Thoracic impedance change equation deduced on the basis of parallel impedance model and Ohm's law

Xiao, Qiujin; Wang, Zhen; Kuang, Ming-Xing; Wen, Ping; Liu, Pei; Jian-Feng, Ji

doi:10.1118/1.3678987

Cited by 6 publications

(6 citation statements)

References 6 publications

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“…For instance, the O wave amplitudes of RV and LV for 72 patients with cardiac insufficiency are −0.130 ± 0.090 Ω/s and −0.109 ± 0.105 Ω/s, respectively, and they are smaller than that of the adults with normal function (see Table. 3, p < .001). It could be proven theoretically that the impedance change on chest surface caused by blood vessels is larger when the included angle between the blood vessels and human body axis (i.e., electrical current line) is smaller (Qiu-Jin et al, 2012). Conversely, the impedance change caused on the chest surface is smaller when the included angle is larger.…”

Section: Impedance Change Components LV and Rvmentioning

confidence: 99%

Waveform analysis of differential graphs of reconstructed impedance cardiography from healthy individuals

Wang

Kuang

et al. 2019

Noninvasive Electrocardiol

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Purpose The aim is to measure and analyze the wave amplitudes and time intervals of differential graphs of reconstructed impedance cardiography (RICG). Methods 180 adults with normal cardiac function between the ages of 18–78 were included in the study. Six mingled impedance changes on chest surface were simultaneously detected for each subject. The differential graphs of five impedance change components of RICG were obtained through waveform separation and software differentiation. The amplitudes of C, X, O, b waves and time intervals of Q‐b and Q‐C were measured and statistically analyzed. Results The amplitudes of C and X waves in PL, PR, AO, and that of C, O, b waves in LV and RV, all decrease as age increases. Wave amplitudes of the female group were bigger than those of the male group (p < .01), while the Q‐C intervals of the female group were shorter than that of the male group (p < .01). Among five impedance change components, the wave amplitude of AO was larger than those of PL and PR (p < .01), and wave amplitudes of PL and PR were bigger than those of LV and RV (p < .01). Q‐C intervals of LV and RV were longer than those of AO, PL and PR (p < .01), while the Q‐b intervals of LV and RV were shorter than the Q‐C intervals of AO, PL, and PR. Conclusions The differential graphs of RICG could reflect indirectly the physiological activities and pathological changes of the heart and of the large blood vessels in thorax.

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Section: Impedance Change Components LV and Rvmentioning

confidence: 99%

Waveform analysis of differential graphs of reconstructed impedance cardiography from healthy individuals

Wang

Kuang

et al. 2019

Noninvasive Electrocardiol

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“…Suppose that ρ t and j t are the average resistivity and current density of the thoracic tissue, respectively. The blood current density j b can be expressed as j b =ρ t j t /ρ b [8] . Substituting it into equation (5-2) yields…”

Section: Relation Between the Thoracic Impedance Change And Chest Cirmentioning

confidence: 99%

“…According to Sramek's formula [6] , the distance L between two voltage electrodes (E 1 , E 2 ) on the chest surface can be approximately expressed as L=0.168H (H is the body height). Substituting it into the equation (5)(6)(7)(8)…”

Section: Relation Between the Thoracic Impedance Change And Chest Cirmentioning

confidence: 99%

“…This is a equation of the thoracic impedance change including the chest circumference [8] . The equation (5)(6)(7)(8)(9) shows that the thoracic impedance change (ΔZ) is directly proportional to the volume change ΔV of the blood vessel, and to the ratio (Z 0 /H)of the basal impedance to the body height, while it is inversely proportional to the square of the chest circumference (C 2 t ).…”

Section: Relation Between the Thoracic Impedance Change And Chest Cirmentioning

confidence: 99%

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Measurement Method and Principle for Thoracic Impedance Graph

Zhao

Kuang

et al. 2017

MATEC Web Conf.

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Thoracic impedance graph is an impedance change curve measured on the surface of the human chest. It reflects indirectly the volume change of the heart and large vessels in the thorax, and it includes rich information about physiological activities and pathological changes. Thoracic impedance graph is measured using the fourelectrode method in this article. Thoracic impedance change is transformed to the voltage change by means of the high frequency current I0, with a constant root-mean-square (rms) current. The voltage change which is directly proportional to thoracic impedance change can be obtained through the amplification, detection and calibration. The direct proportional relationship between the thoracic impedance change and volume change of the blood vessels is deduced by means of the thoracic parallel impedance model.

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“…In another paper from that group [8] they proposed new equation based on a parallel impedance model different from Nyboer's equation is deduced. It was verified with the experiments in 100 healthy adults.…”

Section: The Modelmentioning

confidence: 99%

Impedance cardiography: Recent advancements

Cybulski

Strasz²,

Niewiadomski³

et al. 2012

Cardiol J

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Thoracic impedance change equation deduced on the basis of parallel impedance model and Ohm's law

Abstract: The equation proposed in the present paper is coincident with the actual condition in the measurement of the ICG.

Cited by 6 publications

References 6 publications

Waveform analysis of differential graphs of reconstructed impedance cardiography from healthy individuals

Waveform analysis of differential graphs of reconstructed impedance cardiography from healthy individuals

Measurement Method and Principle for Thoracic Impedance Graph

Impedance cardiography: Recent advancements

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