Testing a Multi-Sensor System For Hydrocephalus Monitoring in External Ventricular Drains

We report a multi-sensor system for monitoring cerebrospinal fluid (CSF) dynamics in hydrocephalus shunts. Flow and biofouling sensors based on electrochemical impedance transduction were integrated into a single thin film die designed to be packaged in-line for compatibility with existing clinical workflows. Custom electronics provided remote impedance measurement, analysis, and data storage. This multi-sensor system was designed for use in external ventricular drains (EVDs), which drain CSF from the brain's ventricles to reduce acute swelling and manage intracranial pressure. The direct fluidic connection via an implanted catheter to the ventricles is similar to that of implanted hydrocephalus shunts, making EVDs a suitable model for preliminary non-invasive sensor validation. The multi-sensor system was validated on the benchtop in an EVD model using both saline and CSF collected from human patients. Flow resolution was 48.8 μL/min within a range of -330 to 660 μL/min (average CSF flow: 50 to 317 μL/min [1]). Successful benchtop validation will inform upcoming clinical tests in patients with EVDs.