Intracranial Pressure Estimation from a Fluid Circuit Model and Peripheral Wearable Sensor

Elevated intracranial pressure (ICP) after traumatic brain injury can impede cerebral blood flow and contribute to secondary ischemic injury. However, direct ICP measurement is currently available only through invasive catheterization in critical care settings, while most tools being studied for noninvasive measurement permit only intermittent. This work examines the use of peripheral blood pressure waveform information to infer changes in ICP with a simple peripheral pressure sensor. Waveforms are reproduced by the direct fitting of a fluid circuit model for arterial and intracranial pressure behavior that was previously developed for use with an intraparenchymal catheter. A regression model is established between mean arterial blood pressure, differential ICP as inferred from the circuit model, and reference ICP measurements from invasive catheterization in eleven hospitalized subjects.