Formative Usability Assessment of Wireless Thermal Anisotropy Devices

Inclusion Criteria: 1. Existing ventricular CSF shunt with a region of intact skin overlying the shunt catheter appropriate in size for application of the study device 2. Signed informed consent by subject or a parent, legal guardian, health care agent, or surrogate decision maker (according to local statutes) 3. Subject or caregiver can clearly communicate and document information in English 4. Verbal assent by minors 12 years of age and older who can understand the study and communicate their decision 5. Subject is at least 5 years old but not more than 80 years old Exclusion Criteria: 1. Presence of an interfering open wound in the device application region 2. Subject-reported history of adverse skin reactions to adhesives