Under Pressure: Pressure Ulcer Reducing Device LTU Biomedical engineers – Robert Karas & Corina Malone UDM Mechanical Engineers– Frank McClosky, Jacob Dodman, & Bobby Lorenz UDM Nurses – Lydia Jacob, Christina Osterhout, & Victoria Murad Advisor: Dr. Gerald LeCarpentier

Client Background Patient: Mr. Russel Stewart Trauma caused a spinal cord injury Developed into a bilateral leg amputee Suffers from a pressure ulcer Needs assistance from a caregiver The Detroit News: Veteran Russel Stewart

Disease State Background 2.5 million patients are treated every year for pressure ulcers 25% of patients who suffer from a spinal cord injury develop pressure ulcers The main risk factors that contribute to pressure ulcer development are pressure distribution, friction, and moisture Stage 1 Stage 2 Skin Layers Subcutaneous Soft Tissues Bone Stage 3 Stage 4 Progression of Pressure Ulcer Formation

Market Analysis Stage 1-3 pressure ulcers are treatable by therapeutic device Stage 4 pressure ulcers require surgery Average cost to treat a pressure ulcer is $43,180 Insurance companies will cover most of the cost of a wheelchair pad Most plans are on a 80/20 coverage

Predicate Devices Pressure Alternating Pressure Reducing Powered Tilt Main limitations: Cost Independence of patient Patient Compliance

Project Goal To create a wheelchair pad that incorporates as many features as the predicate devices to allow the patient to be independent and get the maximum therapeutic aid. This prototype device will eliminate the main factors of pressure ulcer formation. Pressure distribution Moisture control Low friction Bulk weight movement

Design Improvements Automatic Comfortable Easy to Clean Friction Reducing Portable Remote Control Operation Sensor Feedback Support Standard Weight (300 pounds)

Project Development/Improvements Design Concept – Projects 1 Design for Prototype 1 Final Design

Final Design Concept- Projects 2 Key Design Features 8 inflatable bladders 8 force sensors Timed & Remote control of pattern Water wicking material Low friction material Housing Box to attach circuitry to chair Inflated Pressure Alternation Inflated Tilt Phase

Design Components Layers of the seat: Gore-Tex outer material Top foam layer Force sensors Inflatable bladders Bottom foam layer for cushion Deflated Dimensions (15” x 17” x 1”) Inflated Dimensions (15” x 17” x 4”)

Inflatable Bladder Fabrication Double layer of plastic sheeting Cardboard & oven liner Clothes Iron Flexible hose Super glue & electrical tape Deflated dimensions (8.5” x 4.5” x 0”) Inflated dimensions (8.5” x 3.75” x 3.5”) Set-up for bladder fabrication

Inflatable Bladder Testing MTS testing to find burst pressure – 13.6 psi Bicycle pump test to compare burst pressure – 17 psi Weight Capacity test – 375 pounds MTS Testing Fixtures

Gore-Tex Material Testing Waterproof testing to ensure device is easy to clean and the circuitry would survive soiling Puncture Testing to ensure bladders were safe from sharp objects (keys, pencils, other common items held in pocket) Resistant Outer Shell Protective Layer Gore-Tex Membrane Protective Layer Soft Inner Liner Cross Sectional View of Top Layer

Sensor Calibration Weights used ranged from 1-75 pounds Compared to known weights over area of sensor Weights used ranged from 1-75 pounds Linear fit was used on sensor data Calibration was done by coding on Arduino Flexi-force Sensor Calibrating Weights

Circuit Design to Control Designed transistor circuit to allow for control over the pump and individual valves Uses 4 main components Transistor Resistor Diode Capacitor Circuit Design to Control Pump and Valve Circuit Prototype

Seat Fabrication Sensors adhered to bladder Bladders sewn to top foam layer Hoses run through bottom foam layer Foam layers adhered together Outer material sewn together Set-up for Seat Fabrication

Prototype Testing Air splitter achieved even inflation of bladders Remote control worked after extended use Cycle continued after extended use Device could withstand water Hoses could not be felt when seated High force caused change in sequence Student Testing Device Capabilities

Usability Testing Remote could work at different angles Tilt angle of 15 degrees was comfortable and safe Resistant to hoses coming disconnected Weather/soiling resistant Comfort after an extended period of time Client Testing Device Prototype

Safety Risk

Final Budget Final product could sell from $600-$1000 due to high cost of existing pressure relieving devices

Final Timeline COMPLETED TASK REPSONSIBILITY START DATE EXPANDED REPSONSIBILITY START DATE COMPLETION DATE BLADDER FABRICATION FABRICATE SEVERAL BLADDERS FOR DEVICE AND TESTING ROB FEB 22 APRIL 13 ARDUINO CODING CODING FOR VALVES, PUMP, SEQUENCING, POWER, SENSORS UDM ENGINEERS APRIL 1 3 CIRCUIT ASSEMBLY FOR ACTIVATING PUMP AND VALVES MAR 23 COMPONENT TESTING TO DETERMINE SAFETY AND FUNCTIONALITY OF INDIVIDUAL PARTS ROB & CORINA MAR 26 MAR 31 SEAT ASSEMBLY ALL COMPONENTS PUT TOGETHER SECURELY AND EFFECTIVELY CORINA MAR 1 APRIL 20 PROTOTYPE 1 ENSURE ALL DEIVCE COMPONETS WORKED TOGETHER TO ACHIEVE EXPECTED DELIVERABLES ALL TEAM MEMBERS MAR 16 SENSOR CALIBRATION CALIBRATION OF SENSORS TO ENSURE UNIFORM READINGS AND FUNCTIONALITY APRIL 11 APRIL 17 DEVICE TESTING BURST PRESSURE, MAX LOAD, PUNCTURE TEST, APRIL 15 APRIL 19

Pressure Ulcer Reducing Pad : Under Pressure Pad Robert Karas & Corina Malone Dr. Gerald LeCarpentier Objective: Create a device that can be used as a chair cushion to prevent pressure ulcer formation, and provide the patient with a solution that allows them to operate the device independently. Approach: Use inflating bladders to help redistribute pressure and tilt the patient 15 degrees in order to help blood circulation and oxygen levels in the injury site to improve. Also, use force sensors in order to prevent any dangerous amount of pressure on any one point. Impact: Keep patients out of the hospital by using this wheelchair pad that is comfortable, independent, and properly manages the risk factors associated with pressure ulcers. Progress and Results: 8 air bladders fabricated to withstand 375 pounds Calibration and implementation of force sensors Arduino code that operates automatically and has overrides for sensor data or user input 15 degree of tilt achieved by inflatable bladders Outer material can withstand puncture and water Pressure Alternating Tilt Phase Veterans Testing Prototype Bladder Testing Data