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We present an initiative supported by the National Heart Lung, and Blood Institute and the Food and Drug Administration for the development of a repository containing continuous electrocardiographic information to be shared with the worldwide scientific community. We believe that sharing data reinforces open scientific inquiry. It encourages diversity of analysis and opinion while promoting new research...
Brain activities to major and minor chords and to major and minor cadence sequences were measured by sparse scanning fMRI. Areas activated by major and minor chords and cadence sequences were examined. Some of them are known to be related to emotion, motivation, arousal or reward. In general, minor chords activated larger areas of brain regions than major chords. Some activated areas have not been...
Postural control can be a challenging task for many people, including those with cerebral palsy or idiopathic scoliosis. Assessment of postural stability can be used as one element of a comprehensive strategy to identify more efficient treatments and can provide a better understanding of postural control deficits. Several models and techniques have been developed to assess and understand postural...
This paper aims to investigate how robotic devices can be used to understand the mechanism of sensorimotor adaptation in pediatric subjects affected by hemiparetic cerebral palsy. Previous studies showed how healthy adults, after training in presence of a systematic structured disturbing force field, show an “after effect” and therefore they highly adapt and compensate the external disturbance. An...
The increased volume of 3D neuroimaging data has created a need for efficient data management and retrieval. We suggest that image retrieval via robust volumetric features could benefit managing these large image datasets. In this paper, we introduce a new feature extraction method, based on disorder-oriented masks, that uses the volumetric spatial distribution patterns in 3D physiological parametric...
Gait analysis is important in diagnosing and evaluating certain neurological diseases such as Parkinson's disease (PD). In this paper, we show the ability of our wireless inertial sensor system to characterize gait abnormalities in PD. We obtain physical features of pitch, roll, and yaw rotations of the foot during walking, use principal component analysis (PCA) to select features, and use the support...
F-wave persistence is a frequently reported parameter for nerve conduction studies. F-wave activities are generated through backfiring of motor neurons. F-wave persistence is designed to estimate the backfiring rate. Through computational models and probability analyses, we demonstrated that the F-wave persistence definition is deficient in providing a robust and consistent estimate of the backfiring...
This paper develops a method to determine the minimum duration interval which ensures that the process of “sorting” the extracellular action potentials recorded during that interval achieves a desired confidence level of accuracy. During the recording process, a sequential decision theory approach continually evaluates a variant of the likelihood ratio test using the model evidence of the sorting/clustering...
Heart Rate Variability analysis has been shown in several studies to measure the Autonomic Nervous System tone, which is strongly influenced by pain, stress or anxiety. We have previously described and developed an Analgesia/Nociception Index for pain measurement during surgical procedure. This index based on a heart rate variability analysis can be considered as a vagal tone index and used in several...
It is widely accepted and can be easily verified that any specific voxel in a class of brain single photon emission computed tomography (SPECT) volumes is of a univariate normal distribution. In this research, we conjecture that all the voxels in a class of SPECT volumes are also approximately of a multivariate normal (MVN) distribution from which in terms of the Bayes errors of statistics, an optimal...
This paper presents a new methodology of feature extraction of sleep and wake stages of a freely behaving rat based on Continuous Wavelet Transform (CWT). The automatic separation of those stages is very useful for experiments related to learning and memory consolidation since recent scientific evidence indicates that sleep is strongly involved with offline reprocessing of acquired information during...
Movement-related changes such as event-related desynchronizationcan (ERD) and event-related synchronization (ERS) can be found in human subthalamic nucleus (STN) with analysis on local field potentials (LFP) recorded from Parkinson's disease (PD) patients. Besides traditional time-frequency (TF) analysis, we introduced nonlinear analysis, bispectral and approximate entropy (ApEn), to measure the signal...
In recent years Microelectrode recording (MER) analysis has proved to be a powerful localization tool of basal ganglia for Parkinson disease's treatment, especially the Subthalamic Nucleus (STN). In this paper, a signal-dependent method is presented for identification of the STN and other brain zones in Parkinsonian patients. The proposed method, refereed as optimal wavelet feature extraction method...
Threshold problems in electric stimulation of nerve and muscle fibers have been studied from a theoretical standpoint using the excitation functional. Here the excitation functional is extended to magnetic stimulation of excitable nerve and muscle fibers. A unified derivation of the functional is done, for (non myelinated) nerve and muscle fibers, by means of the nonlinear cable equation with a Fitzhugh-Nagumo...
An analog spike detector circuit is presented, which adaptively generates a threshold level for spike detection based on hard-thresholding. Operation of the circuit was tested not only with a neural signal obtained from real in-vivo recording from a live animal, but also with a large sinusoidal baseline variation intentionally added to examine the capability of the circuit to track baseline variations...
Laser speckle contrast imaging (LSCI) has classically been used to image regional blood flow changes in animal models. In this paper, we demonstrate the use of LSCI for elucidating blood flow characteristics in individual microvessels with diameters as small as 24μm. We extracted profiles of speckle contrast values within individual vessels, both along their diameters and along their lengths and inferred...
This study demonstrates that the spiking and local field potential (LFP) activity in the parietal reach region (PRR) of the macaque monkey can be jointly used to control the location of the computer cursor when the correct target location must be inferred symbolically, e.g., leftward arrow for the leftward target, etc. The average correct target acquisition rate during this brain machine control task...
Mechanical impedance is a complex number and a system's property. Impedance of human arm is the control variable when the central nervous system coordinates a motion. This research proposes a new method for measuring the mechanical impedance as a complex number. Impedance is measured at the hand point while sinusoidal perturbation is applied. That helps extracting the real and imaginary part of the...
Within the framework of multibody dynamics, a 3D large scale neuromusculoskeletal model of the human body is presented. To characterize the dynamics of skeletal muscle, a phenomenological model of energy expenditure was developed for estimating energy consumption during normal locomotion. Such model is able for predicting thermal and mechanical energy liberation under submaximal activation, muscle...
In the past decade the field of neural interface systems has enjoyed an increase in attention from the scientific community and the general public, in part due to the enormous potential that such systems have to increase the quality of life for paralyzed patients. While significant progress has been made, serious challenges remain to be addressed from both biological and engineering perspectives....
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