Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2021
Increase in regional cerebral saturation after elective electrical cardioversion of atrial fibrillation is only transient and without beneficial effects on neuropsychological functioning: cerebral saturation during electrical cardioversion.
We aimed to confirm the positive association between a successful electrical cardioversion (ECV) and increase in SctO2 and investigated whether this increase is persisting or not. Secondary, the influence of a successful ECV on the neuropsychological function and the association with SctO2 was assessed as well. SctO2 was measured continuously during elective ECV using near-infrared spectroscopy. ⋯ A transient, instant SctO2 increase was observed after successful ECV. This temporary increase in SctO2 did not influence the neuropsychological functioning of the patients. Though, the quality of life of patients with a successful ECV improved.
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J Clin Monit Comput · Feb 2021
Pulse oximetry based on photoplethysmography imaging with red and green light : Calibratability and challenges.
Remotely measuring the arterial blood oxygen saturation (SpO2) in visible light (Vis) involves different probing depths, which may compromise calibratibility. This paper assesses the feasibility of calibrating camera-based SpO2 (SpO2,cam) using red and green light. Camera-based photoplethysmographic (PPG) signals were measured at 46 healthy adults at center wavelengths of 580 nm (green), 675 nm (red), and 840 nm (near-infrared; NIR). ⋯ Additional measurements on normoxic subjects under temperature cooling (from [Formula: see text] to [Formula: see text]) evidenced a significant bias of - 1.7, CI [- 2.7, - 0.7]%. It was also noted that SpO[Formula: see text] estimated at the cheeks was significantly biased (- 3.6, CI [- 5.7, - 1.5]%) with respect to forehead estimations. Under controlled conditions, SpO[Formula: see text] can be calibrated with red and green light but the accuracy is less than that of SpO[Formula: see text] estimated in the usual red-NIR window.
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J Clin Monit Comput · Feb 2021
Accurate end systole detection in dicrotic notch-less arterial pressure waveforms.
Identification of end systole is often necessary when studying events specific to systole or diastole, for example, models that estimate cardiac function and systolic time intervals like left ventricular ejection duration. In proximal arterial pressure waveforms, such as from the aorta, the dicrotic notch marks this transition from systole to diastole. However, distal arterial pressure measures are more common in a clinical setting, typically containing no dicrotic notch. ⋯ Systolic durations, estimated by each of the end systole estimates, are then compared to the validation systolic duration provided by the PTT based end systole point. Data comes from ten pigs, across two protocols testing the algorithms under different hemodynamic states. The resulting mean difference ± limits of agreement between measured and estimated systolic duration, of [Formula: see text] versus [Formula: see text], for the new and existing algorithms respectively, indicate the new algorithms superiority.