Inclusion Criteria:  Existing ventriculoperitoneal CSF shunt At least one symptom of shunt malfunction as determined by the investigator, including seizure, fever, headache, vision problems, dizziness, disorientation, confusion, vomiting, lethargy, irritability, difficulty waking or staying awake, swelling along shunt tract, enlargement of head, loss of balance, gait disturbance, and loss of sensory or motor function Suspicion of shunt obstruction warrants the performance of a test for this condition in the investigator's judgement Region of intact skin overlying an unambiguously identifiable chronically indwelling ventricular shunt which crosses the clavicle and is appropriate in size for application of the study device Available for follow-up for up to fourteen days Signed informed consent by patient or a parent, legal guardian, health care agent, or legally authorized representative. Verbal assent by minors four years of age and older who are able to understand the study and communicate their decision  Exclusion Criteria:  Presence of multiple shunts, or presence of more than one distal shunt catheter (regardless of function) crossing the clavicle ipsilateral to the shunt with suspected obstruction Use of the study device would interfere with standard patient care, or emergency surgery that cannot be delayed Presence of an interfering open wound or edema over any portion of the shunt Patient-reported history of adverse skin reactions to adhesives Investigator judges that the subject is likely to be lost to follow-up due to unavailability or clinical outcome being unobtainable Participation in the study will interfere with, or be detrimental to, administration of optimal health-care to the subject Prior enrollment in this study (multiple enrollments of the same patient are disallowed) Participation in any other investigational procedural, pharmaceutical, and/or device study that may influence the collection of valid data under this study