Air-cell cushions are often prescribed to wheelchair users to mitigate the effects of prolonged sitting, a leading cause of preventable death. However, the dynamic nature of a user's environment can lead to fluctuations in cushion pressures, requiring frequent clinical adjustments. Kalogon and Etac created a solution to this problem, marketed as Sentinel. This product maintains the pressure value of a single-cell air cushion. It routinely monitors ambient conditions and corrects cushion pressure accordingly. It also monitors for leaks and can fill the cushion to counteract small leaks.