Triaxial Vector Accelerometry: A Method for Quantifying Tremor and Ataxia

A triaxial vector accelerometry system for quantitatively assessing tremor and ataxia is described. Since movement at a specific anatomical site can be three dimensional, previously reported single-and dual-axis methods are not satisfactory for quantitative analysis. The accelerometer contains three identical piezoelectric transducers, and it easily attaches to the wrist, hand, ankle, foot, etc., while the subject performs controlled repetitive movement of a particular anatomical site. Signals from the accelerometer are processed by associated electronic circuitry which provides a graphic write-out of selected parameters. Equations from which these parameters were derived are discussed, as is their integration into performance indexes. A brief report is given on testing of normal volunteers and patients presenting abnormal neuromuscular function.