17.11 A 9mW Ultrasonic Through Transmission Transceiver for Non-Invasive Intracranial Pressure Sensing

Intracranial pressure (ICP) measures the pressure exerted by fluids and tissues inside the skull, typically 7-15mmHg for healthy adults. Conditions such as traumatic brain injury, hydrocephalus, and intracranial hemorrhage often cause elevated ICP (> 20 mmHg), which is life-threatening and requires immediate medical interventions. These conditions also lead to changes in the ICP waveform morphology, especially an increased P2/P1 amplitude ratio, reflecting compromised cerebral compliance [1] (Fig. 17.11.1, top left). Clinicians routinely use ICP monitoring in neurovascular intensive care units (neuro-ICUs) because it provides actionable and timely information for patient care – the recovery of the ICP waveform morphology often suggests effective medical interventions.