Biometric recognition system

A computer program product stored on a computer readable medium which when executed on a handheld computing device incorporating an inertial measurement unit (IMU) comprising a plurality of accelerometers and at least one gyroscope is arranged to perform the steps of:

• obtaining from the IMU, accelerometer signals indicating device translational acceleration along each of X, Y and Z axes as well as a gyroscope signal indicating rotational velocity about the Y axis during a measurement window;
• filtering each of said IMU signals to provide filtered frequency components for said signals during said measurement window;
• providing a spectral density estimation for each of said filtered accelerometer magnitude signal and said filtered gyroscope signal;
• determining an irregularity for each spectral density estimation;
• and
• based on said determined irregularities, attempting to authenticate a user of said device.

A biometric recognition system for a hand held computing device incorporating an inertial measurement unit (IMU) comprising a plurality of accelerometers and at least one gyroscope, said system comprising a first authentication component requiring a higher level of authentication than provided by a tremor analysis component, said system being responsive to said first authentication component authenticating a given user to place said device in first authentication state;

• and
• said tremor analysis component, being responsive to said device entering said first authentication state to periodically verify said user to maintain said device in a second authentication state, said second authentication state providing greater access to said device than said first authentication state, the tremor analysis component being arranged to:
• obtain from said IMU accelerometer signals indicating device translational acceleration along each of X, Y and Z axes as well as a gyroscope signal indicating rotational velocity about the Y axis during a measurement window;
• filter each of said IMU signals to provide filtered frequency components for said signals during said measurement window;
• provide a spectral density estimation for each of said filtered accelerometer magnitude signal and said filtered gyroscope signal;
• and
• based on features extracted from said spectral density estimates, attempt to verify said user of said device.