Optical assessment of apparent phase velocity: carotid-temporal photoplethysmograph flow waves in response to apnea

Abstract

Optic sensors of blood flow can provide noninvasive assessment of elastic properties of extracranial vessels. Photoplethysmographic data can be used to assess pulse velocities as blood is transmitted from the carotid to the temporal artery. Apparent phase velocities give much information regarding the transmission of pulse waves by examining frequency characteristics of flow. The apparent phase velocities through this vascular segment increases in periods of apnea, especially in the higher frequency components, indicating response of increased vascular stiffness of the extracranial arteries.