## Technical DetailsThe maximum sampling rate of the gyro sensor of an Apple iPhone/iPod is 100 Hz.About 20-30 measuring points are thus recorded to describe one movement cycle at a normal rotational frequency of 3-5 Hz. The slower the hand movement is, the more points are recorded and the more precise is its description. To avoid effects of fatigue, the duration of one recording is limited to 5 seconds. Currently, the maximum and average values of amplitude and frequency, the maximum angular velocity and the total angular motion path are determined to describe the rotatory hand movements. For each hemicycle of the movement, the amplitude and frequency are determined from the respective distance between the maximum / minimum peaks. The maximum angular velocity can be determined as the gradient of a regression line at the steepest part of the graph. At least 5 measuring points are used to calculate the regression line. Values of angular velocity are only accepted for evaluation if the regression coefficient is no less than 0.9. To get a valid representation of the best possible hand movement as well as to minimize the effect of artefacts / single outlying values, the average of the top 25% of the respective values is calculated for every "maximum" parameter. For any further questions, please email to: |