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.

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 Personalized modeling for real-time pressure ulcer prevention in sitting posture

2018 ◽  
Vol 27 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Vincent Luboz ◽  
Mathieu Bailet ◽  
Christelle Boichon Grivot ◽  
Michel Rochette ◽  
Bruno Diot ◽  
...  
Keyword(s):  
Real Time ◽  
Pressure Ulcer ◽  
Time Pressure ◽  
Pressure Ulcer Prevention ◽  
Sitting Posture ◽  
Ulcer Prevention

The relationship between pressure ulcer incidence and buttock-seat cushion interface pressure in at-risk elderly wheelchair users

2001 ◽  
Vol 82 (4) ◽  
pp. 529-533 ◽  
Author(s):  
David M. Brienza ◽  
Patricia E. Karg ◽  
Mary Jo Geyer ◽  
Sheryl Kelsey ◽  
Elaine Trefler
Keyword(s):  
At Risk ◽  
Pressure Ulcer ◽  
Interface Pressure ◽  
Wheelchair Users ◽  
Seat Cushion ◽  
The Relationship

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

Using Real-Time Pressure Data for Well Placement Planning

2006 ◽  
Author(s):  
Mike Parker ◽  
Robert N. Bradford ◽  
Laurence Ward Corbett ◽  
Robin Noel Heim ◽  
Christina Leigh Isakson ◽  
...  
Keyword(s):  
Real Time ◽  
Time Pressure ◽  
Pressure Data ◽  
Well Placement

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.

Piezoresistive Polymer-Based Materials for Real-Time Assessment of the Stump/Socket Interface Pressure in Lower Limb Amputees

2017 ◽  
Vol 17 (7) ◽  
pp. 2182-2190 ◽  
Author(s):  
Armando Ferreira ◽  
Vitor Correia ◽  
Emilia Mendes ◽  
Claudia Lopes ◽  
Jose Filipe Vilela Vaz ◽  
...  
Keyword(s):  
Real Time ◽  
Lower Limb ◽  
Interface Pressure ◽  
Socket Interface ◽  
Lower Limb Amputees ◽  
Time Assessment

Neural Network Based Control of Preform Permeation in Resin Transfer Molding Processes With Real-Time Permeability Estimation

2000 ◽  
Author(s):  
David Nielsen ◽  
Ranga Pitchumani
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Resin Transfer Molding ◽  
Local Pressure ◽  
Transfer Molding ◽  
Model Based ◽  
Rtm Process ◽  
Virtual Sensing ◽  
Intelligent Model ◽  
Injection Pressures

Abstract Variabilities in the preform structure in situ in the mold are an acknowledged challenge to effective permeation control in the Resin Transfer Molding (RTM) process. An intelligent model-based controller is developed which utilizes real-time virtual sensing of the permeability to derive optimal decisions on controlling the injection pressures at the mold inlet ports so as to track a desired flowfront progression during resin permeation. This model-based optimal controller employs a neural network-based predictor that models the flowfront progression, and a simulated annealing-based optimizer that optimizes the injection pressures used during actual control. Preform permeability is virtually sensed in real-time, based on the flowfront velocities and local pressure gradient estimations along the flowfront. Results are presented which illustrate the ability of the controller in accurately steering the flowfront for various fill scenarios and preform geometries.

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