Morphology Analysis of Intracranial Pressure Using Pattern Matching Techniques

We present a clustering algorithm based on Dynamic Time Warping (DTW) to automatically classify intracranial pressure (ICP) beats based on their morphology. The algorithm detects, classifies and labels each beat as a low--pressure or high--pressure beat based on morphology. The trend is removed during prepocessing to ensure the classifications are independent of the mean ICP. An ICP beat detection algorithm is used to automatically detect each beat. We measured the performance of the algorithm compared to expert classification of ICP beats acquired from intensive care unit patients using linear and non-- linear temporal alignment techniques. The algorithm achieved a superior performance using non--linear temporal alignment

Significance of Intracranial Pressure Pulse Morphology in Pediatric Traumatic Brain Injury

We investigated the relationship between the intracranial pulse pressure (ICPPP ) and the mean intracranial pressure (ICPM ). In adult patients, several research groups have described a linear relationship between ICPPP and ICPM within the range of cerebral autoregulation. Current monitoring and therapy are mainly based on the mean ICPM , since it is believed that the ICPM contains most of the information provided by the other pulse morphology metrics. In this paper we attempt to answer whether there is further information within the ICP morphology not explained by ICPM that might be of prognostic significance. We screened ICP records of 42 patients admitted to the Pediatric Intensive Care Unit at Doernbecher Children's Hospital for segments in which the ICPM varied at least 5 mmHg during a 1-hour period. We found 54 segments in 9 different pediatric TBI patients (ages 0.2--17.8 years, mean=9.9 years). ICPPP and ICPM were calculated for each pulse using an automatic pressure detection algorithm. The coefficient of linear correlation r was > 0.70 in 43/54 segments (p<0.001), which indicates that there exists a linear relationship between ICPPP and ICPM . However, we found r>0.90 only in 16/54 segments (p=NS) . This result and visual inspection of ICPPP vs. ICPM density plots suggest that ICP pulse pressure is not fully explained by the ICPM