Figure 5.
Summary of error estimates as function of stimulation frequency and pulse number: (a) (shaded). Relative time-integrated error (as % of the time-integrated IChR2(AP), cumulative over the indicated number of light pulses/beats) if IChR2(Vclamp) is used to estimate the true IChR2(AP) (i.e. error between rows II and III in Figure 4a–c). (b–d). Errors if the new (I–V curve-based) approximation is used to estimate the true IChR2(AP) (compare the overlaid traces in rows III of Figure 4a–c, as well as the resultant difference errors displayed in rows IV of Figure 4a–c). (b). Relative time-integrated error (in % of the time-integrated IChR2(AP)); (c). Cumulative absolute time-integrated error (in units of charge nC/μF); (d). Absolute time-integrated error per pacing period (in nC/μF). Light pulses were 5 ms at 1 mW/mm2, delivered at 1 Hz (blue), 5 Hz (red) or 20 Hz (black), as indicated by example traces in Figure 4. Note that 40 pulses correspond to 40 s, 8 s and 2 s time interval for the three pacing frequencies.