Pressure Mapping

A pressure map is a tool which can be used to help determine the best seating option for a person needing a wheelchair cushion.  Pressure mapping, commonly performed by clinicians, helps to quantify the amount of pressure between two contacting objects, such as a person and their seat cushion.

The most commonly used pressure mapping system consists of a thin mat, about 18” wide x 18” deep, with many small sensors.  To measure pressure, the mat is placed on top of the wheelchair seat cushion with the person then sitting on the mat. The sensors in the mat read interface pressure at different locations on the upper thigh and buttocks.  The readings are transferred to a computer where a clinician can see areas of high and low pressure, indicated by a range of colors.  A constant area of high pressure, yellow or red coloring, is cause for concern.

While pressure mapping can be an effective tool for comparing one cushion to another, we feel it is important to remember, it is just one tool. The most valuable measure of the effectiveness of a particular cushion is still the visual inspection of the skin.  If the skin looks good after using a particular cushion for a reasonable amount of time, then the cushion is doing the job it was meant to do.  However if the skin shows signs of reddening or sore development, even if the pressure mapping was positive, there is a problem with the cushion or seating posture.

It is not necessary to have a pressure map in order to order a cushion system from Aquila Corporation.  The information we gather on our order forms helps us customize the cushion for each individual’s needs.  However, if you do pressure map the Airpulse PK after purchase or during a trial, it is important to remember the following:

• The Airpulse PK is a dynamic cushion system that utilizes powered alternating pressure in its design.  It is different than a static air, gel, or foam cushion that does not alternate pressure.  When using the Airpulse PK, you have to view a pressure map over multiple cycles to see the changes and accurately assess the results compared to a pressure map of a static cushion.
• Without proper calibration, the readings will not be accurate and can be off by as much as 50%.
• The pressure mapping operator needs to be trained on properly using this technology and unbiased in their opinion.

Sample Airpulse PK Pressure Map

The Airpulse PK cushion system inflates and deflates two groups of cells to give pressure relief to the skin tissue that would otherwise have constant pressure.  This time lapse pressure mapping sample shows how the Airpulse PK relieves pressure over time to stimulate circulation. This pressure mapping stream, although shown in compressed time, lets you see the areas of the posterior receiving pressure relief as the pressure map changes colors.

Play the video to view pressure mapping in action!

What you are seeing: 

• White – virtually zero pressure and the best it can be
• Blue – low pressure
• Yellow – higher pressure
• Red – highest pressure

These colors are constantly changing when pressure mapping the Airpulse PK, as the cushion itself is moving via the automatic inflation/deflation sequences.  With a static cushion, the colors (pressure readings) would not change unless the person sitting moves.