The evaluation of an intelligent closed loop dynamic sitting system to promote good posture, pressure relief and tissue perfusion

Abstract

Aim

When sitting, buttocks and thighs are subjected to higher pressures, which if sustained can be a risk factor in pressure ulcer development. This study aimed at evaluating the biomechanical and physiological performance of a dynamic sitting system incorporating pressure sensitive air cells technology to provide pressure relief and maintaining skin health.

Materials and methods

Thirteen participants were recruited and asked to adopt five static postures in a random order, each held for 10 min. Measurements at the chair-participant interface included interface pressure, internal pressure of the chair air cells, transcutaneous tissue gas tensions at the ischial tuberosities, and accelerometer data collected from the sternum. Area under the Receiver Operating Characteristic curve was used to evaluate sensitivity and specificity of all parameters in detecting postural change events, examining the 1st spatial derivative.

Results

Data revealed a high inter-subject variability, with interface pressure e.g. peak pressure gradient and contact area data showing statistically significant difference between postures. This was reflected in the physiological response with some individuals exhibiting low O₂ levels and associated high CO₂ (>25 % from baseline). Area under the curve values revealed interface pressure parameters and actimetry data accurate in detecting postural changes events (≥0.6).

Conclusion

The dynamic seating support depended on posture, although there remained some significant differences in interface pressure values and local tissue physiology. Further research is required to assess the impact of these sitting conditions in vulnerable individuals.