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 2009
Long-term assessment of post-cardiac-arrest neurological outcomes with somatosensory evoked potential in rats.
Cardiac arrest (CA) can produce complex changes in somatosensory evoked potentials (SSEPs). Somatosensory evoked potentials (SSEPs) indicate the intactness of somatosensory pathways and are commonly used for brain function monitoring during surgeries. Multiresolution biorthogonal wavelet analysis was applied to SSEPs recorded during established CA experiments and post-CA long-term recovery periods in rats. ⋯ In the long-term recovery period (within 72 hours), both the amplitudes of SSEPs and the interpeak latencies returned to the baseline. Our results suggest that the changes of SSEPs may represent the post-CA neurological injuries and recovery in the somatosensory afferent pathways. The results here lay ground work for establishing the relationship between SSEPs and post-CA neurological injuries and functional outcomes as well as deploying SSEP in clinical settings to monitor patients resuscitated from CA in the future.
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Monitoring of human vital signs - heart rate, respiratory rate, hemoglobin oxygen saturation and others - has become an indispensable part of the standard of care in a hospital setting. For example, vital sign monitoring during administration of general anesthesia is essential, given the role that the anesthesiologist plays in assuming physiologic control. In veterinary settings, however, vital sign monitoring under anesthesia is less common, and may consist simply of a visual assessment of respiratory rate. ⋯ In this paper, we present a unique nose-cone design and associated instrumentation which allows for measurement of respiratory parameters - e.g., anesthesia gas concentration, inspiratory and expiratory O(2), and inspiratory and expiratory CO(2) (capnometry). Such instrumentation facilitates a physiologic assessment of small animals undergoing general anesthesia, an increasingly important consideration as small animals play a greater role in in vivo biomedical studies. In addition, the techniques proposed herein are suitable for measurement on small respiratory volumes associated with neonatal monitoring.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Reduction of the onset response in high frequency nerve block with amplitude ramps from non-zero amplitudes.
High frequency alternating current (HFAC) waveforms reversibly block conduction in mammalian peripheral nerves. The initiation of the HFAC produces an onset response in the nerve before complete block occurs. An amplitude ramp, starting from zero amplitude, is ineffective in eliminating this onset response. ⋯ However, an amplitude ramp was successful in eliminating this onset. This was always possible for the ramps up from 50%, 75 % and 90% block threshold amplitude, but never from 0% or 25% of the block threshold amplitude. This maneuver can potentially be used to maintain complete nerve block, transition to partial block and then resume complete block without initiating another onset.
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BIS monitoring is a processed electroencephalogram (EEG) technology that is designed to follow the effects that anesthetics and sedatives have on cerebral function. Much is know about the technology, it's utility and limitations. The economic case for widespread utilization of this technology is weak. ⋯ Total cost to the heath care system would approach one billion US dollars per year, just for use during general anesthetics. More appropriate use of already available drugs and technology would most likely decrease the incidence of IR as effectively, although individual patients who are at high risk for IR may benefit from this technology. However, based on current health care economic standards general use of BIS monitoring does not seem warranted and appears not to be cost-effective.