PAM: passive marker-based analyzer to test patients with neural diseases

Neurologists observed specific changes in the movement coordination of their patients - compared to healthy control subjects - a long time ago. In the early, preclinical phase the subtle changes cannot be detected by visual inspection. Similarly, variations in the performance of a patient resulting from minor changes in the stage of the disease remain undetected for the human observer. Evaluation of well-defined movement patterns aids the diagnosis even early diagnosis and assessment of the actual state of patients with neural diseases. Passive marker-based motion analysis is especially suitable for testing human movements. The markers are lightweight (1...10 grams), and no wires are needed between the markers and the analyzer. The markers and the analysis cause absolutely no discomfort to the persons. The performance of commercially available motion analyzers by far exceeds the requirements needed to record and evaluate the movement patterns of patients with neural diseases. As a consequence, these devices are too expensive for this purpose. A simple device has been developed that is affordable for routine clinical use. In harmony with the practice of neurologists, parameters have been defined that characterize both the speed and the regularity of movements. These parameters help in staging patients.