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

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.

Author(s):  
Wei Carrigan ◽  
Pavan Nuthi ◽  
Charu Pande ◽  
Caleb P. Nothnagle ◽  
Muthu B. J. Wijesundara

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.


2013 ◽  
Vol 38 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Lorna H Tasker ◽  
Nigel G Shapcott ◽  
Alan J Watkins ◽  
Paul M Holland

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.


2016 ◽  
Vol 2 (2) ◽  
pp. 94
Author(s):  
Labrini Labro ◽  
Olga Margazi ◽  
Georgia Marouli ◽  
Georgios Vasilopoulos

In health area pressure ulcers remain until today a major problem, especially in critically ill patients in whom the incidence is increasing due to their prolonged detention. An important part in the appearance of pressure sores is prevention. Prevention can be achieved in several ways such as by changing patient position or using specialized support surfaces which reduce the pressure in the areas most commonly created the pressure sores. Equally important part in pressure sores problem is manage the problem and it can mainly achieved by the use of specific pads or the use of new, alternative methods to help them heal faster. The support surface is a specialized pressure redistribution device (pressure redistribution) which is designed to support tissue, and/or other therapeutic functions. The optimal supportive surface relieves the pressure, the fragmentation and friction and maintains a constant temperature in the human body. Such a supportive surface redistributes body weight on a possibly largest surface of the body, thereby reducing the pressure at specific parts of the body and therefore tissue damage is prevented.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4356
Author(s):  
Nasim Hajari ◽  
Carlos Lastre-Dominguez ◽  
Chester Ho ◽  
Oscar Ibarra-Manzano ◽  
Irene Cheng

Pressure injury (PI) is a major problem for patients that are bound to a wheelchair or bed, such as seniors or people with spinal cord injuries. This condition can be life threatening in its later stages. It can be very costly to the healthcare system as well. Fortunately with proper monitoring and assessment, PI development can be prevented. The major factor that causes PI is prolonged interface pressure between the body and the support surface. A possible solution to reduce the chance of developing PI is changing the patient’s in-bed pose at appropriate times. Monitoring in-bed pressure can help healthcare providers to locate high-pressure areas, and remove or minimize pressure on those regions. The current clinical method of interface pressure monitoring is limited by periodic snapshot assessments, without longitudinal measurements and analysis. In this paper we propose a pressure signal analysis pipeline to automatically eliminate external artefacts from pressure data, estimate a person’s pose, and locate and track high-risk regions over time so that necessary attention can be provided.


1998 ◽  
Vol 275 (3) ◽  
pp. R677-R682 ◽  
Author(s):  
Susan R. Kayar ◽  
Terry L. Miller ◽  
Meyer J. Wolin ◽  
Eugenia O. Aukhert ◽  
Milton J. Axley ◽  
...  

We present a method for reducing the risk of decompression sickness (DCS) in rats exposed to high pressures of H2. Suspensions of the human colonic microbe Methanobrevibacter smithii were introduced via a colonic cannula into the large intestines of the rats. While the rats breathed H2in a hyperbaric chamber, the microbe metabolized some of the H2diffusing into the intestine, converting H2and CO2to methane and water. Rate of release of methane from the rats, which was monitored by gas chromatography, varied with chamber H2pressure. This rate was higher during decompression than during compression, suggesting that during decompression the microbe was metabolizing H2stored in the rats’ tissues. Rats treated with M. smithii had a 25% (5 of 20) incidence of DCS, which was significantly lower ( P < 0.01) than the 56% (28 of 50) incidence of untreated controls, brought on by a standardized compression and decompression sequence. Thus using a microbe in the intestine to remove an estimated 5% of the body burden of H2reduced DCS risk by more than one-half. This method of biochemical decompression may potentially facilitate human diving.


2021 ◽  
pp. 152808372110326
Author(s):  
Queenie Fok ◽  
Joanne Yip ◽  
Kit-lun Yick ◽  
Sun-pui Ng

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.


Author(s):  
Abinand Manorama ◽  
Tamara Reid Bush

Pressure ulcers have been a concern in healthcare settings, with more than 50% of bedridden or wheelchair-bound patients being affected [1]. Pressure ulcers typically occur on a region of the body that experiences forces from an external structure (e.g. bed, wheelchair). Researchers believe that such forces cause a decrease in blood flow, which results in tissue necrosis, causing pressure ulcers [2].


SIMULATION ◽  
2019 ◽  
Vol 96 (4) ◽  
pp. 375-385 ◽  
Author(s):  
Yuan Yuan ◽  
Zhiwen Zhao ◽  
Tianhong Zhang

In the hardware-in-the-loop (HIL) simulation of the fuel control unit (FCU) for aero-engines, the back pressure has a great impact on the metered fuel, thus influencing the confidence of the simulation. During the practical working process of an aero-engine, the back pressure of the FCU is influenced by the combined effect of the pressure of the combustion chamber, the resistance of the spray nozzles, and the resistance of the distribution valve. There is a need to study the the mimicking technique of FCU back pressure. This paper models the fuel system of an aero-engine so as to reveal the impact of FCU back pressure on the metered fuel and come up with a scheme to calculate the equivalent FCU back pressure. After analyzing the requirements for mimicking the pressure, an automatic regulating facility is designed to adjust the FCU back pressure in real time. Finally, experiments are carried out to verify its performance. Results show that the mimicking technique of back pressure is well suited for application in HIL simulation. It is able to increase the confidence of the simulation and provide guidance to the implementation of mimicking the FCU back pressure.


2020 ◽  
Vol 73 (2) ◽  
pp. 235-238
Author(s):  
Oleh E. Kanikovskiy ◽  
Ihor V. Pavlyk ◽  
Iryna V. Oliinyk ◽  
Vasyl V. Mosondz

The aim of the work was to improve the results of surgical treatment of complicated forms of chronic pancreatitis. Materials and methods: The results of surgical treatment of 181 patients with complicated forms of chronic pancreatitis have been analyzed. All these patients were treated in surgical clinic of 2 nd medical faculty of National Pyrogov Memorial Medical University in Vinnytsya. Results: It is possible preoperative indirectly assess the severity of fibro- degenerative changes in pancreas, that includes 1 – the definition of pain type; 2 – CT or MRI (Marseilles- Rome classification); 3 – assessment of the stage of chronic pancreatitis (Büchler classification); 4 – patient&#39;s nutrition status and preoperative differential diagnosis with pancreatic cancer; 5 – assessment of the fibrosis severity (elastomers). The key point in treatment depended on intraoperative examination: detection of strictures of the main pancreatic duct (pacemaker of chronic pancreatitis); the tissue pressure resistance to the liquid, which is the maximum value&gt; 200 mmHg, in the region of stricture and falls in other parts of the pancreas; pressure in the main pancreas duct, which rises only in 59.5% of patients. The head of the pancreas was involved in the pathological process in 83.8%, in 16.2% it was isolated in the isthmus or the body and tail of the pancreas. In general, the distal pancreas was involved in 37.8%. At computer morphometry of histological samples, the area of connective tissue fields reached 81.4 ± 6.62%, preserved exocrine part in 4.87 ± 1.62%, endocrine – 1.92 ± 0.12%, total area of ducts – 6 , 47 ± 1.12%. Conclusions: The combined Frey-Izbickiy local resection provides a wide excision of the pacemaker (stricture) of chronic pancreatitis. In case of extrapancreatic complications or repeated surgical interventions on the pancreas due to chronic pancreatitis, this effect can be achieved by pancreatoduodenal resection.


2020 ◽  
Vol 36 (4) ◽  
pp. 228-234
Author(s):  
Ziva M. Rosker ◽  
Jernej Rosker ◽  
Nejc Sarabon

Reports on body sway control following microdiscectomy lack reports on side-specific balance deficits as well as the effects of trunk balance control deficits on body sway during upright stances. About 3 weeks post microdiscectomy, the body sway of 27 patients and 25 controls was measured while standing in an upright quiet stance with feet positioned parallel on an unstable support surface, a tandem stance with the involved leg positioned in front or at the back, a single-leg stance with both legs, and sitting on an unstable surface. Velocity, average amplitude, and frequency-direction–specific parameters were analyzed from the center of pressure movement, measured by the force plate. Statistically significant differences between the 2 groups were observed for the medial–lateral body sway frequency in parallel stance on a stable and unstable support surface and for the sitting balance task in medial-lateral body sway parameters. Medium to high correlations were observed between body sway during sitting and the parallel stance, as well as between the tandem and single-legged stances. Following microdiscectomy, deficits in postural balance were side specific, as expected by the nature of the pathology. In addition, the results of this study confirmed the connection between proximal balance control deficits and balance during upright quiet balance tasks.


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