Augmentation index (AIx) calculated from the pressure waveform of an artery is widely used to quantify the arterial stiffness and evaluate the cardiovascular risk. The key for calculating AIx is to locate the inflection point on the waveform signal, which is caused by the wave reflection. This study applies the probability distribution of the pressure waveform to identify the inflection point for estimating AIx. The results show that the pulse wave probability analysis not only can estimate AIx with a better tolerance of noise interference, but also allows for simultaneously monitoring, locating and characterizing other physiologically significant points on the pressure waveform.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/0967-3334/28/8/004 | DOI Listing |
J Invest Surg
December 2025
Department of Surgery, University of Minnesota Twin Cities Medical School, Minneapolis, MN, USA.
Background: Venous waveform analysis is an emerging technique to estimate intravascular fluid status by fast Fourier transform deconvolution. Fluid status has been shown proportional to , the amplitude of the fundamental frequency of the waveform's cardiac wave upon deconvolution. Using a porcine model of distributive shock and fluid resuscitation, we sought to determine the influence of norepinephrine on of the central venous waveform.
View Article and Find Full Text PDFNeurotherapeutics
January 2025
Division of Neurosciences Critical Care, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address:
A wide range of acute brain injuries, including both traumatic and non-traumatic causes, can result in elevated intracranial pressure (ICP), which in turn can cause further secondary injury to the brain, initiating a vicious cascade of propagating injury. Elevated ICP is therefore a neurological injury that requires intensive monitoring and time-sensitive interventions. Patients at high risk for developing elevated ICP undergo placement of invasive ICP monitors including external ventricular drains, intraparenchymal ICP monitors, and lumbar drains.
View Article and Find Full Text PDFGait Posture
December 2024
Marquette University, 1250 W. Wisconsin Ave, Milwaukee, WI 53233, United States; Shriners Children's Chicago, 2211 N. Oak Park Ave, Chicago, IL 60707, United States.
Background: Understanding midfoot joint kinetics is valuable for improved treatment of foot pathologies. Segmental foot kinetics cannot currently be obtained in a standard gait lab without the use of multiple force plates or a pedobarographic plate overlaid with a force plate due to the single ground reaction force (GRF) vector.
Research Question: Can an algorithm be created to distribute the GRF into multiple segmental vectors that will allow for calculation of accurate midfoot and ankle moments?
Methods: 20 pediatric subjects (10 typically developing, 10 with foot pathology) underwent multi-segment foot gait analysis using the Milwaukee Foot Model.
J Neurotrauma
December 2024
Department of Medical Sciences, Section of Neurosurgery, Uppsala University, Uppsala, Sweden.
This study compared the roles of extraparenchymal autonomic nervous system (ANS) control of cerebral blood flow (CBF) versus intraparenchymal cerebrovascular autoregulation in 487 patients with aneurysmal subarachnoid hemorrhage (SAH) and 413 patients with traumatic brain injury (TBI). Vasomotion intensity of extraparenchymal and intraparenchymal vessels were quantified as the amplitude of oscillations of arterial blood pressure (ABP) and intracranial pressure (ICP) in the very low frequency range of 0.02-0.
View Article and Find Full Text PDFJ Acoust Soc Am
December 2024
Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN, Delft, The Netherlands.
Investigation of sound pressure waveforms helps the selection of appropriate metrics to evaluate their effects on marine life in relation to noise thresholds. As marine animals move farther away from a sound source, the temporal characteristics of sound pressure may be influenced by interactions with the sediment and the sea surface. Sound pressure kurtosis and root-mean-square (rms) sound pressure are quantitative characteristics that depend on the shape of a sound pulse, with kurtosis related to the qualitative characteristic "impulsiveness.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!