1,720,981 research outputs found
Bioengineering considerations in the prevention of medical device-related pressure ulcers
No full textBackgroundIn recent years, it has become increasingly apparent that medical device-related pressure ulcers represent a significant burden to both patients and healthcare providers. Medical devices can cause damage in a variety of patients from neonates to community based adults. To date, devices have typically incorporated generic designs with stiff polymer materials, which impinge on vulnerable soft tissues. As a result, medical devices that interact with the skin and underlying soft tissues can cause significant deformations due to high interface pressures caused by strapping or body weight.MethodsThis review provides a detailed analysis of the latest bioengineering tools to assess device related skin and soft tissue damage and future perspectives on the prevention of these chronic wounds. This includes measurement at the device-skin interface, imaging deformed tissues, and the early detection of damage through biochemical and biophysical marker detection. In addition, we assess the potential of computational modelling to provide a means for device design optimisation and material selection.InterpretationFuture collaboration between academics, industrialists and clinicians should provide the basis to improve medical device design and prevent the formation of these potentially life altering wounds. Ensuring clinicians report devices that cause pressure ulcers to regulatory agencies will provide the opportunity to identify and improve devices, which are not fit for purpose
Innovating for improvement - improving pressure damage prevention and treatment in the community using continuous pressure monitoring
No full textEach year, approximately half a million people in the UK develop pressure ulcers (PUs), with most occurring in the community among individuals with underlying comorbidities, frailty, mobility issues and a dependence on carers. Pressure relief is essential for healing, however, some patients find pressure-relieving equipment uncomfortable, hot and noisy, thus refusing to use it and are, therefore, often labelled as non-concordant. This service improvement project evaluated the ForeSite PT® pressure monitor to identify PU risk, support healing and influence patient and carer decision making, assessing its useability, alongside patient and carer education. The technology consisted of a mattress-and chair-sized pressure map, connected to a monitor showing a visual image of the pressure points and recording over a prolonged period (>24 hours). Results were shared with 44 participants (patient and carers), leading to adjustments in care. Continuous pressure monitoring (CPM), combined with postural advice resulted in improved outcomes. While the technology enhanced healing and prevention, its use in home settings presented challenges. Overall, the pre-post approach in a real-world setting demonstrated that technology-driven education and tailored interventions improve PU management and patient empowerment.</p
An evaluation of fluid immersion therapy for the prevention of pressure ulcers
No full textBackground: Individuals with impaired mobility can spend prolonged periods on support surfaces, increasing their risk of developing pressure ulcers. Manufacturers have developed mattresses to maximise contact area. The present study evaluated both the biomechanical and physiological responses to lying postures on a Fluid Immersion Simulation mattress.Methods: Seventeen healthy participants were recruited to evaluate the mattress during three prescribed settings of immersion (high, medium and low). Parameters reflecting biomechanical and physiological responses, and the microclimate were monitored during three postures (supine, lateral and high-sitting) over a 90 minute test session. Transcutaneous oxygen and carbon dioxide gas responses were categorised according to three criteria and data were compared between each condition.Findings: Results indicated that interface pressures remained consistent, with peak sacral values ranging from 21 to 27 mm Hg across all immersion settings and postures. The majority of participants (82%) exhibited minimal changes in gas tensions at the sacrum during all test conditions. By contrast, three participants exhibited decreased oxygen with increased carbon dioxide tensions for all three immersion settings. Supine and high sitting sacral microclimate values ranged between 30.1–30.6 °C and 42.3–44.5% for temperature and relative humidity respectively. During lateral tilt there was a reduction of 1.7–2.5 °C and 3.3–5.3% in these values. The majority of participants reported high comfort scores, although a few experienced bottoming out during the high-sitting posture at the high immersion setting.Interpretation: Fluid Immersion Simulation provides an intelligent approach to increase the support area. Further research is required to provide evidence based guidance on the use of personalised support surfaces
Registering a methodology for imaging and analysis of residual-limb shape after transtibial amputation
No full textSuccessful prosthetic rehabilitation following lower-limb amputation depends upon a safe and comfortable socket-residual limb interface. Current practice predominantly uses a subjective, iterative process to establish socket shape, often requiring several visits to a prosthetist. This study ??proposes an objective methodology for residual-limb shape scanning and analysis by high-resolution, automated measurements. A 3-D printed "analog" residuum was scanned with three surface digitizers on 10 occasions. Accuracy was measured by the scan-height error between repeat analog scans and the computer-aided design (CAD) geometry and the scan versus CAD volume. Subsequently, 20 male residuum casts from ambulatory individuals with transtibial amputation were scanned by two observers, and 10 were repeat-scanned by one observer. The shape files were aligned spatially, and geometric measurements were extracted. Repeatability was evaluated by intraclass correlation, Bland-Altman analysis of scan volumes, and pairwise root-mean-square error ranges of scan area and width profiles. Submillimeter accuracy was achieved when scanning the analog shape using white light and laser scanning technologies. Scanning male residuum casts was highly repeatable within and between observers. The analysis methodology technique provides clinical researchers and prosthetists the capability to establish their own quantitative, objective, multipatient datasets. This could provide an evidence base for training, long-term follow-up, and interpatient outcome comparison, for decision support in socket design
Investigating the influence of intermittent and continuous mechanical loading on skin through non-invasive sampling of IL-1α
No full textPressure ulcers (PUs) are a major burden to both patients, carers and the healthcare system. It is therefore important to identify patients at risk and detect pressure ulcers at an early stage of their development. The pro-inflammatory cytokine IL-1α is a promising indicator of tissue damage. The aim of this study was to compare the temporal skin response, by means of IL-1α expression, to different loading regimens and to investigate the presence of individual variability. The sacrum of eleven healthy volunteers was subjected to two different loading protocols. After a baseline measurement, the left and right side of the sacrum were subjected to continuous and intermittent loading regimen, respectively, at a pressure of 100 mmHg. Data was collected every 20 min, allowing for a total experimental time of 140 min. Sebum, collected at ambient conditions using Sebutape, was analyzed for the pro-inflammatory cytokine IL-1α. Most robust results were obtained using a baseline normalization approach on individual data. The IL-1α level significantly changed upon load application and removal (p<0.05) for both loading regimens. Highest IL-1α ratio increase, 3.7-fold, was observed for 1 h continuous loading. During the refractory periods for both loading regimen the IL-1α levels were still found to be up-regulated compared to baseline (p<0.05). The IL-1α level increased significantly for the two initial loading periods (p<0.05), but stabilized during the final loading period for both loading regimens. Large individual variability in IL-1α ratio was observed in the responses, with median values of 1.91 (range 1.49–3.08), and 2.52 (range 1.96–4.29), for intermittent and continuous loading, respectively, although the differences were not statistically significant. Cluster analysis revealed the presence of two distinct sub-populations, with either a low or high response to the applied loading regimen. The measurement after the first loading period proved to be representative for the subsequent measurements on each site. This study revealed that trends in normalized IL-1α provided an early indicator for tissue status following periods of mechanical loading and refractory unloaded conditions. Additionally, the observed individual variability in the response potentially identifies patients at risk of developing PUs.</p
Evaluating the effects of sedentary behaviour on plantar skin health in people with diabetes
No full textBackground
Diabetes-Related Foot Ulcers (DRFUs) are a common and devastating consequence of Diabetes Mellitus and are associated with high morbidity, mortality, social and economic costs. Whilst peak plantar pressures during gait are implicated cited as a major contributory factor, DRFU occurrence has also been associated with increased periods of sedentary behaviour. The present study was designed aimed to assess the effects of sitting postures on plantar tissue health.
Methods
After a period of acclimatisation, transcutaneous oxygen tensions (TCPO2) and inflammatory cytokines (IL-1α and IL-1RA) were measured at the dorsal and plantar aspects of the forefoot before, during and after a 20-min period of seated-weight-bearing in participants with diabetes (n = 11) and no diabetes (n = 10). Corresponding interface pressures at the plantar site were also measured.
Results
During weight-bearing, participants with diabetes showed increases in tissue ischaemia which were linearly correlated proportional to plantar pressures (Pearson's r = 0.81; p < 0.05). Within the healthy group, no such correlation was evident (p > 0.05). There were also significant increases in post seated weight-bearing values for ratio for IL-1α and IL-1RA, normalised to total protein, post seated weight-bearing in participants with diabetes compared to healthy controls.
Conclusion
This study shows that prolonged sitting may be detrimental to plantar skin health. It highlights the need to further examine the effects of prolonged sitting in individuals, who may have a reduced tolerance to loading in the plantar skin and soft tissues
Pressure signatures can influence tissue response for individuals supported on an alternating pressure mattress
No full textProlonged mechanical loading can lead to the breakdown of skin and underlying tissues which can, in turn, develop into a pressure ulcer. The benefits of pressure relief and/or redistribution to minimise risk have been well documented. Manufacturers have developed alternating air pressure mattresses (APAMs) to provide periodic relief for individuals on prolonged bed-rest. The present study describes the development of a control system, termed Pneumatic Manager which can vary the signature of an APAM, namely its pressure amplitude, cell profile and cycle period. An experimental array was designed to investigate the effects of varying these parameters, particularly with respect to its ability to maintain skin viability in a group of five healthy volunteers lying in a supine position. Transcutaneous gas (TcPO2/TcPCO2) tensions at the sacrum were monitored. In addition, pressures and microclimate parameters at the loaded support interface were also measured.In the majority of test conditions the alternating support produced sacral TcPO2 values, which either remained relatively high or fluctuated in concert with cycle period providing adequate viability. However, in 46% of cases at the extreme pressure amplitude of 100/0 mmHg, there was compromise to the skin viability at the sacrum, as reflected in depressed TcPO2 levels associated with an elevation of TcPCO2 levels above the normal range. In all cases, both the humidity and temperature levels increased during the test period. It is interesting to note that interface pressures at the sacrum rarely exceeded 60 mmHg. Although such studies need to be extended to involve bed-bound individuals, the results provide a design template for the optimum pressure signatures of APAM systems to ensure maintenance of skin viability during pronged loading
Insights into the spectrum of transtibial prosthetic socket design from expert clinicians and their digital records
No full textBackground: transtibial prosthetic sockets are often grouped into patella tendon bearing (PTB) or total surface bearing (TSB) designs, but many variations in rectifications are used to apply these principles to an individual's personalised socket. Prosthetists currently have little objective evidence to assist them as they make design choices. Aims: to compare rectifications made by experienced prosthetists across a range of patient demographics and limb shapes to improve understanding of socket design strategies. Methodology: 163 residual limb surface scans and corresponding CAD/CAM sockets were analysed for 134 randomly selected individuals in a UK prosthetics service. This included 142 PTB and 21 TSB designs. The limb and socket scans were compared to determine the location and size of rectifications. Rectifications were compiled for PTB and TSB designs, and associations between different rectification sizes were assessed using a variety of methods including linear regression, kernel density estimation (KDE) and a Naïve Bayes (NB) classification. Results: differences in design features were apparent between PTB and TSB sockets, notably for paratibial carves, gross volume reduction and distal end elongation. However, socket designs varied across a spectrum, with most showing a hybrid of the PTB and TSB principles. Pairwise correlations were observed between the size of some rectifications (e.g., paratibial carves; fibular head build and gross volume reduction). Conversely, the patellar tendon carve depth was not associated significantly with any other rectification, indicating its relative design insensitivity. The Naïve Bayes classifier produced design patterns consistent with expert clinician practice. For example, subtle local rectifications were associated with a large volume reduction (i.e., a TSB-like design), whereas more substantial local rectifications (i.e., a PTB-like design) were associated with a low volume reduction. Clinical implications: this study demonstrates how we might learn from design records to support education and enhance evidence-based socket design. The method could be used to predict design features for newly presenting patients, based on categorisations of their limb shape and other demographics, implemented alongside expert clinical judgement as smart CAD/CAM design templates.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
