Effect of subsurface pressure on the interface pressure measurement in an in vitro experiment.

Abstract

Introduction It was hypothesized that subsurface pressure (mimicking subcutaneous pressure) variation may affect interface pressure measurement. Method BISCO® (Rogers, CT) foam was placed on a cylinder cuff model for the experiment. Picopress® and a piezoresistive sensor were used for interface pressure measurement. External pressure was applied using an automated pressure cuff at 40 mmHg. Subsurface pressure mimicking subcutaneous pressure from 3 mmHg to 12 mmHg was generated by a pressure pump underneath the foam. Interface pressure was compared between the true pressure, 40 mmHg, versus Picopress® and the piezoresistive sensor using linear mixed effect model (SAS software, version 9.4, SAS Institute, Cary, NC). Result Interface pressure measurement using Picopress® did not differ between the incremental subsurface pressures (mean 45.4 ± 0.4) ( P = 0.54), in contrast to piezoresistive sensor, which demonstrated a difference (mean 42.65 ± 2.7) ( P < 0.001). This difference appeared to be linearly related. Conclusion Subsurface pressure mimicking subcutaneous pressure may affect the overall interface pressure measurement according to the piezoresistive sensor but not Picopress®.