• To demonstrate the feasibility of integrating holographic technology as a heads-up display for navigated cranial and spinal neurosurgical procedures. This entails simply displaying the navigation screen currently used by Medtronic Stealth or Brainlab systems as a holographic image that can be positioned closer to the operative field.
• To develop a systematic, efficient communication and registration process allowing holographic technology to be potentially utilized as a navigation tool in cranial and spinal neurosurgery. This entails developing software, optimizing connection parameters, and devising registration techniques incorporating line-of-sight fiducial markers to allow the holographic device to function as a navigation instrument.

Inclusion Criteria:

• age >= 18
• must be able to read and understand English, and sign the informed consent form

Exclusion Criteria:

• emergent/emergency procedures
• pediatric patients
• pregnant patients
• vulnerable populations

Any patient undergoing an elective cranial or spinal procedure at the University of Pennsylvania, Department of Neurosurgery.