Study of Shunt Flow Sensor Accuracy in Extra-ventricular Drains.

The study hypothesis is that an ultrasonic flow sensor can accurately measure flow in hydrocephalic shunts. The ultrasonic sensor will measure cerebrospinal fluid drainage in hydrocephalus patients with external ventriculostomies and extra-ventricular drainage systems. The sensor measurements will be compared with the volume of fluid collected by the drainage bag. After a 24-hour measurement period, the doctor will change the drainage bag position to simulate the patient sitting up and leaning back, to see if this temporarily stops flow through the drainage line. This data will show whether the sensor accurately measures typical drainage flows seen in hydrocephalus patients. This research will help develop an implantable flow monitor for pediatric hydrocephalus patients.