The cardiovascular system and its alterations are a crucial aspect of physiology and medicine. Non-invasive assessment of the functional properties of circulation is of considerable interest to clinicians and physiologists. In this work we investigate the possibility of detecting alterations of the flow waveform in microcirculation, using non-invasive measurements based on a laser Doppler flowmeter. As a test case, we focus on the effect of ageing. Skin is warmed up to a fixed temperature (44 °C) during measurement, to increase blood flow. The shape of the perfusion waveform during each heart beat after the flow was stabilized was used to estimate dynamic parameters of the microcirculatory system. Both the wave rise time, defined as the delay between the diastolic minimum and the following systolic maximum, and the oscillation fraction, defined as the normalized difference between the maximum and minimum flow, present significant variation with age.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/0967-3334/36/10/2147 | DOI Listing |
J Biomech
January 2025
Walker Department of Mechanical Engineering, The University of Texas at Austin Austin TX USA.
Skipping represents a training alternative to running due to its lower knee contact forces and higher whole-body metabolic cost. The increased metabolic cost of skipping is associated with a higher vertical center-of-mass (COM) displacement during the support and flight phases of the skipping hop compared to running. However, skipping has lower muscle force impulses than running.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Ingeniería y Tecnología, Universidad Nacional Autonoma de Mexico Facultad de Estudios Superiores Cuautitlan, Av. 1o de Mayo S/N, Santa María las Torres, Campo Uno, 54740 Cuautitlán Izcalli, Edo. de Méx., Cuautitlan Izcalli, Estado de México, 54740, MEXICO.
Hemodialysis is a crucial procedure for removing toxins and waste from the body when kidneys fail to perform this function effectively. This study addresses the need to improve the efficiency and biocompatibility of membranes used in dialyzers. We simulate fluid flow through two types of membranes, Cuprophan (cellulosic) and AN69ST (synthetic), to understand the complex mechanisms involved and quantify key variables such as pressure, concentration, and flow.
View Article and Find Full Text PDFJ Neurosurg Case Lessons
January 2025
The Trauma and Neuroscience Institutes, St. John's Hospital and Medical Center, Tulsa, Oklahoma.
Background: Direct carotid-cavernous fistulas (CCFs) are relatively rare but dangerous complications of penetrating traumatic brain injury or maxillofacial trauma. A variety of clinical signs have been described, including ophthalmological and neurological ones. In some cases, severely altered cerebral blood flow can present as massive life-threatening bleeding through the nose, subarachnoid hemorrhage, and/or intraparenchymal hemorrhage.
View Article and Find Full Text PDFDelayed fracture healing (DFH), a common complication of post-fracture surgery, exhibits an incompletely understood pathogenesis. The present study endeavors to investigate the roles and underlying mechanisms of miR-656-3p and Bone Morphogenetic Protein-2 (BMP-2) in DFH. It was recruited 94 patients with normal fracture healing (NFH) and 88 patients with DFH of the femoral neck.
View Article and Find Full Text PDFT-cell prolymphocytic leukemia (T-PLL) is an aggressive lymphoid malignancy with limited treatment options. To discover new treatment targets for T-PLL, we performed high-throughput drug sensitivity screening on 30 primary patient samples ex-vivo. After screening over 2'800 unique compounds, we found T-PLL to be more resistant to most drug classes, including chemotherapeutics, compared to other blood cancers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!