Even though instruments that allow assisting a patient during lower limb rehabilitation activities could be a very useful support for physicians and therapists, few prototypes are described in the literature. Furthermore, cited devices do not implement some functionalities that clinical personnel considers important, such as the measurement of shear forces due to patient imbalance. We collaborated with therapists, in order to identify the main features that a suitable instrument should present. The result of such collaboration led to the design, realization and characterization of two instrumented crutches. They permit to measure either axial or shear forces, and tilt angles in real time. Each crutch is equipped with twelve strain gauge sensors that are connected in three bridge configurations in order to measure axial and shear forces. It presents also a tri-axial accelerometer. Signals coming from these sensors are conditioned by a dedicated low-power electronics implementing filtering and amplifying functions. All measurement data are transmitted wirelessly via Bluetooth to a remote computer. In this way, no further readout unit is required. Sensorized crutch supply is assured by a 9 V battery (1.2 Ah), and controlled by a power management circuit, allowing for a up to 24 hours monitoring. The activity is carried out in collaboration with the Department of Mechanical and Industrial Engineering of the University of Brescia.
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For more info, please contact Mauro Serpelloni.
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