Detecting activity by a wheelchair user

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising tracking pushes by the wheelchair user by a method comprising:
• selecting, by the processor circuit a dominant motion sensor axis based on a calculated motion energy per motion sensor axis;
• performing, by the processor circuit, a frequency domain transformation of the collected motion data for the dominant motion sensor axis;
• and
• determining, by the processor circuit, a fundamental push frequency based on the frequency domain transformed data;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure,
• wherein the frequency domain transformation comprises a fast Fourier transform (FFT) operation, wherein detecting that a push occurred comprises:
• determining, by the processor circuit, a FFT peak of a lowest frequency that rises above a pre-determined threshold level of energy;
• and
• selecting, by the processor circuit, the lowest frequency as a fundamental frequency of pushing.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising tracking pushes by the wheelchair user by a method comprising:
• selecting, by the processor circuit, a dominant motion sensor axis based on a calculated motion energy per motion sensor axis;
• performing, by the processor circuit, a frequency domain transformation of the collected motion data for the dominant motion sensor axis;
• determining, by the processor circuit, a fundamental push frequency based on the frequency domain transformed data;
• and
• filtering the collected data including adjusting an intelligent filter to pass motion sensor signals within a frequency band corresponding to the fundamental push frequency and to reduce motion sensor signals within a frequency band corresponding to harmonics of the fundamental push frequency;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising tracking pushes by the wheelchair user by a method comprising:
• determining a pose angle and a calculated energy based on the motion data;
• detecting, by the processor circuit, that a push occurred based on the determined pose angle and the calculated energy;
• filtering, by the processor circuit, the collected motion data to produced filtered motion data;
• and
• determining, by the processor circuit, a push count based on zero-crossings of the filtered motion data;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising detecting when a wheelchair user is traveling on a ramp by a method comprising:
• determining, by the processor circuit, a ramp classification based on the collected motion data;
• and
• filtering, by the processor circuit, the determined ramp classification using a filter;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising detecting wheelchair user stroke type by a method comprising:
• measuring X axis and Y axis accelerometer data from an accelerometer located on an arm of the user;
• detecting a Y axis accelerometer peak corresponding to a push phase;
• determining adjacent zero crossings to the Y axis accelerometer peak to determine the start and end of the push phase and a return phase;
• determining a length of the push phase;
• detecting X peaks in X axis accelerometer data during the return phase;
• detecting Y peaks in Y axis accelerometer data during the return phase;
• determining signs for the X peaks and the Y peaks;
• determining an ordered sequence of the determined X signs;
• determining an ordered sequence of the determined Y signs;
• determining stroke type based on the sequence of X signs and the sequence of Y signs;
• and
• applying one of the determined stroke type and the determined push phase length in a calorie expenditure tracking system;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data;
• estimating, by a processor circuit, an energy expenditure by the user based on the one or more activities, wherein estimating the energy expenditure by the user comprises:
• measuring at least one of X accelerometer data, Y accelerometer data, Z accelerometer data, X rotational data, Y rotational data, Z rotational data, barometer data, altimeter data, GPS position data, GPS speed data, GPS altitude data, and heart rate data;
• receiving user input regarding at least one of fitness level, age, weight, injury type, and mobility level;
• determining an estimated speed based on the measured data;
• determining an estimated MET value based on the estimated speed;
• determining a ramp state based on the measured data;
• refining the estimated MET value based on the determined ramp state;
• determining an energy expenditure estimate based on the estimated MET value;
• determining a physiological efficiency estimate based on the user input;
• refining the physiological efficiency estimate based on the measured data;
• refining the energy expenditure estimate using the physiological efficiency estimate;
• and
• applying the refined energy expenditure estimate in a calorie expenditure tracking system;
• and
• outputting, by the processor circuit, the estimated energy expenditure.

A method for tracking activity by a wheelchair user, the method comprising:

• collecting motion data of a user device located on an appendage of the user;
• detecting, by a processor circuit, that one or more activities by the wheelchair user occurred based on the motion data, the detecting comprising detecting when the wheelchair user is engaging in a transfer from or shift in the wheelchair by a method comprising:
• collecting motion data of a user device located on an appendage of the user;
• extracting, by the processor circuit, one or more features of interest from the collected motion data;
• detecting, by the processor circuit, that the user engaged in a wheelchair shift or transfer based on the one or more features and one or more corresponding thresholds for the one or more features;
• in response to detecting the wheelchair shift or transfer, updating a current state of a state machine;
• and
• triggering a reminder to the user based on the current state of the state machine;
• estimating, by the processor circuit, an energy expenditure by the user based on the one or more activities;
• and
• outputting, by the processor circuit, the estimated energy expenditure.