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
Revisiting the video stethoscope: an application of digital signal processing software (Goldwave) to monitoring ventilation in intubated patients.
Problems with tracheal intubation and mechanical ventilation are potentially important causes of perioperative morbidity and mortality. We have developed a method of monitoring the ventilation of both lungs during general anesthesia that is an advanced digital version of a more primitive analog technique developed over two decades ago. We used two miniature electret microphones connected to regular chest pieces, placing the assemblies on the anterior chest wall about 4 inches below the clavicle in the midclavicular line. ⋯ We also hypothesized that as a result of noise and anatomical variations that under conditions of bilateral mechanical ventilation the obtained plot would be very different from a simple 45 degree line. The data obtained supports these hypotheses. This preliminary study suggests that our technique may help provide a practical real-time warning system for detecting endotracheal tube malpositions, and may help build on the work of other investigators.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Detection of respiratory rhythm from photoplethysmographic signal by adaptive morphological filter.
An approach using morphological filter technique is proposed to determine the respiratory rhythm from the photoplethysmographic (PPG) signal. As the structuring elements of morphological filter have a decisive effect on the analysis result, in the study the structuring elements are determined by the individual heart rate adaptively. ⋯ Furthermore, the low computational complexity of the algorithm may make it easy to be implemented on Microprogrammed Control Units (MCU) for real-time processing. More experimental data is necessary to improve the reliability and robustness of the algorithm.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Relation between index finger width and hand width anthropometric measures.
Measures of hand and finger anthropometry are very important for designing many hand held devices as well as understanding anthropometric effects on the operation of such devices. Many historical datasets have measured and recorded gross hand dimensions but do not often record the finer dimensions of the hand such as finger anthropometry. ⋯ In this paper we compare two empirical linear models that predicts index finger width at the proximal interphalangeal (PIP) joint (a finger anthropometric measure) based on hand-width (hand anthropometric measure). This will be especially useful for deriving population measures of finger anthropometry from large historical data sets where only gross hand dimensions are available.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Estimating transition point of anesthetic-induced loss of consciousness in mice by detecting motion in response to forced movement.
To characterize transition periods of entrance to and emergence from anesthetic-induced unconsciousness in terms of thalamocortical neural activity, we devised a new method estimating a transition point of anesthetic-induced loss of consciousness. The method continuously monitors an animal's head motion in response to forced movement on treadmill and uses the motion signals as a criterion of the transition. ⋯ Resulting signals from the motion detector could discriminate the points of entrance into and emergence from the anesthetic-induced unconsciousness with resolution corresponding to the sampling frequency. This method makes it possible to track the anesthetic transition period continuously without contaminating EEGs and LFPs.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Combined direct current and high frequency nerve block for elimination of the onset response.
Nerve conduction in peripheral mammalian nerves can be blocked by high frequency alternating current (HFAC) waveforms. However, one of the disadvantages of HFAC block is that it produces an intense burst of firing in the nerve when the HFAC is first turned on. This is a significant obstacle to the clinical implementation of HFAC block. ⋯ This method was experimentally evaluated in an in-vivo mammalian model. Successful no-onset HFAC block was obtained using a DC block of 200 microA and an HFAC block of 30 kHz at 10 Vp-p. This may allow HFAC block to be used in clinical applications for pain relief.