XVI EUROPEAN STROKE CONFERENCE. GLASGOW. UNITED KINGDOM. 29 MAY-1 JUN

Rheoencephalography: a non-invasive method to assess the electrical impedance changes related to the pulsatility of the cerebral blood flow.
J.M.Pons    J.J.Pérez    P. Ortiz    E. Guijarro    A. Navarré    J. Sancho                            
 Consorcio Hospital General Universitario Valencia* Centro de investigación e innovación en bioingeniería Universidad Politécnica de Valencia. ** SPAIN

Objective: Rheoencephalography (REG) measures the electrical impedance changes of the head caused by the pulsatility of the cerebral blood flow (CBF). However, the use of REG in the clinical practice is limited because signal is buried by the extracranial component. Our research group has formulated a mathematical algorithm that allows the extraction of the intracranial component from the REG signal. The main goal of this work is to validate the separation method. For this purpose, an experimental model that arrests mechanically the extracranial blood flow is used.

Material and methods: REG signal was acquired in healthy volunteers in two conditions: (i) normal and (ii) during the arrest of the scalp blood flow by means the scalp compression with a pneumatic cuff. Subsequently, the intracranial component extracted with our algorithm was statistically compared with the REG traces recorded in scalp compression condition.

Results: Intracranial component extracted by our algorithm matches well with the REG trace recorded in scalp compression condition. Additionally, the morphology of the extracted intracranial component agrees with the intraparenchymal impedance traces previously described in the literature.

Conclusions: Our results suggest that the intracranial REG component can be reliably extracted from the raw REG signal by cancelling the scalp blood artifact. This method could provide a new non-invasive technique to assess the cerebral blood flow. Nevertheless, additional works would be necessary to check and to assess the diagnostic capability of our REG technique. This work was supported by grant PI04/0303 from the Instituto de Salud Carlos III (Fondo de Investigación Sanitaria) in the framework of the ‘Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I)’