In vivo testing of noninvasive ICP monitoring methodology in a porcine model

Research has suggested that elevated intracranial pressure (ICP) can cause damage to the optic nerve and reduce visual acuity. There is a need for noninvasive ICP monitoring devices. A simple, portable device capable of measuring relative changes in ICP using a noninvasive methodology would have a significant impact on clinical care. The methodology presented in this paper utilizes transcranial Doppler ultrasonography to monitor ophthalmic artery hemodynamics while small forces are applied to cornea. In vivo testing using a porcine model results in a correlation between pulsatility or resistivity indices and ICP levels. Specifically, the change in these indices while force is applied decreases as ICP increases. The data collection prototype used in these experiments contained an ultrasound transducer instrumented with a load cell to measure force applied to the cornea. These experiments are an initial step towards adapting the data collection prototype into a handheld noninvasive ICP monitoring device.