Apparatus and method for reduction of neurological movement disorder symptoms using wearable device
A multimodal wearable band uses mechanical vibrations to stimulate sensory neurons in the wrist or ankle to reduce the severity of tremors, rigidity, involuntary muscle contractions, and bradykinesia caused by neurological movement disorders and to free users from freezing induced by movement disorders. The device uses sensors to provide output used by a processing unit to determine a stimulation pattern for the user and to determine when stimulation is necessary, and then uses one or more transducers to correspondingly stimulate the user's neurological pathways to lessen the severity of the user's symptoms. The device can also be adapted to integrate with third party devices.
1. A wearable device for modulating movement disorder symptoms of a user, the device comprising:
a. a housing;
b. an attachment system coupled to the housing and configured to attach to a user;
c. a sensor disposed in the housing, the sensor configured to provide a sensor output related to movement of the user;
d. a transducer coupled to the attachment system, the transducer configured to provide outputs to the user; and
e. a processing unit, having (i) an input, operationally coupled to the sensor output, to receive movement data; (ii) noise filtration processing to remove, from the movement data, noise unrelated to a movement disorder symptom so as to produce a filtered movement signal; (iii) feature extraction processing of the filtered movement signal to characterize features of the filtered movement signal to produce a characterized filtered movement signal; and (iv) processing of the characterized filtered movement signal to produce a stimulation signal output, wherein the stimulation signal output is provided to the transducer which causes the transducer to stimulate the user;
wherein the processing unit is configured to provide active noise cancellation by transforming the sensor output into the frequency data by applying a Fourier Transform to the sensor output and (i) selecting the fundamental frequency by applying an argmax function to the transformed sensor output and (ii) using a bandpass filter to remove, from the movement data, a set of frequency data outside a specified range associated with the fundamental frequency.
2. The device of claim 1 , wherein the processing unit is further configured to provide active noise cancellation by (a) transforming movement data in the time domain into frequency domain data, (b) using the frequency domain data to determine a fundamental frequency of the movement disorder symptoms, (c) generating the stimulation signal output, based on the movement data, having a desired phase shift, relative to a phase of the movement data at the fundamental frequency.
3. The device of claim 2 , wherein the sensor includes an inertial motion unit (IMU) configured to calculate acceleration data of the user, and the active noise cancellation processor is further configured to provide active noise cancellation by:
transforming the acceleration data to the frequency data by applying a Fourier Transform;
extracting peak frequencies of the acceleration data from the frequency data;
selecting a window size of the acceleration data based on the peak frequencies; and
capturing a portion of the sensor output based on the selected window size and inverting the captured portion to generate the stimulation signal.
4. The device of claim 3 , wherein in selecting the window size, the processing unit inverts a lowest of the peak frequencies and converts the inverted lowest of the peak frequencies into a time domain.
5. The device of claim 3 , wherein the processing unit is configured to set the window size to a fixed value.
6. The device of claim 1 , wherein the processing unit is further configured to provide, at the stimulation signal output, a train of stimulation signals, each signal in the train having a distinct set of parameters associated with mitigating the movement disorder symptom and wherein the feature extraction processing includes determining displacement or power data associated with the movement of the user, and the processing unit is also configured to use the displacement or power data to determine which stimulation signal in the train has the greatest mitigation effect.
7. The device according to claim 6 , wherein the processing unit is further configured to select the stimulation signal determined to have the greatest mitigation effect for continuous output to the transducer.
8. The device of claim 1 , wherein the processing unit is configured to detect and mitigate a movement disorder symptom selected from the group consisting of tremor, rigidity, bradykinesia, dyskinesia, compulsion to move, and combinations thereof.
9. The device of claim 1 , wherein the processing unit is configured to detect a freezing gait of a user with Parkinson's Disease.
10. The device of claim 9 , wherein the processing unit is further configured to mitigate the freezing gait of the user with Parkinson's Disease by controlling the transducer.
11. The device of claim 1 , wherein the attachment system includes a wristband, and a plurality of transducers is distributed throughout a circumference of the wristband.
12. The device of claim 11 , wherein the wristband is configured with a hook-and-loop fastener, such that the wristband can be fastened with a single hand for ease of use by those whose fine motor control is affected by a neurological movement disorder.
13. The device of claim 11 , wherein the wristband is configured to be expandable via elastic deformation for ease of use by those whose fine motor control is affected by a neurological movement disorder.
14. The device of claim 1 , wherein the device is operated by a button on a face of the device, the button being configured to allow for ease of use by a user whose fine motor control is affected by a neurological movement disorder.
15. The device of claim 1 , wherein the processing unit is configured to operate in two modes, a first mode to monitor movements of the user passively to detect a movement disorder symptom above a threshold and a second mode, following detection of such a movement disorder symptom, to mitigate the movement disorder symptom.
16. The device of claim 1 , further comprising a battery, disposed on the housing, and a magnetic connector coupled to the battery and mounted in the housing for coupling to a mating connector from an external charger, so that the battery can be charged by a user lacking fine motor control.
17. The device of claim 1 , wherein the processing unit is further configured to store the movement data in memory coupled to the processing unit.
18. A method for mitigating a movement disorder symptom of a user, the method comprising:
receiving sensor output related to movement of a user from a sensor;
processing the sensor output to produce a stimulation signal by:
filtering the sensor output to remove noise to produce a filtered signal,
processing the filtered signal by (a) transforming the sensor output into frequency data, (b) using the frequency data to determine a fundamental frequency of a movement disorder symptom, (c) generating the stimulation signal by applying, to the filtered signal, a time delay to produce a desired phase shift at the fundamental frequency, wherein actively processing the filtered signal to transform the sensor output into frequency data includes applying a Fourier Transform to the filtered signal to generate transformed sensor output data and (i) selecting the fundamental frequency by applying an argmax function to the transformed sensor output data and (ii) using a bandpass filter to remove, from the stimulation signal, frequency data outside a specified range associated with the fundamental frequency; and
transmitting the stimulation signal to a transducer coupled to the user to mitigate the set of movement disorder symptoms.
19. A method according to claim 18 , wherein the movement disorder symptom is selected from the group consisting of tremor, rigidity, bradykinesia, dyskinesia, compulsion to move, and combinations thereof.
20. A method according to claim 18 , wherein receiving sensor output related to movement of the user from a sensor includes operating in two modes, a first mode that monitors movements passively to detect a movement disorder symptom above a threshold and a second mode that, following detection of such a movement disorder symptom, enters into active mitigation of the movement disorder symptom.
21. A method according to claim 18 , wherein processing the sensor outputs to produce the stimulation signal further includes:
calculating acceleration data representing acceleration of the user;
transforming the acceleration data to the frequency data by applying a Fourier Transform;
extracting, from the frequency data, peak frequencies of the acceleration data;
selecting a window for the acceleration data based on the peak frequencies; and
capturing a portion of the sensor output based on the selected window and inverting the captured portion to generate the stimulation signal.
22. A method according to claim 21 , wherein selecting the window includes inverting a lowest one of the peak frequencies and converting the inverted lowest one of the peak frequencies into a time domain signal.
23. A method according to claim 21 , wherein selecting the window includes setting the window to a fixed value.
24. A method of diagnosing a movement disorder in a body part of a susceptible subject comprising:
using a processor, providing a stimulation signal to a transducer in order to induce symptoms of a movement disorder;
applying, through the transducer, the stimulation signal to a user;
receiving movement data, related to movement of the user, from a sensor;
filtering the movement data to remove noise to produce a filtered signal;
processing the filtered signal to (a) transform the movement data into frequency data, (b) use the frequency data to determine a fundamental frequency of the movement of the user, and
processing the frequency data to determine if the user is suffering from the movement disorder.