We measured output voltage signals of the vibration sensing units with different open ratios (ORs) considered the proportion of area perforated with acoustic holes in the whole area on the frequency response of the devices as shown in Fig.3D. The frequency ranges we tested encompass the fundamenta...
A sample size of 239 subjects per group (intervention and control) is estimated to detect a 10% absolute difference in the proportion of patients developing pressure sores at 36 h. Discussion The development of pressure ulcers is a common side effect of NIV that negatively affects the patients...