Resting hand tremor is one of the most important biomarkers in Parkinson’s disease (PD). This indicator is mainly described as periodic oscillatory movements when hands are completely supported, i.e., without voluntary muscle contraction. Such characterization is however very difficult to observe in standard clinical analysis, due to the imperceptible low tremor amplitude. Furthermore, in early stages of PD those motions are commonly misclassified as control patterns. Common clinical practice often suggests a physical tremor magnification by forcing postural hand configurations, dealing with natural strain motions that might disturb tremor behavior. In this work was introduced a video characterization that highlights hand tremor patterns from resting and postural setups. Initially, each of videos are represented as a bank of spatial and temporal filters. Then, specific spatio-temporal bands are amplified to stand out tremor patterns. A set of anatomical points of interest was fixed to be quantitatively assessed along the magnified sequence. Temporal variance of these points were associated with tremor recorded in videos. The proposed approach was evaluated in a total of 80 videos recording hands in resting and postural configurations. Variance analysis was performed to measure temporal amplitude differences of tremor in PD and control videos. In resting validation, a gain of 7.76 dB was achieved in parkinsonian and control comparison by using amplified videos. While physical magnification obtains a F-test of 5.19, the proposed optical magnification yields a F-test of 8.19, allowing a better quantification of the disease.

Date Published: 21 December 2018
PDF: 9 pages
Proc. SPIE 10975, 14th International Symposium on Medical Information Processing and Analysis, 1097503 (21 December 2018); doi: 10.1117/12.2512109

Published in SPIE Proceedings Vol. 10975:
14th International Symposium on Medical Information Processing and Analysis
Eduardo Romero; Natasha Lepore; Jorge Brieva, Editor(s)