Bench Study of Transcutaneous Hydrocephalic Shunt Flow Sensor Alignment Accuracy and Repeatability

• Standard deviation of error between operator-measured flow measurements and actual flow measurements. [ Time Frame: Daily and weekly ] [ Designated as safety issue: No ]
  

• Flow measurement accuracy vs. the number of times the measurement is conducted. [ Time Frame: Daily, weekly ] [ Designated as safety issue: No ]
  

The study hypothesis is that a transcutaneously powered ultrasonic flow sensor for hydrocephalic shunts can be repeatedly and accurately read by medical personnel ranging from nurses to senior neurosurgeons.

The test will involve a prototype implantable hydrocephalic shunt flow sensor and readout electronics. The readout electronics use a pickup coil to transcutaneously operate the sensor once the coil is aligned with sensor's inductive coupling coils.

During the test, the shunt flow sensor will be hidden under a thick saline gel pad whose thickness approximates the skin thickness of an older pediatric patient. A syringe pump will provide a known flow rate through tubing connected to the sensor, but the study participants will not know the pump flow setting.

Three neurosurgeons and six floor nurses will perform this study. Each will use the Transonic flowmeter readout to align the pickup coils of the flowmeter with the hidden sensor to make flow measurements.

Each participant will repeat this measurement multiple times over non-consecutive days.

The recorded data will quantify measurement accuracy and repeatability between different operators, and will determine whether operator skill influences flow measurement accuracy.