System identification: a feasible, reliable and valid way to quantify upper limb motor impairments

Background: Upper limb impairments in a hemiparetic arm are clinically quantified by well-established clinical scales, known to suffer poor validity, reliability, and sensitivity. Alternatively, robotics can assess motor impairments by characterizing joint dynamics through system identification. In this study, we establish the merits of...

Towards determination of power loss at a rowing blade: Validation of a new method to estimate blade force characteristics

To analyze on-water rowing performance, a valid determination of the power loss due to the generation of propulsion is required. This power los can be calculated as the dot product of the net water force vector ( ^~ F _w;o ) and the time derivative of the position vector of the point at the blade where ^~ F <sub...

Is the force with you? On the accuracy of human force perception

Haptic technology is more and more widely used to improve human interaction with devices, for example in touch screens of smartphones that vibrate when touched. Another application is haptic-tele-manipulation where a human controls a slave manipulator (e.g. a surgical-robot) by using a master device (e.g. a joystick). In haptic-tele-manipulation...

Delays in admittance-controlled haptic devices make simulated masses feel heavier

In an admittance-controlled haptic device, input forces are used to calculate the movement of the device. Although developers try to minimize delays, there will always be delays between the applied force and the corresponding movement in such systems, which might affect what the user of the device perceives. In this experiment we tested whether...