Estimation of latency changes of evoked potentials with adaptive phase spectral time delay estimation
Tianshuang Qiu, Xuan Kong, Bernice Kaufman · 2002
Addresses the problem of detecting and estimating latency changes for evoked potentials (EPs). EPs have been widely used to quantify neurological system properties. Transient and time-varying changes in latency may indicate impending neurological injury. The traditional time averaging technique used for detecting EP signals is very inefficient since it cannot track rapid time-varying latency changes. The correlation-based method is also unreliable when external periodic interference is present. This paper proposes an adaptive phase spectral time delay estimation method to detect and estimate the time-varying latency changes when both the signal-to-noise ratio (SNR) and the signal-to-interference ratio (SIR) are low. Experiments and computer simulations show that the method proposed can track the time-varying latency effectively and accurately under the condition that both the SNR and the SIR are as low as -5 dB. The method is also suitable for the detection and estimation of EP latency changes in real time.