Heart beat data compression using temporal beats alignment and 2-D transforms

A new heart beat signal compression method using a 2-D transform is presented. This 2-D transform method utilizes the fact that the heart beat signals generally show two types of redundancies-between the adjacent complexes and adjacent samples. An original heart beat data sequence is sliced and aligned beat by beat prior to 2-D transformation. Specifically, the 2-D discrete cosine transform (DCT) is employed as an example. Using selections from a Medtronic ECG and EMG database and from the MIT-BIH arrhythmia database, the simulation results show a substantial improvement in the compression ratio (CR) over 1-D methods for comparable percent root-mean-square difference (PRD). The proposed 2-D aligned heart beat complex compression approach works well with heart beat signals which have normal complexes and arrhythmic patterns. It is compatible with irregular cardiac signals occurring for example during fibrillation.