Blood pressure corrected evoked flow responses wide the fit error is less dependant on the exact parameter value and conse- quently the fit is not sensitive to changes in this parameter. Additionally, per- centage confidence bounds facilitate comparison of precision between different parameters. Statistical analysis of differences in NVC parameter values and reliabilities with and without blood pressure correction was performed using a Wilcoxon sign- rank test. Differences were considered significant for p-values less then 0.01. mCBFV % 40 A 20 0 0 5 10 15 20 25 30 35 40 Time s mCBFV % 40 B 20 0 0 5 10 15 20 25 30 35 40 Time s 5 mBP % C 0 -5 0 5 10 15 20 25 30 35 40 Time s Figure 3 Example of an averaged NVC response (solid A and B) and the fits without (dashed A) and with (dashed B) blood pressure correction. Fitted NVC response with blood pressure corrected model (dotted B). Averaged blood pressure response (solid C). NVC parameters for RG model vs. RGCA model!: 0.67& 0.15 rad/s, : 1.2& 0.6, Tv:1.4& 12 s, K: 22& 19 Results Data from all subjects were used to evaluate the blood pressure correction of the NVC response. An individual example of an averaged NVC response that is fitted with the two models is shown in figure 3. Figure 3A shows the results for the RG model, figure 3B for the RGCA model and figure 3C shows the stimulus averaged blood pressure response. It can be clearly seen that the fitted response of the RGCA model (dashed B) is better following the averaged evoked flow response 87
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