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.

Control Implementation for Real-Time Pressure Adjusting Seat Cushion to Prevent Pressure Ulcers

2018 ◽  
Author(s):  
Pavan Nuthi ◽  
Wei Carrigan ◽  
Charu Pande ◽  
Muthu B. J. Wijesundara
Keyword(s):  
Real Time ◽  
Pressure Ulcer ◽  
Time Pressure ◽  
Pressure Profile ◽  
Health Concern ◽  
Ulcer Formation ◽  
Interface Pressure ◽  
Local Pressure ◽  
Seat Cushion ◽  
Control Implementation

External mechanical loading is a major contributing factor in pressure ulcer formation and is a major health concern for wheelchair users. Seat cushion technologies are employed to reduce the magnitude and duration of this loading using soft seating surfaces and pressure offloading techniques. However, pressure offloading often results in the creation of new high pressure points which can still lead to pressure ulcer formation. In order to mitigate the issue, a novel closed-loop controlled seat cushion system is developed with sensorized air cell arrays which can continuously monitor pressure profile of a seated person and modulate this interface pressure. This paper presents the control implementation of this seat cushion system using a novel scheduling control algorithm based on bang-bang control as well as the corresponding electronics and pneumatic layout. The effectiveness of the system is demonstrated for real-time pressure mapping, offloading, and redistribution of seating interface pressure and its capabilities of instantaneous local pressure measurement as well as automated pressure modulation are verified.

scholarly journals Active Body Pressure Relief System with Time-of-Flight Optical Pressure Sensors for Pressure Ulcer Prevention

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3862 ◽  
Author(s):  
Kang-Ho Lee ◽  
Yeong-Eun Kwon ◽  
Hyukjin Lee ◽  
Yongkoo Lee ◽  
Joonho Seo ◽  
...  
Keyword(s):  
Pressure Ulcer ◽  
Pressure Sensors ◽  
The Body ◽  
Interface Pressure ◽  
Pressure Relief ◽  
Pressure Ulcer Prevention ◽  
Optical Pressure ◽  
Body Pressure Distribution ◽  
Relief System ◽  
Ulcer Prevention

A body pressure relief system was newly developed with optical pressure sensors for pressure ulcer prevention. Unlike a conventional alternating pressure air mattress (APAM), this system automatically regulates air flow into a body supporting mattress with adaptive inflation (or deflation) duration in response to the pressure level in order to reduce skin stress due to prolonged high pressures. The system continuously quantifies the body pressure distribution using time-of-flight (ToF) optical sensors. The proposed pressure sensor, a ToF optical sensor in the air-filled cell, measures changes in surface height of mattress when pressed under body weight, thereby indirectly indicating the interface pressure. Non-contact measurement of optical sensor usually improves the durability and repeatability of the system. The pressure sensor was successfully identified the 4 different-predefined postures, and quantitatively measured the body pressure distribution of them. Duty cycle of switches in solenoid valves was adjusted to 0–50% for pressure relief, which shows that the interface pressure was lower than 32 mmHg for pressure ulcer prevention.

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.

Novel Support Surface To Alleviate Pressure Ulcer Formation During The Rehabilitation Of Immobile Patients: A Preliminary Investigation

2021 ◽  
Vol 102 (10) ◽  
pp. e39-e40
Author(s):  
Wen Li Lui ◽  
Matthew Rong Jie Tay ◽  
Dan Wang ◽  
Keng Hwee Chiam ◽  
Shirlene Toh ◽  
...  
Keyword(s):  
Pressure Ulcer ◽  
Preliminary Investigation ◽  
Support Surface ◽  
Ulcer Formation

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.

scholarly journals Longitudinal In-Bed Pressure Signals Decomposition and Gradients Analysis for Pressure Injury Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4356
Author(s):  
Nasim Hajari ◽  
Carlos Lastre-Dominguez ◽  
Chester Ho ◽  
Oscar Ibarra-Manzano ◽  
Irene Cheng
Keyword(s):  
Spinal Cord Injuries ◽  
Healthcare Providers ◽  
The Body ◽  
Support Surface ◽  
Interface Pressure ◽  
Analysis Pipeline ◽  
Clinical Method ◽  
Longitudinal Measurements ◽  
Pressure Injury ◽  
Life Threatening

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.

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.

scholarly journals Interface pressure, pressure gradient with pressure ulcer development in Intensive Care Units

2014 ◽  
Vol 4 (9) ◽  
Author(s):  
Mr. Supriadi ◽  
Tomoe Nishizawa ◽  
Moriyoshi Fukuda ◽  
Yuka Kon ◽  
Matsuo Junko ◽  
...  
Keyword(s):  
Intensive Care ◽  
Pressure Gradient ◽  
Intensive Care Units ◽  
Pressure Ulcer ◽  
Interface Pressure ◽  
Pressure Ulcer Development

scholarly journals Selective A2A adenosine receptor activation reduces skin pressure ulcer formation and inflammation

2001 ◽  
Vol 281 (1) ◽  
pp. H67-H74 ◽  
Author(s):  
Shayn M. Peirce ◽  
Thomas C. Skalak ◽  
Jayson M. Rieger ◽  
Timothy L. Macdonald ◽  
Joel Linden
Keyword(s):  
Blood Flow ◽  
Pressure Ulcer ◽  
Cell Activation ◽  
Ischemia Reperfusion ◽  
Clinical Problem ◽  
Receptor Activation ◽  
Metal Plate ◽  
Vehicle Group ◽  
Ulcer Formation ◽  
A2a Adenosine Receptor

Activation of A2A adenosine receptors (A2A-AR) by ATL-146e (formerly DWH-146e) prevents inflammatory cell activation and adhesion. Recurrent ischemia-reperfusion (I/R) of the skin results in pressure ulcer formation, a major clinical problem. ATL-146e was evaluated in a novel reproducible rat model of pressure ulcer. A 9-cm2 region of dorsal rat skin was cyclically compressed at 50 mmHg using a surgically implanted metal plate and an overlying magnet to generate reproducible tissue necrosis. Osmotic minipumps were implanted into 24 rats divided into four equal groups to infuse vehicle (control), ATL-146e (0.004 μg · kg−1 · min−1), ATL-146e plus an equimolar concentration of A2A antagonist, ZM-241385, or ZM-241385 alone. Each group received 10 I/R cycles. In non-I/R-treated skin, ATL-146e has no effect on blood flow. I/R-treated skin of the ATL-146e group compared with the vehicle group had 65% less necrotic area, 31% less inhibition of average skin blood flow, and fewer extravasated leukocytes (23 ± 3 vs. 49 ± 6 per 500 μm2). These data suggest that ATL-146e, acting via an A2A-AR, reduces leukocyte infiltration and is a potent prophylactic for I/R injury in skin.

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