Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference
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Conf Proc IEEE Eng Med Biol Soc · Jan 2015
An enhanced cerebral recovery index for coma prognostication following cardiac arrest.
Prognostication of coma outcomes following cardiac arrest is both qualitative and poorly understood in current practice. Existing quantitative metrics are powerful, but lack rigorous approaches to classification. This is due, in part, to a lack of available data on the population of interest. ⋯ We utilized a subset of the collected data to generate features that measured the connectivity, complexity and category of EEG activity. A subset of these features was included in a logistic regression model to estimate a dichotomized cerebral performance category score at discharge. We compared the predictive performance of our method against an established EEG-based alternative, the Cerebral Recovery Index (CRI) and show that our approach more reliably classifies patient outcomes, with an average increase in AUC of 0.27.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2015
Comparative StudyComparison of HRV parameters derived from photoplethysmography and electrocardiography signals.
Heart rate variability (HRV) has become a useful tool in analysis of cardiovascular system in both research and clinical fields. HRV has been also used in other applications such as stress level estimation in wearable devices. HRV is normally obtained from ECG as the time interval of two successive R waves. ⋯ Our results show that the smallest error happens in SDNN and SD2 with relative error of 2.46% and 2%, respectively. The most affected parameter is pNN50 with relative error of 29.89%. In addition, in our trial, using the maximum of PPG gave better results than its second derivative.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2015
The impact of data preprocessing in traumatic brain injury detection using functional magnetic resonance imaging.
Traumatic brain injury (TBI) can adversely affect a person's thinking, memory, personality and behavior. For this reason new and better biomarkers are being investigated. Resting state functional network connectivity (rsFNC) derived from functional magnetic resonance (fMRI) imaging is emerging as a possible biomarker. ⋯ Results suggest that correction for motion variance before spatial smoothing is the best alternative. Following this preprocessing option a significant group difference was found between cerebellum and supplementary motor area/paracentral lobule. In this case the mTBI group exhibits an increase in rsFNC.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2015
An improved artifact removal algorithm for continuous cardiac output and blood pressure recordings.
Measurement artifacts are common in hemodynamic recordings such as cardiac output and blood pressure. Manual artifact removal is cumbersome for large datasets, and automatic processing using algorithms may reduce workload and provide more reproducible outcomes. This paper presents an artifact removal algorithm which is more aggressive compared to a previously described method. ⋯ Precision, recall and F-score was determined by agreement with manual inspection by an expert. Based on the total of all measurements from CO and MAP by LiDCO and CO and MAP by Nexfin, precision was 86%, 79%, 79% and 68% respectively (87%, 62%, 76% and 58% for the reference method), recall was 97%, 94%, 89% and 97% (31%, 6%, 28% and 6% for reference), F-score was 91%, 85%, 84% and 80% (46%, 10%, 41% and 10% for reference). The proposed algorithm offers an improved performance in removing true artifacts, in some cases a reduced ability to preserve true measurements, but an improved overall accuracy.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2015
Estimating instantaneous respiratory rate from the photoplethysmogram.
The photoplethysmogram (PPG) obtained from pulse oximetry shows the local changes of blood volume in tissues. Respiration induces variation in the PPG baseline due to the variation in venous blood return during each breathing cycle. We have proposed an algorithm based on the synchrosqueezing transform (SST) to estimate instantaneous respiratory rate (IRR) from the PPG. ⋯ The median RMS error was 0.39 breaths/min for all subjects which ranged from the lowest error of 0.18 breaths/min to the highest error of 13.86 breaths/min. A Bland-Altman plot showed an agreement between the IRR obtained from PPG and reference respiratory rate with a bias of -0.32 and limits agreement of -7.72 to 7.07. Extracting IRR from PPG expands the functionality of pulse oximeters and provides additional diagnostic power to this non-invasive monitoring tool.