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 2013
Effect of respiratory-induced intensity variations on finger SpO2 measurements in volunteers.
Photoplethysmographic (PPG) signals were recorded from the fingers of 16 healthy volunteers with periods of timed and forced respiration. The aim of this pilot study was to compare estimations of arterial oxygen saturation (SpO2) recorded using a dedicated pulse oximetry system while subjects were breathing regularly with and without a mouthpiece containing a flow resistor. ⋯ SpO2 values were calculated from the pre-recorded PPG signals. Mean SpO2 values were 95.4% with the flow resistor compared with 97.3% with no artificial resistance, with statistical significance demonstrated using a Student's t-test (P = 0.006).
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
A simple and effective semi-invasive method for inducing local hypothermia in rat spinal cord.
Hypothermia has been shown to be an effective treatment for spinal cord injury. Local hypothermia is advantageous because it avoids inducing systemic side effects of general hypothermia while providing the opportunity for greater temperature reduction at the site of injury, which may contribute to increased neuroprotection. We report a new semi-invasive method for inducing local hypothermia in rats' spinal cords. ⋯ We also validated our method in control rats that received only a laminectomy. Furthermore, this method was able to reliably cool and rewarm the cord at a steady rate (Δ5.5°C in 30 min, or 0.2°C/min). Future work will include validating long-term functional improvements of injured rats after treatment and to apply local cooling to other spinal cord injury models, such as compression injuries.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Multicenter Study Clinical TrialNovel screen printed electrode set for routine EEG recordings in patients with altered mental status.
There is a growing need for an easy to use screening tool for the assessment of brain's electrical function in patients with altered mental status (AMS). The purpose of this study is to give a brief overview of the state-of-the-art in electrode technology, and to present a novel sub-hairline electrode set developed in our research group. Screen-printing technology was utilized to construct the electrode set consisting of ten electroencephalography (EEG) electrodes, two electrooculography (EOG) electrodes, two ground electrodes and two reference electrodes. ⋯ The skin-electrode impedances remain stable and low enough at least two days enabling high-quality long-term recordings. Due to the proper material selection, thin ink layers and detachable zero insertion force (ZIF) - connector, electrode was observed to be CT- and MRI-compatible allowing imaging without removing the electrodes. Pilot EEG recordings gave very promising results and an on-going clinical trial with larger number of patients will show the true feasibility of this approach.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Real-time segmentation and tracking of brain metabolic state in ICU EEG recordings of burst suppression.
We provide a method for estimating brain metabolic state based on a reduced-order model of EEG burst suppression. The model, derived from previously suggested biophysical mechanisms of burst suppression, describes important electrophysiological features and provides a direct link to cerebral metabolic rate. We design and fit the estimation method from EEG recordings of burst suppression from a neurological intensive care unit and test it on real and synthetic data.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Hemodynamics at the ostium of cerebral aneurysms with relation to post-treatment changes by a virtual flow diverter: a computational fluid dynamics study.
Computational fluid dynamics (CFD) techniques have been refined for modeling the hemodynamics in cerebral aneurysms. Recent interest has focused on understanding hemodynamic changes by treatment with a flow diverter (FD), i.e. a stent with a dense metal mesh which is placed across the ostium to divert the majority of flow away from the aneurysm. Potential complications include remnant inflow jets but, more seriously, aneurysm hemorrhage. ⋯ Velocities and WSS were reduced in all cases post FD treatment, pressure increased in one case. Heterogeneous distributions of the velocity magnitude were found at the ostium with focal maxima indicating potential risk zones for remnant inflow jets into the aneurysms. Pressures at the ostium correlated with pressure changes inside the aneurysm which could become a pre-treatment indicator for the evaluation of the suitability of a particular aneurysm for FD treatment.