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Chronic non-healing wounds represent an increasing problem. In order to enable physicians and nurses to make evidence based decisions on wound treatment, the professional societies call for supporting tools to be offered to physicians. Oxygen supply, bacteria colonization and other parameters influence the healing process. So far, these parameters cannot be monitored in an objective and routinely manner. Existing methods like the microbiological analysis of wound swabs, mean a great deal of effort and partly a long delay. In this paper 42 fluorescence images from 42 patients with diabetic foot ulcer, recorded with a hyperspectral imaging system (TIVITA®), converted for fluorescence imaging, were analysed. Beside the fluorescence images, information about the bacterial colonization is available from microbiological analysis of wound swabs. After preprocessing, principal component analysis, PCA, is used for data analysis with a 405 nm excitation wavelength, the emission wavelength range 510 - 745 nm is used for analysis. After dividing the data into a training and a test dataset it could be shown, that bacteria are detectable in the wound area. A quantification in bacterial colonization counts (BCC) was not in the focus of the research in this study stage.

Monitoring of perfusion is a cornerstone in surgery, phlebology and basic science to proof wound healing by interventions. In chronic wound management it is of utmost importance to realize and parametrize wound bed perfusion to verify actual, and plan further treatment by noninvasive diagnostics. Up to now monitoring is based on visual inspection of wounds as conventionally practiced over more than decades. The main problems of visual inspection are the lack of standardization and comparability because of interindividual variations. Therefore technical performance with contact free probes based on standardized perfusion measuring is strongly needed. Hyperspectral imaging (HSI) was investigated to overcome manual and visual wound inspection in monitoring of wound healing. HSI works noninvasive, and imaging of relevant perfusion parameters is possible without the need of contrast enhancing drugs. METHODS: HSI technology uses imaging spectroscopic analysis in visual and near infrared spectrum to get information on imaged tissue in less than 10 s. Tissue is radiated by broad spectrum light and the following parameters are calculated from remitted spectra: the grade of oxygenation and the volume proportion of hemoglobin (in superficial and also deeper (8 mm) tissues. The calculated data comprise the "Tissue hemoglobin oxygen saturation" (StO2) as percental oxygenation index to assess superficial perfusion (VIS-spectrum), the "Near infrared perfusion" (NIR) to assess deeper perfusion (near infrared spectrum) and the "Tissue hemoglobin index" (THI) to measure the percental volume of hemoglobin of surface perfusion (VIS-spectrum). The measurements of these parameters are calculated as false color-coded perfusion results on screen. We investigated different kind ofwounds (combustion, infection, ulcerwounds,wounds in immune disorders, traumawounds) determining superficial and deeper oxygen saturation, hemoglobin distribution andwater content using hyperspectral imaging with TIVITA™ Tissue system. RESULTS: Hyperspectral Imaging allowed easy real time determination and visualization of hemodynamically relevant parameters- superficial and deeper oxygen saturation, total hemoglobin and tissue water content. In the patient with scleroderma, acral lesions with decreased perfusion correlated well with necrotic skin aspects. HSI clearly revealed macroscopic conspicuous suture wounds after Dupuytren surgery, infected soft tissue wounds with strong inflammatory hyperemia, edema in burn injuries, spatial geometry of abscess formation and chronic ulcer wounds. All measurements influenced further surveillance decisions. Hyperspectral imaging seems suitable for routine diagnostics and monitoring of skin and soft tissue lesions like acute and chronic wounds. It allows surveillance of postoperative suture wounds and burn wounds. Special indications may be transplant surveillance and monitoring of therapeutical interventions. [ABSTRACT FROM AUTHOR]

Background and objectives: Actinic keratosis (AK) is a frequent cutaneous lesion usually developing on sun-exposed skin and may be evolving into invasive squamous cell carcinoma requiring expensive therapy. Size, site or number of lesions limits the efficacy and/or acceptability of surgical and chemical therapies. Up to now photodynamic therapy (PDT) is recommended as treatment of choice. Material and methods: A patient (75y, m) suffered from recalcitrant AK lesions on the scalp, forearms and face for more than 20y. Various treatments including PDT, ablative laser and cryotherapy or chemical treatments failed to eradicate these lesions especially on the scalp. We used a CE-certified cold atmospheric plasma (CAP) jet, the Maxium® electrosurgery unit with maxium® beamer (KLS Martin GmbH + Co. KG), to treat one scalp lesion in one session (60 s, 20 W, 6 L/min). Results: CAP was able to eradicate AK of the patient in one session and was well tolerated. Histologic examination showed complete cure of AK. Control histology and visits up to 26 months after treatment do not show relapse or other skin deterioration. Conclusion: CAP seems to be an effective, curative and economic (one single treatment) alternative to conventional treatment of recalcitrant AK with field cancerization with excellent tolerability. [ABSTRACT FROM AUTHOR]

There is a lack of imaging tools for the evaluation of spatial alterations in microcirculation including blood oxygen saturation and hemoglobin distribution but recent innovative developments in hyperspectral technology may offer a solution. We examined different hemodynamic disorders in patients suffering from scleroderma, Dupuytren surgery, chronic foot ulcera and skin infections. Superficial and deeper blood oxygen saturation, hemoglobin distribution and water content were determined using hyperspectral imaging (HSI). In the patient with scleroderma, distinct cutaneous low perfused regions correlated with macroscopic skin aspects and seem to be potential therapy control marker. With HSI accurate clinical evaluation of a macroscopic conspicuous wound after Dupuytren surgery was possible and influenced further surveillance decisions. HSI clearly revealed the spatial geometry and also the clinically related perfusion parameters of abscess formation and chronic ulcer wounds. The hemodynamically relevant parameters like blood oxygen saturation (1 mm to approx. 6 mm subcutaneous), total hemoglobin distribution and tissue water content can be easily determined and visualized with HSI in near real time. Hence, this technique seems to be suitable for routine diagnostics of acute and chronic wounds as well as for the examination of systemic hemodynamic disturbances. Special indications may be transplant surveillance and monitoring of therapeutical interventions.

An important clinical potential of cold atmospheric plasma (CAP) lies in tumor and wound treatment, whereby the last-mentioned is well-referenced already. However, the underlying mechanisms of improved wound healing have not been sufficiently clarified yet, in particular the influence of CAP on microcirculation. Hyperspectral imaging (HSI) enables the visualization of microcirculation of large tissue areas, thus this technique seems to be a candidate to examine CAP effects on perfusion and oxygen saturation in wounds. During clinical wound management, one chronic wound caused by peripheral arterial occlusive disease and one acute wound after surgical removal of cervical lymph nodes were examined using HSI before and after CAP treatment. HSI was able to demonstrate CAP effects on microcirculation showing a relevant increase of superficial and deeper cutaneous oxygen saturation together with elevated hemoglobin concentration in treated and also surrounding wound area. For the first time, it was shown that CAP improves the superficial and deeper oxygenation and hemoglobin perfusion in and around the treated area of acute and chronic wounds. This effect may contribute to healing support by CAP in wounds. HSI seems suitable for evaluating and monitoring CAP effects in clinical settings.