# First-in-Human Prospective, Observational, and Comparative Clinical Study of Simultaneous Invasive and Non-Invasive Intracranial Pressure Pulse Wave Monitoring

## TL;DR

A new non-invasive system for monitoring brain pressure waves shows strong agreement with invasive methods, offering safer and more accessible neurocritical care.

## Contribution

The first-in-human validation of a fully passive non-invasive ICP pulse wave monitoring system (Archimedes 02) with strong correlation to invasive measurements.

## Key findings

- Non-invasive ICP pulse waveforms showed strong correlation with invasive ICP waveforms (R¯ = 0.965).
- The system captured key ICP pulse wave features like P2/P1 ratios, reflecting intracranial compliance.
- Non-invasive ICP signal correlated more strongly with invasive ICP than with arterial blood pressure.

## Abstract

What are the main findings?
The novel, fully passive, non-invasive intracranial pressure pulse wave monitoring system (Archimedes 02) demonstrated a strong association with invasive ICP measurements and was able to capture key features of ICP pulse wave morphology.The non-invasive system detected P2/P1 ratios, which reflect intracranial compliance, in a manner consistent with invasive ICP monitoring, indicating that it can capture relevant intracranial dynamics.

The novel, fully passive, non-invasive intracranial pressure pulse wave monitoring system (Archimedes 02) demonstrated a strong association with invasive ICP measurements and was able to capture key features of ICP pulse wave morphology.

The non-invasive system detected P2/P1 ratios, which reflect intracranial compliance, in a manner consistent with invasive ICP monitoring, indicating that it can capture relevant intracranial dynamics.

What are the implications of the main findings?
The Archimedes 02 technology represents a promising, safe, real-time non-invasive approach to ICP pulse wave assessment, potentially reducing complications associated with invasive monitoring such as infection, hemorrhage, and sensor drift.By enabling continuous non-invasive assessment of intracranial compliance, this approach may improve neurocritical care management and expand access to ICP monitoring in settings where invasive techniques are impractical.

The Archimedes 02 technology represents a promising, safe, real-time non-invasive approach to ICP pulse wave assessment, potentially reducing complications associated with invasive monitoring such as infection, hemorrhage, and sensor drift.

By enabling continuous non-invasive assessment of intracranial compliance, this approach may improve neurocritical care management and expand access to ICP monitoring in settings where invasive techniques are impractical.

Monitoring intracranial pressure (ICP) dynamics is critical for the management of traumatic brain injury, stroke, other neurosurgical conditions, and cerebral blood flow autoregulation; however, invasive ICP monitoring carries risks such as infection, hemorrhage, and sensor zero drift. Increasing evidence suggests that ICP waveform morphology provides clinically relevant information beyond mean ICP value alone. In this first-in-human prospective comparative clinical study, we evaluated the feasibility and accuracy of a novel, fully passive, non-invasive ICP pulse waveform monitoring system (Archimedes 02) based on the detection of eyeball mechanical movement. Fifteen intensive care unit patients (6 males, 9 females; mean age 57.1 ± 18.8 years) with clinically indicated invasive ICP monitoring or external ventricular drainage were enrolled. Three-minute monitoring sessions were performed to simultaneously acquire non-invasive ICP pulse waveforms, invasive ICP waveforms, and invasive radial artery blood pressure (ABP) waveforms. Averaged waveforms were derived for each patient and compared graphically and using correlation analysis. Non-invasive ICP pulse waves recorded with Archimedes 02 showed a strong correlation with invasive ICP waveforms (R¯ = 0.965). In contrast, correlations between non-invasive ICP and ABP waveforms (R¯ = 0.699), as well as between invasive ICP and ABP waveforms (R¯ = 0.749), were lower. These findings indicate that the non-invasive signal primarily reflects ICP dynamics rather than arterial blood pressure. This novel non-invasive ICP monitoring approach has the potential to enhance neurocritical care, particularly in settings where invasive monitoring is impractical or unavailable. Further validation in larger and more diverse patient populations is warranted.