Computerized Screening of Essential Tremor and Level of Severity Using Consumer Tablet

Abstract

Essential tremor (ET) is diagnosed and monitored by movement disorder specialists based on clinical observations. While many ET cases are benign, some require pharmacological and surgical management, and there is a need for tools to assist clinicians in making informed decisions. This work aimed to develop a computerized technique to detect the presence and severity of ET. A set of 6 writing and sketching tasks were performed by 39 subjects on a digital tablet. The position and pressure of contact during the sketching were recorded and analyzed to obtain the dynamics of drawing. ET patients were scored on the Fahn-Tolosa-Marin Tremor Rating Scale by blinded movement disorder neurologists, and then separated into two groups: moderate and severe ET. Drawing tasks were more effective than writing tasks in distinguishing the groups, with drawing horizontal and vertical lines being the most sensitive. A new set of composite index feature was found to be most suitable in separating the three groups, with a Spearman correlation coefficient of 0.72. The technique shows significant differences between controls, patients with moderate tremor and those with severe tremor, with an accuracy of 87.2%. Our computerized analysis significantly outperformed non-specialist clinicians in differentiating ET from control. We conclude that computerized analysis of the dynamics of sketching horizontal and vertical lines is a suitable method to assess the presence and severity of ET. INDEX TERMSComputerized diagnosis, essential tremor, feature selection, task selection, writing and sketching task. MOHAMMOD ABDUL MOTIN (Member, IEEE) received the B.Sc.Eng. and M.Sc.Eng.

Wearable Accelerometer and Gyroscope Sensors for Estimating the Severity of Essential Tremor

“…All participants gave their written informed consent before participating in the study. The patient data used in this study has also been reported in our earlier work [55] .…”

“…The study was conducted following the human experiments Helsinki Declaration (revised 2004) and approved by the Monash All participants gave their written informed consent before participating in the study. The patient data used in this study has also been reported in our earlier work [55].…”

Tremor rating scales and laboratory tools for assessing tremor

“…The speed or frequency of cursive strokes can approach that of tremor, making tremor more difficult to discern visually and mathematically [10,65]. Therefore, assessments of tremor in drawings of spirals and lines are usually more discriminating than assessments of handwriting [66].…”

Online Handwriting, Signature and Touch Dynamics: Tasks and Potential Applications in the Field of Security and Health

“…These tasks are useful to support diagnosis of e.g. Parkinson's disease [86,85], Huntington's disease [7], essential tremor [63,80,70,27], developmental dysgraphia [31], fatigue [34], or brachial dystonia [81]. See Figure 6.…”

“…This kind of task is especially challenging for those people affected by cognitive impairment, such as dementia, mild cognitive impairment, etc. This is the case of the house drawing Archimedean spiral, meanders and straight lines -Parkinson's disease [86,85] -Huntington's disease [7] -essential tremor [63,80,70,27] -developmental dysgraphia [31] -fatigue [34] -brachial dystonia [81] Single or overlapped circles -Huntington's disease [7] -schizophrenia [9] Spring task -fatigue [34] -developmental dysgraphia [31,103] -schizophrenia [9,14] -bipolar disorder [14] -Parkinson's disease [93] -Huntington's disease [7] Rainbow task -developmental dysgraphia [31,67] Saw task -developmental dysgraphia [31] Drawing Tasks Security (user identification and verification)…”