Document Type


Date of Award

Summer 8-31-2006

Degree Name

Master of Science in Biomedical Engineering - (M.S.)


Biomedical Engineering

First Advisor

Tara L. Alvarez

Second Advisor

Michael T. Bergen

Third Advisor

Sergei Adamovich

Fourth Advisor

Lisa K. Simone


Many kinds of pressure-relieving mattresses have been developed to prevent pressure sores in patients with spinal cord injuries (SCIs) and obesity. Current technology uses alternating air pressure mattress, foam and low pressure mattress for reducing the incidence of pressure sores in SCI and obesity patients. These mattresses do not have control of pressure in individual air chambers. They are open loop system and they do not receive any feedback from the system. They have at the most control of two different pressures. The purpose of this study is to improve the current assistive technology in reducing pressure sores and to distribute the patient's weight evenly on the air mattress by setting the appropriate pressure in each individual chamber.

The proposed mattress has an independent control of each and every chamber, flexibility in selecting firmness and range, number of chambers to be operated at a time and mode of operation. It is a closed loop system and hence, it can respond to the change in pressure inside the system to keep it stable. National Instruments (NI) software LabVIEW® 8 is used for this purpose. The proposed mattress has an accuracy of approximately 98% and reliability of approximately 96%. Correct operation of the feedback control system to maintain cell pressure in the specified ranges during patient movement was validated with a small pilot study. A patient experiment is proposed to compare this mattress with current available mattresses in the market. It is hypothesized that individual cell pressure control mattress is better than alternating pressure mattress.



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