A novel, low-complexity method for intracardiac signal compression in implantable devices

With an increasing use of implantable devices for the therapy of heart arrhythmia, the need arises for an efficient recording of cardiac signals with the limited resources of an implant. In this paper the authors present a new signal compression algorithm based on the Walsh-Hadamard Transform (WHT), which is suitable for realtime operation with minimal computational needs. Simulations with clinically measured data delivered compression ratios in the range 2.5-4 with just 4% PRD maximum distortion. This figures compare well to the results obtained with other (more complex) ECG compression techniques presented in the literature.