The effect of seat shape on the risk of pressure ulcers using discomfort and interface pressure measurements

2013 ◽  
Vol 38 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Lorna H Tasker ◽  
Nigel G Shapcott ◽  
Alan J Watkins ◽  
Paul M Holland
Keyword(s):  
Pressure Ulcer ◽  
Pressure Ulcers ◽  
Three Dimensional ◽  
Support Surface ◽  
Pressure Measurements ◽  
Interface Pressure ◽  
Pressure Mapping ◽  
Shape Acquisition ◽  
Surrogate Measures ◽  
Interface Pressures

Background: It is clinically known that shape is important when selecting or designing a wheelchair support surface for the prevention of pressure ulcers (a £2 billion annual cost to the National Health Service, UK); however, the effect of different levels of shape contouring has not been adequately studied. Objectives: To investigate the effect of seat shape on the risk of pressure ulcers using discomfort and interface pressure measurements. Study design: Randomised, repeated trial. Methods: Thirty able-bodied participants sat with restricted movement for 30 min in three sessions to evaluate two cushion shapes against a flat baseline surface. Visual Analog Scaling and pressure mapping were used to measure surrogates for pressure ulcer risk, discomfort and interface pressures, respectively. Results: Linear regression revealed a reduction in discomfort ( p < 0.05) on the custom contoured shapes. Interface pressures measured were also lower ( p < 0.05) on the custom contoured shapes, and a negative Pearson’s correlation ( p < 0.05) indicated an association between smaller hip widths and increased discomfort for the commercially shaped cushion. Conclusions: The results of this study confirm that custom contoured shapes were effective at reducing pressure ulcer surrogate measures in the participants of this study and therefore suggests that the contribution of a cushion’s three-dimensional contours on pressure ulcer risk should be further researched. Clinical relevance The measurement of seat shape, discomfort and interface pressure in surrogate participants can help inform the design of wheelchair seating for individuals who are insensate or otherwise at risk of developing pressure ulcers. This knowledge can now be implemented using modern three-dimensional shape acquisition, analysis and fabrication technologies.

Interface Pressure at Different Degrees of Backrest Elevation With Various Types of Pressure-Redistribution Surfaces

2014 ◽  
Vol 23 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Juliane Lippoldt ◽  
Elisabeth Pernicka ◽  
Thomas Staudinger
Keyword(s):  
Healthy Volunteers ◽  
Pressure Ulcers ◽  
Ventilator Associated Pneumonia ◽  
Interface Pressure ◽  
Trendelenburg Position ◽  
Pressure Mapping ◽  
Air Suspension ◽  
Interface Pressures ◽  
Peak Pressures ◽  
Reverse Trendelenburg Position

BackgroundIncreased elevation of the head of the bed is linked to a higher risk for sacral pressure ulcers. A semirecumbent position of at least 30° is recommended for the prevention of ventilator-associated pneumonia in patients treated with mechanical ventilation. Therefore, prevention of pressure ulcers and prevention of pneumonia seem to demand contradictory, possibly incompatible, positioning.ObjectivesTo measure pressure at the interface between sacral skin and the supporting surface in healthy volunteers at different degrees of upright position with different types of mattresses.MethodsAn open, prospective, randomized crossover trial was conducted with 20 healthy volunteers. Interface pressure was measured by using a pressure mapping device with the participant in a supine position at 0, 10°, 30°, and 45° elevation and in the reverse Trendelenburg position at 10° and 30°. Four types of mattresses were examined: 2 different foam mattresses and 2 air suspension beds, 1 of the latter with low-air-loss technology.ResultsPeak sacral interface pressures increased significantly only at 45° of backrest elevation (P &lt; .001). A mattress system with low-air-loss technology significantly reduced peak interface pressures at all angles (P &lt; .001). The reverse Trendelenburg position led to lower peak pressures for all positions (P = .01).ConclusionsBackrest elevation up to 30° might be a compromise between the seemingly incompatible demands of skin integrity and the prevention of ventilator-associated pneumonia. The reverse Trendelenburg position and a mattress system with low-air-loss technology could be additional useful tools to help prevent skin breakdown at the sacrum.

A Pressure Modulating Sensorized Soft Actuator Array for Pressure Ulcer Prevention

2017 ◽  
Author(s):  
Wei Carrigan ◽  
Pavan Nuthi ◽  
Charu Pande ◽  
Caleb P. Nothnagle ◽  
Muthu B. J. Wijesundara
Keyword(s):  
Pressure Ulcer ◽  
Time Pressure ◽  
Soft Materials ◽  
Pressure Profile ◽  
The Body ◽  
Support Surface ◽  
Ulcer Formation ◽  
Interface Pressure ◽  
Promising Alternative ◽  
Pressure Modulation

Pressure ulcers are a serious reoccurring complication among wheelchair users with impaired mobility and sensation. It is postulated that external mechanical loading, specifically on bony prominences, is a major contributing factor in pressure ulcer formation. Prevention strategies mainly center on reducing the magnitude and duration of external forces acting upon the body. Seat cushion technologies for reducing pressure ulcer prevalence often employ soft materials and customized cushion geometries. Air cell arrays used in time-based pressure modulation techniques are seen as a promising alternative; however, this approach could be further enhanced by adding real-time pressure profile mapping to enable automated pressure modulation customizable for each user’s condition. The work presented here describes the development of a prototype support surface and pressure modulation algorithm which can monitor interface pressure as well as automatically offload and redistribute concentrated pressure. This prototype is comprised of arrays of sensorized polymeric soft air cell actuators which are modulated by a pneumatic controller. Each actuator’s pressure can be changed independently which results in a change to the interface pressure allowing us to offload targeted regions and provide local adjustment for redistribution. The pressure mapping, redistribution, and offloading capabilities of the prototype are demonstrated using pressure modulation algorithms described here.

scholarly journals A Comparative Study of 2-Hour Interface Pressure in Different Angles of Laterally Inclined, Supine, and Fowler’s Position

2021 ◽  
Vol 18 (19) ◽  
pp. 9992
Author(s):  
Soo-Yeon Kim ◽  
Yong-Soon Shin
Keyword(s):  
Comparative Study ◽  
Pressure Difference ◽  
Pressure Ulcers ◽  
Peak Pressure ◽  
Area Ratio ◽  
The Other ◽  
Pressure Measurements ◽  
Interface Pressure ◽  
Risk Area ◽  
Position Change

Insufficient research exists for position change intervals to eradicate pressure ulcers. We tried to provide evidence for the position change interval by comparing peak pressure, risk area ratio, and the time to reach 30 mmHg and 60 mmHg, and presented this in detail, according to the angle in the three positions. The study conducted RCTs on a total of 64 healthy adults. For two hours, interface pressure measurements were compared with 30° and 90° tilting at the inclined, 0° and 45° head-of-bed (HOB) elevation at the supine, and 30° and 45° HOB elevation at the Fowler’s position. The peak pressure on 30° tilting remained less than 60 mmHg for 2 h, unlike 90° tilting. To reach 60 mmHg took 78.18 min at 30° tilting, within 30 min at the 30° supine, 30° and 45° at the Fowler’s position, and 39.55 min at 0° supine. The pressure difference according to the angles was only significant at 30° and 90° tilting, with no difference in the other groups. To prevent pressure ulcers, position changes are required every 2 h in the 30° tilting position, every 1.5 to 2 h at 0° supine, and at least every 1.5 h for all the other positions.

Role of Patient Specifics on Mechanical Risk and Load Relief During Support of Bony Prominences

2013 ◽  
Author(s):  
Ahmet Erdemir
Keyword(s):  
Pressure Ulcer ◽  
Pressure Ulcers ◽  
Region Of Interest ◽  
Clinical Effectiveness ◽  
Incidence Rates ◽  
Patient Specific ◽  
Support Surface ◽  
Load Relief ◽  
Bony Prominence ◽  
Pressure Ulcer Development

Prolonged mechanical loading of tissue in between a bony prominence and a support surface can lead to pressure ulcers. Despite recent initiatives to curb down incidence rates, the health care burden of pressure ulcer prevention remains significant [1]. Etiology of pressure ulcers are commonly attributed to interface pressures. As a result, interventions, e.g., support surfaces, routinely aim to reduce contact pressures. However, the clinical effectiveness of such an objective can be questionable [2]. Recent studies have shown that internal mechanics of the tissue can be associated with pressure ulcer development [3], potentially indicating the inefficacy of interventions targeted solely at contact pressure relief. Tissue characteristics at a bony prominence, e.g., tissue thickness and material properties, also influence load distribution within and on the surface of the tissue. Given the variability in patient populations and for a bony region of interest [4], it is possible that patient specific risk and load relief (with the use of support surface) may differ widely.

Relationship between socket pressure and EMG of two muscles in trans-femoral stumps during gait

2005 ◽  
Vol 29 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Jung Hwa Hong ◽  
Mu Seong Mun
Keyword(s):  
Muscle Activity ◽  
Three Dimensional ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Interface Pressure ◽  
Prosthetic Socket ◽  
In Trans ◽  
Pressure Changes ◽  
Interface Pressures ◽  
Socket Interface

The biomechanical interaction between the leg stump and the prosthetic socket is critical in achieving close-to-normal ambulation. Although many investigations have been performed to understand the biomechanics of trans-tibial sockets, few studies have measured the socket interface pressure for trans-femoral amputees. Furthermore, no report has examined how the residual muscle activities in the trans-femoral stump affect the socket interface pressure characteristics during gait. In this study, an experimental method was developed to measure the trans-femoral socket interface pressures and EMG of muscles in the stumps of two trans-femoral amputees. Also, the measurement of three-dimensional prosthetic locomotion was synchronized to understand detailed socket biomechanics. Based on the experimental results, a significant correlation ( P 50.05) was found between the measured temporal EMG amplitude and the interface pressure at the knee flexor (biceps femoris) and extensor (rectus femoris). Therefore, the residual muscle activity of a trans-femoral amputee's stump could be an important factor affecting socket-interface pressure changes during ambulation.

scholarly journals Towards the Development of an Alternating Pressure Overlay for the Treatment of Pressure Ulcers Using Miniaturised Air Cells

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 33
Author(s):  
Malindu Ehelagastenna ◽  
Ishan Sumanasekara ◽  
Hishan Wickramasinghe ◽  
Indrajith D. Nissanka ◽  
Gayani K. Nandasiri
Keyword(s):  
Pressure Ulcers ◽  
High Pressures ◽  
Integrated Control ◽  
Control Unit ◽  
Back Pressure ◽  
The Body ◽  
Support Surface ◽  
Interface Pressure ◽  
Tissue Pressure ◽  
Actuator System

This paper presents a study on design and development of an alternating pressure overlay consists of inflatable mini air bladders, which could be used in relieving and reducing tissue pressure for the treatment of pressure ulcers. Pressure ulcers, which are predominant in the bony prominences of the body, is a skin deformity due to the limitation of blood circulation to the muscle tissues as a result of high pressures applied on the skin for longer duration. This research aims to design miniaturised air bladders which could provide alternating pressure sequences for the treatment of the pressure ulcers. The optimally designed air bladders provide proper envelopment of the patient’s body and create a high resolution of pressure distribution. The optimum geometry and the 3-D deformation profile of the air bladders are analysed using the finite element method. Based on the interface pressure the pressure overlay has been divided into five pressure zones. Furthermore, the real-time interface pressure profile between the body and the overlay is mapped by using the back pressure of mini air bladders. The actuator system includes an integrated control unit that regulates the internal pressures via electropneumatic valves operated based on the back pressure sensor feedback. This actuator system provides the alternating pressure patterns required for inflation and deflation of the mini air bladders controlling the airflow of the support surface, providing proper pressure distributions to heal the ulcers.

scholarly journals Reviewing the Literature on the Effectiveness of Pressure Relieving Movements

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Rachel Schofield ◽  
Alison Porter-Armstrong ◽  
May Stinson
Keyword(s):  
At Risk ◽  
Pressure Ulcer ◽  
Pressure Ulcers ◽  
Ischial Tuberosity ◽  
Pressure Ulcer Prevention ◽  
Interface Pressures ◽  
Ischial Tuberosities ◽  
Ulcer Prevention

Sitting for prolonged periods of time increases seating interface pressures, which is known to increase the risk of developing pressure ulcers. Those at risk of developing pressure ulcers are advised to perform pressure relieving movements such as “pushups” or “forward leans” in order to reduce the duration and magnitude of pressure acting on the vulnerable ischial tuberosity region. The aim of this review was to synthesize and critique the existing literature investigating the effectiveness of pressure relieving movements on seating interface pressures. The twenty-seven articles included in this paper highlight the need for further research investigating the effect of recommended pressure relieving movements on the pressures around the ischial tuberosities. Furthermore, this review found that the majority of individuals at risk of developing pressure ulcers do not adhere with the pressure relieving frequency or magnitude of movements currently recommended, indicating a need for pressure ulcer prevention to be explored further.

Functional textiles for prevention of pressure ulcers – a review

2020 ◽  
Vol 24 (3) ◽  
pp. 185-198
Author(s):  
Monica Puri Sikka ◽  
Samridhi Garg
Keyword(s):  
Pressure Ulcer ◽  
Critical Analysis ◽  
Pressure Ulcers ◽  
Future Research ◽  
Support Surface ◽  
Content Type ◽  
Functional Textiles ◽  
Spacer Fabric ◽  
The Future ◽  
Common Man

Purpose This paper aims to summarize researches conducted related to functional textiles for prevention of pressure ulcers and critical analysis of the outcomes to pave path for the future research in this area for benefit of the patients. Pressure ulcers, also known as bed sores, pressure sores and decubitus ulcers, are localized areas of tissue damage that develop due to pressure usually over a bony prominence. A standard hospital mattress has an interface pressure of 100 mmHg which can result in pressure ulcers unless repositioning occurs at regular intervals. Moisture accumulation on the skin is an important physical factor predisposing a patient to the occurrence of pressure ulcers and tissue breakdown. The disability leads to several requirements of functional clothing and textile products. The textiles play a variety of roles in this concern, from simply having good aesthetic appearance to preventing life threatening risks. An ideal support surface prevents pressure ulcers by providing pressure redistribution and maintaining a healthy skin microenvironment. The use of the textiles for the care of elderly disabled and bedridden persons can play an important role, as their quality of life can be improved by making use of functional and good-looking textiles. Design/methodology/approach This review paper aims to summarize researches conducted related to functional textiles for prevention of pressure ulcers and critical analysis of the outcomes to pave path for the future research in this area for benefit of the patients. Findings In the past years, there have been several functional textiles developed for the prevention of pressure ulcer. They are designed to maintain proper microclimate around patient skin. Sheepskin is one of the oldest used bed overlays which prevent pressure ulcer but its prolonged use leads to uneasy feeling for the patient. A sensor in bed for pressure detection is one of the good alternatives as it provides proper indication on when to change the position of the patient so that the pressure can be shifted and ulcers is prevented. These sensors are costly and complex to setup so for common man they are not easily available. Multilayer textiles on the other hand are complex to make as the properties are dependent upon the fiber content, yarn structure, fabric structure and technique of layering them together. Spacer fabric provides good air and moisture permeability, but there is a scope to study this type of fabric by varying the fibers type and thickness of the spacer fabric. A bedding material which is not much complex and can be easily purchased and used by common man for in-house usage is the need of the hour. Originality/value There is no comprehensive review available regarding research in this area with critical analysis of the outcomes for future study.

Design and fabrication of anisotropic textile brace for exerting corrective forces on spinal curvature

2021 ◽  
pp. 152808372110326
Author(s):  
Queenie Fok ◽  
Joanne Yip ◽  
Kit-lun Yick ◽  
Sun-pui Ng
Keyword(s):  
Medical Condition ◽  
Three Dimensional ◽  
Case Series ◽  
The Body ◽  
Spinal Curvature ◽  
Radiographic Examination ◽  
Interface Pressure ◽  
Pressure System ◽  
Case Series Study ◽  
Point Pressure

This study focuses on the fabrication of an anisotropic textile brace that exerts corrective forces based on the three-point pressure system to treat scoliosis, which is a medical condition that involves deformity of the spine. The design and material properties of the proposed anisotropic textile brace are discussed in detail here. A case series study with 5 scoliosis patients has been conducted to investigate the immediate in-brace effect and biomechanics of the proposed brace. Radiographic examination, three-dimensional scanning of the body and interface pressure measurements have been used to evaluate the immediate effect of the proposed brace on reducing the spinal curvature and asymmetry of the body contours and its biomechanics. The results show that the proposed brace on average reduces the spinal curvature by 11.7° and also increases the symmetry of the posterior trunk by 14.1% to 43.2%. The interface pressure at the corrective pad ranges from 6.0 to 24.4 kPa. The measured interface pressure shows that a sufficient amount of pressure has been exerted and a three-point pressure distribution is realized to reduce the spinal curvature. The obtained results indicate the effectiveness of this new approach which uses elastic textile material and a hinged artificial backbone to correct spinal deformity.

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