Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2023
Letter Case ReportsStimulation artefact on EEG trace with BIS monitoring during D-wave recording.
The D-wave reflects the corticospinal fibre potentials and is frequently recorded intraoperatively for intramedullary spinal tumours to ensure maximum safe resection. A 38-year-old male had an intramedullary spinal cord tumour surgically removed while being monitored with D-wave from a single distal electrode technique. ⋯ Regular spike artefacts were observed in the EEG signal recorded by the BIS® monitor during the application of the single-pulse transcranial electrical stimulus and were used as a visual indicator of stimulus delivery. Finally, we propose a novel method of confirming stimulus delivery during D-wave recording based on stimulation artefacts in the EEG signal recorded by the BIS® monitor.
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J Clin Monit Comput · Jun 2023
Evaluation of patient state index, bispectral index, and entropy during drug induced sleep endoscopy with dexmedetomidine.
Multiple electroencephalographic (EEG) monitors and their associated EEG markers have been developed to aid in assessing the level of sedation in the operating room. While many studies have assessed the response of these markers to propofol sedation and anesthetic gases, few studies have compared these markers when using dexmedetomidine, an alpha-2 agonist. Fifty-one patients underwent drug induced sleep endoscopy with dexmedetomidine sedation. ⋯ Lightening secondary to RASS score assessment is significantly captured by all three commercial EEG metrics (p < 0.001). Commercial EEG monitors can capture changes in the brain state associated with the RASS score during dexmedetomidine sedation. PSI and Entropy were highly correlated and may be better suited for assessing deeper levels of sedation.
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J Clin Monit Comput · Jun 2023
Automated electrocardiogram signal quality assessment based on Fourier analysis and template matching.
We developed and tested a novel template matching approach for signal quality assessment on electrocardiogram (ECG) data. A computational method was developed that uses a sinusoidal approximation to the QRS complex to generate a correlation value at every point of an ECG. The strength of this correlation can be numerically adapted into a 'score' for each segment of an ECG, which can be used to stratify signal quality. ⋯ The routine performs in linear O(n) time and occupies O(1) heap space in runtime. This approach can be used to lower the burden of pre-processing in ECG signal analysis. Given its runtime (O(n)) and memory (O(1)) complexity, there are potential applications for signal quality stratification and arrhythmia detection in wearable devices or smartphones.
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J Clin Monit Comput · Jun 2023
Comparative StudyA comparison of the NeurOs® and the INVOS 5100C® cerebral oximeter during variations of the partial pressure of carbon dioxide and fractional inspiratory concentration of oxygen.
This prospective method comparison study compared cerebral oxygen saturation (ScO2) measurement performance of the new cerebral oximeter (NeurOs®, Mespere LifeSciences, Ontario, Canada) in comparison to the established INVOS 5100C® (Medtronic, Boulder, USA) cerebral oximeter. We performed measurements during different levels of carbon dioxide pressure (PaCO2) during hyper- and hypoventilation and different levels of arterial oxygen saturation (SaO2) induced by variation of the inspiratory fraction of oxygen (FiO2). 59 anesthetized cardiac and vascular surgical patients were studied during hemodynamically stable conditions. Two versions of the NeurOs® oximeter were used in 39 and 20 patients, respectively: an older version with one bi-hemispherical sensor attached to the midline of the forehead and a newer version with two sensors that were attached to the left and right forehead. ⋯ The ScO2 measurement performance of the NeurOs® cerebral oximeter is not interchangeable with the INVOS® cerebral oximeter during variations of ventilation and oxygenation in elective cardiac or vascular surgical patients. The lack of reactivity to changes in ventilation (by variation of PaCO2) and oxygen delivery (by variation of FiO2) question the reliability of NeurOs® measurements to reflect changes in cerebral blood flow and cerebral oxygen balance. This holds true not only for different sensor positions at the forehead but also for different modes of penetration.