Systems and methods for tremor detection and quantification

Abstract

Systems and methods are disclosed for detecting tremors in a subject. One method comprises receiving data from a digital device, the data comprising a plurality of digital device positions and a plurality of timestamps, each timestamp in the plurality of timestamps being associated with a digital device position in the plurality of digital device positions. The method further comprises determining a plurality of frequencies of hand movements of the subject based on the plurality of digital device positions and plurality of timestamps. The method further comprises determining a subportion of the data corresponding to frequencies of hand movements above a low tremor threshold, and determining a magnitude of tremors of the subject's hand based, at least in part, on the subportion of the data.

What is claimed is: 
     
         1 . A computer-implemented method for detecting tremors in a subject, comprising:
 receiving data from a digital device, the data comprising a plurality of digital device positions and a plurality of timestamps, each timestamp in the plurality of timestamps being associated with a digital device position in the plurality of digital device positions;   determining a plurality of frequencies of hand movements of the subject based on the plurality of digital device positions and plurality of timestamps;   determining a subportion of the data corresponding to frequencies of hand movements above a low tremor threshold; and   determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising:
 determining sections of data received from the digital device with missing samples or a non-uniform sampling rate; and   resampling the data to a uniform sampling rate by interpolating the missing position information based on the plurality of digital device positions in the data.   
     
     
         3 . The computer-implemented method of  claim 1 , further comprising:
 determining low-pass data by passing the data through a low-pass filter; and   determining an estimate of a direction and a speed of the digital device based, at least in part, on the low-pass data.   
     
     
         4 . The computer-implemented method of  claim 1 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered velocity vector signal by passing the subportion of the data through a first derivative filter; and   determining the magnitude of tremors of the hand of the subject based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal.   
     
     
         5 . The computer-implemented method of  claim 4 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered acceleration signal by passing the bandpass or high-pass filtered velocity vector signal through a second derivative filter; and   determining the magnitude of tremors of the hand of the subject based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal and the bandpass or high-pass filtered acceleration signal.   
     
     
         6 . The computer-implemented method of  claim 4 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining low-pass data by passing the data through a low-pass filter; and   determining the magnitude of tremors based, at least in part, on the portion of the bandpass or high-pass filtered velocity vector signal that is at a predetermined angle relative to the low-pass data.   
     
     
         7 . The computer-implemented method of  claim 1 , wherein the data corresponds to the subject drawing a clockface. 
     
     
         8 . The computer-implemented method of  claim 7 , further comprising:
 determining one or more perimeter lines in the data corresponding to a perimeter of the clockface; and   determining the magnitude of tremors based, at least in part, on the one or more perimeter lines in the data.   
     
     
         9 . A system for detecting tremors in a subject, the system comprising:
 a data storage device storing instructions for detecting tremors in a subject; and   a processor configured to execute the instructions to perform a method including:
 receiving data from a digital device, the data comprising a plurality of digital device positions and a plurality of timestamps, each timestamp in the plurality of timestamps being associated with a digital device position in the plurality of digital device positions; 
 determining a plurality of frequencies of hand movements of the subject based on the plurality of digital device positions and plurality of timestamps; 
 determining a subportion of the data corresponding to frequencies of hand movements above a low tremor threshold; and 
 determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data. 
   
     
     
         10 . The system of  claim 9 , the method further comprising:
 determining sections of data received from the digital device with missing samples or a non-uniform sampling rate; and   resampling the data to a uniform sampling rate by interpolating the missing position information based on the plurality of digital device positions in the data.   
     
     
         11 . The system of  claim 9 , the method further comprising:
 determining low-pass data by passing the data through a low-pass filter; and   determining an estimate of a direction and a speed of the digital device based, at least in part, on the low-pass data.   
     
     
         12 . The system of  claim 9 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered velocity vector signal by passing the subportion of the data through a first derivative filter; and   determining the magnitude of tremors of the hand of the subject based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal.   
     
     
         13 . The system of  claim 12 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered acceleration signal by passing the bandpass or high-pass filtered velocity vector signal through a second derivative filter; and   determining the magnitude of tremors of the hand of the subject based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal and the bandpass or high-pass filtered acceleration signal.   
     
     
         14 . The system of  claim 12 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining low-pass data by passing the data through a low-pass filter; and   determining the magnitude of tremors based, at least in part, on the portion of the bandpass or high-pass filtered velocity vector signal that is at a predetermined angle relative to the low-pass data.   
     
     
         15 . The system of  claim 9 , wherein the data corresponds to the subject drawing a clockface. 
     
     
         16 . The system of  claim 15 , the method further comprising:
 determining one or more perimeter lines in the data corresponding to a perimeter of the clockface; and   determining the magnitude of tremors based, at least in part, on the one or more perimeter lines in the data.   
     
     
         17 . A non-transitory computer readable medium for use on a computer system containing computer-executable programming instructions for performing a method for detecting tremors in a subject, the method comprising:
 receiving data from a digital device, the data comprising a plurality of digital device positions and a plurality of timestamps, each timestamp in the plurality of timestamps being associated with a digital device position in the plurality of digital device positions;   determining a plurality of frequencies of hand movements of the subject based on the plurality of digital device positions and plurality of timestamps;   determining a subportion of the data corresponding to frequencies of hand movements above a low tremor threshold; and   determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data.   
     
     
         18 . The computer readable medium of  claim 17 , the method further comprising:
 determining sections of data received from the digital device with missing samples or a non-uniform sampling rate; and   resampling the data to a uniform sampling rate by interpolating the missing position information based on the plurality of digital device positions in the data.   
     
     
         19 . The computer readable medium of  claim 17 , the method further comprising:
 determining low-pass data by passing the data through a low-pass filter; and   determining an estimate of a direction and a speed of the digital device based, at least in part, on the low-pass data.   
     
     
         20 . The computer readable medium of  claim 17 , wherein determining a magnitude of tremors of the hand of the subject based, at least in part, on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered velocity vector signal by passing the subportion of the data through a first derivative filter; and   determining the magnitude of tremors of the hand of the subject based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal.   
     
     
         21 . A computer-implemented method for detecting tremors in a subject, comprising:
 receiving data from a digital device, the data comprising a plurality of digital device positions and a plurality of timestamps, each timestamp in the plurality of timestamps being associated with a digital device position in the plurality of digital device positions;   determining a magnitude of tremors of the hand of the subject based, at least in part, on the data comprising the plurality of digital device positions and the plurality of timestamps; and   determining a degree of cognitive impairment of the subject based, at least in part, on the data comprising the plurality of digital device positions and the plurality of timestamps.   
     
     
         22 . The computer implemented method of  claim 21 , the method further comprising:
 determining a plurality of frequencies of hand movements of the subject based on the plurality of digital device positions and the plurality of timestamps;   determining a subportion of the data corresponding to frequencies of hand movements of the subject above a lower tremor threshold; and   determining the magnitude of tremors of the hand of the subject based in part on the subportion of data.   
     
     
         23 . The computer implemented method of  claim 22 , the method further comprising:
 determining sections of data received from the digital device with missing samples or a non-uniform sampling rate; and   resampling the data to a uniform sampling rate by interpolating the missing position information based on the plurality of digital device positions in the data.   
     
     
         24 . The computer-implemented method of  claim 22 , further comprising:
 determining low-pass data by passing the data through a low-pass filter; and   determining an estimate of a direction and a speed of the digital device based, at least in part, on the low-pass data.   
     
     
         25 . The computer-implemented method of  claim 22 , wherein determining a magnitude of tremors of the hand of the subject based in part on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered velocity vector signal by passing the subportion of the data through a first derivative filter; and   determining the magnitude of tremors of the subject's hand based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal.   
     
     
         26 . The computer-implemented method of  claim 25 , wherein determining a magnitude of tremors of the hand of the subject based in part on the subportion of the data further comprises:
 determining a bandpass or high-pass filtered acceleration signal by passing the bandpass or high-pass filtered velocity vector signal through a second derivative filter; and   determining the magnitude of tremors of the subject's hand based, at least in part, on analysis of the bandpass or high-pass filtered velocity vector signal and the bandpass or high-pass filtered acceleration signal.   
     
     
         27 . The computer-implemented method of  claim 25 , wherein determining a magnitude of tremors of the hand of the subject based in part on the subportion of the data further comprises:
 determining low-pass data by passing the data through a low-pass filter; and   determining the magnitude of tremors based, at least in part, on the portion of the bandpass or high-pass filtered velocity vector signal that is at a predetermined angle relative to the low-pass data.   
     
     
         28 . The computer-implemented method of  claim 21 , wherein the data corresponds to the subject drawing a clockface. 
     
     
         29 . The computer-implemented method of  claim 28 , further comprising:
 determining one or more perimeter lines in the data corresponding to a perimeter of the clockface; and   determining the magnitude of tremors based, at least in part, on the one or more perimeter lines in the data.