Preliminary Evaluation of a Fiber Optic Cerebral Oximetry System in Patients Undergoing Neurosurgery

A serious concern in the treatment of patients after major neurosurgical procedures and particularly in the days after traumatic head injury is to prevent secondary damage from raised intracranial pressure (ICP) due to swelling of the brain [1]. For many years, management of patients at serious risk of raised intracranial pressure has included intracranial pressure monitoring via a cranial bolt inserted into a burr hole drilled through the skull [2]. We have developed an optical fiber probe which may be inserted via a cranial bolt, allowing oxygen saturation measurements to be made directly from the brain tissue. A preliminary study was undertaken to determine whether or not it is possible to obtain photoplethysmographic (PPG) signals from the brain tissue and to verify the effectiveness of the type of fibers used and the chosen ‘depth of penetration’ of the fibers