1. Pressure Ulcer Reducing Wheelchair Pad
Robert Karas1, Corina Malone1, Frank McClosky2,
Jacob Dodman2, and Bobby Lorenz2
Dr. Gerald LeCarpentier1, Dr. Darrell Kleinke2
1Biomedical Engineering Department, Lawrence Technological University 2Mechanical Engineering Department, University of Detroit Mercy
Project Goal
Develop a seat cushion that will help minimize the risk factors associated with pressure ulcers, including pressure distribution, friction, and moisture. This device is designed to be user friendly and can accommodate a wide variety of patients who suffer from or are at risk for pressure ulcer development. This device will not only be used for wheelchair bound individuals, but any client that has to be in the seated or supine position for a prolonged period of time. This device was designed to help patients redistribute pressure, and eliminate the need for a caregiver to readjust the client.
Testing Methods
Inflatable Bladder Testing
Material Testing System (MTS) machine to test bladder burst pressure using two parallel plates.
Weight Capacity Testing to determine the weight in which the pump and bladders stop supporting the load.
Inflatable Bladders
Gore-Tex Material Testing
Waterproof testing to ensure that water will not penetrate surface.
Puncture testing to ensure that common items in pocket will not puncture inflatables.
Resistant Outer Shell
Disease-State Background
Protective Layer
Gore-Tex Membrane
2.5 million Americans develop pressure ulcers annually.
25% of clients with a spinal cord injury develop pressure ulcers in conjunction with their pre-existing injury.
$43,180 is the average yearly cost to treat a pressure ulcer.
Factors that increase risk for pressure ulcers include pressure, friction, moisture, and temperature.
Protective Layer
Soft Inner Liner
Stage 1
Stage 2
Skin Layers
Subcutaneous
Soft Tissues
Prototype Testing
Ensure that the Arduino can control individual bladders.
Confirm that pressure distribution occurs and that the tilt angle of 15 degrees is accomplished for therapeutic effect of device.
Bone
Stage 3
Stage 4
Pressure Ulcer Progression
Current Solutions
Pressure Alternating Pressure Reducing Patient Tilting
Pressure Distribution Phase
Client Tilt Phase
Prototype Results
Burst pressure of 13.6 psi, which is under the predicted pressure of 8 psi.
Weight capacity of 400 pounds. Desired capacity of 300 pounds is feasible.
Material is waterproof and can resist puncture with common items.
Overall tilt is the therapeutic minimum of 15 degrees.
The main limitations of the predicate devices are the need for a caretaker or nurse to continually rotate and/or reposition the patient, the high cost of these devices, and the inability of these devices to predict when a patient is at risk for pressure ulcer development.
Final Prototype Design
Project Design Parameters
Current and Future Work
Automatic
Comfortable
Easy to Clean
Friction Reducing
Portable
Remote Control Operation
Sensor Feedback
Support Standard Weight (300 pounds)
Time Dependent Cycle
Waterproof
Remote
Arduino Microcontroller
9V Battery
To finalize the design and make the device ready to be delivered to the client a housing unit will be fabricated to house the electronic components including the circuit, battery, wiring and hosing to secure device. Future research could examine the long term effects of using the Under Pressure Pad in comparison to other pressure reducing devices, and study the effectiveness of how pressure is distributed in the various sequences of inflated bladders.
Pressure Sensors
Solenoid Valves
Pump
Inflatable Bladders
12 V Battery
Acknowledgements
This project would not have been a success without the generous help of the Veteran Affairs hospital for funding this project. Thank you Lawrence Technological University and University of Detroit Mercy for allowing us to use your facilities to test and manufacture device.
Circuit to Control Pump and Valves