Comparison of Continuous Non-Invasive and Invasive Intracranial Pressure Measurement

"The CCFP Analyser has a passive mode and an active mode. When used in active mode, the device generates a tone burst that is transmitted to the ear to elicit contraction of the stapedius muscle. The passive mode requires no stimulus or sound burst.~For the lying, sitting, standing, and 10-degree head-down tilt conditions, the active mode will be used. Each condition comprises 13 stimuli of 0.3s duration.~Overnight recording of non-invasive ICP will be done using the passive mode of the CCFP device."

DPOAE measurement uses a clinical acoustic probe to record the ear's response to two simultaneous tones. DPOAE measurements will be made for 13 tones. The total measurement time for each condition is 2-4 minutes.