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
Pilot investigation of anterior fontanelle photoplethysmographic signals and their suitability in estimating arterial oxygen saturation.
There is a need for more reliable, non-invasive and alternative measurement sites for the monitoring of arterial blood oxygen saturation in critically ill newborns at times of peripheral compromise. A pilot investigation on 14 Intensive Care Unit (ICU) newborns was conducted utilizing custom-made reflectance photoplethysmographic (PPG) sensors placed at the fontanelle and foot. The results suggest that the fontanelle is sensitive to changes in saturation, where saturation values obtained from the custom sensor were compared against commercial pulse oximeter values and results from a blood gas analyzer, however careful placement of the sensor at the fontanelle is an issue that needs further investigation.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Hypnosis control based on the minimum concentration of anesthetic drug for maintaining appropriate hypnosis.
This paper proposes a novel hypnosis control method using Auditory Evoked Potential Index (aepEX) as a hypnosis index. In order to avoid side effects of an anesthetic drug, it is desirable to reduce the amount of an anesthetic drug during surgery. For this purpose many studies of hypnosis control systems have been done. ⋯ The minimum effect-site concentration is estimated utilizing the property of aepEX pharmacodynamics. The infusion rate of propofol is adjusted so that effect-site concentration of propofol may be kept near and always above the minimum effect-site concentration. Simulation results of hypnosis control using the proposed method show that the minimum concentration can be estimated appropriately and that the proposed control method can maintain hypnosis adequately and reduce the total infusion amount of propofol.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Real-time cardiorespiratory coherence is blind to changes in respiration during general anesthesia.
A novel real-time cardiorespiratory coherence (CRC) algorithm has been developed to monitor nociception during general anesthesia. CRC uses custom designed filters to track and analyze the respiratory sinus arrhythmia (RSA) as it moves in time and frequency. CRC is a form of sensor fusion between heart rate and respiration, estimating the strength of linear coupling between the two signals. The aim of this study was to estimate the effect of changes in respiration rate (RR) and peak airway pressure (PPaw) on CRC. The response of CRC was compared to a prior offline wavelet-based algorithm (WTCRC) as well as traditional univariate heart rate variability (HRV) measures. A nociception index was created for each algorithm, ranging from 0 (no nociception) to 100 (strong nociception). ⋯ Real-time CRC was blind to the changes in respiration, and was less sensitive than many of the traditional HRV measures. A nociception index based on CRC can thus function across a wider range of respiratory conditions than can many traditional univariate HRV measures. The real-time CRC algorithm shows promise for monitoring nociception during general anesthesia.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
Electrical safety of conducted electrical weapons relative to requirements of relevant electrical standards.
TASER(®) conducted electrical weapons (CEW) deliver electrical pulses that can inhibit a person's neuromuscular control or temporarily incapacitate. TASER X26, X26P, and X2 are among CEW models most frequently deployed by law enforcement agencies. The X2 CEW uses two cartridge bays while the X26 and X26P CEWs have only one. The TASER X26P CEW electronic output circuit design is equivalent to that of any one of the two TASER X2 outputs. The goal of this paper was to analyze the nominal electrical outputs of TASER X26, X26P, and X2 CEWs in reference to provisions of several international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance. ⋯ Our measurements and analyses confirmed that the nominal electrical outputs of TASER X26, X26P and X2 CEWs lie within safety bounds specified by relevant requirements of the above standards.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2013
A brain-machine interface for control of burst suppression in medical coma.
Burst suppression is an electroencephalogram (EEG) marker of profound brain inactivation and unconsciousness and consists of bursts of electrical activity alternating with periods of isoelectricity called suppression. Burst suppression is the EEG pattern targeted in medical coma, a drug-induced brain state used to help recovery after brain injuries and to treat epilepsy that is refractory to conventional drug therapies. The state of coma is maintained manually by administering an intravenous infusion of an anesthetic, such as propofol, to target a pattern of burst suppression on the EEG. ⋯ We compute the BSP in real time from the EEG segmented into a binary time-series by deriving a two-dimensional state-space algorithm. We then derive a stochastic controller using both a linear-quadratic-regulator strategy and a model predictive control strategy. The BMI can promptly change the level of burst suppression without overshoot or undershoot and maintains precise control of time-varying target levels of burst suppression in individual rodents in real time.