Estimation of latency changes of evoked potentials with adaptive phase spectral time delay estimation

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.