Real-time signal restoration by natural-observation system

Biomedical signals such as blood pressure and ECG signals are time-varying and nonstationary. When measuring these signals by medical instruments, the system produces distortions. One therefore needs to restore the original signal from the distorted signal for precise diagnosis and analysis. The authors used a natural-observation system to overcome this problem. In the natural-observation system, the original signals are derived by a series of operators that emphasize the present time. Here, the authors discuss real-time time-varying signal restoration. They applied to the restoration problem a natural-observation system as a representation method for time-varying and nonstationary signals. They thus achieved complete restoration of some signals and band-limited restoration of all signals