43 research outputs found
First true blood pressure measurement with micropulse detection of arterial opening achieved
\ua9 2025. The Author(s). There is a well-accepted need for a new more accurate solution to automatic blood pressure measurement, in spite of clinical convenience continuing to encourage the adoption of oscillometric devices with their known poor accuracy throughout healthcare. Our solution avoids estimates, mathematical modelling, oscillometric algorithms, and inadequate calibration against numerous private clinical data sets. Here we show that our new technique detects, from an arm cuff, micropulses associated with arterial opening between systolic and diastolic pressures; hence detecting systole at the first micropulse and diastole at the last, during cuff deflation. Our technique has equivalent accuracy to the gold standard auscultatory method, and is significantly better than the requirements of the current international standard for blood pressure devices. Our results provide scientific evidence for the effectiveness of our technique, and demonstrate significant clinically important improvements. We anticipate that our technique can be automated easily and economically. We acknowledge that this early study is an initial manual evaluation, but expect this new technique to be an automated universal solution for true blood pressure measurement, and a vital step change in an important clinical measurement in healthcare of the worldwide population
Longest sediment flows yet measured show how major rivers connect efficiently to deep sea
Here we show how major rivers can efficiently connect to the deep-sea, by analysing the longest runout sediment flows (of any type) yet measured in action on Earth. These seafloor turbidity currents originated from the Congo River-mouth, with one flow travelling >1,130 km whilst accelerating from 5.2 to 8.0 m/s. In one year, these turbidity currents eroded 1,338-2,675 [>535-1,070] Mt of sediment from one submarine canyon, equivalent to 19–37 [>7–15] % of annual suspended sediment flux from present-day rivers. It was known earthquakes trigger canyon-flushing flows. We show river-floods also generate canyon-flushing flows, primed by rapid sediment-accumulation at the river-mouth, and sometimes triggered by spring tides weeks to months post-flood. It is demonstrated that strongly erosional turbidity currents self-accelerate, thereby travelling much further, validating a long-proposed theory. These observations explain highly-efficient organic carbon transfer, and have important implications for hazards to seabed cables, or deep-sea impacts of terrestrial climate change
