DETECTING STIMULUS PULSES

A method for detecting a stimulus pulse by using two or more electrical signals derived from a living body, the method comprising the following steps: (a) for each electrical signal, digitizing the signal with an analog-to-digital converter to produce a sampled signal Sk; (b) for each signal Sk at a sample time ti, computing a primary difference Δkp(ti)=abs[Sk(ti)−Sk(ti−p)]; (c) determining the minimum value of all of the computed differences, such minimum being a detector output D(ti); (d) comparing the detector output D(ti) with a detection threshold; and (e) indicating that a stimulus pulse has been detected when the detector output D(ti) is above the detection threshold.