A ventriculoperitoneal (VP) shunt is used in Hydrocephalus cases to drain excess cerebral spinal fluid (CSF) from the ventricles to reduce the pressure in the ventricular cavity. Some VP shunts may be equipped with an adjustable or programmable shunt valve configured to open and drain excess CSF in an instance in which a predetermined pressure set point is reached within the ventricular cavity.
In some cases, the VP shunt may become blocked or clogged preventing pressure relief in the ventricular cavity; however, the symptoms of a blocked VP shunt and the symptoms of nasal congestion, typical of a common cold, may be substantially similar. A ventricular pressure measurement is used to differentiate between nasal congestion and blockage of the VP shunt. In some cases, invasive procedures such as drilling a hole in the skull are used to take a ventricular pressure measurement. In other instances, computerized axial tomography (CT) scans or X-rays may be taken over a period of several days and changes in the CT or X-ray images may be indicative of a ventricular pressure change. In still another instances, an ultrasound of the retinal vessel may be used for indirect measurement of ventricular pressure. As such, there is no non-invasive method to quickly and directly measure ventricular pressure.