1,885 research outputs found
Measles Rash Identification Using Residual Deep Convolutional Neural Network
Measles is extremely contagious and is one of the leading causes of
vaccine-preventable illness and death in developing countries, claiming more
than 100,000 lives each year. Measles was declared eliminated in the US in 2000
due to decades of successful vaccination for the measles. As a result, an
increasing number of US healthcare professionals and the public have never seen
the disease. Unfortunately, the Measles resurged in the US in 2019 with 1,282
confirmed cases. To assist in diagnosing measles, we collected more than 1300
images of a variety of skin conditions, with which we employed residual deep
convolutional neural network to distinguish measles rash from other skin
conditions, in an aim to create a phone application in the future. On our image
dataset, our model reaches a classification accuracy of 95.2%, sensitivity of
81.7%, and specificity of 97.1%, indicating the model is effective in
facilitating an accurate detection of measles to help contain measles
outbreaks
Objective Assessment of Area and Erythema of Psoriasis Lesion Using Digital Imaging and Colourimetry
Psoriasis is a non-contagious skin disease which typically consists of red plaques covered
by silvery-white scales. It affects about 3% of world population. During treatment,
dermatologists monitor the extent of psoriasis continuously to ascertain treatment
efficacy. Psoriasis Area and Severity Index (PAS!) is the current gold standard method
used to assess the extent of psoriasis. In PAS!, there are four parameters to be scored i.e.,
the surface area affected, erythema (redness), thickness and scaliness of the plaques.
Determining PAS! score is a tedious task and thus it is not used in daily clinical practice.
In addition, the PAS! parameters are visually determined and may result in intra-observer
and inter-observer variations, even by experienced dermatologists. Objective methods in
assessing area and erythema of psoriasis lesion have been developed in this thesis.
Psoriasis lesion can be recognized by its colour dissimilarity with normal skin. Colour
dissimilarity is represented by colour difference in CIELAB colour space, a widely used
colour space to measure colour dissimilarity. Each pixel in CIELAB colour space can be
represented by its lightness (L'), hue (hob), and chroma (Cab). Colour difference between
psoriasis lesion and normal skin is analyzed in hue-chroma plane of CIELAB colour
space. Centroids of normal skin and lesion in hue-chroma space are obtained from
selected samples. Euclidean distances between all pixels with these two centroids are
then calculated. Each pixel is assigned to the class of the nearest centroid. The erythema
of psoriasis lesion is affected by degree of severity and skin pigmentation. In order to
assess the erythema objectively, patients are grouped according to their skin pigmentation
level. The L* value of normal skin which represents skin pigmentation level is utilized to
group the patient into the three skin types namely fair, brown and dark skin types. Light
difference (t.L*), hue difference (t.hab), and chroma difference (t.C'ab) of CIELAB
colour space between reference lesions and the surrounding normal skin are analyzed. It
is found that the erythema score of a lesion can be determined by their hue difference
(t.hab) value within a particular skin type group. Out of 30 body regions, the proposed
method is able to give the same PAS! area score as reference for 28 body regions. The
proposed method is able to determine PAS! erythema score of 82 lesions obtained from
22 patients objectively without being influenced by other characteristic of the lesion such
as area, pattern, and boundary
Multispectral imaging methods for the diagnosis of skin cancer lesions
En col·laboració amb la Universitat Autònoma de Barcelona (UAB) i la Universitat de Barcelona (UB).Skin cancer is the most prevalent form of cancer, and melanoma is one of the most threat disease of it. But it can be cured if it is detected early enough. Multispectral imaging is a potential method to differenciate melanoma from nevi as it provides spectral images with information of absorbance and reflectance. With this aim, spectral images along the visible and near infrared range (from 415nm to 995nm) of 165 lesions including nevi, melanomas and basal cell carcinomas were processed in this master thesis. After obtaining all data in terms of reflectance and absorbance and other related parameters for each pixel of the segmented lesions, a statistical analysis was carried out to quantify their spatial distribution all over each lesion. Algorithms such as Support vector machine (SVM) and Discriminant Analysis (DA) were used as a means of classifying the lesions. The results show that DA linear classifier provides a better diagnosis than the SVM. BCCs are easier to discriminate from nevi than melanomas
Anal signs of child sexual abuse: a case–control study
Background:
There is uncertainty about the nature and specificity of physical signs following anal child sexual abuse. The study investigates the extent to which physical findings discriminate between children with and without a history of anal abuse.<p></p>
Methods:
Retrospective case note review in a paediatric forensic unit.<p></p>
Cases: all eligible cases from 1990 to 2007 alleging anal abuse.<p></p>
Controls: all children examined anally from 1998 to 2007 with possible physical abuse or neglect with no identified concern regarding sexual abuse. Fisher’s exact test (two-tailed) was performed to ascertain the significance of differences for individual signs between cases and controls. To explore the potential role of confounding, logistic regression was used to produce odds ratios adjusted for age and gender.<p></p>
Results:
A total of 184 cases (105 boys, 79 girls), average age 98.5 months (range 26 to 179) were compared with 179 controls (94 boys, 85 girls) average age 83.7 months (range 35–193). Of the cases 136 (74%) had one or more signs described in anal abuse, compared to 29 (16%) controls. 79 (43%) cases and 2 (1.1%) controls had >1 sign. Reflex anal dilatation (RAD) and venous congestion were seen in 22% and 36% of cases but <1% of controls (likelihood ratios (LR) 40, 60 respectively), anal fissure in 14% cases and 1.1% controls (LR 13), anal laxity in 27% cases and 3% controls (LR 10).<p></p>
Novel signs seen significantly more commonly in cases were anal fold changes, swelling and twitching. Erythema, swelling and fold changes were seen most commonly within 7Â days of last reported contact; RAD, laxity, venous congestion, fissure and twitching were observed up to 6Â months after the alleged assault.<p></p>
Conclusions:
Anal findings are more common in children alleging anal abuse than in those presenting with physical abuse or neglect with no concern about sexual abuse. Multiple signs are rare in controls and support disclosed anal abuse
Investigating the Impact of Demographic Factors on Contactless Fingerprint Interoperability
Improvements in contactless fingerprinting have resulted in contactless fingerprints becoming a faster and more convenient alternative to contact fingerprints. The interoperability between contactless fingerprints and contact fingerprints and how demographic factors can change interoperability has been challenging since COVID-19; the need for hygienic alternatives has only grown because of the sudden focus during the pandemic. Past work has shown issues with the interoperability of contactless prints from kiosk devices and phone fingerprint collection apps. Demographic bias in photography for facial recognition could affect photographed fingerprints. The paper focuses on evaluating match performance between contact and contactless fingerprints and evaluating match score bias based on five skin demographics; melanin, erythema, and the three measurements of the CIELab color space. The interoperability of three fingerprint matchers was tested. The best and worst Area Under the Curve (AUC) and Equal Error Rate (EER) values for the best-performing matcher were an AUC of 0.99398 and 0.97873 and an EER of 0.03016 and 0.07555, respectively, while the best contactless AUC and EER were 0.99337 and 0.03387 indicating that contactless match performance can be as good as contact fingerprints depending on the device. In contrast, the best and worst AUC and EER for the cellphone contactless fingerprints were an AUC of 0.96812 and 0.85772 and an EER of 0.08699 and 0.22130, falling short of the lowest performing contact fingerprints. Demographic analysis was on the top two of the three matchers based on the top one percent of non-match scores. Resulting efforts found matcher-specific bias for melanin showing specific ranges affected by low and high melanin values. While higher levels of erythema and general redness of the skin improved performance. Higher lightness values showed a decreased performance in the top-performing matcher
Correlation of Acute Radiation Dermatitis to Tissue Oxygenation in Radiation Therapy treated Breast Cancer Subjects
Over 95% of radiation therapy (RT) treated breast cancer subjects undergo an adverse skin reaction known as radiation dermatitis (RD). Assessment of severity or grading of RD is clinically visual and hence subjective. Our objective is to determine sub-clinical tissue oxygenation (StO2) changes in response to RT treatment in breast cancer subjects using near-infrared spectroscopic imaging and correlate these changes to RD grading. A WIRB approved 6-8 week longitudinal pilot study was carried out on 10 RT-treated subjects at Miami Cancer Institute. Significant changes (p \u3c 0.05) in StO2 of irradiated and contralateral chest wall and axilla regions with weeks of treatment were observed. The overall drop in StO2 was higher in irradiated regions compared to its contralateral region. This drop was negatively correlated to RD scaling. Pre-RT assessment of StO2 also related to severity in RD. The long-term goal is physiological based prediction of RD severity via tissue oxygenation measurements
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A dose-ranging, parallel group, split-face, single-blind phase II study of light emitting diode-red light (LED-RL) for skin scarring prevention: study protocol for a randomized controlled trial.
BackgroundSkin fibrosis is a significant global health problem that affects over 100 million people annually and has a profoundly negative impact on quality of life. Characterized by excessive fibroblast proliferation and collagen deposition, skin fibrosis underlies a wide spectrum of dermatologic conditions ranging from pathologic scars secondary to injury (e.g., burns, surgery, trauma) to immune-mediated diseases. Effective anti-scarring therapeutics remain an unmet need, underscoring the importance of developing novel approaches to treat and prevent skin fibrosis. Our in vitro data show that light emitting diode-red light (LED-RL) can modulate key cellular and molecular processes involved in skin fibrosis. In two phase I clinical trials (STARS 1 and STARS 2), we demonstrated the safety and tolerability of LED-RL at fluences of 160 J/cm2 up to 480 J/cm2 on normal human skin.Methods/designCURES (Cutaneous Understanding of Red-light Efficacy on Scarring) is a dose-ranging, randomized, parallel group, split-face, single-blind, mock-controlled phase II study to evaluate the efficacy of LED-RL to limit post-surgical skin fibrosis in subjects undergoing elective mini-facelift surgery. Thirty subjects will be randomly allocated to three treatment groups to receive LED-RL phototherapy or temperature-matched mock irradiation (control) to either periauricular incision site at fluences of 160 J/cm2, 320 J/cm2, or 480 J/cm2. Starting one week post-surgery (postoperative days 4-8), treatments will be administered three times weekly for three consecutive weeks, followed by efficacy assessments at 30 days, 3 months, and 6 months. The primary endpoint is the difference in scar pliability between LED-RL-treated and control sites as determined by skin elasticity and induration measurements. Secondary outcomes include clinical and photographic evaluations of scars, 3D skin imaging analysis, histological and molecular analyses, and adverse events.DiscussionLED-RL is a therapeutic modality of increasing importance in dermatology, and has the potential to limit skin fibrosis clinically by decreasing dermal fibroblast activity and collagen production. The administration of LED-RL phototherapy in the early postoperative period may optimize wound healing and prevent excessive scarring. The results from this study may change the current treatment paradigm for fibrotic skin diseases and help to pioneer LED-RL as a safe, non-invasive, cost-effective, portable, at-home therapy for scars.Trial registrationClinicalTrials.gov, NCT03795116 . Registered on 20 December 2018
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