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Media Relations Department

CONTACT: Julie Clausen, 505-844-0948,


'Active' Wheelchair Seat Designed to Prevent Pressure Ulcers

ALBUQUERQUE, N.M. -- A battery-powered pneumatic seat cushion designed to prevent pressure ulcers from occurring in persons confined to wheelchairs has been developed as a result of a cooperative program involving Sandia National Laboratories, the University of New Mexico, and two companies.

The cushion, which rests on the regular seat of a wheelchair, features four pairs of air bladders that are cyclically inflated and deflated by battery-powered pistons. This prevents sustained pressure on any one area, which can retard blood flow and oxygen exchange and cause tissue to become weakened. In the right environment of moisture and temperature, bacteria can start to attack vulnerable tissue and cause pressure ulcers.

Pressure sores are commonly treated surgically, costing as much as $200,000. The annual medical cost of treating pressure ulcers is estimated to be between $3 billion to $5 billion.

The "Generic Total Contact Seat" was developed through a joint venture involving the New Mexico Technology Deployment Pilot Project (NMTDPP) and Numotech Inc. of Sun Valley, Calif. The NMTDPP consists of Sandia National Laboratories, the Department of Energy, UNM's Research Institute for Assistive and Training Technologies (RIATT), and Laguna Industries Inc. The seat will be manufactured by Numotech.

The standard method of preventing pressure sores from occurring has been the use of passive contoured seats, which distribute seating pressure as uniformly as possible. However, even these have only achieved limited success.

Early work on an "active" concept was done by a group of researchers from the University of California at Los Angeles and the Sepulveda Veterans Medical Center in Los Angeles. Together with a small company called Numotech, they had developed an active pneumatic seat to use in a clinical setting to heal pressure ulcers nonsurgically. While effective, the device was too large and clumsy to be used in a home environment. The researchers contacted NMTDPP for help in reducing the size, power, and weight of the unit.

Sandia engineers involved with the NMTDPP incorporated the power unit and pumping system directly into the seat cushion. Weight and power consumption were reduced by half. Their work was coordinated closely with Numotech to ensure that the final design could be manufactured and integrated into their production process.

Part of the funding for the work came from the Department of Energy to the New Mexico Technology Deployment Pilot Project (TDP), which is a partnership between RIATT, Sandia, and Laguna Industries. The goal of the TDP is to apply national laboratory technologies toward products to improve the productivity and quality of life of persons with disabilities.

Sandia National Laboratories is a multiprogram DOE, operated by a subsidiary of Lockheed Martin Corp. With facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national defense, energy, environmental technologies, and economic competitiveness.

SANDIA TECHNICAL CONTACTS: Keith Miller, 505/845-8812; John Bode, 505/844-9440; Mark Vaughn, 505/845-9159

Julie Clausen,

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Last modified: June 12, 2001

Sandia National Laboratories is operated by Lockheed Martin Corp. for the U.S. Department of Energy.