| 1. |
- Echeverria, N. I., et al.
(författare)
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Análisis de la fotopletismografía para determinación de variaciones en el tono vascular y la presión arterial : Estudio basado en redes neuronales [Photoplethysmography waveform analysis for classification of vascular tone andarterial blood pressure: Study based on neural networks]
- 2023
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Ingår i: REVISTA ESPANOLA DE ANESTESIOLOGIA Y REANIMACION. - : Elsevier BV. - 0034-9356 .- 2340-3284. ; 70:4, s. 209-217
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Tidskriftsartikel (refereegranskat)abstract
- Background: To test whether a Shallow Neural Network (S-NN) can detect and classify vasculartone dependent changes in arterial blood pressure (ABP) by advanced photopletysmographic(PPG) waveform analysis.Methods: PPG and invasive ABP signals were recorded in 26 patients undergoing scheduled general surgery. We studied the occurrence of episodes of hypertension (systolic arterial pressure(SAP) > 140 mmHg), normotension and hypotension (SAP < 90 mmHg). Vascular tone accordingto PPG was classified in two ways: 1) By visual inspection of changes in PPG waveform amplitude and dichrotic notch position; where Classes I-II represent vasoconstriction (notch placed> 50% of PPG amplitude in small amplitude waves), Class III normal vascular tone (notch placedbetween 20-50% of PPG amplitude in normal waves) and Classes IV-V-VI vasodilation (notch <20% of PPG amplitude in large waves). 2) By an automated analysis, using S-NN trained andvalidated system that combines seven PPG derived parameters.Results: The visual assessment was precise in detecting hypotension (sensitivity 91%, specificity86% and accuracy 88%) and hypertension (sensitivity 93%, specificity 88% and accuracy 90%). Normotension presented as a visual Class III (III-III) (median and 1st-3rdquartiles), hypotensionas a Class V (IV-VI) and hypertension as a Class II (I-III); all p < 0.0001. The automated S-NNperformed well in classifying ABP conditions. The percentage of data with correct classificationby S-ANN was 83% for normotension, 94% for hypotension, and 90% for hypertension.Conclusions: Changes in ABP were correctly classified automatically by S-NN analysis of the PPGwaveform contour.
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| 2. |
- Garcia-Fernandez, J., et al.
(författare)
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Maniobras de reclutamiento en anestesia : ¿qué más excusas para no usarlas?
- 2018
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Ingår i: Revista Española de Anestesiología y Reanimación. - : Elsevier. - 0034-9356 .- 2340-3284. ; 65:4, s. 209-217
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Forskningsöversikt (refereegranskat)abstract
- Pulmonary recruitment manoeuvres (RM) are intended to reopen collapsed lung areas. RMs are present in nature as a physiological mechanism to get a newborn to open their lungs for the first time at birth, and we also use them, in our usual anaesthesiological clinical practice, after induction or during general anaesthesia when a patient is desaturated. However, there is much confusion in clinical practice regarding their safety, the best way to perform them, when to do them, in which patients they are indicated, and in those where they are totally contraindicated. There are important differences between RM in the patient with adult respiratory distress syndrome, and in a healthy patient during general anaesthesia. Our intention is to review, from a clinical and practical point of view, the use of RM, specifically in anaesthesia.
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| 3. |
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| 4. |
- Le Guen, K, et al.
(författare)
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Development of a four-element conical electron lens dedicated to high resolution Auger electron-ion(s) coincidence experiments
- 2002
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 73:11, s. 3885-3894
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Tidskriftsartikel (refereegranskat)abstract
- A four-element conical electron lens has been developed in view of its integration to a double toroidal electron energy analyzer (DTA) dedicated to Auger electron-ion coincidence measurements. The lens design, using electron trajectory numerical simulations, was entirely guided by the perspective of analyzing energetic electrons with high resolution in the multicoincidence regime. The design, construction, and experimental characterization stages of this electron optics system are described in this article. Emphasis is put on the importance of third generation synchrotron radiation sources when performing such multicoincidence experiments.
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