# A Novel Noninvasive Technique for Intracranial Pressure Waveform Monitoring in Critical Care

## TL;DR

This study introduces a noninvasive tool called B4C that accurately monitors intracranial pressure waveforms in critical care patients, showing strong correlation with invasive methods.

## Contribution

The B4C sensor offers a novel noninvasive method for assessing intracranial pressure waveform morphology in neurocritical care.

## Key findings

- B4C showed strong correlation with invasive ICP monitoring for P2/P1 and TTP in patients without cranial damage.
- A B4C cut-off of 1.2 predicted intracranial hypertension with high accuracy (AUROC 0.9).
- B4C provided reliable amplitude ratios that correlated with ICP waveform variations.

## Abstract

Background: We validated a new noninvasive tool (B4C) to assess intracranial pressure waveform (ICPW) morphology in a set of neurocritical patients, correlating the data with ICPW obtained from invasive catheter monitoring. Materials and Methods: Patients undergoing invasive intracranial pressure (ICP) monitoring were consecutively evaluated using the B4C sensor. Ultrasound-guided manual internal jugular vein (IJV) compression was performed to elevate ICP from the baseline. ICP values, amplitudes, and time intervals (P2/P1 ratio and time-to-peak [TTP]) between the ICP and B4C waveform peaks were analyzed. Results: Among 41 patients, the main causes for ICP monitoring included traumatic brain injury, subarachnoid hemorrhage, and stroke. Bland–Altman’s plot indicated agreement between the ICPW parameters obtained using both techniques. The strongest Pearson’s correlation for P2/P1 and TTP was observed among patients with no cranial damage (r = 0.72 and 0.85, respectively) to the detriment of those who have undergone craniotomies or craniectomies. P2/P1 values of 1 were equivalent between the two techniques (area under the receiver operator curve [AUROC], 0.9) whereas B4C cut-off 1.2 was predictive of intracranial hypertension (AUROC 0.9, p < 000.1 for ICP > 20 mmHg). Conclusion: B4C provided biometric amplitude ratios correlated with ICPW variation morphology and is useful for noninvasive critical care monitoring.