Tremor quantification and its measurements on parkinsonian patients

Tremor is a rhythmic involuntary oscillatory movement of body parts, with a relatively fixed frequency and amplitude. It can be observed in healthy subjects as well as in patients with various diseases. Tremor constitutes one of the most important symptoms of neurological disorders. Among the pathological cases, essential and parkinsonian tremor are the most often observed types. However, its objective assessment is very difficult. The methods used for quantification require application of such devices as low G accelerometers and piezoelectric detectors. In the present paper a simple measuring unit consisting of accelerometer transducer with built in A/D conversion and SPI bus is interfaced to a micro controller. The micro -controller acquires the tremor signal in all the three axes. The micro controller then transmits the signal to a PC, where the suitable program acquires the signal, which can be processed using MATLAB program for measuring and quantifying the tremor frequency and amplitude. After establishing the set of processing rules through MATLAB programming a portable and stand alone system can be designed. The proposed system for acquisition and processing of tremor signals can be used as an aid in both medical diagnosing and prognosis of certain neurological disorders.