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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This paper describes an accurate, economical, and portable device that helps to locate the position of an endotracheal tube (ETT) in situ. The device uses an array of magnetic field sensors to detect an anomaly in magnetic field caused by magnet embedded near the cuff of an ETT, and displays an intuitive map of relative magnetic field intensity under the sensor area. The device provides real-time feedback of the position to a clinician, so that corrective measures can be taken if the ETT is determined to be outside of normal positioning with respect to the patient's airway. Variations of the proposed design are suitable for continuous monitoring.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Comparative StudyK-space and image space combination for motion artifact correction in multicoil multishot diffusion weighted imaging.
Motion during diffusion encodings leads to phase errors in different shots of a multishot acquisition. Phase differences in k-space data among shots result in phase cancellation artifacts in the reconstructed image. ⋯ We introduce a new k-space and image-space combination (KICT) method for motion artifacts cancellation that avoids incomplete phase error correction. Further, the method preserves the phase of the object, which is important for parallel imaging applications.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Comparative StudyPerformance evaluation of three methods for respiratory signal estimation from the electrocardiogram.
A comparative study of three methods for estimating respiratory signal through electrocardiogram (ECG) was carried out. The three methods analyzed were based on R wave area, R peak amplitude and heart rate variability (HRV). For each method, cross-correlation coefficient and spectral coherence in a range of frequencies up to 0.5 Hz were computed between the ECG derived respiratory signals (EDR) and the three real respiratory signals: oronasal, and two inductance plethysmographies recordings (chest and abdominal). Results indicate that EDR methods based on R wave area and HRV are better correlated and show a wider spectral coherence with real respiratory signals than the other EDR method based on R peak amplitude.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Fetal distress diagnosis using heart rate variability analysis: design of a high frequency variability index.
Routine monitoring of Fetal Heart Rate (FHR) during labor enables diagnosis of fetal distress and appropriate management by the medical staff. Diagnosis of fetal distress relies mainly on a subjective visual assessment of FHR variations using baseline level, oscillations magnitude, decelerations and their time-relation to the parturient uterine contractions. Strong intra and inter-observer discrepancies exist with this widely used technique, and sometimes requires fetal scalp blood sample pH measurement, which is not fully reliable either. ⋯ We tested this new index on 21 fetuses where FHR was recorded during labor for an observational clinical trial. FHR recordings were separated in two groups given the fetal arterial pH obtained after birth: group 1 - no distress, pH >= 7.15, N=16 and group 2 - fetal distress, pH 7.15, N=5. The new index was significantly higher in group 1 than in group 2 (non parametric Mann Whitney U-test, p=0.01).
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Interpolation of the subjective score of visually-induced motion sickness by using physiological parameters.
In order to investigate the effect of visually-induced motion sickness in actual video images, this study proposes a method of interpolation for the subjective score, which has low time and quantitative resolutions, by using physiological parameters. The model which represents the change in subjective score of VIMS was expressed as multiple regression equations in which input parameters are cardiovascular indices such as heart rate variability. The estimation results indicated that the model can represent, in higher resolution, the change in the subjective score of the subjects who have induced nausea.