Increased training load promotes sleep propensity and slow-wave sleep in endurance runners: Can a high-heat-capacity mattress topper modulate this effect?

The present study aimed to: (1) investigate sleep architecture in response to an overload training and taper periods among endurance runners; and (2) assess the sleep benefits of a high-heat-capacity mattress topper. Twenty-one trained male endurance runners performed a 2-week usual training regimen (baseline) followed by 2-week overload and taper periods. From overload to the end of the taper period, they were assigned into two groups based on the mattress topper used: high-heat-capacity mattress topper (n = 11) or low-heat-capacity mattress topper (n = 10). Training load was assessed daily using the session rating of perceived exertion. Following each period, sleep was monitored by polysomnography, and nocturnal core body temperature was recorded throughout the night. Irrespective of the group, awakening episodes > 5 min decreased following overload compared with baseline (-0.48, p = 0.05). Independently of mattress topper, each 100 A.U. increase in 7-day training load prior to polysomnographic recording was associated with higher slow-wave sleep proportion (ß = +0.13%; p = 0.05), lower sleep-onset latency (ß = -0.49 min; p = 0.05), and a reduction in the probability of transition from N1 sleep stage to wakefulness (ß = -0.12%; p = 0.05). Sleeping on a high-heat-capacity mattress topper did not affect any sleep variable compared with a low-heat-capacity mattress topper. Increased training loads promote slow-wave sleep and sleep propensity, highlighting the adaptative nature of sleep to diurnal activity and the role of sleep in physiological recovery. Further studies are required on the potential benefits of high-heat-capacity mattress toppers on sleep architecture among athletes.

A novel in-bed body posture monitoring for decubitus ulcer prevention using body pressure distribution mapping.

BACKGROUND: Decubitus ulcers are prevalent among the aging population due to a gradual decline in their overall health, such as nutrition, mental health, and mobility, resulting in injury to the skin and tissue. The most common technique to prevent these ulcers is through frequent repositioning to redistribute body pressures. Therefore, the main goal of this study is to facilitate the timely repositioning of patients through the use of a pressure mat to identify in-bed postures in various sleep environments. Pressure data were collected from 10 healthy participants lying down on a pressure mat in 19 various in-bed postures, correlating to the supine, prone, right-side, and left-side classes. In addition, pressure data were collected from participants sitting at the edge of the bed as well as an empty bed. Each participant was asked to lie in these 19 postures in three distinct testing environments: a hospital bed, a home bed, and a home bed with a foam mattress topper. To categorize each posture into its respective class, the pre-trained 2D ResNet-18 CNN and the pre-trained Inflated 3D CNN algorithms were trained and validated using image and video pressure mapped data, respectively. RESULTS: The ResNet-18 and Inflated 3D CNN algorithms were validated using leave-one-subject-out (LOSO) and leave-one-environment-out (LOEO) cross-validation techniques. LOSO provided an average accuracy of 92.07% ± 5.72% and 82.22% ± 8.50%, for the ResNet-18 and Inflated 3D CNN algorithms, respectively. Contrastingly, LOEO provided a reduced average accuracy of 85.37% ± 14.38% and 77.79% ± 9.76%, for the ResNet-18 and Inflated 3D CNN algorithms, respectively. CONCLUSION: These pilot results indicate that the proposed algorithms can accurately distinguish between in-bed postures, on unseen participant data as well as unseen mattress environment data. The proposed algorithms can establish the basis of a decubitus ulcer prevention platform that can be applied to various sleeping environments. To the best of our knowledge, the impact of mattress stiffness has not been considered in previous studies regarding in-bed posture monitoring.

Can a prolonged healing pressure injury be benefited by using an AI mattress? A case study.

BACKGROUND: Pressure injuries are a common and serious issue for bedridden residents in long-term-care facilities. Areas of bony prominences, such as the scapula, sacrum, and heels, are more likely to develop pressure injuries. The management of pressure injury wounds include dressing changes, repositioning, away from moisture, decreasing the occurrence of friction and shear, and more. Some supportive surfaces are also used for pressure injury cases such as gel pads, alternating pressure air mattresses, and air-fluidized beds. The aim of this case study was to determine whether the use of an artificial intelligent mattress can improve a nursing home resident with prolonged pressure injury. CASE PRESENTATION: A retrospective study design was conducted for this case study. A 79-year-old male developed a pressure injury in the sacrum. His pressure injury was initially at stage 4, with a score of 12 by the Braden scale. The PUSH score was 16. During 5.5 months of routine care plus the use of the traditional alternative air mattress, in the nursing home, the wound stayed in stage 3 but the PUSH score increased up to 11. An artificial intelligence mattress utilizing 3D InterSoft was used to detect the bony prominences and redistribute the external pressure of the skin. It implements a color guided schematic of 26 colors to indicate the amount of pressure of the skin. RESULTS: The wound size was decreased and all eczema on the resident's back diminished. The PUSH score was down to 6, as the artificial intelligent mattress was added into the routine care. The staff also reported that the resident's quality of sleep improved and moaning decreased. The hemiplegic side is at greater risk of developing pressure injury. CONCLUSIONS: This novice device appeared to accelerate wound healing in this case. In the future, more cases should be tested, and different care models or mattress can be explored.

Impact of head-of-bed elevation angle on the development of pressure ulcers and pneumonia in patients on mechanical ventilation: a systematic review and meta-analysis.

BACKGROUND: Mechanical ventilation is crucial for patient management in intensive care units, but it comes with complications such as pressure ulcers and ventilator-associated pneumonia (VAP). The impact of head-of-bed elevation angles on these complications remains a critical area for investigation. METHODS: This systematic review and meta-analysis followed PRISMA guidelines and involved searches across PubMed, Embase, Web of Science, and Cochrane Library, conducted on September 19, 2023, with no date or language restrictions. We included randomized controlled trials that compared different head-of-bed elevation angles in adult ICU patients on mechanical ventilation. Data were extracted on study characteristics, quality assessed using the Cochrane risk of bias tool, and statistical analyses performed using chi-square tests for heterogeneity and fixed or random-effects models based on heterogeneity results. RESULTS: Six studies met inclusion criteria out of an initial 601 articles. These studies showed minimal heterogeneity (I2 = 0.0% for pressure ulcers, p = 0.930; and for VAP, p = 0.797), supporting the use of fixed-effect models. Results indicated that a higher elevation angle (45°) significantly increased the risk of pressure ulcers (OR = 1.95, 95% CI: 1.12-3.37, p < 0.05) and decreased the incidence of VAP compared to a lower angle (30°) (OR = 0.51, 95% CI: 0.31-0.84, p < 0.05). CONCLUSIONS: While higher head-of-bed elevation can reduce the risk of VAP in mechanically ventilated patients, it may increase the risk of pressure ulcers. Clinical strategies should carefully balance these outcomes to optimize patient care in ICU settings. REGISTRATION: PROSPERO 2024 CRD42024570232.

Cooling during transportation of newborns with hypoxic ischemic encephalopathy using phase change material mattresses in low-resource settings: a randomized controlled trial in Hanoi, Vietnam.

OBJECTIVE: To determine the effectiveness of phase-change-material mattress (PCM) during transportation of newborns with hypoxic ischemic encephalopathy (HIE). STUDY DESIGN: Randomized controlled trial of newborns with HIE from June 2016 to December 2019. Patients were randomized to transport with PCM or without PCM (control) when transferred to a cooling center in northern Vietnam. Primary outcome measure was mortality rate, secondary outcomes including temperature control and adverse effects. RESULT: Fifty-Two patients in PCM-group and 61 in control group. Median rectal temperature upon arrival was 34.5 °C (IQR 33.5-34.8) in PCM-group and 35.1 °C (IQR 34.5-35.9) in control group (p = 0.023). Median time from birth to reach target temperature was 5.0 ± 1.4 h and 5.5 ± 1.2 h in the respective groups (p = 0.065). 81% of those transported with PCM versus 62% of infants transported without (p = 0.049) had reached target temperature within the 6-h timeframe. There was no record of overcooling (< 32 °C) in any of the groups. The was no difference in mortality rate between the two groups (33% and 34% respectively (p > 0.05)). CONCLUSION: Phase-change-material can be used as a safe and effective cooling method during transportation of newborns with HIE in low-resource settings. TRIAL REGISTRATION: The study was retro-prospectively registered in Clinical Trials (04/05/2022, NCT05361473).

Innovative air mattress for the prevention of pressure ulcers in neonates.

OBJECTIVE: Pressure ulcers (PUs) severely impact health outcomes in neonatal intensive care, with up to 28% prevalence and doubled mortality rates. Due to their only partially developed stratum corneum, neonates are highly susceptible to PUs because of a lack of adequate support surfaces. The occipital region of the head and hip are the main risk areas due to immobility and newborn body proportions. The main goal of the study was to investigate the impact of reduction in local pressure in these body areas by two air mattress designs and different filling states. METHOD: Two innovative air-filled mattress prototypes (prototype 1 and prototype 2), consisting of three different segments (head, trunk and feet regions), were developed to reduce local interface pressures by optimising pressure distribution, and were assessed with three air pressure filling states (0.2kPa, 0.4kPa and 0.6kPa). A baby doll was used to investigate pressure distribution and local pressure impact. It measured 51cm and the weight was modified to be 1.3kg, 2.3kg and 3.3kg, representing premature to term newborn weights, respectively. A specialised foam mattress and an unsupported surface were considered as controls. RESULTS: The interface pressures at the hip region for newborn models could be reduced by up to 41% with mattress prototype 1 and 49% with prototype 2 when filled with 0.2kPa air pressure. It was found that the size and the pressure inside air segments was crucial for interface pressure. CONCLUSION: Our results demonstrated that air mattresses achieved lower interface pressures compared to conventional support surfaces, and that the benefit of the air mattresses depended on their filling status. The importance of using innovative, segmented designs that were tailored to meet the specific needs of highly vulnerable paediatric patients was demonstrated.

Comparing the effectiveness of active and reactive mattresses in pressure injury healing: a pilot study.

OBJECTIVE: A feasibility study to test the proposed methodology for a larger randomised control trial was conducted, investigating the comparative effectiveness of the two types of pressure management support surfaces with regards to healing pressure injuries (PI). A secondary objective was to provide insights into the user acceptability of the two types of pressure management support surfaces. METHOD: A randomised control feasibility study was conducted in a community health setting in Canberra, Australia. Patients aged ≥65 years with an existing Stage 2 PI who slept in a bed were eligible. Participants were randomised to either the active mattress group or the reactive mattress group for use on their bed. All participants received standard wound care by community nursing staff and were provided an air-flotation cushion for use when not in bed. Photographs were taken and used for blind assessment of wound healing. Secondary information was gathered through a survey regarding user acceptability of the support surfaces and changes in habits regarding PI prevention strategies. RESULTS: In total, five patients were recruited, with one passing away prior to mattress allocation. Results were inconclusive with regards to comparative effectiveness and user acceptability due to the small sample size; however, secondary data indicated an increasing implementation of PI prevention strategies. CONCLUSION: This study confirmed the need for further high quality research comparing reactive and active pressure mattresses. Trends indicate the importance of including education on PI prevention strategies to promote changes in behaviour. Changes to the proposed methodology will be made to increase recruitment in the primary study.

Determinants of Perceived Comfort: Multi-Dimensional Thinking in Smart Bedding Design.

Sleep quality is an important issue of public concern. This study, combined with sensor application, aims to explore the determinants of perceived comfort when using smart bedding to provide empirical evidence for improving sleep quality. This study was conducted in a standard sleep laboratory in Quanzhou, China, from March to April of 2023. Perceived comfort was evaluated using the Subjective Lying Comfort Evaluation on a seven-point rating scale, and body pressure distribution was measured using a pressure sensor. Correlation analysis was employed to analyze the relationship between perceived comfort and body pressure, and multiple linear regression was used to identify the factors of perceived comfort. The results showed that body pressure was partially correlated with perceived comfort, and sleep posture significantly influenced perceived comfort. In addition, height, weight, and body mass index are common factors that influence comfort. The findings highlight the importance of optimizing the angular range of boards based on their comfort performance to adjust sleeping posture and equalize pressure distribution. Future research should consider aspects related to the special needs of different populations (such as height and weight), as well as whether users are elderly and whether they have particular diseases. The design optimization of the bed board division and mattress softness, based on traditional smart bedding, can improve comfort and its effectiveness in reducing health risks and enhancing health status.

A Review of Patient Bed Sensors for Monitoring of Vital Signs.

The analysis of biomedical signals is a very challenging task. This review paper is focused on the presentation of various methods where biomedical data, in particular vital signs, could be monitored using sensors mounted to beds. The presented methods to monitor vital signs include those combined with optical fibers, camera systems, pressure sensors, or other sensors, which may provide more efficient patient bed monitoring results. This work also covers the aspects of interference occurrence in the above-mentioned signals and sleep quality monitoring, which play a very important role in the analysis of biomedical signals and the choice of appropriate signal-processing methods. The provided information will help various researchers to understand the importance of vital sign monitoring and will be a thorough and up-to-date summary of these methods. It will also be a foundation for further enhancement of these methods.

Unobtrusive Skin Temperature Estimation on a Smart Bed.

The transition from wakefulness to sleep occurs when the core body temperature decreases. The latter is facilitated by an increase in the cutaneous blood flow, which dissipates internal heat into the micro-environment surrounding the sleeper's body. The rise in cutaneous blood flow near sleep onset causes the distal (hands and feet) and proximal (abdomen) temperatures to increase by about 1 °C and 0.5 °C, respectively. Characterizing the dynamics of skin temperature changes throughout sleep phases and understanding its relationship with sleep quality requires a means to unobtrusively and longitudinally estimate the skin temperature. Leveraging the data from a temperature sensor strip (TSS) with five individual temperature sensors embedded near the surface of a smart bed's mattress, we have developed an algorithm to estimate the distal skin temperature with a minute-long temporal resolution. The data from 18 participants who recorded TSS and ground-truth temperature data from sleep during 14 nights at home and 2 nights in a lab were used to develop an algorithm that uses a two-stage regression model (gradient boosted tree followed by a random forest) to estimate the distal skin temperature. A five-fold cross-validation procedure was applied to train and validate the model such that the data from a participant could only be either in the training or validation set but not in both. The algorithm verification was performed with the in-lab data. The algorithm presented in this research can estimate the distal skin temperature at a minute-level resolution, with accuracy characterized by the mean limits of agreement [-0.79 to +0.79 °C] and mean coefficient of determination R2=0.87. This method may enable the unobtrusive, longitudinal and ecologically valid collection of distal skin temperature values during sleep. Therelatively small sample size motivates the need for further validation efforts.

Detecting Patient Position Using Bed-Reaction Forces for Pressure Injury Prevention and Management.

A key best practice to prevent and treat pressure injuries (PIs) is to ensure at-risk individuals are repositioned regularly. Our team designed a non-contact position detection system that predicts an individual's position in bed using data from load cells under the bed legs. The system was originally designed to predict the individual's position as left-side lying, right-side lying, or supine. Our previous work suggested that a higher precision for detecting position (classifying more than three positions) may be needed to determine whether key bony prominences on the pelvis at high risk of PIs have been off-loaded. The objective of this study was to determine the impact of categorizing participant position with higher precision using the system prediction F1 score. Data from 18 participants was collected from four load cells placed under the bed legs and a pelvis-mounted inertial measurement unit while the participants assumed 21 positions. The data was used to train classifiers to predict the participants' transverse pelvic angle using three different position bin sizes (45°, ~30°, and 15°). A leave-one-participant-out cross validation approach was used to evaluate classifier performance for each bin size. Results indicated that our prediction F1 score dropped as the position category precision was increased.

Associations between bed-sharing in infancy and childhood internalizing and externalizing symptoms.

Bed-sharing is a controversial but common parenting practice with claimed benefits for emotional and behavioral development. Using data from the UK Millennium Cohort Study (N = 16,599), this prospective study investigated whether bed-sharing at 9 months is associated with childhood internalizing and externalizing symptom trajectories. Children were grouped by their patterns of co-developing internalizing and externalizing symptoms from 3 to 11 years of age using a parallel process latent class growth analysis. There were no associations between bed-sharing at 9 months of age and internalizing and externalizing symptom trajectories across childhood. This finding suggests that bed-sharing at 9 months has no positive or negative influence on the development of internalizing and externalizing symptoms across childhood. Clinicians should inform parents that bed-sharing during the second half of the first year is unlikely to have an impact on the later emotional and behavioral development of the children.

Effects of traditional and dry bed baths on patients admitted in intensive units: A randomized crossover clinical trial.

BACKGROUND: The bed bath is an important part of nursing care. There are few studies evaluating the effects of traditional and dry bed baths on patients. AIM: This study was performed with the aim of investigating the effect of traditional and dry bed baths given to intensive care unit patients on the patients' hemodynamic parameters, the duration of the bathing procedure and the cost of consumable items. METHODS: This was a randomized crossover clinical trial and a prospective study. The study was conducted in a General Surgery Intensive Care Unit with 22 intensive care patients aged 18 and over, who had a nursing diagnosis of bathing personal care deficiency. Each patient was given two types of bed baths at an interval of 24 h: a traditional bed bath and a dry bed bath performed with single-use tissues. Immediately before each bath, in the 5th, 10th and 15th minute of bathing, immediately after bathing and 30 min after bathing, body temperature, heart rate, blood pressure, breathing rate and peripheral oxygen saturation measurement changes over time were compared within the group using the Friedman test. The Wilcoxon signed ranks test was used to compare the variables of bathing duration and bathing consumable item costs between the bathing procedures. RESULTS: It was found that at the completion of traditional and dry bed bathing, the participants' body temperature, blood pressure, heart rate and breathing rate parameters were statistically significantly lower than before bathing, whereas peripheral oxygen saturation values showed a significant increase (p < 0.05). It was found that the dry bed bath took a statistically significantly shorter time than the traditional bed bath and that the cost of consumable bathing materials was less (p < 0.05). CONCLUSIONS: It was concluded that traditional and dry bed baths given to intensive care patients affected their hemodynamic parameters and that the dry bed bath was superior to the traditional bed bath in that it took less time and that it cost less.

Use of a Shear Reduction Surface for Prehospital Transport: A Randomized Crossover Study.

OBJECTIVE: To compare the effectiveness of an antishear mattress overlay (ASMO) with a standard ambulance stretcher surface in reducing pressure and shear and increasing patient comfort. METHODS: In this randomized, crossover design, adults in three body mass index categories served as their own controls. Pressure/shear sensors were applied to the sacrum, ischial tuberosity, and heel. The stretcher was placed in sequential 0°, 15°, and 30° head-of-bed elevations with and without an ASMO. The ambulance traveled a closed course, achieving 30 mph, with five stops at each head-of-bed elevation. Participants rated discomfort after each series of five runs. RESULTS: Thirty individuals participated. Each participant had 30 runs (15 with an ASMO, 15 without), for a total of 900 trial runs. The peak-to-peak shear difference between support surfaces was -0.03 N, indicating that after adjustment for elevation, sensor location, and body mass index, peak shear levels at baseline (starting pause) were 0.03 N lower for the ASMO than for the standard surface ( P = .02). The peak-to-peak pressure difference between surfaces was -0.16 mm Hg, indicating that prerun peak-to-peak pressure was 0.16 mm Hg lower with the ASMO versus standard surface ( P = .002). The heel received the most pressure and shear. Discomfort score distributions differed between surfaces at 0° ( P = .004) and 30° ( P = .01); the overall score across all elevations was significantly higher with the standard surface than with the ASMO ( P = .046). CONCLUSIONS: The ASMO reduced shear, pressure, and discomfort. During transport, the ambulance team should provide additional heel offloading.

Incidence of Pressure Injuries in Patients at Risk Using a Powered Alternating Pressure Air Mattress: A Noninterventional Study in a Real-World Setting.

PURPOSE: The aim of the study was to determine the clinical value of using a powered alternating pressure air mattress (P-APAM) in the prevention of pressure injury (PI) in patients at medium to high risk. DESIGN: Noncomparative, observational study. SUBJECTS AND SETTING: The sample comprised 86 patients who were >18 years old, were classified as having medium to high risk of PI, had no PI at baseline, and were lying more than 15 hours a day on a specific P-APAM. Data were collected between September 2018 and July 2019, in 4 nursing homes, and 1 long-term care geriatrics hospital department in France. METHODS: In addition to guideline-based care for PI prevention, patients were followed up for 35 days following placement on the P-APAM. The main outcome was the percentage of patients who developed between day 0 and day 35 at least 1 PI of at least stage 2 on the sacrum, spine, or heel. Secondary outcomes were patient assessments of comfort, caregiver satisfaction, mattress noise level, and mattress safety. RESULTS: No patients experienced a PI (incidence = 0%; 95% confidence interval, 0.00%-4.28%). Patients were satisfied or very satisfied with the mattress in most cases in terms of comfort (77.9%) and stability (73.0%). Patients also rated the noise level of the mattress as satisfactory or very satisfactory in all cases (100%). CONCLUSION: When combined with guideline-based PI prevention measures, use of the P-APAM was associated with a low incidence of PI.

Characterizing the Compressive Force at L5/S1 During Patient Transfer From Bed to Wheelchair.

The peak compressive forces at L5/S1 during patient transfers have been estimated. However, no study has considered the actual patient body weight that caregivers had to handle during transfers. We developed a simple kinematic model of lifting to address this limitation. Fifteen prospective health care providers transferred a 70-kg individual who mimicked a patient ("patient") from bed to wheelchair. Trials were acquired with the patient donning (weighted) and doffing (unweighted) a 5-kg weight belt. Trials were also acquired with and without knee assistance and a mechanical lift. During trials, kinematics and kinetics of transfers were recorded to estimate the peak compressive force at L5/S1 using static equilibrium equations. The peak compressive force was associated with the transfer method (P < .0005), and the compressive force was 68% lower in lift-assisted than manual transfer (2230 [SD = 433] N vs 6875 [SD = 2307] N). However, the peak compressive force was not associated with knee assistance, nor with a change in the patient body weight. Our results inform that mechanical loading exceeding the National Institute for Occupational Safety and Health safety criterion occurs during patient transfers, confirming a high risk of lower back injuries in caregivers. However, the risk can be mitigated with the use of a mechanical lift.

Significant reduction in full-thickness pressure injuries through the quality improvement project that implements alternating pressure air mattresses.

To assess a quality improvement project using alternating pressure air mattresses' impact on reducing full-thickness pressure injuries by enhancing setting accuracy and device utilization. We retrospectively evaluated adult acute care unit patients with inclusion criteria (Braden scores ≤12 or existing full-thickness pressure injuries) between May 2020 and August 2023. A wound team attempted to enhance the accuracy, utilization and effectiveness of alternating pressure air mattress implementation. The implementation outcomes were setting accuracy and accurate utilization rates. The clinical outcome was the full-thickness pressure injury proportion. Utilization and allocation gaps were also calculated. The setting accuracy and accurate utilization rates increased (0.59 to 0.88 and 0.15 to 0.37, respectively). The full-thickness pressure injury proportion decreased (0.17 to 0.06), with a strong negative correlation coefficient (-0.789) (p < 0.001) with accurate utilization rates. The full-thickness pressure injury proportion declined faster during the project's complete phase than the partial phase (-0.0046 vs. -0.0016; p < 0.05). The utilization gap narrowed (99 to 60); however, the allocation gap increased (1 to 13), suggesting increased alternating pressure air mattress usage among ineligible patients. Targeting high-risk patients for alternating pressure air mattress utilization and ensuring correct settings, both performed by a dedicated team, substantially reduces the full-thickness pressure injury incidence.

Organizational development and management factors involved in the prevention and effective therapy of pressure ulcers: The results of the national survey conducted among Hungarian public hospitals.

The prevention of pressure ulcer (PU) or pressure injury (PI) wounds is of public health importance in developed countries, including Hungary. The study aimed to assess the PU/PI prevention and care practices of Hungarian public hospitals and identify organizational and management factors. In 2022, a national, questionnaire-based survey of inpatient institutions relevant to PU/PI care was conducted, providing a picture of the practices of 86 hospitals for the year 2019. The questionnaire was processed using descriptive statistics and regression analysis. The survey results show that good practices in Hungary are isolated, the reporting system is inhomogeneous, and documentation is not uniform across our institutional system. Of the 86 institutions, 71.0% operate a PU prevention team, 64.0% use prophylactic dressings, and 88.3% use an anti-decubitus mattress, with an average ratio of 26.1% to the number of beds. Less than half of the institutions reported the incidence of hospital acquired pressure injuries (HAPIs). In this sample, we found no significant association between hospital type and hospital size with the incidence of full-thickness HAPIs (stage III and IV wounds). Developing a comprehensive PU/PI reporting system and updating the national PU/PI prevention and care guidelines are essential in Hungary.

Effects of a mattress cover with special airflow technology on the structure and function of the sacral and heel skin during loading: A two-arm exploratory crossover trial.

Prolonged mechanical loading of the skin and underlying soft tissue cause pressure ulceration. The use of special support surfaces are key interventions in pressure ulcer prevention. They modify the degree and duration of soft tissue deformation and have an impact on the skin microclimate. The objective of this randomized cross-over trial was to compare skin responses and comfort after lying for 2.5 h supine on a support surface with and without a coverlet that was intended to assist with heat and moisture removal at the patient/surface interface. In addition, physiological saline solution was administered to simulate an incontinence episode on the mattress next to the participants' skin surface. In total, 12 volunteers (mean age 69 years) with diabetes mellitus participated. After loading, skin surface temperature, stratum corneum hydration and skin surface pH increased, whereas erythema and structural stiffness decreased at the sacral area. At the heel skin area, temperature, erythema, and stratum corneum hydration increased. These results indicate occlusion and soft tissue deformation which was aggravated by the saline solution. The differences in skin response showed only minor differences between the support surface with or without the coverlet.

[Modeling and comfort analysis of arrayed air cushion mattress for pressure ulcer prevention and assisted repositioning].

Assisting immobile individuals with regular repositioning to adjust pressure distribution on key prominences such as the back and buttocks is the most effective measure for preventing pressure ulcers. However, compared to active self-repositioning, passive assisted repositioning results in distinct variations in force distribution on different body parts. This incongruity can affect the comfort of repositioning and potentially lead to a risk of secondary injury, for certain trauma or critically ill patients. Therefore, it is of considerable practical importance to study the passive turning comfort and the optimal turning strategy. Initially, in this study, the load-bearing characteristics of various joints during passive repositioning were examined, and a wedge-shaped airbag configuration was proposed. The airbags coupled layout on the mattress was equivalently represented as a spring-damping system, with essential model parameters determined using experimental techniques. Subsequently, different assisted repositioning strategies were devised by adjusting force application positions and sequences. A human-mattress force-coupled simulation model was developed based on rigid human body structure and equivalent flexible springs. This model provided the force distribution across the primary pressure points on the human body. Finally, assisted repositioning experiments were conducted with 15 participants. The passive repositioning effectiveness and pressure redistribution was validated based on the simulation results, experimental data, and questionnaire responses. Furthermore, the mechanical factors influencing comfort during passive assisted repositioning were elucidated, providing a theoretical foundation for subsequent mattress design and optimization of repositioning strategies.