An interesting method that involves direct manipulations on the tympanic membrane rather than relying on the acoustic reflex was proposed as one of the embodiments of a US patent by Ragauskas.15. Ragauskas, A.: US20067147605 (2006). First, a measurement of the position of the tympanic membrane needs to be obtained while ICP is zero (denoted as the baseline position). Equalization of ICP to the atmospheric pressure according to the inventor can be achieved non-invasively by tilting the head up, or the measurement can be taken during a neurosurgical operation. Later on, ICP can be measured by exerting an external pressure to the tympanic membrane and applying simultaneously the same pressure onto the oval window and inner ear (e.g. through the Eustachian tube) until the eardrum is moved back to the baseline position, which will happen when the exerted external pressure equals ICP. No data is provided in the patent nor is available from other sources that could support the utility of the concept in clinical practice.
