wounds who were assessed from January to March 2021 at the Wound Outpatients Clinic. The wound photographs were analyzed using Image J 1.53e and a smartphone with WoundDoc Plus® 2.8.2 via digital planimetry. Statistical analyses were performed using the binomial test, t-test, and Mann-Whitney.

RESULTS

Median wound areas (p=0.3263) did not differ between the group with 2 or 3 risk factors for delayed healing (Md: 31.7) and the group with up to 1 risk factor (Md: 5.3). A low exudate level was associated with the up-to-1-risk-factor-for-delayed-healing group (p=0.0405), while a medium level was associated with the two-or-three-risk-factor group (p=0.0247). A heat map displayed the tissue percentages in the wound bed. In the group with 2 or 3 risk factors for delayed healing, 91.7% (11/12) had less than 70% granulation tissue, which was the primary factor for this group (p<0.0001). Additionally, 66.7% (8/12) of patients with 2 or 3 risk factors for delayed healing exhibited discolored and/or dark red granulation tissue as the primary factor (p=0.0130).

CONCLUSION

This novel identification of wound area and tissue types as a percentage, using digital planimetry, can play a crucial role in assisting nurses in decision-making related to the appropriate management of devitalized tissues. Furthermore, this measurements may facilitate the conducting of virtual wound consultations and offer valuable support in the development of protocols aimed at preventing infection and biofilm formation in the wound bed.

Intelligent Care Management for Diabetic Foot Ulcers: A Scoping Review of Computer Vision and Machine Learning Techniques and Applications

Ten percent of adults in the United States have a diagnosis of diabetes and up to a third of these individuals will develop a diabetic foot ulcer (DFU) in their lifetime. Of those who develop a DFU, a fifth will ultimately require amputation with a mortality rate of up to 70% within five years. The human suffering, economic burden, and disproportionate impact of diabetes on communities of color has led to increasing interest in the use of computer vision (CV) and machine learning (ML) techniques to aid the detection, characterization, monitoring, and even prediction of DFUs. Remote monitoring and automated classification are expected to revolutionize wound care by allowing patients to self-monitor their wound pathology, assist in the remote triaging of patients by clinicians, and allow for more immediate interventions when necessary. This scoping review provides an overview of applicable CV and ML techniques. This includes automated CV methods developed for remote assessment of wound photographs, as well as predictive ML algorithms that leverage heterogeneous data streams. We discuss the benefits of such applications and the role they may play in diabetic foot care moving forward. We highlight both the need for, and possibilities of, computational sensing systems to improve diabetic foot care and bring greater knowledge to patients in need.

Comparison of digital and traditional skin wound closure assessment methods in mice

BACKGROUND

Chronic skin wounds are a common complication of many diseases such as diabetes. Various traditional methods for assessing skin wound closure are used in animal studies, including wound tracing, calliper measurements and histological analysis. However, these methods have poorly defined wound closure or practical limitations. Digital image analysis of wounds is an increasingly popular, accessible alternative, but it is unclear whether digital assessment is consistent with traditional methods. This study aimed to optimise and compare digital wound closure assessment with traditional methods, using a diabetic mouse model. Diabetes was induced in male C57BL/6J mice by high-fat diet feeding combined with low dose (65 mg/kg of body weight) streptozotocin injections. Mice fed normal chow were included as controls. After 18 weeks, four circular full-thickness dorsal skin wounds of 4 mm diameter were created per mouse. The wounds were photographed and measured by callipers. Wound closure rate (WCR) was digitally assessed by two reporters using two methods: wound outline (WCR-O) and re-epithelialisation (WCR-E). Wounded skin tissues were collected at 10-days post-wounding and wound width was measured from haematoxylin and eosin-stained skin tissue.

RESULTS

Between reporters, WCR-O was more consistent than WCR-E, and WCR-O correlated with calliper measurements. Histological analysis supported digital assessments, especially WCR-E, when wounds were histologically closed.

CONCLUSIONS

WCR-O could replace calliper measurements to measure skin wound closure, but WCR-E assessment requires further refinement. Small animal studies of skin wound healing can greatly benefit from standardised definitions of wound closure and more consistent digital assessment protocols.

Artificial intelligence with temporal features outperforms machine learning in predicting diabetes

Diabetes mellitus type 2 is increasingly being called a modern preventable pandemic, as even with excellent available treatments, the rate of complications of diabetes is rapidly increasing. Predicting diabetes and identifying it in its early stages could make it easier to prevent, allowing enough time to implement therapies before it gets out of control. Leveraging longitudinal electronic medical record (EMR) data with deep learning has great potential for diabetes prediction. This paper examines the predictive competency of deep learning models in contrast to state-of-the-art machine learning models to incorporate the time dimension of risk. The proposed research investigates a variety of deep learning models and features for predicting diabetes. Model performance was appraised and compared in relation to predominant features, risk factors, training data density and visit history. The framework was implemented on the longitudinal EMR records of over 19K patients extracted from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN). Empirical findings demonstrate that deep learning models consistently outperform other state-of-the-art competitors with prediction accuracy of above 91%, without overfitting. Fasting blood sugar, hemoglobin A1c and body mass index are the key predictors of future onset of diabetes. Overweight, middle aged patients and patients with hypertension are more vulnerable to developing diabetes, consistent with what is already known. Model performance improves as training data density or the visit history of a patient increases. This study confirms the ability of the LSTM deep learning model to incorporate the time dimension of risk in its predictive capabilities.

Determining the measurement accuracy in assessing the progress of wound healing

Introduction

Wound management is a challenge in terms of the way, duration and cost of treatment both for the patient and health providers. The healing of skin wounds is a highly multi-step coordinated process. Objective monitoring of treatment at every stage is necessary to assess the applied therapy.

Aim

To show the possibility of using the AutoCad software (ACS) as a tool with a slight measurement error for accurate measurement of the venous leg ulcers on the lower limbs.

Material and methods

To determine the error of the measurement method Circle Templates For Drafting for four different sizes were used as ulcer models. Seventy-six wounds of various sizes from patients with venous leg ulcers (VLUs) were photographed and outlined with a marker on a transparent foil. The wounds were measured both using ACS and digital planimetry with C-Geo software (CGS). Data were analysed using Wilcoxon test, intraclass correlation coefficient (ICC) and Bland-Altman analysis.

Results

The mean relative error of the surface wound model area measured by the ACS was 0.30 ±0.31% (range: 0.004-1.25) and a median of 0.18%. Areas and perimeters measured with ACS were higher than areas and perimeters measured with CGS, and the difference was statistically significant.

Conclusions

The analysis of the wound images obtained in the ACS showed a very high potential of the software in terms of the accuracy of the analysed areas, which significantly increases the possibility of the analysis and reduces the measurement error in relation to planimetry using a digital digitizer.

Comparison of Digital Planimetry and Ruler Methods for the Measurement of Extraction Socket Wounds

Background and objectives: The purpose of the study was to evaluate and compare ruler and digital planimetry methods to measure extraction socket wounds. Materials and Methods: In total, 41 extraction socket wounds were selected for assessment of wound area by ruler and digital planimetry methods. In the simple ruler method, the periodontal probe was utilized to measure the length and breadth of the extraction wound, whereas in the digital planimetry technique, Pictzar software was used. Data were analyzed using R software version 4.1.1 and Excel. For intergroup comparisons of wound surface area, Welch t-tests were used, and paired t-tests were used for intragroup comparisons. Intra-class correlation coefficients (ICC) and 95% confidence intervals (CIs) were used to evaluate the inter-method reliabilities of surface area. Results: Both ruler and digital planimetry techniques showed post-operative reductions in surface area. A significant difference was reported between the two techniques; however, the ruler method measurements were overestimated compared to those obtained with digital planimetry. Conclusions: This study concludes that digital planimetry techniques provide more accurate results when compared with the simple ruler method.

Digital Planimetry With a New Adaptive Calibration Procedure Results in Accurate and Precise Wound Area Measurement at Curved Surfaces

BACKGROUND

The purpose of this study was to determine the accuracy of wound area measurement at a curved surface using a digital planimetry (DP) with the newly proposed adaptive calibration.

METHODS

Forty wound shapes were printed and placed at the side surfaces of cylinders with diameters of 9.4 and 6.2 cm. Area measurements were carried out using a commercial device SilhouetteMobile (Aranz, New Zealand) and the planimetric app Planimator. Planimetric area measurements were carried out using 2 one-dimensional calibration markers placed above and below the wound shape. The method of adaptive calibration for DP was described. Reference area values of wound shapes were obtained by pixel counting on digital scans made with an optical scanner. Relative errors (REs) and relative differences (RDs) for area measurements were analyzed.

RESULTS

The median of REs for the DP with adaptive calibration (DPwAC) was equal to 0.60% and was significantly smaller than the median for the SilhouetteMobile device (SMD) (2.65%), and significantly smaller than the median for the DP (2.23%). The SD of RDs for the DPwAC of 0.87% was considerably lower than for the SMD (6.45%), and for the DP without adaptive calibration (2.51%). The mean of RDs for the DPwAC (0.082%) was not significantly different from zero, which means that the systematic error was not present for the DPwAC.

CONCLUSIONS

The use of the adaptive calibration in DP to measure the areas at curved surface resulted in a significant increase of accuracy and precision, and removal of systematic error. The DPwAC revealed 4.4 times lower error and 7.4 times higher precision of area measurement at curved surfaces than the SMD.

Tigilanol Tiglate-Mediated Margins: A Comparison With Surgical Margins in Successful Treatment of Canine Mast Cell Tumours

Tigilanol tiglate (TT) is a novel small molecule registered as a veterinary pharmaceutical for intratumoural treatment of canine mast cell tumours (MCTs). The drug has a multifactorial mode of action resulting in rapid destruction of the treated tumour by haemorrhagic necrosis and subsequent slough of the necrotic tumour to reveal a tissue deficit that is left to heal by second intention with minimal to no veterinary intervention. Here we introduce the concept of TT-mediated margins, the calculated margin of tissue loss analogous to surgically applied margins to help clinicians conceptualise tissue deficits formed following tumour destruction by TT relative to surgical excision. We used data from 51 dogs that were recurrence-free 12 months after a single administered TT dose into a single target MCT <10 cm³ in volume in a randomised, controlled clinical trial in the USA. We calculated TT-mediated margins based on length of the longest axis of (i) the tumour prior to treatment and (ii) the maximum tissue deficit formed 7–14 days after TT treatment. We compared these TT-mediated margins for each tumour to two surgical approaches to MCT excision in general practise: modified proportional margins (with 2 cm upper limit) and 3 cm fixed margins. For most dogs, TT-mediated margins were less than half the length of the margins calculated for the two surgical approaches in removing the same tumour. There was a trend for TT-mediated margins to increase with increasing tumour volume. Nonetheless, even for the larger tumours in this study (>2 cm³ volume), 50% of TT-mediated margins were less than half the length of the two surgical margins. Eighteen cases were lower limb MCTs, sites often surgically challenging in veterinary practise. On these lower limbs, TT-mediated margins were less than half the length of the corresponding proportional margins in 56% of cases and larger than proportional margins in only two cases. This study suggests that, in many cases, smaller and more targeted margins could be expected when treating MCTs <10 cm³ volume with TT compared with surgical excision. TT-mediated margins are a novel approach to conceptualise tissue deficits after intratumoural TT treatment.

Evaluation of three different techniques for measuring wound area in diabetic foot ulcers: a reproducibility study

OBJECTIVE

Wound surface area can be measured with several assessment tools, including a manual planimetric method, ImageJ software and three-dimensional wound measurement (3DWM) methods. This study aimed to determine the advantages of each method as well as the concordance between them.

METHOD

This reproducibility study included adult patient volunteers with diabetic foot ulcers (DFUs). Wounds with ambiguous borders were excluded. All included wounds were sequentially assessed with each of the three measurement methods, and the time for each measurement was recorded with a chronometer. SPSS and MedCalc package software were used for all statistical analyses.

RESULTS

A total of 20 patients with 20 DFUs took part in the study. According to the measurement method, the average wound area was 6.41cm² by the manual planimetric method, 6.53cm² by ImageJ and 6.32cm² by 3DWM. Correlation analyses revealed correlation coefficients of 0.997 between the manual planimetric method and ImageJ, 0.929 between the manual planimetric method and 3DWM, and 0.929 between ImageJ and 3DWM. Bland-Altman analysis was used to determine whether these three measurement methods could be used interchangeably. There was no significant difference between the three measurement methods and, therefore, it was concluded that they could be used interchangeably. Wound area measurement times were 173.35±19.38 seconds by the manual planimetric method, 61.60±9.21 seconds by ImageJ and 36.90±6.91 seconds by the 3DWM method.

CONCLUSION

The three measurement methods studied can be used interchangeably, as each method is highly concordant with the other two. The fastest method was 3DWM and the manual planimetric method was the slowest.

Assessment of a smartphone-based application for diabetic foot ulcer measurement

The accurate measurement of diabetic foot ulcer (DFU) wound size is essential as the rate of wound healing is a significant prognostic indicator of the likelihood of complete wound healing. Mobile phone photography is often used for surveillance and to aid in telemedicine consultations. However, there remains no accurate and objective measurement of wound size integrated into these photos. The NDKare mobile phone application has been developed to address this need and our study evaluates its accuracy and practicality for DFU wound size assessment. The NDKare mobile phone application was evaluated for its accuracy in two- (2D) and three-dimensional (3D) wound measurement. One hundred and fifteen diabetic foot wounds were assessed for wound surface area, depth and volume accuracy in comparison to Visitrak and the WoundVue camera. Thirty five wounds had two assessors with different mobiles phones utilizing both applications to assess the reproducibility of the measurements. The 2D surface area measurements by NDKare showed excellent concordance with Visitrak and WoundVue measurements (ICC: 0.991 [95% CI: 0.988, 0.993]) and between different users (ICC: 0.98 [95% CI: 0.96, 0.99)]. The 3D NDKare measurements had good agreement for depth and fair agreement for volume with the WoundVue camera. The NDKare phone application can consistently and accurately obtain 2D measurements of diabetic foot wounds with mobile phone photography. This is a quick and readily accessible tool which can be integrated into comprehensive diabetic wound care.

A toolkit for the quantitative evaluation of chronic wounds evolution for early detection of non-healing wounds

BACKGROUND

Chronic wounds resulting from a number of conditions do not heal properly and can pose serious health problems. Beyond clinician visual inspection, an objective evaluation of the wound is required to assess wound evolution and the effectiveness of therapies.

AIM

Our objective is to provide a methodology for the analysis of wound area vs. time for the early prediction of non-healing wounds evolution.

METHODS

We propose a two-step approach consisting of: i) wound area quantification from planimetries and ii) classification of wound healing through the inference of characteristic parameters. For the first step, we describe a user-friendly software (Woundaries) to automatically calculate the wound area and other geometric parameters from hand-traced planimetries. For the second, we use a procedure for the objective classification of wound time evolution and the early assessment of treatment efficacy. The methodology was tested on simulations and retrospectively applied to data from 85 patients to compare the effect of a biological therapy with respect to general basic therapeutics.

RESULTS

Woundaries provides measurements of wound surface equivalent to a validated device. The two-step methodology allows to determine if a wound is healing with high sensitivity, even with limited amount of data. Therefore, it allows the early assessment of the efficacy of a therapy.

CONCLUSION

The performance of this methodology for the quantification and the objective evaluation of wound area evolution suggest it as a useful toolkit to assist clinicians in the early assessment of the efficacy of treatments, leading to a timely change of therapy.

Insulin, but Not Metformin, Supports Wound Healing Process in Rats with Streptozotocin-Induced Diabetes

PURPOSE

Optimal glycemic control is crucial for proper wound healing in patients with diabetes. However, it is not clear whether other antidiabetic drugs support wound healing in mechanisms different from the normalization of blood glucose control. We assessed the effect of insulin and metformin administration on the wound healing process in rats with streptozotocin-induced diabetes.

METHODS

The study was conducted on 200 male Wistar rats with streptozotocin-induced diabetes. In the last phase of the study, 45 rats, with the most stable glucose levels in the range of 350-500 mg/dL, were divided into three groups: group I received human non-protamine insulin subcutaneously (5 IU/kg body mass) once a day, group II received metformin intragastrically (500 mg/kg b.m.), and group III (control) was given saline subcutaneously. After 14 days of antidiabetic treatment, a 2 cm × 2 cm thin layer of skin was cut from each rat's dorsum and a 4 cm disk with a hole in its center was sewn in to stabilize the skin and standardize the healing process. The wound healing process was followed up for 9 days, with assessment every 3 days. Biopsy samples were subjected to hematoxylin and eosin staining and immunohistochemical assays.

RESULTS

Analysis of variance revealed significant influence of treatment type (insulin, control, or metformin) on the relative change in wound surface area. The wound healing process in rats treated with insulin was more effective than in the metformin and control groups. Wound tissue samples taken from the insulin-treated animals presented significantly lower levels of inflammatory infiltration. Immunohistochemical assessment showed the greatest density of centers of proliferation Ki-67 in insulin-treated animals.

CONCLUSION

These results suggest that an insulin-based treatment is more beneficial than metformin, in terms of accelerating the wound healing process in an animal model of streptozocin-induced diabetes.

Evaluation of upper labial frenectomy: A randomized, controlled comparative study of conventional scalpel technique and Er:YAG laser technique

Objectives

Abnormalities in the maxillary frenum may lead to esthetic or functional limitations and need to be corrected with a surgical intervention called frenectomy. The aim of the study was to compare frenectomies performed using Er:YAG laser technology with those using a conventional scalpel technique. Comparisons were of patients' experiences, treatment times, bleeding during treatment and wound healing.

Material and methods

The trial was performed as a prospective, randomized and controlled, single‐blind investigation. A total of 40 patients requiring frenectomy were randomly assigned to groups which underwent either conventional or Er:YAG laser treatment. Patients' experiences, treatment time, bleeding and wound healing were evaluated immediately after surgery and 5 days, 12 days and 3 months after surgery.

Results

Significant increase in time spent in surgery and bleeding was seen with conventional scalpel surgery. Directly after surgery the wound area was significantly larger in the laser group but at the 5‐day evaluation no difference could be observed between the groups. Finally, patients were satisfied with both methods, giving them the same assessments.

Conclusion

In the frenectomy procedure, laser surgery is faster and causes less bleeding and may be advantageous in frenectomies.

A Device to Predict Short-Term Healing Outcome of Chronic Wounds

Objective: While myriads of studies have suggested that a survey of wound pH environment could indicate wound healing activities, it is not clear whether wound alkalinity can be used as a prognostic indicator of nonhealing wounds. Currently available systems cannot reliably assess the pH environment across wounds, which is the objective of this study. Approach: A disposable device, DETEC® pH, was developed and characterized on its ability to map wound alkalinity by pressing a freshly recovered wound dressing against its test surface. By comparing the wound's alkalinity and size reduction rates (∼7 days) following pH measurement, we assessed the capability of wound alkalinity to prognosticate subsequent short-term wound size reduction rates. Results: The device had high accuracy and specificity in determining the alkalinity of simulated wound fluids soaked onto wound dressing. The type of wound dressing type had an insignificant effect on its detection sensitivity. Upon testing discarded wound dressings from human patients, the device quickly determined alkaline and acidic wounds. Finally, statistical analyses of wound size reduction rates in wounds with various alkalinities confirmed that wound alkalinity has a strong influence on, at least, short-term wound healing activity. Innovation: Without directly contacting the patient, this device provides a quick assessment of wound alkalinity to prognosticate immediate and short-term wound healing activities. Conclusion: DETEC® pH may serve as a prognosis device for wound care specialists during routine wound assessment to predict wound healing progress. This information can assist the decision-making process in a clinical setting and augur well for chronic wound treatment. DETEC® pH can also be used as an aid for home health care nurses or health care providers to screen nonhealing wounds outside clinics.

Imaging in Chronic Wound Diagnostics

Significance: Chronic wounds affect millions of patients worldwide, placing a huge burden on health care resources. Although significant progress has been made in the development of wound treatments, very few advances have been made in wound diagnosis. Recent Advances: Standard imaging methods like computed tomography, single-photon emission computed tomography, magnetic resonance imaging, terahertz imaging, and ultrasound imaging have been widely employed in wound diagnostics. A number of noninvasive optical imaging modalities like optical coherence tomography, near-infrared spectroscopy, laser Doppler imaging, spatial frequency domain imaging, digital camera imaging, and thermal and fluorescence imaging have emerged over the years. Critical Issues: While standard diagnostic wound imaging modalities provide valuable information, they cannot account for dynamic changes in the wound environment. In addition, they lack the capability to predict the healing outcome. Thus, there remains a pressing need for more efficient methods that can not only indicate the current state of the wound but also help determine whether the wound is on track to heal normally. Future Directions: Many imaging probes have been fabricated and shown to provide real-time assessment of tissue microenvironment and inflammatory responses in vivo. These probes have been demonstrated to noninvasively detect various changes in the wound environment, which include tissue pH, reactive oxygen species, fibrin deposition, matrix metalloproteinase production, and macrophage accumulation. This review summarizes the creation of these probes and their potential implications in wound monitoring.

The effect of the macrophage migration inhibitory factor (MIF) on excisional wound healing in vivo

Background: The macrophage migration inhibitory factor (MIF) has been determined as a cytokine exerting a multitude of effects in inflammation and angiogenesis. Earlier studies have indicated that MIF may also be involved in wound healing and flap surgery. Methods: We investigated the effect of MIF in an excisional wound model in wildtype, Mif^-/- and recombinant MIF treated mice. Wound closure rates as well as the macrophage marker Mac-3, the pro-inflammatory cytokine tumor necrosis factor α (TNFα) and the pro-angiogenic factor von Willebrand factor (vWF) were measured. Finally, we used a flap model in Mif^-/- and WT mice with an established perfusion gradient to identify MIF's contribution in flap perfusion. Results: In the excision wound model, we found reduced wound healing after MIF injection, whereas Mif deletion improved wound healing. Furthermore, a reduced expression of Mac-3, TNFα and vWF in Mif^-/- mice was seen when compared to WT mice. In the flap model, Mif^-/- knockout mice showed mitigated flap perfusion with lower hemoglobin content and oxygen saturation as measured by O₂C measurements when compared to WT mice. Conclusions: Our data suggest an inhibiting effect of MIF in wound healing with increased inflammation and perfusion. In flaps, by contrast, MIF may contribute to flap vascularization.

Human decellularized dermal matrix seeded with adipose-derived stem cells enhances wound healing in a murine model: Experimental study

Objective

Full-thickness cutaneous wounds treated with split-thickness skin grafts often result in unaesthetic and hypertrophic scars. Dermal substitutes are currently used together with skin grafts in a single treatment to reconstruct the dermal layer of the skin, resulting in improved quality of scars. Adipose-derived stem cells (ASCs) have been described to enhance wound healing through structural and humoral mechanisms. In this study, we investigate the compatibility of xenogen-free isolated human ASCs seeded on human acellular dermal matrix (Glyaderm®) in a murine immunodeficient wound model.

Methods

Adipose tissue was obtained from abdominal liposuction, and stromal cells were isolated mechanically and cultured xenogen-free in autologous plasma-supplemented medium. Glyaderm® discs were seeded with EGFP-transduced ASCs, and implanted on 8 mm full-thickness dorsal wounds in an immunodeficient murine model, in comparison to standard Glyaderm® discs. Re-epithelialization rate, granulation thickness and vascularity were assessed by histology on days 3, 7 and 12. Statistical analysis was conducted using the Wilcoxon signed-rank test. EGFP-staining allowed for tracking of the ASCs in vivo. Hypoxic culture of the ASCs was performed to evaluate cytokine production.

Results

ASCs were characterized with flowcytometric analysis and differentiation assay. EGFP-tranduction resulted in 95% positive cells after sorting. Re-epithelialization in the ASC-seeded Glyaderm® side was significantly increased, resulting in complete wound healing in 12 days. Granulation thickness and vascularization were significantly increased during early wound healing. EGFP-ASCs could be retrieved by immunohistochemistry in the granulation tissue in early wound healing, and lining vascular structures in later stages.

Conclusion

Glyaderm® is an effective carrier to deliver ASCs in full-thickness wounds. ASC-seeded Glyaderm® significantly enhances wound healing compared to standard Glyaderm®. The results of this study encourage clinical trials for treatment of full-thickness skin defects. Furthermore, xenogen-free isolation and autologous plasma-augmented culture expansion of ASCs, combined with the existing clinical experience with Glyaderm®, aid in simplifying the necessary procedures in a GMP-laboratory setting.

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ASCs obtained from human liposuction fat were isolated mechanically and cultured xenogen-free in autologous plasma-supplemented medium.

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Hypoxic culture of the ASCs was performed to evaluate increased cytokine production.

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Glyaderm® discs were seeded with EGFP-transduced ASCs, and implanted on full-thickness dorsal wounds in an immunodeficient murine model, in comparison to standard Glyaderm® discs.

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Reëpithelialisation, granulation and vascularization in the ASC-seeded Glyaderm® side were significantly increased, resulting in complete wound healing in 12 days.

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EGFP-ASCs could be retrieved by IHC in the granulation tissue in early wound healing, and lining vascular structures in later stages.

Non-contact ulcer area calculation system for neuropathic foot ulcer

BACKGROUND

Around 125,785 new cases in year 2013-14 of leprosy were detected in India as per WHO report on leprosy in September 2015 which accounts to approximately 62% of the total new cases. Anaesthetic foot caused by leprosy leads to uneven loading of foot leading to ulcer in approximately 20% of the cases. Much efforts have gone in identifying newer techniques to efficiently monitor the progress of ulcer healing. Current techniques followed in measuring the size of ulcers, have not been found to be so accurate but are still is followed by clinicians across the globe. Quantification of prognosis of the condition would be required to understand the efficacy of current treatment methods and plan for further treatment. This study aims at developing a non contact technique to precisely measure the size of ulcer in patients affected by leprosy.

METHODS

Using MATLAB software, GUI was designed to process the acquired ulcer image by segmenting and calculating the pixel area of the image. The image was further converted to a standard measurement using a reference object. The developed technique was tested on 16 ulcer images acquired from 10 leprosy patients with plantar ulcers. Statistical analysis was done using MedCalc analysis software to find the reliability of the system.

RESULTS

The analysis showed a very high correlation coefficient (r=0.9882) between the ulcer area measurements done using traditional technique and the newly developed technique, The reliability of the newly developed technique was significant with a significance level of 99.9%.

CONCLUSIONS

The designed non-contact ulcer area calculating system using MATLAB is found to be a reliable system in calculating the size of ulcers. The technique would help clinicians have a reliable tool to monitor the progress of ulcer healing and help modify the treatment protocol if needed.

Measuring Surface Area of Skin Lesions with 2D and 3D Algorithms

Purpose

The treatment of skin lesions of various kinds is a common task in clinical routine. Apart from wound care, the assessment of treatment efficacy plays an important role. In this paper, we present a new approach to measure the skin lesion surface in two and three dimensions.

Methods

For the 2D approach, a single photo containing a flexible paper ruler is taken. After semi-automatic segmentation of the lesion, evaluation is based on local scale estimation using the ruler. For the 3D approach, reconstruction is based on Structure from Motion. Roughly outlining the region of interest around the lesion is required for both methods.

Results

The measurement evaluation was performed on 117 phantom images and five phantom videos for 2D and 3D approach, respectively. We found an absolute error of 0.99±1.18  cm² and a relative error 9.89± 9.31% for 2D. These errors are <1  cm² and <5% for five test phantoms in our 3D case. As expected, the error of 2D surface area measurement increased by approximately 10% for wounds on the bent surface compared to wounds on the flat surface. Using our method, the only user interaction is to roughly outline the region of interest around the lesion.

Conclusions

We developed a new wound segmentation and surface area measurement technique for skin lesions even on a bent surface. The 2D technique provides the user with a fast, user-friendly segmentation and measurement tool with reasonable accuracy for home care assessment of treatment. For 3D only preliminary results could be provided. Measurements were only based on phantoms and have to be repeated with real clinical data.

Emerging imaging technologies in dermatology: Part II: Applications and limitations

Clinical examination is critical for the diagnosis and identification of response to treatment. It is fortunate that technologies are continuing to evolve, enabling augmentation of classical clinical examination with noninvasive imaging modalities. This article discusses emerging technologies with a focus on digital photographic imaging, confocal microscopy, optical coherence tomography, and high-frequency ultrasound, as well as several additional developing modalities. The most readily adopted technologies to date include total-body digital photography and dermoscopy, with some practitioners beginning to use confocal microscopy. In this article, applications and limitations are addressed. For a detailed discussion of the principles involved in these technologies, please refer to the first part of this review article.

Validation of three-dimensional wound measurements using a novel 3D-WAM camera

To monitor wound healing, it is essential to obtain accurate and reliable wound measurements. Various methods have been used to measure wound size including three-dimensional (3D) measurement devices enabling wound assessment from a volume perspective. However, the currently available methods are inaccurate, costly, or complicated to use. As a consequence, we have developed a 3D-wound assessment monitor (WAM) camera, which is able to measure wound size in three-dimension and to assess wound characteristics. The aim of the study was to assess the intrarater and interrater reliability of the 3D wound measurements using the 3D camera and to compare these with traditional measurement methods. Four raters measured 48 wounds using the 3D camera, digital imaging method (2D area), and gel injection into the wound cavity (volume). The data were analyzed using linear mixed effect model. Intraclass and interclass correlation coefficient (ICC) and Bland-Altman plots were used to assess intrarater and interrater reliability for the 3D camera and agreement between the methods. The Bland-Altman plots for intrarater reliability showed minor differences between the measurements, especially the 3D area and perimeter measurements. Moreover, ICCs were very high for both the intrarater and interrater reliability for the 2D area, 3D area, and perimeter measurements (ICCs > 0.99), although slightly lower for the volume measurements (ICC = 0.946-0.950). Finally, a high agreement was found between the 3D camera and the traditional methods (2D area and volume) assessed by narrow 95% prediction intervals and high ICCs above 0.97. In conclusion, the 3D-WAM camera is an accurate and reliable method, which is useful for several types of wounds. However, the volume measurements were primarily useful in large, deep wounds. Moreover, the 3D images are based on digital technology and therefore carry the possibility for use in remote settings.

Ways to increase precision and accuracy of wound area measurement using smart devices: Advanced app Planimator

Introduction

Wound surface area measurement is important as therapeutic decisions may depend on the change of wound surface area over time. Digital planimetry is a popular technique in wound area measurement. It is accurate and repeatable when calibration is performed with 2 rulers placed at opposite sides of a wound. The aim of the current study was improving accuracy and precision of wound area measurement using capabilities of smart devices.

Methods

The correction of area measurement based on calculated camera tilt angle and the calculation of calibration coefficient of linear dimensions as weighted average were proposed. These and other improvements were applied in the Planimator app for Android, which was then used in the study. Accuracy and precision of the Planimator app were compared to the Visitrak device, the SilhouetteMobile device, the AreaMe software, and to the digital planimetry based on 2-ruler calibration with pictures taken by the smartphone, compact, and D-SLR cameras. Areas of 40 wound shapes of area ranged from 0.14 to 31.72 cm² were measured with each device. Medians of relative errors (REs) were compared in the accuracy tests and standard deviations (SDs) of relative differences (RDs) were compared in the tests of precision.

Results

The median of REs for the Planimator app was not significantly different from the medians of REs for the digital planimetry based on pictures from the compact or D-SLR cameras, but it was significantly lower than the medians of REs for the Visitrak and SilhouetteMobile devices, the AreaMe software and the digital planimetry based on pictures from a smartphone camera. The SD of RDs for the Planimator app was not significantly different from the SDs of RDs for the digital planimetry based on pictures from the compact or D-SLR cameras, but it was significantly lower than the SDs of RDs for the Visitrak and SilhouetteMobile devices, the AreaMe software and the digital planimetry based on pictures from a smartphone camera. The Planimator app installed at a smartphone revealed to be 2-fold more accurate and 1.5-fold more precise than the measurements with using ImageJ software based on pictures taken with the same smartphone.

Conclusions

The Planimator app occurred to have the same accuracy and precision as measurements with digital planimetry with 2-ruler calibration and based on pictures from a compact camera or a D-SLR camera. This app showed better accuracy and precision than the Visitrak and SilhouetteMobile devices, the AreaMe software and the digital planimetry based on pictures from a smartphone camera.

Error rate of automated calculation for wound surface area using a digital photography

BACKGROUND

Although measuring would size using digital photography is a quick and simple method to evaluate the skin wound, the possible compatibility of it has not been fully validated.

PURPOSE

To investigate the error rate of our newly developed wound surface area calculation using digital photography.

METHODS

Using a smartphone and a digital single lens reflex (DSLR) camera, four photographs of various sized wounds (diameter: 0.5-3.5 cm) were taken from the facial skin model in company with color patches. The quantitative values of wound areas were automatically calculated. The relative error (RE) of this method with regard to wound sizes and types of camera was analyzed.

RESULTS

RE of individual calculated area was from 0.0329% (DSLR, diameter 1.0 cm) to 23.7166% (smartphone, diameter 2.0 cm). In spite of the correction of lens curvature, smartphone has significantly higher error rate than DSLR camera (3.9431±2.9772 vs 8.1303±4.8236). However, in cases of wound diameter below than 3 cm, REs of average values of four photographs were below than 5%. In addition, there was no difference in the average value of wound area taken by smartphone and DSLR camera in those cases.

CONCLUSION

For the follow-up of small skin defect (diameter: <3 cm), our newly developed automated wound area calculation method is able to be applied to the plenty of photographs, and the average values of them are a relatively useful index of wound healing with acceptable error rate.