Novel Audio Steganography Technique for ECG Signals in Point of Care Systems (NASTPOCS)

Point of care testing (POCT) in patients with ischemic heart disease is impelled by the time critical need for quick, specific and accurate results for initiation of therapy instantly. The driving force behind POCT using ECG signals is to provide test immediately and conveniently to cardiac patients. This will intensify the probability of patient, physician and care team receiving the results faster, which facilitate immediate clinical management decisions to be taken. In wireless communication the biomedical data may be susceptible to potential attacks leading to following security challenges. To safeguard the privacy and integrity of biomedical data. To make sure that only authorized people can have the access to secret information. This paper proposes a five level wavelet decomposition based steganography technique applied to ECG signals along with RSA encryption and scrambling matrix based encoding technique to protect confidential information related to patient hidden inside ECG signals. To assess the efficiency of the proposed algorithm on the patient ECG signal, the two distortion measurement metrics like percentage RMSE difference (PRD) and PSNR(peak signal to noise ratio) have been compared with existing algorithm results and energy of watermarked ECG signal is compared with original ECG for Coiflet, Bioorthogonal and symlet wavelets. It is found that the proposed algorithm provides very high security protection for information related to patient and as well as with very less distortion of ECG signal, so that it remains diagnosable even after retrieval of patient related secret information.