A method of determining a change in health of a user, the method comprising: sensing, from a handheld sized device with a sensor capable of sensing motions, a first motion of a body part of a user; based on the sensed first motion, generating a first multi-dimensional motion signal at a first time, the first motion signal including a gravitational component and one or more indicators relating to the user's status; generating first micro-motions data using the first motion signal, the first micro-motions data comprising a non-transitory representation of the first motion signal and status information for the user at the first time; time-stamping the first micro-motions data thereby generating first micro-motions data having a first timestamp associated with the first time; sensing a second motion of the body part of the user; based on the sensed second motion, generating a second motion signal at a second time; generating second micro-motions data using the second motion signal, the second micro-motions data comprising a non-transitory representation of the second motion signal and status information for the user at the second time; time-stamping the second micro-motions data thereby generating second micro-motions data having a second timestamp associated with the second time; generating by using a signal processing algorithm a first neuro-mechanical identifier based upon the first micro-motions data for the user; generating by using the signal processing algorithm a second neuro-mechanical identifier based upon the second micro-motions data for the user; comparing, with an electronic circuit, the first neuro-mechanical identifier and the second neuro-mechanical identifier; and determining whether there is a change in status for the user between the first micro-motions data having the first timestamp and the second micro-motions data having the second timestamp based on the comparing of the first neuro-mechanical identifier and the second neuro-mechanical identifier. sensing, from a handheld sized device with a sensor capable of sensing motions, a first motion of a body part of a user; based on the sensed first motion, generating a first multi-dimensional motion signal at a first time, the first motion signal including a gravitational component and one or more indicators relating to the user's status; generating first micro-motions data using the first motion signal, the first micro-motions data comprising a non-transitory representation of the first motion signal and status information for the user at the first time; time-stamping the first micro-motions data thereby generating first micro-motions data having a first timestamp associated with the first time; sensing a second motion of the body part of the user; based on the sensed second motion, generating a second motion signal at a second time; generating second micro-motions data using the second motion signal, the second micro-motions data comprising a non-transitory representation of the second motion signal and status information for the user at the second time; time-stamping the second micro-motions data thereby generating second micro-motions data having a second timestamp associated with the second time; generating by using a signal processing algorithm a first neuro-mechanical identifier based upon the first micro-motions data for the user; generating by using the signal processing algorithm a second neuro-mechanical identifier based upon the second micro-motions data for the user; comparing, with an electronic circuit, the first neuro-mechanical identifier and the second neuro-mechanical identifier; and determining whether there is a change in status for the user between the first micro-motions data having the first timestamp and the second micro-motions data having the second timestamp based on the comparing of the first neuro-mechanical identifier and the second neuro-mechanical identifier. <EOS>