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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While liposomes and nanoparticles have been the subject of intense research for more than 40 years, few particles have been translated into clinical practice. Advantages of these particles include the potential to overcome the cardiac, renal or neural toxicity of systemic chemotherapy, the opportunities for multivalent targeting, the gradual yet significant accumulation within tumors due to leaky blood vessels and the myriad of new approaches to locally alter the properties of the particle in the region of interest. Given the complexity of the design and co-optimization of the surface architecture, shell formulation and drug loading, methods to image the pharmacokinetics of nanoparticles in living systems are an essential part of an efficient research methodology. Here, we describe our efforts to label the shell and drug core of lipid-shelled particles with a goal of facilitating translation of activatable particles.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Data mining of patients on weaning trials from mechanical ventilation using cluster analysis and neural networks.
The process of weaning from mechanical ventilation is one of the challenges in intensive care. 149 patients under extubation process (T-tube test) were studied: 88 patients with successful trials (group S), 38 patients who failed to maintain spontaneous breathing and were reconnected (group F), and 23 patients with successful test but that had to be reintubated before 48 hours (group R). Each patient was characterized using 8 time series and 6 statistics extracted from respiratory and cardiac signals. A moving window statistical analysis was applied obtaining for each patient a sequence of patterns of 48 features. ⋯ Neural networks were applied to discriminate between patients from groups S, F and R. The best performance obtained was 84.0% of well classified patients using a linear perceptron trained with a feature selection procedure (that selected 19 of the 48 features) and taking as input the main cluster centroid. However, the classification baseline 69.8% could not be improved when using the original set of patterns instead of the centroids to classify the patients.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Pulse pressure variation estimation using a sequential Monte Carlo method.
We describe a novel automatic algorithm to continuously estimate the pulse pressure variation (PPV) index from arterial blood pressure (ABP) signals. The algorithm utilizes our recently developed sequential Monte Carlo method (SMCM) based on a maximum A-Posterior adaptive marginalized particle filter (MAM-PF). The PPV index is one of most specific and sensitive dynamic indicators of fluid responsiveness in mechanically ventilated patients. We report the assessment results of the proposed algorithm on real ABP signals.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Electrode design for high frequency block: effect of bipolar separation on block thresholds and the onset response.
The delivery of high frequency alternating currents (HFAC) to peripheral nerves has been shown to produce a rapid and reversible nerve conduction block at the site of the electrode, and holds therapeutic promise for diseases associated with undesired or pathological neural activity. It has been known since 1939 that the configuration of an electrode used for nerve block can impact the quality of the block, but to date no formal study of the impact of electrode design on high frequency nerve block has been performed. Using a mammalian small animal model, it is demonstrated that the contact separation distance for a bipolar nerve cuff electrode can impact two important factors related to high frequency nerve block: the amplitude of HFAC required to block the nerve (block threshold), and the degree to which the transient "onset response" which always occurs when HFAC is first applied to peripheral nerves, is present. This study suggests that a bipolar electrode with a separation distance of 1.0 mm minimizes current delivery while producing high frequency block with a minimal onset response in the rat sciatic nerve.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2009
Clinical TrialA hybrid platform based on EOG and EEG signals to restore communication for patients afflicted with progressive motor neuron diseases.
An efficient alternative channel for communication without overt speech and hand movements is important to increase the quality of life for patients suffering from Amiotrophic Lateral Sclerosis or other illnesses that prevent correct limb and facial muscular responses. Often, such diseases leave the ocular movements preserved for a relatively long time. The aim of this study is to present a new approach for the hybrid system which is based on the recognition of electrooculogram (EOG) and electroencephalogram (EEG) measurements for efficient communication and control. ⋯ A comparison of the performance of the EOG-based system has been made with a BCI system that uses P300 waveforms. As a next step, we plan to integrate EOG and EEG sides. The final goal of the project is to realize a unique noninvasive device able to offer the patient the partial restoration of communication and control abilities with EOG and EEG signals.