Mitigation of Motion Artifacts in Handheld Laser Speckle Contrast Imaging Illustrated on Psoriasis Lesions

&lt;italic&gt;Background&lt;/italic&gt;: Handheld laser speckle contrast imaging (LSCI) is crucial in clinical settings, but motion artifacts (MA) can compromise perfusion image reliability. Current prevention and suppression methods are often impractical or complex. Machine vision techniques, promising in medical imaging, could improve signal quality, but their use in suppressing MA is still unexplored. &lt;italic&gt;Objective&lt;/italic&gt;: We propose an innovative method based on linear regression for MA correction (MAC) in LSCI and validate it in vivo. &lt;italic&gt;Methods&lt;/italic&gt;: We performed paired handheld and mounted LSCI measurements on 14 subjects with psoriasis using the previously validated handheld perfusion imager (HAPI). By marking lesion boundaries for clinical purposes, the HAPI used a monochromatic camera for both speckle imaging and motion detection, simplifying hardware requirements. Accurate estimation of relative displacements between the test object and LSCI probe allowed us to apply MAC to the perfusion images. &lt;italic&gt;Results&lt;/italic&gt;: Local perfusion values correlated with applied speed were used to calculate and correct MA. The difference between mean perfusion in handheld and mounted modes after MAC significantly decreased (median error 14.2 perfusion units (p.u.) on lesions before correction (&lt;inline-formula&gt;&lt;tex-math notation="LaTeX"&gt;p&lt; 0.0005&lt;/tex-math&gt;&lt;/inline-formula&gt;) and 0.5 p.u. after correction (&lt;inline-formula&gt;&lt;tex-math notation="LaTeX"&gt;$p=0.2$&lt;/tex-math&gt;&lt;/inline-formula&gt;)). &lt;italic&gt;Conclusion&lt;/italic&gt;: The findings provide evidence for robust handheld LSCI and validate the MA technique in psoriasis case. Of the two causes of MA-onsurface speeds and wavefront tilt-we address the former and correct mean perfusion, assuming constant temporal perfusion at each location. &lt;italic&gt;Significance&lt;/italic&gt;: We describe a practical, non-contact, marker-free technique for reliable handheld perfusion imaging, supporting further clinical translation in plastic surgery and burns.</p

Speed detection to suppress motion artifacts (MA) in laser speckle contrast imaging

Introduction: Laser speckle contrast imaging (LSCI) is an optical technique for noninvasive assessment of microcirculatory blood flow. LSCI has a broad application in medicine including dermatology. Since laser speckles are the basis for this imaging modality, any external motions during a measurement from both patient and operator affect the blood flow images. This challenge is called motion artefacts (MA).Objective: Here, we propose a complete procedure for analysis of speckles, that is, pre-segmentation, segmentation, motion detection, spatial alignment, perfusion map calculation and MA suppression.Methods: The handheld perfusion imager (HAPI) operated in both handheld and mounted schemes, has been used for measurements on 14 psoriasis subjects. We make use of the black marker dots (made by the clinical investigator to determine visual psoriasis lesion boundaries) for calculation of two-dimensional displacements of HAPI during each measurement (i.e. on-surface displacements). Results: We have integrated the on-surface displacements to translate each speckle image back to the initial position at the start of the measurement (i.e. spatial alignment). Moreover, in handheld measurements, MA corrected blood flow maps (also called perfusion maps) are formed by extrapolation of a linear fit from local perfusion versus detected speed to the zero speed, that is, a value ideally always lower than the local mean perfusion.Conclusion: Using a single camera for both speckle imaging and motion detection, we have shown that our MA suppression technique makes handheld perfusion maps fairly similar to the associated mounted perfusion maps not only visually but also in terms of image histograms and mean values.<br/

Barriers towards intermodality for pursuing to-work commuters modal shift to bus rapid transit

Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Adalimumab, etanercept and ustekinumab for treating plaque psoriasis in children and young people: systematic review and economic evaluation

Background: Psoriasis is a chronic inflammatory disease that predominantly affects the skin. Adalimumab (HUMIRA®, AbbVie, Maidenhead, UK), etanercept (Enbrel®, Pfizer, New York, NY, USA) and ustekinumab (STELARA®, Janssen Biotech, Inc., Titusville, NJ, USA) are the three biological treatments currently licensed for psoriasis in children. Objective: To determine the clinical effectiveness and cost-effectiveness of adalimumab, etanercept and ustekinumab within their respective licensed indications for the treatment of plaque psoriasis in children and young people. Data sources: Searches of the literature and regulatory sources, contact with European psoriasis registries, company submissions and clinical study reports from manufacturers, and previous National Institute for Health and Care Excellence (NICE) technology appraisal documentation. Review methods: Included studies were summarised and subjected to detailed critical appraisal. A network meta-analysis incorporating adult data was developed to connect the effectiveness data in children and young people and populate a de novo decision-analytic model. The model estimated the cost-effectiveness of adalimumab, etanercept and ustekinumab compared with each other and with either methotrexate or best supportive care (BSC), depending on the position of the intervention in the management pathway. Results: Of the 2386 non-duplicate records identified, nine studies (one randomised controlled trial for each drug plus six observational studies) were included in the review of clinical effectiveness and safety. Etanercept and ustekinumab resulted in significantly greater improvements in psoriasis symptoms than placebo at 12 weeks’ follow-up. The magnitude and persistence of the effects beyond 12 weeks is less certain. Adalimumab resulted in significantly greater improvements in psoriasis symptoms than methotrexate for some but not all measures at 16 weeks. Quality-of-life benefits were inconsistent across different measures. There was limited evidence of excess short-term adverse events; however, the possibility of rare events cannot be excluded. The majority of the incremental cost-effectiveness ratios for the use of biologics in children and young people exceeded NICE’s usual threshold for cost-effectiveness and were reduced significantly only when combined assumptions that align with those made in the management of psoriasis in adults were adopted. Limitations: The clinical evidence base for short- and long-term outcomes was limited in terms of total participant numbers, length of follow-up and the absence of young children. Conclusions: The paucity of clinical and economic evidence to inform the cost-effectiveness of biological treatments in children and young people imposed a number of strong assumptions and uncertainties. Health-related quality-of-life (HRQoL) gains associated with treatment and the number of hospitalisations in children and young people are areas of considerable uncertainty. The findings suggest that biological treatments may not be cost-effective for the management of psoriasis in children and young people at a willingness-to-pay threshold of £30,000 per quality-adjusted life-year, unless a number of strong assumptions about HRQoL and the costs of BSC are combined. Registry data on biological treatments would help determine safety, patterns of treatment switching, impact on comorbidities and long-term withdrawal rates. Further research is also needed into the resource use and costs associated with BSC. Adequately powered randomised controlled trials (including comparisons against placebo) could substantially reduce the uncertainty surrounding the effectiveness of biological treatments in biologic-experienced populations of children and young people, particularly in younger children. Such trials should establish the impact of biological therapies on HRQoL in this population, ideally by collecting direct estimates of EuroQol-5 Dimensions for Youth (EQ-5D-Y) utilities. Study registration: This study is registered as PROSPERO CRD42016039494. Funding: The National Institute for Health Research Health Technology Assessment programme

The Future of Swelling Elastomers: An Elastomer Manufacturer's View of Swelling Elastomer Developments and Market Trends

Swelling elastomers have gained acceptance as very effective products for creating sealing in various industries, including those creating energy from fossil fuels and geothermal resources. This paper outlines the research and development work being conducted not only in the application of these elastomers but also in the development work required to create new generations of elastomers. It touches on fundamental research into the mechanics of swelling with the intent to create a better and more predictable sealing as well as more advanced elastomers. It lifts the veil on the direction of work being done on new elastomers being developed in order to enable a better control of swelling. By doing so, the research is opening up field of applications for new equipment designs and mechanical possibilities in the future. Additionally, it addresses the need for a better and more in-depth dialogue between both chemical and mechanical engineers, and the elastomer companies and their customers on the potential that both swelling and non-swelling elastomers can offer to the industry as a whole

Perfusion measured by laser speckle contrast imaging as a predictor for expansion of psoriasis lesions

BACKGROUND: Skin microvasculature changes are crucial in psoriasis development and correlate with perfusion. The noninvasive Handheld Perfusion Imager (HAPI) examines microvascular skin perfusion in large body areas using laser speckle contrast imaging (LSCI). OBJECTIVES: To (i) assess whether increased perilesional perfusion and perfusion inhomogeneity are predictors for expansion of psoriasis lesions and (ii) assess feasibility of the HAPI system in a mounted modality. METHODS: In this interventional pilot study in adults with unstable plaque psoriasis, HAPI measurements and color photographs were performed for lesions present on one body region at week 0, 2, 4, 6 and 8. The presence of increased perilesional perfusion and perfusion inhomogeneity was determined. Clinical outcome was categorized as increased, stable or decreased lesion surface between visits. Patient feedback was collected on a 10‐point scale. RESULTS: In total, 110 lesions with a median follow‐up of 6 (IQR 6.0) weeks were assessed in 6 patients with unstable plaque psoriasis. Perfusion data was matched to 281 clinical outcomes after two weeks. A mixed multinomial logistic regression model revealed a predictive value of perilesional increased perfusion (OR 9.90; p < 0.001) and perfusion inhomogeneity (OR 2.39; p = 0.027) on lesion expansion after two weeks compared to lesion stability. HAPI measurements were considered fast, patient‐friendly and important by patients. CONCLUSION: Visualization of increased perilesional perfusion and perfusion inhomogeneity by noninvasive whole field LSCI holds potential for prediction of psoriatic lesion expansion. Furthermore, the HAPI is a feasible and patient‐friendly tool