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Comparison of cerebrovascular reactivity tests: a pilot human study

; session 2, n=10) ( Table 1 ). The tests used to induce CBF AR were breath-holding (BH), hyperventilation (HV), CO 2 inhalation (CO 2) , Valsalva maneuver (VAL), Trendelenburg position (TREN), reverse Trendelenburg (R TREN) position. For all fourteen subjects, modalities recorded were fronto-temporal REG; near infrared spectroscopy (NIRS) on head and leg; electrocardiogram; respiratory volume and pressure; exhaled CO 2 level during respiratory tests; forehead skin blood flow by laser Doppler flow (LDF); and peripheral bio-impedance pulses. For ten of the subjects

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An efficient and automatic ECG arrhythmia diagnosis system using DWT and HOS features and entropy- based feature selection procedure

extraction converts the ECG signal to a collection of features and the feature extraction techniques are classified to frequency, temporal and time–frequency methods. Temporal methods do not provide good distinction because the variations in the amplitude and duration in the electrocardiogram signal are subtle [ 7 ]. Also, the frequency techniques are not appropriate for analyzing ECG data, because these techniques cannot obtain the temporal information of signals. Therefore, an appropriate time–frequency method could be the best option. The wavelet transform (WT) is the

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A system to monitor segmental intracellular, interstitial, and intravascular volume and circulatory changes during acute hemodialysis

in the body and may be a valuable aid in clinical diagnosis and research. Two different types of bioelectric impedance instruments are available. Fixed frequency bioelectrical impedance plethysmographic (IPG) techniques are valuable noninvasive tools that provide information about overall segmental volumes, blood flows, and hemodynamic status with a high degree of temporal resolution [ 9 , 10 , 11 , 12 ]. The second type, electrical bioimpedance spectroscopy (BIS) [ 13 , 14 ] is a multifrequency technique that, when coupled with computeraided equivalent

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Monitoring thoracic fluid content using bioelectrical impedance spectroscopy and Cole modeling

inflatable leg sleeves each with 12 overlapping airchambers ( Figure 1 ). Both leg sleeves are inflated in parallel: the chambers are inflated individually in temporal succession starting from the foot to the upper leg (distal to proximal). Inflation ends when the pressure in each air chamber has reached a predefined target value. In our study, the chamber pressure was distributed with a spatial gradient along the leg, such that at the end of an inflation cycle the pressure reached 100 mmHg in the four most distal chambers, 80 mmHg in the four intermediate chambers, and 60

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Recognition of lung volume condition based on phase space mapping using electrical impedance tomography

tenets of the Helsinki Declaration, and has been approved by the authors’ institutional review board or equivalent committee. Results As mentioned before, the temporal data of volume signals cannot be well differentiated by the arrival of lung volume to the desired state. In this paper, the idea of applying the nonlinear method and converting the lung volume signal into phase space maps was presented. Figures 4 and 5 delineate the phase space mapping of a suitable and an unsuitable Global Signal respectively. As it can be observed, no information can be

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Application of genetic algorithm in extracting cell dielectric characteristics with electrorotation

theory due to its capacity for quick adaptation to the problem and faster convergence without requiring derivative information. Theory Inhomogeneous particle modeling Living particles like cells are heterogeneous and a multi shell model could take their heterogeneous structures into account 13 . In order to describe non-spherical shells and the plasma membrane dielectric anisotropy, the extended form of this model has been used [ 14 , 15 ]. Maxwell–Wagner polarizations will occur where the various shells join. The temporal dynamics and degrees of these diverse

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Spatial resolution in electrical impedance tomography: A topical review

approached in EIT systems, dynamic imaging and static imaging. In dynamic imaging (with a focus on temporal resolution), boundary voltages are measured at different time intervals, and the first data at initial time (t 1 ) is treated as the reference data set for another data set measured at a second time (t 2 ). By back projecting the difference an image is reconstructed [ 31 ]. In static images (spatial resolution), the absolute values of a cross-sectional resistivity distribution are reconstructed from voltage measurements, which is a function of an unknown resistivity

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Possibilities in the application of machine learning on bioimpedance time-series

temporal information from continuous measurements over time might not be fully utilized by conventional methods. In addition to organ ischemia, examples of a few other bioimpedance applications where this method could be relevant is cell culture monitoring (21), wound healing (22), meat quality assessment (23), needle guidance (24) and analysis of periodical bioimpedance signals related to respiration (25) or pulsation (26) or their morphology. While the example in this study has been on a regression problem, this method is easy to convert into a classification problem

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The feasibility of using compression bioimpedance measurements to quantify peripheral edema

to the BIS at dry weight. The amount of fluid removed by ultrafiltration during the session gives us a conversion factor to relate this asymptotic dry weight BIS to the patient’s actual dry weight a hypothesis we plan to test in future clinical studies. Future laboratory and clinical studies are needed to determine the best approach to improve our understanding of edema and how to best characterize it clinically in order to improve fluid status management and patient outcomes. Conclusions This study has demonstrated a good temporal resolution in the

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