Peak appearance time in pulse waveforms of intracranial pressure and cerebral blood flow velocity

Figures

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  FIGURE 1. An example of normalized pulses of intracranial pressure (ICP) and cerebral blood flow velocity (CBFV) with annotated peaks (P1, P2, P3 for ICP pulse and F1, F2, F3 for CBFV pulse) and peak appearance times (tPn–peak appearance time of the nth peak of ICP pulse, tFn–peak appearance time of the nth peak of CBFV pulse).

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  FIGURE 2. Flow diagram of the exclusion process performed to select viable signals with a recorded period of hypocapnia or ICP plateau wave.

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  FIGURE 3. An example of smoothed (within the window of 40 pulses) recordings from a single patient during hypocapnia. From top to bottom: intracranial pressure (ICP), cerebral blood flow velocity (CBFV), peak appearance times (PATs) of the first, second, and third ICP peaks (tP1, tP2, tP3) and the first, second and third CBFV peaks (tF1, tF2, tF3). Shaded areas indicate selected periods of baseline and hypocapnia.

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  FIGURE 4. An example of smoothed (within the window of 40 pulses) recordings from a single patient during the plateau wave. From top to bottom: intracranial pressure (ICP), cerebral blood flow velocity (CBFV), peak appearance times (PATs) of the first, second, and third ICP peaks (tP1, tP2, tP3) and the first, second and third CBFV peaks (tF1, tF2, tF3). Shaded areas indicate selected periods of baseline and the flat part of the plateau wave.

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  FIGURE 5. Peak appearance times (PATs) of the first, second and third peaks of intracranial pressure (P1, P2, P3) and cerebral arterial blood flow velocity (F1, F2, F3). Box-plots in the left column present PATs during hypocapnia and preceding baseline. Right column shows PATs during ICP plateau waves and corresponding baselines. N–number of patients in the group, p–p-value of Wilcoxon signed rank test, ns–p-values greater than 0.05.

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  FIGURE 6. Observed changes in peak appearance times during hypocapnia presented in handpicked pulse waveforms of intracranial pressure (ICP, left-hand charts) and pulse cerebral blood flow velocity (CBFV, right-hand charts). The arrows indicate direction of changes in peak appearance times.

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  FIGURE 7. Observed changes in peak appearance times during episodes of intracranial pressure (ICP) plateau waves presented in handpicked pulse waveforms of ICP (left-hand charts) and cerebral blood flow velocity (CBFV, right-hand charts). The arrows indicate direction of changes in peak appearance times.