We have fetched databases from various universities’ medical schools and found that the MIT-BIH Arrhythmia Database is the widely used, internationally accepted in both online and offline applications.

Amongst the various signals such as EEG, ECG, in the MIT-BIH Arrhythmia Database, we have shortlisted ECG signals to start with, because ECG signals are comparatively easier to analyze than EEG and other signals.

A typical ECG Signal:
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A typical EEG Signal:
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We have also found out how to analyze the ECG signals theoretically. Now we will have to implement in MATLAB or LabView.

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The QRS complex stands for the key portion of the ECG wave that involves the depolarization of the right and left ventricles. The QRS complex thus contains the peak of the pulse, and indicates that a heartbeat has occurred.

QRS detection is the most important parameter in the determination of heart rate variability. Although not every QRS complex contains three separate Q, R and S waves, any conventional combination of these can be considered a QRS complex. However, in order to understand the ECG reading and analyze it, it is necessary to label each part of the complex. Once they are identified, they can be employed to characterize heartbeats.

Once the QRS has been detected, the location of the QRS in time can be annotated as a beat, and a sequence of beat annotation over time can be charted. A heart rate algorithm that takes the sequence of beat annotations, measures the time difference between beats to calculate a heart rate at every moment in time can then analyze this sequence of beat annotations.

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Now, with the necessary heart rate information extracted, basic thresholds can be put on a heart rate variability system in order to determine if the patient has exited a normal state. If the heart rate is below 60 bpm or above 100 bpm for a normal adult, an alarm can be raised to alert the medical personnel that the patient requires particular attention. This can be done through an SMS which will be sent via the ARM7 system powered with the BLUETOOTH module.