Institute of Biomechanics of Valencia, Valencia, Spain 

The research project PUMA (Pressure Ulcer Measurement and Actuation), founded by the European Commission, and coordinated by the Institute of Biomechanics of Valencia (IBV) in Spain has developed an innovative portable, noninvasive device for the prevention and early detection of the risk of pressure ulcer formation and to reverse its appearance in tetraplegic spinal cord injured patients who rely on wheelchairs.

Fig. 1 – The PUMA project aims to develop a portable and non-invasive system to prevent and detect the risk of pressure ulcer development and reverse its onset.
Pressure ulcers, also called decubitus ulcers, ischemic ulcers, or more commonly, bedsores, are localized injuries in the skin and/or underlying tissue that are initiated by a sustained impaired blood flow. Pressure ulcers are a medical problem that may develop in the more than 5 million users of wheelchairs in the European Union. The cost to the European public system of this disease is estimated to exceed 20,000 million euros a year.

How It Works

According to Ignacio Bermejo, the director of Innovation in Rehabilitation and Personal Autonomy at IBV, the PUMA device has three independent systems that could be used to prevent ulcers and to detect and eliminate the risk of formation. It suggests that postural changes for the wheelchair user can make large strides in avoiding the development of these ulcers.

The postural control system of the wheelchair, along with a cushion that uses “smart” textiles that can measure pressures and short pants worn by the patient also made of smart materials can be used to measure the state of the skin and apply electro stimulation.

Both the seat pad and the pants broadcast information in real time to a computer system built into the chair that can be controlled from an application on a mobile phone. This app evaluates the data and can identify postural risks in each situation, the researchers say. (See Figure 1)

For example, the application could detect the amount of time spent in the same position and, depending on the context, propose various actions to prevent the formation of an ulcer: changes in posture of the chair (back, seat, and footrest), modifying the seating pad or directly applying electro stimulation in risk areas.

The research into the wheelchair onboard device was conducted over the course of two years.

As José Laparra, technical project manager explained: “First we collected information on tetraplegic patients in wheelchairs on their needs and anthropometric and physiological characterization that adversely affect the occurrence of pressure ulcers, then studied and compared different measuring systems for detecting the state of the fabric and embedded them in smart textiles.”

Together with IBV, these other groups participated in the project: the Danish company QIMOVA AS as coordinator of the initiative, SMEs BerkelBike (The Netherlands), SensingTex (Spain), Institute for Innovation (Estonia), and the Belgian Centre for Research Textile (CENTEXBEL).

The National Hospital for Paraplegics, Toledo, Spain, conducted clinical validation with patients using a prototype and Fundosa Accessibility ILUNION group company (formerly Vía Libre) contributed equipment prosthetists to customize the technologies for the users.