The Effects of Incontinence Pad Application on Loaded Skin With Reference to Biophysical and Biochemical Parameters: An Exploratory Cohort Study Using a Repeated-Measures Design.

PURPOSE: The purpose of this study was to evaluate temporal changes in skin responses following exposure to moisture alone or moisture in combination with mechanical loading. DESIGN: Comparison cohort with a repeated-measures design. SUBJECTS AND SETTINGS: The sample comprised 12 healthy volunteers. Participants were purposely sampled from 2 different age groups; half were 32 to 39 years old and half were 50 to 62 years old. Participants identified as White, Black, or mixed; 83% (n = 10) identified as White; 8 (67%) were female. METHODS: Four sites at the sacrum were challenged with the application of specimens taken from 2 absorbent products; the pad specimens were applied dry or saturated with synthetic urine (SU; pH = 8); a further site from the sacral skin was also selected and used as a control. Skin assessments were performed at different points in time: (1) 60 minutes after exposure to dry or SU-saturated pad specimens; (2) 60 minutes after exposure to pads and mechanical loading (application of pressure in the form of 45°C high sitting); and (3) 30 minutes after removal of all pads (recovery period). Outcome measures were transepidermal water loss (TEWL), stratum corneum (SC) hydration, erythema, pH, and skin inflammatory biomarkers measured at each of the time points described earlier. RESULTS: The control site and those exposed to dry pads showed minimal time-dependent changes irrespective of the parameter investigated. In contrast, significant increases in TEWL (P = .0000007) and SC hydration responses (P = .0000007) were detected at the sites under absorbent pad specimens after saturation with SU (exposure to moisture). In some participants, TEWL and SC hydration parameters were significantly higher during pressure application. Skin pH remained in the mildly acidic range throughout the test session, and no consistent trends were observed with erythema. Skin inflammatory biomarkers also exhibited considerable variability across participants; none changed significantly over time. Significant differences (P = .02) were also detected following the exposure of moisture in combination with pressure. CONCLUSION: We evaluated an array of parameters to identify changes following skin exposure to 2 absorbent pads in the presence and absence of SU and mechanical loading. Analysis revealed changes in skin barrier properties in the presence of moisture and/or pressure. This observation suggests a need for frequent pad changing as well as periods of skin off-loading to protect the skin health of individuals with incontinence.

Characterisation of superficial corneocyte properties over category I pressure ulcers: Insights into topographical and maturation changes.

BACKGROUND: Pressure ulcers (PUs) are chronic wounds that are detrimental to the quality of life of patients. Despite advances in monitoring skin changes, the structure and function of skin cells over the site of pressure ulcers are not fully understood. OBJECTIVE: The present study aims to evaluate local changes in the properties of superficial corneocytes in category 1 PU sites sampled from a cohort of hospitalised patients. METHODS: Cells were collected from a PU-compromised site and an adjacent control area and their topographical, maturation and mechanical properties were analysed. RESULTS: Corneocytes at the PU-compromised site were characterised by higher levels of immature cornified envelopes (p < 0.001) and greater amounts of desmoglein-1 (corneodesmosomal protein) (p < 0.001) compared to the adjacent control area. The cells at the control site presented the typical ridges-and-valleys topographical features of sacrum corneocytes. By contrast, the PU cells presented circular nano-objects at the cell surface, and, for some patients, the cell topography was deformed. CEs at the PU site were also smaller than at the control site. Although differences were not observed in the mechanical properties of the cells, those of the elderly patients were much softer compared with young subjects. CONCLUSION: This is the first study investigating the changes in corneocyte properties in category I pressure ulcers. Superficial cells at the PU sites showed altered topographical and maturation characteristics. Further studies are required to elucidate if these changes are a consequence of early loss of skin integrity or a result of mechanical and microclimate insults to the skin surface.

Evaluation of in-shoe plantar pressure and shear during walking for diabetic foot ulcer prevention.

OBJECTIVE: To investigate reliability and changes of in-shoe plantar pressure and shear during walking at three cadences with two insole designs. This was a precursor to the investigation of plantar loading in people with diabetes for potential foot ulcer prevention. METHOD: A sensorised insole system, capable of measuring plantar pressure and shear at the heel, fifth metatarsal head (5MH), first metatarsal head (1MH) and hallux, was tested with ten healthy participants during level walking. Reliability was evaluated, using intra-class correlation coefficient (ICC), while varying the cadences and insole types. Percentage changes in pressure and shear relative to values obtained at self-selected cadence with a flat insole design were investigated. RESULTS: Mean±standard deviation of maximum pressure, medial-lateral and anterior-posterior shear of up to 380±24kPa, 46±2kPa and -71±4kPa, respectively, were measured. The ICC in ranges of 0.762-0.973, 0.758-0.987 and 0.800-0.980 were obtained for pressure, anterior-posterior and medial-lateral shear, respectively. Opposite anterior-posterior shear directions between 5MH and 1MH (stretching), and between 1MH and hallux (pinching) were observed for some participants. Increasing cadence increased pressure and anterior-posterior shear (by up to +77%) but reduced medial-lateral shear at the heel and hallux (by up to -34%). Slower cadence increased anterior-posterior shear (+114%) but decreased medial-lateral shear (-46%) at the hallux. The use of a flexible contoured insole resulted in pressure reduction at the heel and 5MH but an increase in anterior-posterior shear at the heel (+69%) and hallux (+75%). CONCLUSION: The insole system demonstrated good reliability and is comparable to reported pressure-only systems. Pressure measurements were sensitive to changes in cadence and insole designs in ways that were consistent with the literature. However, our plantar shear showed localised shear changes with cadences and insoles for the first time, as well as stretching and pinching effects on plantar tissue. This opens new possibilities to investigate plantar tissue viability, loading characteristics and orthotic designs aimed towards foot ulcer prevention.

Spatial and temporal changes in biophysical skin parameters over a category I pressure ulcer.

In acute care facilities, the detection of pressure ulcers (PUs) relies on visual and manual examination of the patient's skin, which has been reported to be inconsistent and may lead to misdiagnosis. In skin and wound research, various biophysical parameters have been extensively employed to monitor changes in skin health. Nonetheless, the transition of these measures into care settings as part of a routine clinical assessment has been limited. This study was designed to examine the spatial and temporal changes in skin biophysical parameters over the site of a category I PU, in a cohort of hospitalised patients. Thirty patients, each presenting with a category I PU, were enrolled in the study. Skin integrity was assessed at the PU-compromised site and two adjacent areas (5 and 10 cm away). Data was collected over three sessions to examine both temporal differences and longitudinal changes. Skin integrity was assessed using two biophysical parameters, namely, transepidermal water loss (TEWL) and stratum corneum (SC) hydration. In addition, the influence of intrinsic factors, namely, incontinence and mobility status, on the parameters was evaluated. TEWL values at the sites compromised by PU were statistically significantly greater (P < .001) than corresponding values at the adjacent control sites at 5 and 10 cm, which were consistent with a normative range (<20 g/h/m2 ). By contrast, SC hydration values did not reveal clear distinctions between the three sites, with high inter-patient variation detected at the sites. Nevertheless, individual profiles were consistent across the three sessions, and the PU site was observed to be either abnormally dry or overhydrated in different individuals. No consistent temporal trend in either parameter was evident. However, intrinsic factors were shown to influence the parameters, with females, bedridden and incontinent patients presenting significantly higher TEWL and SC hydration values (P < .05). TEWL was able to identify differences in skin responses at skin sites compromised with a category I PU when compared to healthy adjacent skin sites. Accordingly, this parameter could be included in the clinical assessment for the identification of PU risk. Further studies are required to elucidate the role of hydration and skin barrier function in the development of PUs and their ability to monitor temporal changes in skin integrity.

Inflammatory biomarkers in sebum for identifying skin damage in patients with a Stage I pressure ulcer in the pelvic region: A single centre observational, longitudinal cohort study with elderly patients.

Pressure Ulcers (PU) are a major burden for affected patients and healthcare providers. Current detection methods involve visual assessments of the skin by healthcare professionals. This has been shown to be subjective and unreliable, with challenges associated with identifying erythema in darker colour skin. Although there exists a number of promising non-invasive biophysical techniques such as ultrasound, capacitance measurements, and thermography, the present study focuses on directly measuring the changes in the inflammatory status of the skin and underlying tissues. Therefore, in this study, we aim to analyse inflammatory cytokines collected through non-invasive sampling techniques to detect early signs of skin damage. Thirty hospitalised patients presenting with Stage I PU were recruited to evaluate the inflammatory response of skin at the site of damage and an adjacent healthy control site. Sebutapes were collected over three sessions to investigate the temporal changes in the inflammatory response. The panel of cytokines investigated included high-abundance cytokines, namely, IL-1α and IL-1RA, and low abundance cytokines; IL-6, IL-8, TNF-α, INF-γ, IL-33, IL-1ß and G-CSF. Spatial and temporal differences between sites were assessed and thresholds were used to determine the sensitivity and specificity of each biomarker. The results suggest significant (P < .05) spatial changes in the inflammatory response, with upregulation of IL-1α, IL-8, and G-CSF as well as down-regulation of IL-1RA over the Stage I PU compared with the adjacent control site. There were no significant temporal differences between the three sessions. Selected cytokines, namely, IL-1α, IL-1RA, IL-8, G-CSF, and the ratio IL-1α/IL-1RA offered clear delineation in the classification of healthy and Stage-I PU skin sites, with receiver operating characteristic curves demonstrating high sensitivity and specificity. There were limited influences of intrinsic and extrinsic factors on the biomarker response. Inflammatory markers provided a high level of discrimination between the sites presenting with Stage I PU and an adjacent healthy skin site, in a cohort of elderly inpatients. Indeed, the ratio of IL-1α to IL-1RA provided the highest sensitivity and specificity, indicative that inflammatory homeostasis is affected at the PU site. There was a marginal influence of intrinsic and extrinsic factors, demonstrating the localised effects of the inflammation. Further studies are required to investigate the potential of inflammatory cytokines incorporated within Point of Care technologies, to support routine clinical use.

A Wearable Insole System to Measure Plantar Pressure and Shear for People with Diabetes.

Pressure coupled with shear stresses are the critical external factors for diabetic foot ulceration assessment and prevention. To date, a wearable system capable of measuring in-shoe multi-directional stresses for out-of-lab analysis has been elusive. The lack of an insole system capable of measuring plantar pressure and shear hinders the development of an effective foot ulcer prevention solution that could be potentially used in a daily living environment. This study reports the development of a first-of-its-kind sensorised insole system and its evaluation in laboratory settings and on human participants, indicating its potential as a wearable technology to be used in real-world applications. Laboratory evaluation revealed that the linearity error and accuracy error of the sensorised insole system were up to 3% and 5%, respectively. When evaluated on a healthy participant, change in footwear resulted in approximately 20%, 75% and 82% change in pressure, medial-lateral and anterior-posterior shear stress, respectively. When evaluated on diabetic participants, no notable difference in peak plantar pressure, as a result of wearing the sensorised insole, was measured. The preliminary results showed that the performance of the sensorised insole system is comparable to previously reported research devices. The system has adequate sensitivity to assist footwear assessment relevant to foot ulcer prevention and is safe to use for people with diabetes. The reported insole system presents the potential to help assess diabetic foot ulceration risk in a daily living environment underpinned by wearable pressure and shear sensing technologies.

Characterisation of superficial corneocytes in skin areas of the face exposed to prolonged usage of respirators by healthcare professionals during COVID-19 pandemic.

INTRODUCTION: During the COVID-19 pandemic healthcare workers (HCWs) have used respiratory protective equipment for prolonged periods, which has been associated with detrimental effects on the underlying skin. The present study aims to evaluate changes in the main cells (corneocytes) of the stratum corneum (SC) following prolonged and consecutive use of respirators. METHODS: 17 HCWs who wore respirators daily during routine hospital practice were recruited to a longitudinal cohort study. Corneocytes were collected via tape stripping from a negative control site (area outside the respirator) and from the cheek which was in contact with the device. Corneocytes were sampled on three occasions and analysed for the level of positive-involucrin cornified envelopes (CEs) and the amount of desmoglein-1 (Dsg1), as indirect measurements of immature CEs and corneodesmosomes (CDs), respectively. These were compared to biophysical measurements (Transepidermal water loss, TEWL, and SC hydration) at the same investigation sites. RESULTS: A large degree of inter-subject variability was observed, with maximum coefficients of variation of 43% and 30% for the level of immature CEs and Dsg1, respectively. Although it was observed that there was not an effect of prolonged respirator usage on the properties of corneocytes, the level of CDs was greater at the cheek than the negative control site (p < 0.05). Furthermore, low levels of immature CEs correlated with greater TEWL values after prolonged respirator application (p < 0.01). It was also noted that a smaller proportion of immature CEs and CDs was associated with a reduced incidence of self-reported skin adverse reactions (p < 0.001). CONCLUSIONS: This is the first study that investigated changes in corneocyte properties in the context of prolonged mechanical loading following respirator application. Although differences were not recorded over time, the levels of CDs and immature CEs were consistently higher in the loaded cheek compared to the negative control site and were positively correlated with a greater number of self-reported skin adverse reactions. Further studies are required to evaluate the role of corneocyte characteristics in the evaluation of both healthy and damaged skin sites.

Development of an Efficient Extraction Methodology to Analyse Potential Inflammatory Biomarkers from Sebum.

INTRODUCTION: Proteins, such as cytokines and chemokines, are present in varying concentrations in a range of biofluids, with an important signalling role in maintaining homeostasis. Commercial tapes have been employed to non-invasively collect these potential biomarkers in sebum from the skin surface to examine their concentrations in conditions including acne, atopic dermatitis, and pressure ulcers. However, the identification of robust biomarker candidates is limited by the low abundance of specific proteins extracted by current methodologies. Therefore, this study was designed to develop an optimized extraction method for potential inflammatory biomarkers in sebum collected with Sebutapes. METHODS: Commercial tapes (Sebutapes) coated with synthetic sebum were used to systematically evaluate the effects of chemical and mechanical stimuli on extraction efficiency. Varying concentrations of high- and low-abundance biomarkers (IL-1α, IL-6, IL-8, INF-γ, TNF-α, and IL-1RA) were used to spike the synthetic sebum samples. Methodological variables included different surfactants, mechanical stimuli, and buffer volume. Extraction efficiency was estimated using immunoassay kits from the extracted buffer. RESULTS: The results revealed that the use of a surfactant, i.e., ß-dodecyl maltoside, in addition to the mechanical stimuli, namely, sonication and centrifugation, resulted in an increased recovery of cytokines, ranging from 80% for high-abundant cytokines, such as IL-1α and IL-1RA, and up to 50% for low-abundance cytokines, including TNF-α, IL-6 and IL-8. Compared to previous methods, the new extraction protocol resulted in between a 1.5-2.0-fold increase in extraction efficiency. CONCLUSION: The study revealed that there was a high degree of variability in the extraction efficiency of different cytokines. However, improved efficiency was achieved across all cytokines with selective surfactants and mechanical stimuli. The optimised protocol will provide means to detect low levels of potential biomarkers from skin surface, enabling the evaluation of local changes in pro- and anti-inflammatory cytokines present in different skin conditions.

A systematic review of movement monitoring devices to aid the prediction of pressure ulcers in at-risk adults.

The present study sought to explore the impact of movement monitoring devices on risk prediction and prevention of pressure ulcers (PU) among adults. Using systematic review methodology, we included original research studies using a prospective design, written in English, assessing adult patients' movement in bed, using a movement monitoring device. The search was conducted in March 2021, using PubMed, CINAHL, Scopus, Cochrane, and EMBASE databases, and returned 1537 records, of which 25 met the inclusion criteria. Data were extracted using a pre-designed extraction tool and quality appraisal was undertaken using the evidence-based librarianship (EBL). In total, 19 different movement monitoring devices were used in the studies, using a range of physical sensing principles. The studies focused on quantifying the number and types of movements. In four studies the authors compared the monitoring system with PU risk assessment tools, with a variety of high and low correlations observed. Four studies compared the relationship between movement magnitude and frequency and the development of PUs, with variability in results also identified. Two of these studies showed, as expected, that those who made less movements developed more PU; however, the two studies also unexpectedly found that PUs occurred in both low movers and high movers. In the final two studies, the authors focused on the concordance with recommended repositioning based on the results of the monitoring device. Overall, concordance with repositioning increased with the use of a monitoring device. The synthesis of the literature surrounding bed monitoring technologies for PU risk prediction showed that a range of physical sensors can be used to detect the frequency of movement. Clinical studies showed some correlation between parameters of movement and PU risk/incidence, although the heterogeneity of approaches limits generalisable recommendations.

Continuous pressure monitoring of inpatient spinal cord injured patients: implications for pressure ulcer development.

STUDY DESIGN: Cohort observational study. OBJECTIVES: To examine the movement profiles of individuals with spinal cord injury (SCI) during their inpatient rehabilitative phase using continuous pressure monitoring (CPM), evaluating the trends in those with skin damage. SETTING: SCI specialist rehabilitation centre in the United Kingdom. METHODS: Individuals with SCI (n = 12) were assessed using CPM in the bed and chair over a 24-72 h. Pressure data was used as a surrogate for movement using both nursing interpretation and an intelligent algorithm. Clinical features were obtained including participants age, injury level, ASIA score, co-morbidities and prescribed support surfaces. Trends between movement profiles (frequency and intervals), SCI demographics and observed skin damage were assessed using cross-tabulation and histograms. RESULTS: The data revealed significant correlations (p < 0.05) between the nursing observation and algorithm for predicting movement, although the algorithm was more sensitive. Individuals with high level injuries (C1-T6) were observed to have a lower frequency of movement and larger intervals between movements when compared to low level injuries (T7-L5) during both lying and sitting periods. The individuals observed to have skin damage were predominantly those who had both a low frequency of movement and extended gaps between movements. CONCLUSIONS: Movements for pressure relief in both the bed and chair environments were dependent on the level of injury in individuals with SCI during their inpatient rehabilitation. Distinct movement patterns corresponded with those who acquired skin damage, revealing the potential clinical applications for technologies to monitor PU risk and inform personalised care.

A combined imaging, deformation and registration methodology for predicting respirator fitting.

N95/FFP3 respirators have been critical to protect healthcare workers and their patients from the transmission of COVID-19. However, these respirators are characterised by a limited range of size and geometry, which are often associated with fitting issues in particular sub-groups of gender and ethnicities. This study describes a novel methodology which combines magnetic resonance imaging (MRI) of a cohort of individuals (n = 8), with and without a respirator in-situ, and 3D registration algorithm which predicted the goodness of fit of the respirator. Sensitivity analysis was used to optimise a deformation value for the respirator-face interactions and corroborate with the soft tissue displacements estimated from the MRI images. An association between predicted respirator fitting and facial anthropometrics was then assessed for the cohort.

Biomechanical and Physiological Evaluation of Respiratory Protective Equipment Application.

Purpose: Respiratory protective equipment is widely used in healthcare settings to protect clinicians whilst treating patients with COVID-19. However, their generic designs do not accommodate the variability in face shape across genders and ethnicities. Accordingly, they are regularly overtightened to compensate for a poor fit. The present study aims at investigating the biomechanical and thermal loads during respirator application and the associated changes in local skin physiology at the skin-device interface. Materials and Methods: Sixteen healthy volunteers were recruited and reflected a range of gender, ethnicities and facial anthropometrics. Four single-use respirators were evaluated representing different geometries, size and material interfaces. Participants were asked to wear each respirator in a random order while a series of measurements were recorded, including interface pressure, temperature and relative humidity. Measures of transepidermal water loss and skin hydration were assessed pre- and post-respirator application, and after 20 minutes of recovery. Statistical analysis assessed differences between respirator designs and associations between demographics, interface conditions and parameters of skin health. Results: Results showed a statistically significant negative correlation (p < 0.05) between the alar width and interface pressures at the nasal bridge, for three of the respirator designs. The nasal bridge site also corresponded to the highest pressures for all respirator designs. Temperature and humidity significantly increased (p < 0.05) during each respirator application. Significant increases in transepidermal water loss values (p < 0.05) were observed after the application of the respirators in females, which were most apparent at the nasal bridge. Conclusion: The results revealed that specific facial features affected the distribution of interface pressures and depending on the respirator design and material, changes in skin barrier function were evident. The development of respirator designs that accommodate a diverse range of face shapes and protect the end users from skin damage are required to support the long-term use of these devices.

An Exploratory Study of the Effects of the pH of Synthetic Urine on Skin Integrity in Healthy Participants.

BACKGROUND: Incontinence-associated dermatitis (IAD) develops from prolonged exposure of skin to urine and/or stool and represents a common complication in older adults, reducing the quality of life. Increased pH is an important etiologic factor of IAD; however, the relationship between urinary pH and skin barrier disruption remains unclear. OBJECTIVE: The aim of this study is to examine the effects of synthetic urine (s-urine) at various pHs on transepidermal water loss (TEWL), stratum corneum hydration (SCH), and skin surface pH. METHODS: S-urine solutions (pH 5.0-9.0) were applied to the volar forearms of 15 healthy participants for 2 h, with another site serving as the untreated control. Measurements of TEWL, SCH, and skin surface pH were obtained at baseline (BL) and after each challenge. Skin buffering capacity was also examined in 5 volunteers by recording skin pH at BL, after 2 h exposure and every 5 min for 40 min. RESULTS: TEWL and SCH were increased following exposure to s-urine compared to BL values. Although there was a tendency for pH to increase after exposure, further investigation showed that changes are only temporal as pH value is restored to BL within 5 mins. There were no significant differences between solutions. CONCLUSIONS: This study revealed that urine disrupts healthy skin integrity; however, its effects are not pH dependent. Transient changes were observed on the acid mantle of the skin due to its innate buffering capacity. Future studies need to examine the effects of urine combined with bacteria responsible for pH elevation in patients with urinary incontinence.

Development of ultra-high-performance supercritical fluid chromatography-mass spectrometry assays to analyze potential biomarkers in sweat.

Liquid chromatography-mass spectrometry methods were required to afford the rapid separation and detection of purines and small organic acids. These compounds are found in sweat and sebum and are potential biomarkers for the early detection of pressures sores. Two ultra-high-performance supercritical fluid chromatography-mass spectrometry assays have been successfully developed for both classes of compounds. Separation for purines was achieved using a gradient of supercritical carbon dioxide and methanol with a 1-aminoanthracene sub 2 µm particle size column followed by positive ion electrospray ionization. Separation for organic acids was achieved using a gradient of supercritical carbon dioxide and methanol (50 mM ammonium acetate 2% water) with a Diol sub 2 µm particle size column followed by negative ion electrospray ionization. Calibration curves were created in the absence of internal standards and R2 values > 0.96 were achieved using single ion monitoring methods for the protonated purines and the deprotonated acids. The two new assays afford rapid analytical methods for the separation and detection of potential biomarkers in human sweat leading to the early detection and prevention of pressure sores.

Quantifying skin sensitivity caused by mechanical insults: A review.

BACKGROUND: Skin sensitivity (SS) is a commonly occurring response to a range of stimuli, including environmental conditions (e.g., sun exposure), chemical irritants (e.g., soaps and cosmetics), and mechanical forces (e.g., while shaving). From both industry and academia, many efforts have been taken to quantify the characteristics of SS in a standardised manner, but the study is hindered by the lack of an objective definition. METHODS: A review of the scientific literature regarding different parameters attributed to the loss of skin integrity and linked with exhibition of SS was conducted. Articles included were screened for mechanical stimulation of the skin, with objective quantification of tissue responses using biophysical or imaging techniques. Additionally, studies where cohorts of SS and non-SS individuals were reported have been critiqued. RESULTS: The findings identified that the structure and function of the stratum corneum and its effective barrier properties are closely associated with SS. Thus, an array of skin tissue responses has been selected for characterization of SS due to mechanical stimuli, including: transepidermal water loss, hydration, redness, temperature, and sebum index. Additionally, certain imaging tools allow quantification of the superficial skin layers, providing structural characteristics underlying SS. CONCLUSION: This review proposes a multimodal approach for identification of SS, providing a means to characterise skin tissue responses objectively. Optical coherence tomography (OCT) has been suggested as a suitable tool for dermatological research with clinical applications. Such an approach would enhance the knowledge underlying the multifactorial nature of SS and aid the development of personalised solutions in medical and consumer devices.

Detection of posture and mobility in individuals at risk of developing pressure ulcers.

Pressure mapping technologies provide the opportunity to estimate trends in posture and mobility over extended periods in individuals at risk of developing pressure ulcers. The aim of the study was to combine pressure monitoring with an automated algorithm to detect posture and mobility in a vulnerable population of Spinal Cord Injured (SCI) patients. Pressure data from able-bodied cohort studies involving prescribed lying and sitting postures were used to train the algorithm. This was tested with data from two SCI patients. Variations in the trends of the centre of pressure (COP) and contact area were assessed for detection of small- and large-scale postural movements. Intelligent data processing involving a deep learning algorithm, namely a convolutional neural network (CNN), was utilised for posture classification. COP signals revealed perturbations indicative of postural movements, which were automatically detected using individual- and movement-specific thresholds. CNN provided classification of static postures, with an accuracy ranging between 70-84% in the training cohort of able-bodied subjects. A clinical evaluation highlighted the potential of the novel algorithm to detect postural movements and classify postures in SCI patients. Combination of continuous pressure monitoring and intelligent algorithms offers the potential to objectively detect posture and mobility in vulnerable patients and inform clinical-decision making to provide personalized care.

Investigating the release of inflammatory cytokines in a human model of incontinence-associated dermatitis.

Incontinence-associated dermatitis (IAD) is a painful complication in elderly patients, leading to reduced quality of life. Despite recent attention, its underlying inflammatory mechanisms remain poorly understood. This study was designed to quantify the release of inflammatory cytokines in a human model of IAD. The left volar forearm of ten healthy volunteers was exposed to synthetic urine and synthetic faeces for 2 h, simulating the effects of urinary and faecal incontinence, respectively, and the subsequent cytokine response compared to that of an untreated control site. Inflammatory cytokines were collected using both the Sebutape® absorption method and dermal microdialysis and quantified using immunoassays. Results from the former demonstrated an upregulation in IL-1α, IL-1RA and TNF-α. Synthetic urine caused a higher median increase in IL-1α from baseline compared to synthetic faeces, whereas synthetic faeces were associated with significantly higher median TNF-α levels compared to synthetic urine (p = 0.01). An increase in IL-1α/IL-1RA ratio was also observed with significant differences evident following exposure to synthetic urine (p = 0.047). Additionally, microdialysis revealed a time-dependent increase in IL-1ß and IL-8 following exposure of up to 120 min to synthetic urine and synthetic faeces, respectively. This study demonstrated the suitability of both sampling approaches to recover quantifiable cytokine levels in biofluids for the assessment of skin status following exposure to synthetic fluids associated with incontinence. Findings suggest some differences in the inflammatory mechanisms of IAD, depending on moisture source, and the potential of the cytokines, IL-1α and TNF-α, as responsive markers of early skin damage caused by incontinence.

The identification of biophysical parameters which reflect skin status following mechanical and chemical insults.

BACKGROUND: Skin is constantly exposed to mechanical and chemical insults, in the form of prolonged loading, overhydration or exposure to irritants. An array of non-invasive biophysical tools has been adopted to monitor the changes in skin response. The present study aims to identify a set of robust parameters sensitive to mechanical and chemical challenges to skin integrity. MATERIALS AND METHODS: Eleven healthy participants were recruited to evaluate the skin response following mechanical loading, tape stripping, overhydration and chemical irritation. Forearm skin responses were recorded at baseline and at three time points following the insult. Measurements included transepidermal water loss, sub-epidermal moisture, erythema and laser Doppler imaging. Thresholds were informed by basal values, and the sensitivity of parameters to detect skin changes was evaluated. RESULTS: High degree of variability in skin response was observed with selected biophysical parameters, such as sub-epidermal moisture, laser Doppler imaging and erythema, even in the absence of an applied insult. Temporal skin response revealed distinct response profiles during each evoked insult. Indeed, the sensitivity of the biophysical parameters was influenced by the threshold values and time point of measurement. Some statistically significant correlations were determined between the biophysical parameters. CONCLUSION: The study revealed that thresholds derived from single biophysical parameters were limited in detecting skin changes following insults. A complementary evaluation using combined parameters has the potential to provide a more sensitive assessment. Further research is required to identify robust biophysical parameters, to aid the early detection of skin damage in clinical settings.