A method to record, store, and analyze multiple physiologic pressure recordings

To investigate the pathophysiology of syringomyelia, we developed a system to simultaneously record arterial, central venous, airway, cervical subarachnoid and intrathecal pressures. In addition, our system records electrocardiograms (ECGs) and provides us with the means to analyze all pressures during individual and averaged cardiac cycles. During the described study, flow magnetic resonance imaging and cardiac-gated ultrasound images were also used. To compare our pressure readings with these images, we needed to account for the low-frequency changes in the recorded pressures resulting from normal respiration. We therefore wrote a program to derive mean pressure waves during the cardiac cycle that averaged out the pressure effects of the respiratory cycle. Simultaneous cerebrospinal pressure, hemodynamic pressure and ECG were plotted. This allowed us to establish the simultaneous relationship between pressures, syrinx size and cerebellar tonsil pulsation during the cardiac cycle. This system may prove valuable to other researchers investigating the interactions between multiple physiological parameters during the cardiac cycle