Denoising knee joint vibration signals using adaptive time-frequency representations

A novel denoising method for improving the signal-to-noise ratio (SNR) of knee joint vibration signals (also known as vibroarthrographic or VAG signals) is proposed. The denoising methods considered are based on signal decomposition techniques such as wavelets, wavelet packets, and the matching pursuit method. Performance evaluation with synthetic signals simulated with characteristics expected of VAG signals indicated good denoising results with the matching pursuit method. Nonstationary signal features extracted and identified from time-frequency distributions of denoised VAG signals have shown good potential in screening for articular cartilage pathology.