1,721,063 research outputs found
The complex interplay between mechanical forces, tissue response and individual susceptibility to pressure ulcers
No full textObjective: The most recent edition of the International Clinical Practice Guideline for the Prevention and Treatment of Pressure Ulcers/Injuries was released in 2019. Shortly after, in 2020, the first edition of the SECURE Prevention expert panel report, focusing on device-related pressure ulcers/injuries, was published as a special issue in the Journal of Wound Care. A second edition followed in 2022. This article presents a comprehensive summary of the current understanding of the causes of pressure ulcers/injuries (PU/Is) as detailed in these globally recognised consensus documents. Method: The literature reviewed in this summary specifically addresses the impact of prolonged soft tissue deformations on the viability of cells and tissues in the context of PU/Is related to bodyweight or medical devices. Results: Prolonged soft tissue deformations initially result in cell death and tissue damage on a microscopic scale, potentially leading to development of clinical PU/Is overtime. That is, localised high tissue deformations or mechanical stress concentrations can cause microscopic damage within minutes, but it may take several hours of continued mechanical loading for this initial cell and tissue damage to become visible and clinically noticeable. Superficial tissue damage primarily stems from excessive shear loading on fragile or vulnerable skin. In contrast, deeper PU/Is, known as deep tissue injuries, typically arise from stress concentrations in soft tissues at body regions over sharp or curved bony prominences, or under stiff medical devices in prolonged contact with the skin. Conclusion: This review promotes deeper understanding of the pathophysiology of PU/Is, indicating that their primary prevention should focus on alleviating the exposure of cells and tissues to stress concentrations. This goal can be achieved either by reducing the intensity of stress concentrations in soft tissues, or by decreasing the exposure time of soft tissues to such stress concentrations. Declaration of interest: The author has no conflicts of interest
Impact of Skin Tone on Skin Tolerance to Shear in the Context of Pressure Injuries: Theory and Computer Modeling
No full textOBJECTIVETo investigate the impact of darker skin tones on skin tolerance to shear forces in the context of pressure injuries (PIs) and explore the mechanobiological hypothesis that people with darker skin may be at an increased PI risk due to altered biomechanical skin properties resulting from a lower water content (WC) as some literature suggests. METHODSThe authors developed a computational modeling framework simulating skin with varying Poisson ratios to represent different WC levels in the stratum corneum (SC), focusing on the effects of ethnicity and WC on mechanical stresses in superficial skin during weightbearing postures. Mechanical properties of the tissues were based on literature values. Pure compression and compression with shear were applied to the skin model. RESULTSA lower Poisson ratio in the SC, indicating lower WC, is associated with higher tissue stresses and more intense stress concentrations, especially under combined compression and shear loading. The initial reduction in the Poisson ratio had the most significant impact on increased tissue loading. These results support the hypothesis that the lower WC in darker skin, associated with increased transepidermal water loss, may lead to altered biomechanical behavior and increased PI risk. CONCLUSIONSThe modeling suggests that reduced WC and increased transepidermal water loss, notably present in darker skin tones, lead to higher stress concentrations within the SC, thus elevating the PI risk. Comprehensive clinical and biomechanical data across various skin tones are needed to improve the practice of PI prevention in individuals with darker skin.Acknowledgments:
This work was partially supported by the Israeli Ministry of Science & Technology (Medical Devices Program grant 3-17421, awarded to Prof Amit Gefen in 2020). The authors have disclosed no other financial relationships related to this article. Submitted August 22, 2023; accepted in revised form April 16, 2024
Little news is good news? What is missing in the recently published EN 13726:2023 test standard for wound dressings
No full textSpecial thanks to Ms. Victoria Teng of Mölnlycke Health Care for organizing fluid handling capacity testing
A Markov cost-effectiveness modeling framework for evaluating wound dressings: A concept for practical implementation of economic evaluations in an informed dressing selection process
No full textAims: Exemplify the potential of using health economy modeling and simulations to support and optimize wound dressing purchasing decisions. Materials and methods: We developed a Markov cost-effectiveness modeling framework fusing clinical and industry sources of healing and cost outcomes for evaluating dressings, focusing on polymeric membrane dressings compared to passive foam dressings without active inflammation modulation components. We calculated the wound care costs for patients with and without diabetes, as well as for infected and non-infected wounds, to illustrate the effectiveness of this model in supporting decision-making. Results: The model results demonstrated that polymeric membrane dressings reduce the cumulative treatment costs compared to passive foam dressings, due to fewer dressing changes and lower associated labor costs, regardless of the initial product price differences. Conclusion: Cost-effectiveness calculations should be performed in healthcare facilities to support purchasing decisions based on true cost analyses. Making purchasing decisions focusing on the dressing price alone may provide wrong estimates of the real cost differences.This work was partially supported by the Israeli Ministry of Science & Technology (Medical Devices Program Grant no. 3-17421, awarded to Professor Amit Gefen in 2020) and by an unrestricted educational grant from Ferris Mfg. Corp. (Fort Worth, TX, USA)
Revisiting negative pressure wound therapy from a mechanobiological perspective supported by clinical and pathological data
No full textNegative pressure wound therapy is used often in the management of surgical incisions, chronic wounds and subacute lesions, and there are numerous publications discussing its clinical application and outcomes. However, whilst clinical use and associated literature have expanded since these systems became commercially available in the 90s, important research and discussion around the mode of action have waned, leading to a deficit in the understanding of how this important therapy influences healing. Further, much research and many publications are predominantly reflective, discussing early theorem, some of which have been proven incorrect, or at least not fully resolved leading to misunderstandings as to how the therapy works, thus potentially denying the clinician the opportunity to optimise use towards improved clinical and economic outcomes. In this narrative review, we discuss established beliefs and challenges to same where appropriate and introduce important new research that addresses the manner in which mechanical strain energy (i.e., deformations) is transferred to tissue and how this influences biological response and healing. In addition, we assess and discuss the effect of different negative pressure dressing formats, how they influence the mode of action and how this understanding can lead to more efficient and effective use and clinical economic outcomes.Funding informationMinistry of Innovation, Science andTechnology, Grant/Award Number:001702603; Mölnlycke Health Car
Utilizing Image Processing Techniques for Wound Management and Evaluation in Clinical Practice: Establishing the Feasibility of Implementing Artificial Intelligence in Routine Wound Care
No full textOBJECTIVE: To develop a generalizable and accurate method for automatically analyzing wound images captured in clinical practice and extracting key wound characteristics such as surface area measurement. METHODS: The authors used image processing techniques to create a robust algorithm for segmenting pressure injuries from digital images captured by nurses during clinical practice. The algorithm also measured the real-world wound surface area. They used the hue-saturation-value color space to analyze red color values and to detect and segment the wound region within the entire image. To assess the accuracy of the algorithm's wound segmentation, the authors compared the results against wound image annotations. RESULTS: The algorithm performed impressively, achieving an intersection-over-union score of up to 0.85 and 100% intersection with the annotations. The algorithm effectively analyzed wound images obtained during clinical practice and accurately extracted the surface area of the documented pressure injuries. These results support the feasibility and applicability of this methodology. CONCLUSIONS: Accurate determination of wound size and healing supports decision-making regarding treatment and is essential to successful outcomes. This innovative approach for visual assessment of chronic wounds highlights the potential of computerized wound analysis in clinical practice. By leveraging advanced computational techniques, healthcare providers can gain valuable insights into wound progression, enabling more accurate assessments to support their decision-making.This work was supported by a competitive grant from the Victorian Medical Research Acceleration Fund, with funding co-contribution from the Department of Nursing at the University of Melbourne, the Melbourne Academic Centre for Health, and Mölnlycke Health Care. This work was also partially supported by the Israeli Ministry of Science & Technology (Medical Devices Program grant no. 3-17421, awarded to Professor Amit Gefen in 2020). The authors thank Ms Carla Bondini for her assistance with data collection and management for this study and Mr Daniel Kapp for proofreading the manuscript. The authors have disclosed no other financial relationships related to this article. Submitted February 1, 2024; accepted in revised form April 16, 2024. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.ASWCjournal.com)
The frictional energy absorber effectiveness and its impact on the pressure ulcer prevention performance of multilayer dressings
No full textPressure ulcers including heel ulcers remain a global healthcare concern. This study comprehensively evaluates the biomechanical effectiveness of the market-popular ALLEVYN (R) LIFE multilayer dressing in preventing heel ulcers. It focuses on the contribution of the frictional sliding occurring between the non-bonded, fully independent layers of this dressing type when the dressing is protecting the body from friction and shear. The layer-on-layer sliding phenomenon, which this dressing design enables, named here the frictional energy absorber effectiveness (FEAE), absorbs approximately 30%-45% of the mechanical energy resulting from the foot weight, friction and shear acting to distort soft tissues in a supine position, thereby reducing the risk of heel ulcers. Introducing the novel theoretical FEAE formulation, new laboratory methods to quantify the FEAE and a review of relevant clinical studies, this research underlines the importance of the FEAE in protecting the heels of at-risk patients. The work builds on a decade of research published by our group in analysing and evaluating dressing designs for pressure ulcer prevention and will be useful for clinicians, manufacturers, regulators and reimbursing bodies in assessing the effectiveness of dressings indicated or considered for prophylactic use.This project has received funding from the EuropeanUnion's Horizon 2020 research and innovation pro-gramme under the Marie Skłodowska-Curie Grant Agree-ment No. 811965; project STINTS (Skin Tissue Integrityunder Shear). This work was also partially supported bythe Israeli Ministry of Science & Technology (MedicalDevices Program Grant no. 3-17421, awarded to ProfessorAmit Gefen in 2020). In addition, Smith & Nephew Lim-ited provided financial funding for this study
Soft-Tissue Simulation for Cranio-Maxillofacial Surgery: Clinical Needs and Technical Aspects
No full textComputerized soft-tissue simulation can provide unprecedented means for predicting facial outlook pre-operatively. Surgeons can virtually perform several surgical plans to have the best surgical results for their patients while considering corresponding soft-tissue outcome. It could be used as an interactive communication tool with their patients as well. There has been comprehensive amount of works for simulating soft-tissue for cranio-maxillofacial surgery. Although some of them have been realized as commercial products, none of them has been fully integrated into clinical practice due to the lack of accuracy and excessive amount of processing time. In this chapter, state-of-the-art and general workflow in facial soft-tissue simulation will be presented, along with an example of patient-specific facial soft-tissue simulation method
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