Validation for tremor quantification of an electromagnetic tracking device

• Published in: Movement disorders Vol. 16; no. 2; pp. 265 - 271
• Main Authors: O'Suilleabhain, Padraig E., Dewey Jr, Richard B.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.03.2001; Wiley
• Subjects: Adult; Aged; Aged, 80 and over; Algorithms; Biological and medical sciences; Electromagnetic Phenomena - instrumentation; Electromagnetic Phenomena - methods; electromagnetic tracking device; Equipment Design; essential tremor; Humans; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Parkinson Disease - complications; Parkinson's disease; Severity of Illness Index; Tremor - diagnosis; Tremor - etiology; tremor quantification; Human; Nervous system diseases; Tremor; Parkinson disease; Quantization; Electromagnetic device; Cerebral disorder; Involuntary movement; Test validation; Measurement technique; Central nervous system disease; Body movement; Tracking(movable target); Adult; Degenerative disease; Neurological disorder; Extrapyramidal syndrome
• ISSN: 0885-3185; 1531-8257
• DOI: 10.1002/mds.1064

An electromagnetic tracking system was used to record arm motion in subjects with Parkinson's disease (n = 23), essential tremor (n = 28) or without neurological disease (n = 4). Tremor magnitude was calculated by averaging the three‐dimensional displacement of individual tremor bursts. Tremor magnitude calculated in this manner was quite closely correlated with a clinician's estimate (r = 0.88 and 0.86 for Parkinsonian and essential tremors, respectively) and was reproducible (r = 0.93 for repeated recordings). The accuracy of the device and algorithm was confirmed by mechanically generating oscillations of known magnitudes and frequencies. This device is adaptable for quantifying different types of tremors and its accuracy is easy to verify. Because position rather than acceleration is tracked, tremor amplitude can be stated in readily comprehensible units. © 2001 Movement Disorder Society.