An alternating pressure pad includes a first series and a second series of inflatable cells. The first and second series of inflatable cells are interleaved, with one series within the other series. Each cell of the first series of inflatable cells and each cell of the second series of inflatable cells extends transversely across the alternating pressure pad and defines a non-linear and non-repeating path, with the path defined by substantially all of the cells of the first series being identical to the path defined by substantially all of the cells of the second series.
An alternating pad consisting of transverse inflatable cells (1 and 2) alternately inflated and deflated. An internal cell (5) is provided at the outermost edges of each transverse cell (1,2). The internal cell (5) is constantly inflated at a higher pressure than the traverse cells (1, 2). The internal cell (5) is at a lower height than the cells (1,2) and preferably of a chamfered shape to provide optimum pressure relief across the whole surface of the pad. The internal cell (5) provides stable patient exit, entry or transfer from a bed or seat.
A pressure pad has two sets of cells with a sensor pad positioned under the pad. During inflation, part of the flow goes to the sensor pad to exhaust and the rest fills the cells. Any change in patient position/weight causing a change in airflow in tube will alter the differential pressure measured at a pressure transducer. Based on this feedback a microprocessor directly controls the power level to the pump, thus adjusting the airflow to the cells to prevent bottoming or to rung at a minimum pressure. The pressure pad is segmented into a heel section, upper leg section, torso section, and a head section. The heel, head, and upper leg sections are maintained at a lower pressure, and the torso section at a higher pressure. A control module to control the flow in the segments is provided inside the pressure pad. The pressure pad can be an alternating or static pad.
A support surface 10 includes a series of inflatable cells 30, 40 inflated alternately by a compressor 11. The cells 30, 40 are exhausted via an exhaust port 50 having a restrictor 60 of known diameter. A pressure transducer 70 measures the cell 30, 40 pressure. Some of the cells 30, 40 during their deflating/inflating cycle are exhausted through the exhaust port 50 and the cell pressure decay over a time is monitored. A microprocessor calculates the mathematical function related to the cell pressure decay with time, compares the value with compiled data and adjusts the output of the compressor accordingly. The sequence of exhausting via a port 50 is repeated at every inflation/deflation cycle and the pressure decay monitored and compared with the known data and the compressor output adjusted automatically to provide a new operating pressure. Therefore, any change in the person's position, e.g., supine, to side or sitting are accommodated by the cell pressure automatically being adjusted to prevent bottoming or high interface pressures.
