DATA ACQUISITION

Pilot study on healthy subjects to define the parameters setting

The objective of this pilot study, conducted within the University of Milano-Bicocca, was to design, implement, and validate a software pipeline for the acquisition and processing of raw inertial data, aimed at supporting the clinician’s assessment and monitoring of upper limb movements in a supervised setting. 

To validate the pipeline, an experimental protocol was defined which involved the acquisition of data from 24 healthy subjects using 3 Inertial Measurement Units (IMUs) sensors, integrating accelerometers, gyroscopes, and magnetometers. These sensors were placed on the shoulder, arm and wrist. Subjects were instructed to perform 10 functional tasks both correctly and by simulating specific motor deficits (slowness, reduced range of motion, and tremor), which were previously discussed with rehabilitation experts. 

Results showed that the pipeline works well in detecting the simulated anomalous movements, correctly discriminating the quality of an execution and suggesting that the selected metrics could be a reliable tool in real scenarios. Particularly, automatic feature selection retained mainly accelerometers, with a combination of axes depending on the task, placed only on the wrist and the arm. While the sensor on the shoulder was limited in variance, its exclusion contrasts with pathological subjects’ distinctive compensatory strategies, which involve a specific kinematic of the shoulder that was not replicated by experiment participants, and that will be considered in future developments. 

This work created the basis for an objective assessment tool and prepared the way for future steps.