Smartphone-based evaluation of parkinsonian hand tremor: quantitative measurements vs clinical assessment scores

With an ever-growing number of technologically advanced methods for the diagnosis and quantification of movement disorders, comes the need to assess their accuracy and see how they match up with widely used standard clinical assessment tools. This work compares quantitative measurements of hand tremor in twenty-three Parkinson's disease patients, with their clinical scores in the hand tremor components of the Unified Parkinson's Disease Rating Scale (UPDRS), which is considered the "gold standard" in the clinical assessment of the disease. Our measurements were obtained using a smartphone-based platform, which processes the phone's accelerometer and gyroscope signals to detect and measure hand tremor. The signal metrics used were mainly based on the magnitude of the acceleration and the rotation rate vectors of the device. Our results suggest relatively strong correlation (r>0.7 and p<;0.01) between the patients' UPDRS hand tremor scores and the signal metrics applied to the measured signals.