Figure 3: Measurement errors at different contact angles
Measurement errors of four commercially available contact force sensing catheters across their measurement range. Each row shows the results for different catheter models. Different catheter-to-tissue angles are displayed in columns (0° equals perpendicular to tissue, 90° equals parallel to tissue). The x-axis of each graph shows the real force exerted on the tissue and the y-axis the measurement error made by the catheter. Points above the black line in each graph mean the catheter overestimates the force and points below the black line mean the catheter underestimates the force. Different colors indicate different catheters. A local smoothing function was used for easier interpretation of the measurement data (loess function, span = 0.3). For the Stablepoint catheter, measured-force values above 50g are not displayed at angles >45°.