Method and system for assessing motion symptoms
A state of progression in an individual of a disease or treatment having motion symptoms is determined. A time series of accelerometer data is obtained from an accelerometer worn on an extremity of the person, over an extended period during everyday activities of the person. The accelerometer data is processed to produce a plurality of measures of kinetic state of the individual at a respective plurality of times throughout the extended period, each measure of kinetic state comprising at least one of: a measure for bradykinesia, and a measure for dyskinesia. A measure of dispersion of the measures of kinetic state is determined. An output is generated, indicating that motion symptoms are at an initial stage if the measure of dispersion is less than a threshold, or indicating that motion symptoms are at an advanced stage if the measure of dispersion is greater than the threshold.
1. A method of determining a state of progression in an individual with Parkinson's disease, the method comprising:
receiving a time series of accelerometer data obtained from an accelerometer of a wrist-mounted device worn on a wrist of the individual over an extended period of time during everyday activities of the individual;
determining, by a processor and based on the time series of accelerometer data, a plurality of measures of kinetic state of the individual at a plurality of times throughout the extended period of time, each measure of kinetic state comprising a measure for bradykinesia and a measure for dyskinesia;
determining, by the processor, a measure of dispersion of the measures of kinetic state including a measure of dispersion of the measure for bradykinesia and a measure of dispersion of the measure for dyskinesia;
calculating, by the processor, a Fluctuation Score using a function including a weighted sum of the measure of dispersion of the measure for bradykinesia and the measure of dispersion of the measure for dyskinesia;
responsive to the Fluctuation Score being less than a threshold, displaying, by a display device, a first output indicating that Parkinson's disease is at an initial stage to assess treatment thereof; and
responsive to the Fluctuation Score being greater than the threshold, displaying, by the display device, a second output indicating that Parkinson's disease is at an advanced stage to assess treatment thereof.
2. The method of claim 1 , wherein the measure of dispersion comprises a measure of an interquartile range of the measures of kinetic state.
3. The method of claim 1 , wherein the measure of dispersion comprises a measure of a standard deviation of the measures of kinetic state.
4. The method of claim 1 , wherein the measure of dispersion comprises a measure of a variance of the measures of kinetic state.
5. The method of claim 1 , wherein the extended period of time comprises more than one day.
6. The of claim 5 , wherein the extended period of time comprises 10 days.
7. The method of claim 1 , wherein during the extended period of time, the accelerometer data is obtained only when the individual is awake.
8. The method of claim 1 , wherein the weights are equal.
9. The method of claim 1 , wherein the measure of dispersion is determined by summing each measure of bradykinesia with a contemporaneous measure of dyskinesia to produce a combined measure of kinetic state, and the Fluctuation Score is determined from the dispersion of the combined measures of kinetic state.
10. The method of claim 1 , wherein the method is used to obtain Fluctuation Scores for a plurality of individuals, and further comprising aggregating a plurality of measures of dispersion in order to assess a state or progression of Parkinson's disease or treatment therefor, for the group of individuals.