FOCUSED IMPEDANCE METHOD TO DETECT LOCALIZED LUNG VENTILATION DISORDERS IN COMBINATION WITH CONVENTIONAL SPIROMETRY

2015 ◽  
Vol 27 (03) ◽  
pp. 1550029 ◽  
Author(s):  
M. Abdul Kadir ◽  
Tanvir Noor Baig ◽  
K. Siddique-e Rabbani
Keyword(s):  
Electrical Impedance ◽  
Vital Capacity ◽  
Lung Ventilation ◽  
Healthy Male Subject ◽  
The Body ◽  
New Technique ◽  
Impedance Method ◽  
Impedance Change ◽  
Surface Electrodes ◽  
Exhaled Air

Conventional spirometry gives information on the overall ventilation of a person's lung; it cannot detect localized disorders in ventilation as occurring in pulmonary edema, pneumonia, tumor, TB, etc. Here we propose a new technique involving the recently developed focused impedance method (FIM) in combination with conventional spirometry to detect localized lung ventilation disorders. Electrical impedance of lung tissue changes as a function of air content and FIM provides a measurement of localized electrical impedance with sensitivity down to reasonable depths inside the body using a few surface electrodes; here we used a six-electrode version. At least four quadrants of the lungs in the frontal plane can be separately measured using a hand-held probe with spring backed skin surface electrodes. Firstly, spatial sensitivity distribution of the six-electrode FIM was obtained using finite element simulation which verified the focusing effect and its depth sensitivity. Percent change in impedance between maximum inspiration and expiration were measured at four quadrants of the chest of a healthy male subject giving four different values; that at the lower right quadrant was found to be the maximum, as also expected based on anatomy. Changes in impedance at this quadrant of the same subject were found to vary proportionately with exhaled air volumes, measured using a bellows-type spirometer. Similar FIM measurements at lower right lung of seven healthy subjects were found to be almost proportional (R2 = 0.7) to the total exhaled air volumes (vital capacity). This was the basis of the new technique. For a healthy individual, the ratio of the local impedance change to vital capacity (VC) will fall within a certain range for each of the four lung quadrants. A lower value at any quadrant would indicate disorder within that quadrant, while a larger value would indicate disorder in a region outside the particular quadrant. The FIM electrode probe can then be moved to take measurements at the other quadrants to locate the region of disorder. This preliminary study indicates that FIM in combination with conventional spirometry could be used to detect localized ventilation defects.

scholarly journals Probing for stomach using the Focused Impedance Method (FIM)

2019 ◽  
Vol 10 (1) ◽  
pp. 73-82
Author(s):  
Rashida Haque ◽  
Muhammad Abdul Kadir ◽  
K Siddique-e Rabbani
Keyword(s):  
Low Income ◽  
Electrical Impedance ◽  
Impedance Measurement ◽  
The Body ◽  
Low Income Countries ◽  
Impedance Method ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
Sensitivity Equations ◽  
Element Simulation

Abstract For probing deep organs of the body using electrical impedance, the conventional method is to use Electrical Impedance Tomography (EIT). However, this would be a sophisticated machine and will be very expensive when a full 3D EIT is developed in the future. Furthermore, for most low income countries such expensive devices may not deliver the benefits to a large number of people. Therefore, this paper suggests the use of simpler techniques like Tetrapolar Impedance Measurement (TPIM) or Focused Impedance Method (FIM) in probing deeper organs. Following a method suggested earlier by one of the authors, this paper studies the possibility of using TPIM and FIM for the stomach. Using a simplified model of the human trunk with an embedded stomach, a finite element simulation package, COMSOL, was used to obtain transfer impedance values and percentage contribution of the stomach region in the total impedance. For this work, judicious placement of electrodes through qualitative visualizations based on point sensitivity equations and equipotential concepts were made, which showed that reasonable contribution of the stomach region is possible through the use of TPIM and FIM. The contributions were a little over 20% which is of similar order of the cross-sectional area percentage of the stomach with respect to that of the trunk. For the case where the conductivity of the stomach region was assumed about 4 times higher, the contributions increased to about 38%. Through further studies this proposed methods may contribute greatly in the study of deeper organs of the body.

scholarly journals THE EFFECT OF FRAME RATE AND CALIBRATION ON LUNG MONITORING WITH ELECTRICAL IMPEDANCE TOMOGRAPHY

2020 ◽  
Vol 49 (4) ◽  
pp. 107-111
Author(s):  
Kristyna Koldova ◽  
David Slajfercik
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Lung Ventilation ◽  
Analysis Data ◽  
The Body ◽  
Frame Rate ◽  
Impedance Tomography ◽  
Tissue Impedance ◽  
Significance Level ◽  
Rate Analysis

Electrical impedance tomography (EIT) is a non-invasive method that records changes in tissue impedance in the selected cross-section of the body and is mainly used to monitor patient lung ventilation. The aim of this study was to analyze the effect of the set frame rate and how calibration of the EIT system effects final record when monitoring lungs using EIT system PulmoVista 500 (Dräger Medical, Germany). Ten healthy male volunteers were measured with frame rates 10, 20, 30, 40 and 50 Hz for analysis, followed by calibrated and uncalibrated measurements. The subjects were breathing spontaneously in horizontal supine position. In the frame rate analysis, data with the references 30 and 50 Hz were compared with others using a paired T-test. The same test was used for comparing data from a calibrated and uncalibrated records. This study shows that the effect of both frame rate and calibration is negligible at the significance level of 5%.

scholarly journals Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis

2013 ◽  
Vol 39 (6) ◽  
pp. 742-746 ◽  
Author(s):  
Liégina Silveira Marinho ◽  
Nathalia Parente de Sousa ◽  
Carlos Augusto Barbosa da Silveira Barros ◽  
Marcelo Silveira Matias ◽  
Luana Torres Monteiro ◽  
...  
Keyword(s):  
Radionuclide Imaging ◽  
Electrical Impedance ◽  
Imaging Technique ◽  
Lung Ventilation ◽  
Bronchial Stenosis ◽  
Impedance Tomography ◽  
Postural Changes ◽  
Regional Lung ◽  
History Of ◽  
Regional Lung Ventilation

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

scholarly journals Helping students to understand physiological aspects of regional distribution of ventilation in humans: a experience from the electrical impedance tomography

2018 ◽  
Vol 42 (4) ◽  
pp. 655-660
Author(s):  
Marcelo Alcantara Holanda ◽  
Nathalia Parente de Sousa ◽  
Luana Torres Melo ◽  
Liégina Silveira Marinho ◽  
Helder Veras Ribeiro-Filho ◽  
...  
Keyword(s):  
Medical Students ◽  
Electrical Impedance ◽  
Respiratory Mechanics ◽  
Pulmonary Ventilation ◽  
Regional Distribution ◽  
Lung Ventilation ◽  
Respiratory Physiology ◽  
Impedance Tomography ◽  
Lateral Decubitus ◽  
Basic Concepts

Undergraduate biomedical students often have difficulties in understanding basic concepts of respiratory physiology, particularly respiratory mechanics. In this study, we report the use of electrical impedance tomography (EIT) to improve and consolidate the knowledge about physiological aspects of normal regional distribution of ventilation in humans. Initially, we assessed the previous knowledge of a group of medical students ( n = 39) about regional differences in lung ventilation. Thereafter, we recorded the regional distribution of ventilation through surface electrodes on a healthy volunteer adopting four different decubitus positions: supine, prone, and right and left lateral. The recordings clearly showed greater pulmonary ventilation in the dependent lung, mainly in the lateral decubitus. Considering the differences in pulmonary ventilation between right and left lateral decubitus, only 33% of students were able to notice it correctly beforehand. This percentage increased to 84 and 100%, respectively ( P < 0.01), after the results of the ventilation measurements obtained with EIT were examined and discussed. A self-assessment questionnaire showed that students considered the practical activity as an important tool to assist in the understanding of the basic concepts of respiratory mechanics. Experimental demonstration of the physiological variations of regional lung ventilation in volunteers by using EIT is feasible, effective, and stimulating for undergraduate medical students. Therefore, this practical activity may help faculty and students to overcome the challenges in the field of respiratory physiology learning.

scholarly journals Sepakbola: Kapasitas Vital Paru dan Tingkat Kebugaran Jasmani

2020 ◽  
Vol 5 (1) ◽  
pp. 30-39
Author(s):  
Rusmanto ◽  
Rola Angga Lardika ◽  
Novri Gazali
Keyword(s):  
Physical Fitness ◽  
Blood Vessels ◽  
Vital Capacity ◽  
The Body ◽  
Process Data ◽  
Fitness Level ◽  
Physiological Conditions ◽  
The Status ◽  
T Distribution

Lung vital capacity is the status of physiological conditions associated with the ability to treat respiration together with the increasing of physical fitness, so lung vital capacity is a process involving the mechanism of the heart and blood vessels and blood which aims to provide O2 to cells in the body and transport CO2 out of body. The purpose of this study is to determine the correlation between lung vital capacity and the physical fitness level of Pendor Football Athletes from Universitas Riau. The collecting of data in this study is data from lung vital capacity tests and physical fitness with a sample of 20 athletes. Analysis of the data that used to process data is Product Moment correlation. For determining the significance of data, it uses formulation of t distribution. The results that obtained from lung vital capacity have a significant correlation with the level of physical fitness, this is indicated by the results obtained by r count (0622) > r table (α = 0.05) = 0.456. Meanwhile, t distribution test is obtained the result of t count (3,369) > t  table (1,734). So H0 is refused  and Ha is accepted. Thus it can be concluded that there is a significant correlation between the lung vital capacity (x) and the level of physical fitness (y).

In vivo Measurement of Intra- and Extracellular Space of Brain Tissue by Electrical Impedance Method

1990 ◽  
pp. 22-24
Author(s):  
Sadao Suga ◽  
S. Mitani ◽  
Y. Shimamoto ◽  
T. Kawase ◽  
S. Toya ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Extracellular Space ◽  
Electrical Impedance ◽  
Impedance Method ◽  
In Vivo Measurement

Transfer Path Analysis of a Vehicle Subframe: Measurements in Six Degrees of Freedom

1997 ◽  
Author(s):  
Lars Ivarsson
Keyword(s):  
Path Analysis ◽  
Transfer Functions ◽  
The Body ◽  
Impedance Method ◽  
Transfer Path ◽  
Rotational Components ◽  
Improve Measurement ◽  
Engine Mount ◽  
Six Dof ◽  
Transfer Path Analysis

Abstract A Transfer path analysis (TPA) is undertaken for a car subframe concerning six DOF of freedom and two coupling points up to 500 Hz. Integrated stingers have been developed to improve measurement results. The relative importance of the rotational components is investigated. The blocked impedance method has been used to couple the subframe to the car body using measured mobilities via two isolators out of four. The sound sensitivity is measured directly for the coupled system and compared with the total sum of the calculated transfer path components which are calculated with measured mobilities and transfer functions. Calculated and measured results show good agreement. The importance of the rotational paths depends on the characteristics of the isolator and the structures where it is mounted. It was found that the front mount position is more sensitive to rotations compared to the rear mount position. The rear mount position is also a much stiffer construction. It was found that above 220 Hz, the rotational paths are of the same importance as the translational paths when both points were connected to the body frame. It was also found that for the rear mount position, only one translational transfer path dominates. These conclusions do not differ especially for different excitation directions at the engine mount position.

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