Continuous recording of changes in intracranial pressure using interference echoes of ultrasonic wave: A preliminary report of practicality and clinical evaluation

Abstract

We attempted to examine intracranial pressure (ICP) noninvasively using probes receiving interference echoes of ultrasound from thin layers between the skull and the surface of the cerebrum. The reception of echo through bone flaps less than 5-mm thick was good. Normal adults (4) and patients (4) were examined by attaching ultrasound probes to the frontotemporal scalp. Recordings were performed during rest, Valsalva maneuver, hyperventilation, and pumping of a shunt-flushing device. Ultrasound recordings of ICP were compared with those of the scalp using two different time windows. The effect of scalp vessels on the ultrasound recordings of ICP was evaluated. The waves from a pressure transducer and the ultrasound probe were similar. This method was found to be useful for ICP recording.

Invasive and noninvasive means of measuring intracranial pressure: a review

“…However, the measurement of the quantitative relationship between the cranial diameter and ICP is not reproducible because of the small change in repeat measurements in a single individual compared to interindividual variability (Petkus et al 2002). Kuchiwaki et al (1992) inferred ICP from the dura mater thickness based on interference echoes of the ultrasonic wave method on four healthy volunteers and four patients with IH, but did not conduct any larger validation studies. Michaeli and Rappaport (2002) described how dynamic monitoring of the ICP waves can be translated into a nICP measurement using advanced signal processing.…”