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
Optimizing cardiac resuscitation outcomes using wavelet analysis.
Ventricular fibrillation (VF) is the most lethal of cardiac arrhythmias that leads to sudden cardiac death if untreated within minutes of its occurrence. Defibrillation using electric shock resets the heart to return to spontaneous circulation (ROSC) state, however the success of which depends on various factors such as the viability of myocardium and the time lag between the onset of VF to defibrillation. Recent studies have reported that performing cardio pulmonary resuscitation (CPR) procedure prior to applying shock increases the survival rate especially when VF is untreated for more than 5 minutes. ⋯ Existing works in the literature have demonstrated correlation between the characteristics of the VF waveform and the outcome (ROSC) of the defibrillation. The proposed work improves on this by attempting to arrive at a near real-time monitoring tool in aiding the EMS staff. Using data collected from 16 pigs during VF, the proposed wavelet methodology achieved an overall accuracy of 94% in successfully predicting the shock outcomes.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Hemodynamic models of cerebral aneurysms for assessment of effect of vessel geometry on risk of rupture.
Surgical decisions on treatment of cerebral aneurysms are based predominantly on aneurysm size. This study has assessed the influence of parent vessel geometry on intra-aneurysmal flow patterns and mass flow rate using computational fluid dynamics and finite element modeling of straight and curved vessels feeding saccular aneurysms of varying size and aspect ratio. ⋯ The dependency of parent vessel geometry is a function of aneurysm aspect ratio and shows minimal dependency at an aspect ratio of 1.68. These findings could be used for improved quantification of risk of rupture of cerebral aneurysms detected from clinical imaging modalities and to aid surgical decision making.
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Nerve localization using peripheral nerve stimulation (PNS) is affected by tissue properties, the anatomy surrounding the nerve, and characteristics of the stimulus waveform. A better understanding of the factors influencing PNS should lead to improved nerve localization techniques for use in regional anesthesia. A finite element approach is described here that includes capacitive effects and accounts for frequency-dependent tissue properties in a computationally efficient manner. The modeling approach can be applied to other bioelectric problems where capacitive effects may be important.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Noninvasive cardiac output estimation using a novel photoplethysmogram index.
Cardiac output (CO) monitoring is essential for indicating the perfusion status of the human cardiovascular system under different physiological conditions. However, it is currently limited to hospital use due to the need for either skilled operators or big, expensive measurement devices. Therefore, in this paper we devise a new CO indicator which can easily be incorporated into existing wearable devices. ⋯ After least squares linear regression, the precision between CO(imp) and CO estimated from IHAR (CO(IHAR)) was 1.40 L/min. The total percentage error of the results was 16.2%, which was well below the clinical acceptance limit of 30%. The results suggest that IHAR is a promising indicator for wearable and noninvasive CO monitoring.
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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.