Limitations of popular methods used for calibrating sensors for the measurement of sub-bandage pressure

Sensors commonly used to record sub-bandage pressures may be less reliable than is commonly believed. The techniques employed for the calibration or validation of these devices can sometimes produce a highly inaccurate prediction of their performance in vivo. In this review, the various calibration methods referenced in the literature are briefly described and the limitations of each discussed. The significance of these limitations is illustrated by reference to the results of published studies cited in a systematic review which report widely different values for the accuracy of one particular device, the Kikuhime pressure measuring system (ZiboCare, Denmark). The use of inappropriate calibration techniques therefore casts serious doubt upon the pressure values quoted historically in many published scientific and clinical studies in which these particular instruments have been employed. It is proposed that an international standard method be developed to ensure that all sensors intended for the measurement of sub-bandage pressure are characterised using a validated, clinically relevant technique. A programme of education is also required to correct some of the widely held misconceptions often expressed in the literature concerning the use of the Laplace equation to calculate sub-bandage pressure.