Continuous assessment of ECG signal quality

A system for assessing an electrocardiogram (ECG) signal quality, the system comprising a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the processor to:

• approximate an expected value E(.) using a plurality of filters, each comprising a one pole, low pass Infinite Impulse Response filter, to determine a Kurtosis calculation of an ECG signal by:
• determining a mean of the ECG signal using a first low pass filter,
• removing the mean determined using the first low pass filter from the ECG signal,
• approximating a Second moment using a second low pass filter after removing the mean from the ECG signal,
• squaring the Second moment after approximating a Second moment using a second low pass filter to output a denominator value,
• approximating a Fourth moment using a third low pass filter after removing the mean from the ECG signal to output a numerator value, and
• determining the Kurtosis calculation by dividing the numerator value by the denominator value;
• determine whether the Kurtosis calculation satisfies a first threshold to continuously assess a quality of the ECG signal;
• determine contact impedance between the wireless sensor device and the user;
• and determine whether the contact impedance satisfies a second threshold, wherein quality of electrode skin contact is assessed;
• determine a user activity level via at least one MEMS sensor of the wireless sensor device;
• and determine whether the user activity level satisfies a third threshold, wherein extent of user activity is assessed;
• determine source of noise based on comparing:
• Kurtosis calculation with the first threshold, contact impedance with the second threshold, and user activity level with the third threshold;
• and
• generate appropriate alerts, wherein the alerts include information regarding quality of the ECG signal and source of the noise.