Estimating intracranial pressure using pulsatile cerebral blood flow measured with diffuse correlation spectroscopy.

Alexander Ruesch,Deepshikha Acharya,Jason Yang,Matthew A Smith,Jana M Kainerstorfer,Matthew A Smith,Samantha Schmitt,Matthew A Smith

doi:10.1364/boe.386612

Alexander Ruesch, Deepshikha Acharya + Show 6 more

Open Access

https://doi.org/10.1364/boe.386612

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Journal: Biomedical Optics Express	Publication Date: Feb 19, 2020
Citations: 41	License type: cc-by

Affiliation: Carnegie Mellon University

Abstract

Measuring intracranial pressure (ICP) is necessary for the treatment of severe head injury but measurement systems are highly invasive and introduce risk of infection and complications. We developed a non-invasive alternative for quantifying ICP using measurements of cerebral blood flow (CBF) by diffuse correlation spectroscopy. The recorded cardiac pulsation waveform in CBF undergoes morphological changes in response to ICP changes. We used the pulse shape to train a randomized regression forest to estimate the underlying ICP and demonstrate in five non-human primates that DCS-based estimation can explain over 90% of the variance in invasively measured ICP.

Highlights

The pressure environment of the brain, located in a confined space inside the skull, is driven by three volume compartments – cerebrospinal fluid (CSF), cerebral blood volume, and brain tissue
For every non-human primates (NHP), data were collected in sets of approximately 90 minutes per intracranial pressure (ICP) baseline, with the total amount of data collected for animals varying between 9.1 and 16.6 hours
Changes in ICP translated into both changes in arterial blood pressure (ABP) and ∆cerebral blood flow (CBF)

Summary

Introduction

The pressure environment of the brain, located in a confined space inside the skull, is driven by three volume compartments – cerebrospinal fluid (CSF), cerebral blood volume, and brain tissue. According to the Monro-Kellie Doctrine [1], intracranial pressure (ICP) remains constant if the net volume of all compartments are unchanged. This delicate equilibrium can be disrupted in diseases that alter the volume of one of the three compartments outside the limits for which the other two can compensate. The brain tissue can swell in cases of traumatic brain injury (TBI) and infections such as meningitis. Blood volume can change in hemorrhagic and ischemic stroke. CSF can be produced excessively or absorbed insufficiently in diseases such as hydrocephalus [2]

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