Figure 2

Trend plots of RAP [correlation coefficient (R) between the intracranial pressure (ICP) wave amplitude (A) and the mean ICP level (P)] of Signals 1 and 2 in patient 2. For patient 2, the trend plots of (a) RAP determined during 100 consecutive 4-min periods for signals 1 (blue line) and 2 (red line) show marked differences (average of RAP_{Signal 1} 0.50; average of RAP_{Signal 2} -0.04). The horizontal lines at RAP 0.6 illustrate a commonly used upper normal threshold for RAP. The intracranial locations of the ICP sensors 1 and 2 are illustrated in (b).