Features of the non-contact carotid pressure waveform: Cardiac and vascular dynamics during rebreathing.

This report amplifies and extends prior descriptions of the use of laser Doppler vibrometry (LDV) as a method for assessing cardiovascular activity, on a non-contact basis. A rebreathing task (n = 35 healthy individuals) was used to elicit multiple effects associated with changes in autonomic drive as well as blood gases including hypercapnia. The LDV pulse was obtained from two sites overlying the carotid artery, separated by 40 mm.

Cardiorespiratory interactions: Noncontact assessment using laser Doppler vibrometry.

The application of a noncontact physiological recording technique, based on the method of laser Doppler vibrometry (LDV), is described. The effectiveness of the LDV method as a physiological recording modality lies in the ability to detect very small movements of the skin, associated with internal mechanophysiological activities. The method is validated for a range of cardiovascular variables, extracted from the contour of the carotid pulse waveform as a function of phase of the respiration cycle.

Laser Doppler vibrometry measurement of the mechanical myogram.

Contracting muscles show complex dimensional changes that include lateral expansion. Because this expansion process is intrinsically vibrational, driven by repetitive actions of multiple motor units, it can be sensed and quantified using the method of Laser Doppler Vibrometry (LDV). LDV has a number of advantages over more traditional mechanical methods based on microphones and accelerometers.

Hidden state models for noncontact measurements of the carotid pulse using a laser Doppler vibrometer.

The method of laser Doppler vibrometry (LDV) is used to sense movements of the skin overlying the carotid artery. When pointed at the skin overlying the carotid artery, the mechanical movements of the skin disclose physiological activity relating to the blood pressure pulse over the cardiac cycle. In this paper, signal modeling is addressed, with close attention to the underlying physiology.

Central adaptations to repetitive grasping in healthy aging.

Augmented cortical activity during repetitive grasping mitigates repetition-related decrease in cortical efficiency in young adults. It is unclear if similar processes occur with healthy aging. We recorded movement-related cortical potentials (MRCP) during 150 repetitive handgrip contractions at 70% of maximal voluntary contraction (MVC) in healthy young (n = 10) and old (n = 10) adults.