Pressure measurement devices: from technical assessment to clinical performance

Background

Technical assessment of pressure measurement devices (PMDs) should guarantee for their appropriate use in the clinics. The study aims at proving the validity of the assessment methodology ISS proposed [1], and at quantifying the impact of PMD performance on clinical assessment.

Materials and methods

Three commercial PMDs were first assessed and then compared during barefoot walking: PMDa and PMDb - resistive technology, 1sens/cm² – were assessed on-site, while PMDc – capacitive technology, 4sens/cm² - was tested on-the-bench and on-site [1]. The PMDs were aligned on the floor to capture successive at-regimen steps of the left foot of one trained volunteer; 10 complete steps were acquired in both directions for each PMD; data were temporally normalised and averaged; main kinetic parameters were extracted.

Results

Preliminary results (Table 1 and Figure 1): i) PMDc resulted accurate and was used as a reference; ii) PMDa was found inaccurate on-site and delivered unreliable gait data; iii) PMDb was found accurate on-site but performed significantly worse than PMDc during gait.

Table 1 Results from the on-the-bench and on-site assessment, and with respect to some clinically relevant parameters.

Figure 1

Peak Pressure and Vertical Force curves obtained by the three tested PMDs; mean curve ± sd curve averaged over 10 left steps.

Conclusions

To conclude: i) on-site assessment up to 250kPa proved to be necessary but not sufficient to guarantee for a good PMD performance during gait; ii) a thorough on-the-bench assessment is effective and recommended; iii) use of PMDb data might be misleading in research and risky in the clinics. The study is going on with the comparison among other commercial PMDs and under a wide range of testing conditions.