Pulse Transit Time (PTT) is the time it takes the pulse pressure waveform to propagate through a length of the arterial tree. The pulse pressure waveform results from the ejection of blood from the left ventricle and moves with a velocity much greater than the forward movement of the blood itself.
With increased vessel wall stiffness (decreased compliance), DELTA V decreases and pulse wave velocity increases. With increased blood pressure, the arterial walls are more strongly stretched and pulse wave velocity increases. Accordingly, for a fixed vessel distance, as the pulse transit time increases the blood pressure decreases.
In this application note, pulse transit time will be measured between the R-wave and the peak of the pressure wave at the finger, as measured by the pulse plethysmograph.
fNIR Imaging Systems are stand-alone functional brain imaging solutions for continuous NIR spectroscopy (NIRS). They provide an in-lab cognitive function assessment and eliminate a great many of the drawbacks of a functional MRI. fNIR optical imaging technology measures neural activity and hemodynamic response in the prefrontal cortex. Subjects wear an fNIR sensor (IR light sources […]
BIOPAC provides software and hardware that allow for research teams to record and analyze respiration activity in physiological experimentation. Here are a few notable studies covering HRV, EMG, and EEG measurement. DON’T STRESS (Jing Wei, Hong Luo, Si J. Wu, Paul P. Zheng, Genyue Fu, and Kang Lee) Humans encounter various stressful situations everyday at work, home, and school. Such stress when experienced at high degrees and/or […]
Alan Macy Answers Proust Questionnaire BIOPAC co-founder and R&D Director, Alan Macy, was interviewed recently by Roger Durling for the Santa Barbara Independent. The article, “The S.B. Questionnaire: Alan Macy,” provided a background excerpt of the Santa Barbara entrepreneurs’ past as well as his answers to the Proust Questionnaire. The biomedical technology developed at BIOPAC reflects an ambitious […]