Abstract
Introduction: Non-invasive measurement of the Intracranial Pressure (ICP) is still a challenging issue in health monitoring and TBI. An accurate device to monitor the ICP non-invasively is a necessity particularly for patients in any clinical and transient situations.
Method: One novel non-invasive method can be based on transcranial acoustics signal processing in which the signals from intracranial and extracranial signals of different frequencies can be captured to be correlated to the ICP. For this reason, acoustics and vibration characteristics of intracranial contents such as CSF, skull, etc. should be obtained and calibrated. Additionally, the fluid structure interaction impedance is a necessity in acoustics analysis.
Analysis: In this study, the effects of CSF pressure variation on the vibration of the skull at low- and high-frequency modes have been examined. The human skull is approximately modelled as a hemispherical shell with mechanical characteristics of skull bone. CSF is considered as an inviscid and incompressible fluid since the range of in vivo CSF pressure variation is less than 80 mm Hg (brain death). We study the influence of CSF by pressure wave acoustic equation, which is based on the fluid parameters such as density and sound speed. This unsymmetrical eigenvalue problem is solved by a finite element scheme to obtain the first 100 natural frequencies. In addition, the symmetrical and unsymmetrical mode shapes are obtained to show the skull vibration sensitivity due to CSF static pressure.
Results: The primary results show that the increase in CSF pressure causes small decrease in the unsymmetrical and symmetrical vibration frequency modes. Moreover, the modes of skull vibration sensitivity with respect to the CSF pressure variation are calculated. The sensitivity diagram demonstrates that the skull vibration in higher frequency modes is more sensitive to CSF pressure variation than lower vibration modes.
Method: One novel non-invasive method can be based on transcranial acoustics signal processing in which the signals from intracranial and extracranial signals of different frequencies can be captured to be correlated to the ICP. For this reason, acoustics and vibration characteristics of intracranial contents such as CSF, skull, etc. should be obtained and calibrated. Additionally, the fluid structure interaction impedance is a necessity in acoustics analysis.
Analysis: In this study, the effects of CSF pressure variation on the vibration of the skull at low- and high-frequency modes have been examined. The human skull is approximately modelled as a hemispherical shell with mechanical characteristics of skull bone. CSF is considered as an inviscid and incompressible fluid since the range of in vivo CSF pressure variation is less than 80 mm Hg (brain death). We study the influence of CSF by pressure wave acoustic equation, which is based on the fluid parameters such as density and sound speed. This unsymmetrical eigenvalue problem is solved by a finite element scheme to obtain the first 100 natural frequencies. In addition, the symmetrical and unsymmetrical mode shapes are obtained to show the skull vibration sensitivity due to CSF static pressure.
Results: The primary results show that the increase in CSF pressure causes small decrease in the unsymmetrical and symmetrical vibration frequency modes. Moreover, the modes of skull vibration sensitivity with respect to the CSF pressure variation are calculated. The sensitivity diagram demonstrates that the skull vibration in higher frequency modes is more sensitive to CSF pressure variation than lower vibration modes.
| Original language | American English |
|---|---|
| DOIs | |
| State | Published - Jun 7 2017 |
| Externally published | Yes |
| Event | 12th World Congress on Brain Injury - New Orleans, United States Duration: Mar 29 2017 → Apr 1 2017 Conference number: 12 https://doi.org/10.1080/02699052.2017.1312145 |
Conference
| Conference | 12th World Congress on Brain Injury |
|---|---|
| Country/Territory | United States |
| City | New Orleans |
| Period | 3/29/17 → 4/1/17 |
| Internet address |
ASJC Scopus Subject Areas
- Neuroscience (miscellaneous)
- Developmental and Educational Psychology
- Clinical Neurology