Non-contact measurement of tremor for the characterisation of Parkinsonian individuals: Comparison between Kinect and Laser Doppler vibrometer

Parkinson’s disease is a progressive neurodegenerative disorder affecting the central
nervous system. One of its main and most evident symptoms is the tremor, which usually
manifests at rest with varying intensity during time. An important diagnostic challenge is the
differential diagnosis between Parkinson’s disease and the other most widely represented
tremor syndrome, i.e. Essential (or senile) tremor. At present there are no standard methods for
the quantification of tremor and the diagnosis of both Parkinson’s disease and Essential tremor
is mainly done on the base of clinical criteria and by using rating scales. The aim of this work
is to objectively and non-invasively assess the tremor linked to the quoted diseases, using noncontact
techniques: Laser Doppler Vibrometer (LDV) and Kinect for Windows device. Two
subjects with Parkinson’s disease and one with Essential tremor were tested in different
conditions: at rest, during a cognitive task, with forward stretched arms and in “Wing
position”. The results from data processing in terms of tremor frequency seem to be
comparable, with a mean deviation of 0.31 Hz. Furthermore, the values computed are
consistent with what is stated in the literature (i.e. 4-12 Hz). So, both LDV and Kinect device
can be considered suitable to be used as an objective means for the assessment and monitoring
of Parkinson’s disease tremor, helping the clinician in the choice of the most suitable treatment
for the patients.