Dubeau S, Vinet A, Richer LP
… +2 more, Guardo R, Armour JA
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959458
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Recent clinical evidence suggests that abnormal neural input can contribute to the onset perpetuation of atrial arrhythmias, such that neural elements have become potential targets for ablation. A better understanding of...Recent clinical evidence suggests that abnormal neural input can contribute to the onset perpetuation of atrial arrhythmias, such that neural elements have become potential targets for ablation. A better understanding of the influence of the cardiac autonomous nervous system is required to improve therapy. We have developed a multi-channel system to record neural activity simultaneously at different intra and pericardiac locations. The paper presents the specific requirements to be met for recording neuronal extracellular potentials in these repertoires of neurons and the solutions that were adopted.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959457
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This paper presents a scalp eletroencephalogram (EEG) rhythmic pattern detection scheme based on neural networks. rhythmic discharges detection is applicable to the majority of seizures seen in newborns, and is listed as...This paper presents a scalp eletroencephalogram (EEG) rhythmic pattern detection scheme based on neural networks. rhythmic discharges detection is applicable to the majority of seizures seen in newborns, and is listed as detecting 90% of all the seizures. In this approach some features based on various methods are extracted and compared by a modified multilayer neural network in order to find rhythmic discharges. Statistical performance comparison with seizure detection schemes of Gotman et al. and Liu et al. is performed.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959456
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A new method using autoregressive modelling and pole tracking is proposed to detect cyclical activity within the oxygen saturation signal , SpO(2), for subjects with Obstructive Sleep Apnoea (OSA). OSA is a sleep conditi...A new method using autoregressive modelling and pole tracking is proposed to detect cyclical activity within the oxygen saturation signal , SpO(2), for subjects with Obstructive Sleep Apnoea (OSA). OSA is a sleep condition whereby the upper airway is obstructed and cessation in respiration (apnoea) occurs. The three types of detected activity include: apnoea, mix, and normal breathing, where mix refers to breathing with a low-frequency component . Overall classifications produced by the analysis are in close agreement with expert scoring of the database. Furthermore, the pole-zero analysis method allows, for the first time, the mix sections to be identified automatically.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959455
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While many brain machine interface (BMI) systems have been presented in the literature, most of these systems present the user with an always on interface with no way to shut the interface down when not needed. This pape...While many brain machine interface (BMI) systems have been presented in the literature, most of these systems present the user with an always on interface with no way to shut the interface down when not needed. This paper proposes two extensions of previous BMI work to create an asynchronous BMI in which the system only produces outputs when needed. The first classifies incoming signals into not only task related states, but also an idle state. A refinement of this system utilizes a Markov Model (MM) of the task to impose order on the sequence of states produced by the system. This MM filter improves the accuracy of the system an average of 16%.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959454
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This paper reports a novel autonomous bio-microactuator powered by primary cultured cardiomyocytes and the control and evaluation of the contraction of skeletal muscle cell line C2C12 cells by means of electrical stimula...This paper reports a novel autonomous bio-microactuator powered by primary cultured cardiomyocytes and the control and evaluation of the contraction of skeletal muscle cell line C2C12 cells by means of electrical stimulation. To exploit contractions of cardiomyocytes, we fabricated a PDMS bulb-shaped dispenser and allowed cardiomyocytes to directly adhere to it. The displacement of the bulb-shaped dispenser by cardiomyocytes was larger than previously reported. Then, we employed electrical stimulation to control the contraction of muscle cells. The differentiated C2C12 cells (myotubes) were stimulated electrically, which was analyzed digitally. We succeeded in regulating contractions of C2C12 myotubes by electrical stimulations and manifested the relationship between contraction and the pulse frequency.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959453
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Few practical methods of communicating with people who are locked-in currently exit. This study investigates conscious control of physiological signals, specifically electrodermal activity, to generate two distinguishabl...Few practical methods of communicating with people who are locked-in currently exit. This study investigates conscious control of physiological signals, specifically electrodermal activity, to generate two distinguishable and reproducible states. These states can be translated into a binary signal to control a communication device for people who are locked in. Breathing rates, mental arithmetic and mental music were investigated as means of controlling electrodermal activity. Features extracted from the signals included mean, range and number of electrodermal reactions. For these of four subjects, at least one mental technique caused a reproducible, statistically significant the potential of using mental exercises to develop volitional control of electrodermal activity.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959452
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Use of spectral prior in optical tomography has significantly improved accuracy and quality of images, when applied in two-dimensional (2-D) models. However, the size of the problem increases substantially when applied i...Use of spectral prior in optical tomography has significantly improved accuracy and quality of images, when applied in two-dimensional (2-D) models. However, the size of the problem increases substantially when applied in 3-D. Two methods are presented here that make 3-D spectral imaging computationally feasible. The data-subset approach uses a smaller subset of variable measurement s to reduce the size of the inverse problem. The basic principle consists of using a dynamic criterion to select optimal subset that capture the major changes in the imaging domain. Additionally, the sensitivity matrix is analyzed and made sparse based on a memory requirements (to 8% of full matrix) and provides less tha 2% percent difference in quantification compared to use of full matrices in the image reconstruction.
Song R, Klose AD, Scheel AK
… +3 more, Netz U, Beuthan J, Hielscher AH
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959451
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We have developed an images reconstruction algorithm to recover spatial distribution of optical properties in human finger joints for early diagnosis and monitoring of rheumatoid arthritis (RA). An optimization method it...We have developed an images reconstruction algorithm to recover spatial distribution of optical properties in human finger joints for early diagnosis and monitoring of rheumatoid arthritis (RA). An optimization method iteratively employs a light propagation and scattering coefficients distribution for near-infrared (NIR) light inside the joint tissue. We developed the differences in cross-sectional images obtained by using the reconstruction algorithms with 2-dimensional and 3-dimensional light propagation models. In particular we examined how these different approaches affect the discrimination between healthy and RA joints.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959449
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We envision the building of many realistic cortical neurons on a single Integrated Ciruit (IC). This goal requires efficiently utilizing the similarilities between silicon and biological physics. We present recent result...We envision the building of many realistic cortical neurons on a single Integrated Ciruit (IC). This goal requires efficiently utilizing the similarilities between silicon and biological physics. We present recent results building Silicon models of biological channel utilizing the physics connections to MOSFET devices and the gating effect modulating its channel. Usingthis approach, we present recent results on voltage-clamp measurements for Silicon Sodium and Potassium Channels, biologically realistic action potentials from these channels, models of programmable and learning synapses with biological responses,and active models of dendritic cables. These results, combined with recent advances in reconfigurable analog IC approaches, currently allows the detailed implementation of a pyramidal cell in a few mm in 0.35 m CMOS. Using modern CMOS processes, one could envision 1000s of realistic neurons on an IC with millions of state variables (computing nodes) on a single IC, accelerating the day we can build synthetic systems to represent significant cortical regions.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959448
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In this work we present a technique for applying Blind Source Separation (BSS) to single channel recordings of Electromagnetic (EM) brain signals. Single channel recordings of brain signals are preprocessed through the m...In this work we present a technique for applying Blind Source Separation (BSS) to single channel recordings of Electromagnetic (EM) brain signals. Single channel recordings of brain signals are preprocessed through the method of delays, and the delay matrix processed with the BSS technique described here called LSDIAGTD which uses temporal decorrelation to implement the now popular Independent Component Analysis (ICA) algorithm. This allows the identification and extraction of statistically independent sources underlying these single channel recordings. In particular we depict the analysis of single channel recordings from a Brain-Computer Interfacing paradigm. We show that BSS technique applied in this way extracts a series of codebook vectors representing the spectral content underlying the recorded signal. It then becomes possible to identify and extract particular rhythmic activity underlying the recordings. We show that rhythmic activity in the 8 to 12Hz band can be extracted in the case of imagined hand movements for a particular BCI paradigm.
Yaguchi A, Nagase K, Ishikawa M
… +3 more, Iwasaka T, Odagaki M, Hosaka H
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959447
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Computer simulation and myocardial cell models were used to evaluate a low-energy defibrillation technique. A generated spiral wave, considered to be a mechanism of fibrillation, and fibrillation were investigated using...Computer simulation and myocardial cell models were used to evaluate a low-energy defibrillation technique. A generated spiral wave, considered to be a mechanism of fibrillation, and fibrillation were investigated using two myocardial sheet models: a two-dimensional computer simulation model and a two-dimensional experimental model. A new defibrillation technique that has few side effects, which are induced by the current passing into the patient's body, on cardiac muscle is desired. The purpose of the present study is to conduct a basic investigation into an efficient defibrillation method. In order to evaluate the defibrillation method, the propagation of excitation in the myocardial sheet is measured during the normal state and during fibrillation, respectively. The advantages of the low-energy defibrillation technique are then discussed based on the stimulation timing.
Nogawa M, Yamakoshi T, Ikarashi A
… +2 more, Tanaka S, Yamakoshi K
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959446
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In order to develop a simple and reliable assessment method of the stress induced psychosomatic and hemodynamic responses against various stress situations, especially for evaluating of the effectiveness of stress reduct...In order to develop a simple and reliable assessment method of the stress induced psychosomatic and hemodynamic responses against various stress situations, especially for evaluating of the effectiveness of stress reduction methods, a multipurpose non-invasive continuous cardiovascular monitoring system was developed. The monitoring system could measure beat-by-beat finger blood pressure (SBP, MBP, DBP based on the volume-compensation method), cardiac output (CO, electrical admittance method), total peripheral resistance (TPR=MBP/CO), and the other hemodynamic related parameters (e.g. RR-interval, respiratory rate, pulse wave velocity, etc.). As controlled stress conditions, the human subjects would be exposed to the various stresses such as flash video display, electrical stimulation and so on. In this study, after 5 minutes resting, the stress induced hemodynamic responses were measured during 10-min presentation of floating vertical stripes image using 5 healthy subjects. The image presentation was discontinued when the subject gave his/her self-assessment due to considerable discomfort. The results showed that although BP increased during the presentation in all the subjects, there observed two types of cardiovascular responses; one is a type of increase in CO (or of almost unchanging or decrease in TRP), and the other of increase in TPR. These results strongly suggested that the detection of the change in TPR might be an important factor for the evaluation of stress conditions. Further investigations would be required for the reasons why these two types were observed in the same stressful condition.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959445
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This paper introduces the Hilbert Analysis (HA), which is a novel digital signal processing technique, for the investigation of tremor. The HA is formed by two complementary tools, i.e. the Empirical Mode Decomposition (...This paper introduces the Hilbert Analysis (HA), which is a novel digital signal processing technique, for the investigation of tremor. The HA is formed by two complementary tools, i.e. the Empirical Mode Decomposition (EMD) and the Hilbert Spectrum (HS). In this work we show that the EMD can automatically detect and isolate tremulous and voluntary movements from experimental signals collected from 31 patients with different conditions. Our results also suggest that the tremor may be described by a new class of mathematical functions defined in the HA framework. In a further study, the HS was employed for visualization of the energy activities of signals. This tool introduces the concept of instantaneous frequency in the field of tremor. In addition, it could provide, in a time-frequency-energy plot, a clear visualization of local activities of tremor energy over the time. The HA demonstrated to be very useful to perform objective measurements of any kind of tremor and can therefore be used to perform functional assessment.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959444
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The present paper describes procedures for the evaluation of sleep quality and for stress management based on the analysis of the HRV and respiration signals. The analysis is though for a device aimed to provide support...The present paper describes procedures for the evaluation of sleep quality and for stress management based on the analysis of the HRV and respiration signals. The analysis is though for a device aimed to provide support to people who want to develop a healthier lifestyle, with major focus on cardiovascular disease prevention.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959443
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Protein production has experienced great advances in recent years. In particular, high throughput protein production, coupled with the use of robotics, outputs thousands of mixtures in micro-array wells. To detect the pr...Protein production has experienced great advances in recent years. In particular, high throughput protein production, coupled with the use of robotics, outputs thousands of mixtures in micro-array wells. To detect the presence of protein crystal formation, images of these wells are acquired regularly using robotic cameras. Traditionally, a crystallographer would manually process each image--identifying the wells that resulted in protein crystal formation. This manual inspection process is slow and given the high rate of mixture output, it has become near impossible for crystallographers keep up. Our aim is to create an automated method of detecting which wells have crystals and which ones do not. We make use of a neural network that is trained based on manually classified ground truth data. After it is trained, the automatic classifier would give a binary output --a value of one for the detection of crystals and precipitates in images and a value of zero otherwise. In our previous papers, the core methods of using multi-scale Laplacian image representation to extract image features and the implementation of the neural network classifier were discussed. Here we present a new, optimized approach to training the neural network and results from a large-scale test. We claim that the neural network can be better trained if the training image dataset is optimized in the sense that ambiguous images are removed during the initial training processes. Incremental training is implemented so that the network can be improved as more data becomes available. From initial results with training based on a 6,000 optimized image dataset, the accuracy of the improved classifier approaches 95% in identifying a wide array of images.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959441
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This paper is intended to demonstrate the effect of coupled surface plasmon polaritons (SPPs) on the optical response of a one-dimensional metal grating nanostructure patterned by electron beam lithography (EBL) on the s...This paper is intended to demonstrate the effect of coupled surface plasmon polaritons (SPPs) on the optical response of a one-dimensional metal grating nanostructure patterned by electron beam lithography (EBL) on the silicon surface. Variations of the structure parameters allow continuously tuning of these high-transmission bands across the nanostructure plasmon resonance. This phenomenon gives rise to a selective spectral response and a local field enhancement which can be used in the context of nano-optics. We have examined the emission and reflectance spectra through various fabricated structure layers to determine the emissive angle in SPPs modes. The presented results show that the enhanced reflectance through grating nanostructures is important for such a planar design of novel optical biosensor.
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959440
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Recently an adaptive transmit eigenbeamforming with orthogonal space-time block coding (Eigen-OSTBC) has been proposed. This model was simulated over macrocell environment with a uniform linear array (ULA) at the base st...Recently an adaptive transmit eigenbeamforming with orthogonal space-time block coding (Eigen-OSTBC) has been proposed. This model was simulated over macrocell environment with a uniform linear array (ULA) at the base station (BS) for next-generation (NG) wireless/mobile network. In this paper, we introduce a telemedicine simulation framework employing the Eigen-OSTBC scheme for the investigation of communication system characteristics in the application of biological data such as electrocardiogram (ECG). The geometrical-based hyperbolically distributed scatterers (GBHDS) channel model for macrocell environments was simulated with angular spreads (AS) taken from measurement data. Simulation results showed that the performance improvement introduced by the Eigen-OSTBC scheme can be observed even without extensive numerical analysis as traditionally expected. It is also showed that the received signal is highly correlated with the original transmitted signal.
Mahmoud SS, Fang Q, Davidović DM
… +1 more, Cosic I
Conf Proc IEEE Eng Med Biol Soc
· 2006 · PMID 17959438
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Previously, electrocardiogram (ECG) signals have been analyzed in either a time-indexed or spectral form. The reality, is that the ECG and all other biological signals belong to the family of multicomponent nonstationary...Previously, electrocardiogram (ECG) signals have been analyzed in either a time-indexed or spectral form. The reality, is that the ECG and all other biological signals belong to the family of multicomponent nonstationary signals. Due to this reason, the use of time-frequency analysis can be unavoidable for these signals. The Husimi and Wigner distributions are normally used in quantum mechanics for phase space representations of the wavefunction. In this paper, we introduce the Husimi distribution (HD) to analyze the normal and abnormal ECG signals in time-frequency domain. The abnormal cardiac signal was taken from a patient with supraventricular arrhythmia. Simulation results show that the HD has a good performance in the analysis of the ECG signals comparing with the Wigner-Ville distribution (WVD).