Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947143
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Management information systems (MIS) and decision support systems (DSS), used as part of broader healthcare technology management, are considered to be health technologies. As such, they should meet the criteria of affor...Management information systems (MIS) and decision support systems (DSS), used as part of broader healthcare technology management, are considered to be health technologies. As such, they should meet the criteria of affordability, appropriateness, cost-effectiveness, ease of use and sustainability if they are to be implementable and have a lasting impact on healthcare service delivery. They should also facilitate and support improved quality of healthcare. We have developed a suite of management-support tools around a concept of integrated healthcare resource planning and management (iHRPM). We believe that these tools meet the above-mentioned criteria and therefore lend themselves to widespread applicability in diverse healthcare and socio-economic contexts, not least in supporting performance monitoring and benchmarking.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947142
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Each individual U.S. Air Force, Army, and Navy Surgeon General has integrated oversight of global medical supplies and resources using the Joint Medical Asset Repository (JMAR). A Business Intelligence system called the...Each individual U.S. Air Force, Army, and Navy Surgeon General has integrated oversight of global medical supplies and resources using the Joint Medical Asset Repository (JMAR). A Business Intelligence system called the JMAR Executive Dashboard Initiative (JEDI) was developed over a three-year period to add real-time interactive data-mining tools and executive dashboards. Medical resources can now be efficiently reallocated to military, veteran, family, or civilian purposes and inventories can be maintained at lean levels with peaks managed by interactive dashboards that reduce workload and errors.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947141
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The proposed feedforward controller is composed of three parts: a lookup table controller, an artificial neural network controller and a decision block. The lookup table controller has the information about the relation...The proposed feedforward controller is composed of three parts: a lookup table controller, an artificial neural network controller and a decision block. The lookup table controller has the information about the relation between the activation levels of muscles and the output at steady state. To compensate for the delayed tracking ability of the lookup table controller for rapid movement, an artificial neural network (ANN) controller is used in parallel with the lookup table control. The ANN controller is trained to learn the inverse dynamics of the musculoskeletal model. The decision block determines the contribution ratio of each controller based on the frequency analysis of the reference trajectory. The control algorithm was tested on single joint elbow model with a flexor and an extensor. Results show that the combined controller reduces the overall output errors.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947140
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Incorporating an instability predictor into a portable sensor has a number of clinically relevant applications. This study investigated the feasibility of developing a real-time assessment tool to predict stepping during...Incorporating an instability predictor into a portable sensor has a number of clinically relevant applications. This study investigated the feasibility of developing a real-time assessment tool to predict stepping during standing by monitoring Center of Pressure (COP) measurements. Forward and backward perturbations were performed on 16 able-bodied subjects using a pulley system attached to the subjects' waist. A linear relationship was found between the peak COP velocity (COPv) and the peak COP position caused by the perturbations. As the peak COPv occurs considerably before the peak COP, the peak COP estimated using a regression equation from the peak COPv may serve as an instability predictor. By comparing stepping thresholds with the estimated peak COP, we found that the stepping predictor successfully predicted instability (stepping) earlier than those predictors using actual COP. Results show that the proposed model is a viable solution to predict stepping, and the feasibility of incorporating the model into a neuroprosthesis system for standing.
Tovar F, Escobedo C, Rodríguez G
… +4 more, García J, Vilá A, Corona F, Sacristán E
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947139
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Development of a new generation pneumatic of Ventricular Assist Device (VAD) required the design of cannulae to improve its optimal performance. In this case, a relevant restrictive design parameter was the material of t...Development of a new generation pneumatic of Ventricular Assist Device (VAD) required the design of cannulae to improve its optimal performance. In this case, a relevant restrictive design parameter was the material of the cannulae. Silicone was the best choice in a hemocompatible focus, but this is a material with very low stiffness. If the material is flexible, the most important parameter that affects either the structural performance or the hydrodynamic resistance is the amount of side holes on the cannulae tip, known as the effective drainage area. In order to obtain an estimation of the structural performance and of the hydrodynamic resistance, a study based on two independent analysis is needed: the structural and the in vitro drop pressure analysis. Structural analyses based on computer simulations were made in order to estimate the bending behavior of four silicone prototypes of cannulae tips. On the other hand, experiments under hydrostatic conditions were made to test and compare the pressure loss and flow rate relationship. A cannula tip with six side holes showed good hydrostatic performance, having almost the same as the one with nine side holes. Plus, it presented and a satisfactory structural behavior. This study assisted the design process of an auricular silicone cannula, recommending the use of cannulae with six side holes for a specific VAD.
Gandhi H, Green D, Kounios J
… +2 more, Clark CM, Polikar R
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947137
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The diagnosis of Alzheimer's disease (AD) at an early stage is a major concern due to growing number of elderly population affected by the disease, as well as the lack of a standard diagnosis procedure available to commu...The diagnosis of Alzheimer's disease (AD) at an early stage is a major concern due to growing number of elderly population affected by the disease, as well as the lack of a standard diagnosis procedure available to community clinics. Recent studies have used wavelets and other signal processing methods to analyze EEG signals in an attempt to find a non-invasive biomarker for AD. These studies had varying degrees of success, in part due to small cohort size. In this study, multiresolution wavelet analysis is performed on event related potentials of the EEGs of a relatively larger cohort of 44 patients. Particular emphasis was on diagnosis at the earliest stage and feasibility of implementation in a community health clinic setting. Extracted features were then used to train an ensemble of classifiers based stacked generalization approach. We describe the approach, and present our promising preliminary results.
Phlypo R, Van Hese P, Hallez H
… +4 more, Boon P, Van de Walle R, D'Asseler Y, Lamhieu I
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947136
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Epileptic patients often show interictal epileptic discharges (IED's) in the electroencephalogram (EEG) recorded between seizures. This epileptiform activity is in many cases related to the location of the seizure onset,...Epileptic patients often show interictal epileptic discharges (IED's) in the electroencephalogram (EEG) recorded between seizures. This epileptiform activity is in many cases related to the location of the seizure onset, and is believed to reflect the frequency of the seizures. We present a fully automated technique that is able to extract the IED's from the EEG, despite the obscuring artifacts. The presented technique is based on a multi-objective optimization by maximizing the signal's kurtosis and minimizing its distance to a defined template. Preliminary results show that this technique automatically extracts a source on which spike detection techniques should perform better than on the regular channel selection procedure.
Funase A, Yagi T, Barros AK
… +2 more, Cichocki A, Takumi I
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947135
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Electroencephalogram (EEG) related to fast eye movement (saccade), has been the subject of application oriented research by our group toward developing a brain-computer interface (BCI). Our goal is to develop novel BCI b...Electroencephalogram (EEG) related to fast eye movement (saccade), has been the subject of application oriented research by our group toward developing a brain-computer interface (BCI). Our goal is to develop novel BCI based on eye movements system employing EEG signals online. Most of the analysis of the saccade-related EEG data has been performed using ensemble averaging approaches. However, ensemble averaging is not suitable for BCI. In order to process raw EEG data in real time, we performed saccade-related EEG experiments and processed data by using the non-conventional fast ICA with reference signal (FICAR). The FICAR algorithm can extract desired independent components (IC) which have strong correlation against a reference signal. Visually guided saccade tasks and auditory guided saccade tasks were performed and the EEG signal generated in the saccade was recorded. The EEG processing was performed in three stages: PCA preprocessing and noise reduction, extraction of the desired IC using Wiener filter with reference signal, and post-processing using higher order statistics fast ICA based on maximization of kurtosis. Form the experimental results and analysis we found that using FICAR it is possible to extract form raw EEG data the saccade-related ICs and to predict saccade in advance by about 10 [ms] before real movements of eyes occurs. For single trail EEG data we have successfully extracted the desire ICs with recognition rate about 70%. In next steps, saccade-related EEG signals and saccade-related ICs in visually and auditory guided saccade task are compared in the point of the latency between starting time of a saccade and time when a saccade-related EEG signal or an IC has maximum value and in the point of the peak scale where a saccade-related EEG signal or an IC has maximum value. As results, peak time when saccade-related ICs have maximum amplitude is earlier than peak time when saccade-related EEG signals have maximum amplitude. This is very important advantage for developing our BCI. However, S/N ratio in being processed by FICAR is not improved comparing S/N ratio in being processed by ensemble averaging.
Hira AY, Nebel de Mello A, Faria RA
… +3 more, Odone Filho V, Lopes RD, Zuffo MK
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947134
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This article discusses a telemedicine model for emerging countries, through the description of ONCONET, a telemedicine initiative applied to pediatric oncology in Brazil. The ONCONET core technology is a Web-based system...This article discusses a telemedicine model for emerging countries, through the description of ONCONET, a telemedicine initiative applied to pediatric oncology in Brazil. The ONCONET core technology is a Web-based system that offers health information and other services specialized in childhood cancer such as electronic medical records and cooperative protocols for complex treatments. All Web-based services are supported by the use of high performance computing infrastructure based on clusters of commodity computers. The system was fully implemented on an open-source and free-software approach. Aspects of modeling, implementation and integration are covered. A model, both technologically and economically viable, was created through the research and development of in-house solutions adapted to the emerging countries reality and with focus on scalability both in the total number of patients and in the national infrastructure.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947133
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In the last years the home monitoring development is increased both for its capability as a real time tool to manage patients health and to reduce hospitalization costs. The home monitoring system is a complex structure...In the last years the home monitoring development is increased both for its capability as a real time tool to manage patients health and to reduce hospitalization costs. The home monitoring system is a complex structure that needs the collaboration of different disciplines, from medicine to engineering, and technologies. This project has been developed with the integration of different groups of research as to unify all the necessary knowledge. According to physician exigencies a signal processing library has been implemented to describe in a synthetic and effective way the pathological status of patients with moderate cardiovascular risk. Consequently a software and hardware architecture have been designed to acquire ECG signal, to extract HRV and respiratory information through a multiparametric approach and to store the results. This home monitoring system has been projected to work during an appropriate physical training section and its function is both diagnostic and therapeutic as well as for rehabilitation. The aim of this work is to describe the structure of the signal processing library.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947132
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Recent developments of information technologies are leading the advent of the era of ubiquitous healthcare, which means healthcare services at any time and at any places. The ubiquitous healthcare service needs a wearabl...Recent developments of information technologies are leading the advent of the era of ubiquitous healthcare, which means healthcare services at any time and at any places. The ubiquitous healthcare service needs a wearable system for more continual measurement of biological signals of a user, which gives information of the user from wearable sensors. In this paper, we propose a wearable context aware system for ubiquitous healthcare, and its systematic design process of a ubiquitous healthcare service. Some wearable sensor systems are introduced with Zigbee communication. We develop a context aware framework to send information from wearable sensors to healthcare service entities as a middleware to solve the interoperability problem between sensor makers and healthcare service providers. And, we propose a systematic process of design of ubiquitous healthcare services with the context aware framework. In order to show the feasibility of the proposed system, some application examples are given, which are applied to remote monitoring, and a self check service.
Peng R, Sclabassi RJ, Liu Q
… +2 more, Justin G, Sun M
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947131
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This paper presents a method to synthesize multi-view video frames to facilitate coding and transmission of patient monitoring video. The synthesis is carried out in the DCT domain by means of interlacing. The synthesize...This paper presents a method to synthesize multi-view video frames to facilitate coding and transmission of patient monitoring video. The synthesis is carried out in the DCT domain by means of interlacing. The synthesized video provides a higher video coding efficiency, better synchronization of the video streams from multiple cameras, as well as the improved data loss resilience and protection of the video content. The viability of the presented method was demonstrated by experimental results on patient monitoring video.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947130
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A laboratory simulation has been devised for use in developing and testing physiologic monitoring systems' performance in the presence of electrosurgical interference. This facilitated the development through iterative o...A laboratory simulation has been devised for use in developing and testing physiologic monitoring systems' performance in the presence of electrosurgical interference. This facilitated the development through iterative optimization of an EEG based parameter whose performance is improved during electrosurgery. The system was found to have an improvement of 94% in response to electrosurgery interference in the laboratory simulation. It was found to be improved 78% from all interference sources when tested clinically during actual surgery. This demonstrates the efficacy of the simulation.
Denti P, Bertoldo A, Vicini P
… +1 more, Cobelli C
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947129
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Glucose minimal model parameters are commonly estimated by applying weighted nonlinear least squares to each individual subject's data. Sometimes, parameter precision is not satisfactory, especially in "data poor" condit...Glucose minimal model parameters are commonly estimated by applying weighted nonlinear least squares to each individual subject's data. Sometimes, parameter precision is not satisfactory, especially in "data poor" conditions. In this work, the use of population analysis through nonlinear-mixed effects models is evaluated and its performance tested against the parameter estimates obtained by the standard individual approach through weighted nonlinear least squares. In particular, we compared the performance of two likelihood approximation methods to estimate nonlinear mixed-effects model parameters, i.e. the first-order conditional estimation (FOCE) and the Laplace approximation (Laplace) methods. The results show that nonlinear mixed-effects population modeling using the FOCE approximation can be successfully used in order to accurately estimate individual minimal model parameters.
Marchetti G, Barolo M, Jovanovic L
… +2 more, Zisser H, Seborg DE
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947128
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In order for an "artificial pancreas" to become a reality for ambulatory use, a practical closed-loop control strategy must be developed and critically evaluated. In this paper, an improved PID control strategy for blood...In order for an "artificial pancreas" to become a reality for ambulatory use, a practical closed-loop control strategy must be developed and critically evaluated. In this paper, an improved PID control strategy for blood glucose control is proposed and evaluated in silico using a physiologic model of Hovorka et al. The key features of the proposed control strategy are: (i) a switching strategy for initiating PID control after a meal and insulin bolus; (ii) a novel time-varying setpoint trajectory, (iii) noise and derivative filters to reduce sensitivity to sensor noise, and (iv) a systematic controller tuning strategy. Simulation results demonstrate that the proposed control strategy compares favorably to alternatives for realistic conditions that include meal challenges, incorrect carbohydrate meal estimates, changes in insulin sensitivity, and measurement noise.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947127
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To date, the application of physiologically based pharmacokinetic (PBPK) models in support of drug discovery remains limited, in part due to information deficit and uncertainty regarding model parameters. Fuzzy set theor...To date, the application of physiologically based pharmacokinetic (PBPK) models in support of drug discovery remains limited, in part due to information deficit and uncertainty regarding model parameters. Fuzzy set theory provides a suitable way to objectively account for parameter uncertainty in models. Here, we present a fuzzy set-based PBPK modeling framework and demonstrate its utility in predicting diazepam pharmacokinetics in human plasma, following intravenous dosing, from available animal in vivo and literature data. For computationally expensive PBPK models, the sparse grid method is proposed as an efficient alternative to commonly used fuzzy arithmetic algorithms for function simulation.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947126
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We quantify the ability of 0.9% NaCl (saline) and 5% dextrose in water (D5W) to protect tissues during RF ablation. Using computer simulations and phantom experiments, we determined that D5W provides significantly more e...We quantify the ability of 0.9% NaCl (saline) and 5% dextrose in water (D5W) to protect tissues during RF ablation. Using computer simulations and phantom experiments, we determined that D5W provides significantly more electrical isolation than saline, which reduces unwanted heating of the adjacent tissue. Saline actually increased the amount of RF current in the adjacent tissue. Based on these results, we conclude that D5W is preferable to saline as a protective fluid.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947125
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In this paper we analyze a popular divisive normalization model of V1 with respect to the relationship between its underlying coding strategy and the extraclassical physiological responses of its constituent modeled neur...In this paper we analyze a popular divisive normalization model of V1 with respect to the relationship between its underlying coding strategy and the extraclassical physiological responses of its constituent modeled neurons. Specifically we are interested in whether the optimization goal of redundancy reduction naturally leads to reasonable neural responses, including reasonable distributions of responses. The model is trained on an ensemble of natural images and tested using sinusoidal drifting gratings, with metrics such as suppression index and contrast dependent receptive field growth compared to the objective function values for a sample of neurons. We find that even though the divisive normalization model can produce "typical" neurons that agree with some neurophysiology data, distributions across samples do not agree with experimental data. Our results suggest that redundancy reduction itself is not necessarily causal of the observed extraclassical receptive field phenomena, and that additional optimization dimensions and/or biological constraints must be considered.
Açikgöz N, Ozdamar O, Delgado RE
… +1 more, Bohórquez J
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17947124
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The Auditory Steady-state Responses (ASSR) elicited by click stimuli can be utilized for hearing screening as is traditionally done with click-evoked Auditory Brainstem Responses (ABR). In a typical ASSR or ABR hearing s...The Auditory Steady-state Responses (ASSR) elicited by click stimuli can be utilized for hearing screening as is traditionally done with click-evoked Auditory Brainstem Responses (ABR). In a typical ASSR or ABR hearing screening, several recordings at different intensities are required to find the response threshold. In this study the use of binaural click stimulus with time ramping intensity produces dual-ear evoked potentials in only one recording session, decreasing significantly the recording time. To achieve this performance a one second sweep consisting of repetitive click stimuli, with logarithmically ramping up intensity, is presented to one or both ears simultaneously. Unique repetition frequencies for each ear are used in order to differentiate the responses coming from each ear. The stimuli sweep is repeated and the EEG data corresponding to each sweep is averaged until a pre-specified residual noise level is achieved. Hilbert-transform-based envelope detection filters in the time domain are used to estimate the signal and noise energy around the main stimulation rate. Because the stimulus time-intensity functions are known, thresholds can be estimated from the response onset time position by estimating the significance of the signal to noise ratio. Preliminary results indicate a strong agreement of the obtained thresholds with behavioral thresholds.