In Vivo and In Situ Ischemic Tissue Characterization Using Electrical Impedance Spectroscopya

Casas, Óscar; Bragós, Ramon; Riu, Pere J.; Rosell, J.; Tresànchez, Màrius; Warren, Mark; Rodríguez‐Sinovas, Antonio; Carreño, Ana; Cinca, Joan

doi:10.1111/j.1749-6632.1999.tb09448.x

Cited by 98 publications

(75 citation statements)

References 6 publications

(4 reference statements)

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“…This is alleviated in the pulsatile curve in which, although there still has a extension to negative part of imaginary axis at high frequency, it can be regarded as extrapolation of the Cole-Cole curve without affecting Cole parameters' fitting accuracy. During curve fitting, by using pulse curve, we don't need to adopt additional inductive component (ECFC model [9]) or multiple Cole systems [5][10] due to tissue heterogeneity. A simple 1 st order Cole-Cole model is sufficient (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…3. Of the Cole-Cole parameters obtained above, R 0 and R ∞ are geometry-related which are sensitive to body segment dimension changes, electrode movement, and blood pressure changes, etc; f c is relatively stable against body segment geometrical variations; α is insensitive to tissue property variation [5]; Therefore, f c is a good candidate for characterizing blood bioimpedance properties. (R 0 , R ∞ and the ratio R 0 /R ∞ are also helpful with careful calibrations)…”

Section: Figurementioning

confidence: 99%

“…e.g. in [5], normal and ischemic tissues are differentiated by comparing r 0 and f c . in [6], Zhao et al calculated plasma resistance, intracellular resistance and cell membrane capacitance of blood using three measuring frequencies.…”

Section: Introductionmentioning

confidence: 99%

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Blood Impedance Characterization from Pulsatile Measurements

Dai

Adler

2006

2006 Canadian Conference on Electrical and Computer Engineering

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Section: Discussionmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

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Blood Impedance Characterization from Pulsatile Measurements

Dai

Adler

2006

2006 Canadian Conference on Electrical and Computer Engineering

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“…HL-1 cardiac myocytes, an atrial-derived mouse cardiomyocyte cell line obtained from Dr. W. C. Claycomb, were cultured at 37°C, under a 5% CO 2 atmosphere, in Claycomb medium supplemented with 10% FBS (JRH Biosciences), 4 mM L-glutamine, 100 U/ml penicillin, 100 g/ml streptomycin (all from GIBCO), and 100 M norepinephrine (Sigma). Cells were seeded at a 20,000 cells/cm 2 density in a culture flask precoated with 25 g/ml fibronectin-0.02% gelatin solution until a 70 -80% confluence was achieved, as previously described (3).…”

Section: Hl-1 Cardiomyocytes and Freshly Isolated Rat Cardiomyocytesmentioning

confidence: 99%

Protective effect of gap junction uncouplers given during hypoxia against reoxygenation injury in isolated rat hearts

Rodríguez‐Sinovas

Garcı́a-Dorado²,

Ruiz‐Meana³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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“…We are concentrating our notice on thermographic methods [1,2,3] and on electroimpedance measurement instrumentation [4]. Those are non-invasive and safe methods, developed also in other laboratories [5,6,7,8,9]. But even in vitro and in vivo experiments on human tissues show high practical importance of the methods still reliable reference data are necessary for proving validity of those techniques.…”

Section: Introductionmentioning

confidence: 99%

Thermographic and electrical measurements for cardiac surgery inspection

Nowakowski

Kaczmarek

Wtorek

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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-The aim of the paper is to analyze validity of new methods applicable for cardiac surgery intra-operation inspection. In vivo measurements on pigs using passive and active thermography as well as electroimpedance spectroscopy applied to investigation of the heart tissue properties during open chest cardiac surgery are related. The measurement results clearly show that each of proposed modalities is giving different information valuable for evaluation of the heart muscle biological properties. This information may have very high importance in terms of intra-operation inspection as well as for decisions of proper medical interventions. Series of cardiac operations on anaesthetized pigs involving controlled heart infarct followed by extensive histopathologic study allowed to made objective evaluation of the value of the discussed methods. Keywords -Thermography, bio-electroimpedance spectroscopy, heart inspection, cardio-surgery I. INTRODUCTIONOne of the main goals of using modern technology for inspection of open-heart surgery is to decrease the number of post-operation complications and mortality. We are concentrating our notice on thermographic methods [1,2,3] and on electroimpedance measurement instrumentation [4]. Those are non-invasive and safe methods, developed also in other laboratories [5,6,7,8,9]. But even in vitro and in vivo experiments on human tissues show high practical importance of the methods still reliable reference data are necessary for proving validity of those techniques. Here we discuss some in vivo experiments on domestic pigs followed by full histopathologic study of inspected hearts to compare the measured data with the reliable knowledge of the state of a tested heart muscle. II. METHODOLOGYThere is no other animal having the heart and the circulation system so close to the human than domestic swine. Experiments on pigs were carried out according to the permission of the Local Committee for Ethics and Good Practice. Experiments on 5 pigs of average weight 32±3 kilograms are here reported. Blood pressure, heart rate, body temperature, and heart temperature of a tested pig were measured simultaneously. The pigs were intubated after induction. Then, Fentanyl and NO continued the anesthesia. The thorax cavity was opened using the sternum approach as it is shown in Fig.1. Two parts of the pericardium were opened out. By clamping the left descending artery (LAD) the myocardial infarction was induced. The artery was clamped in the proximity of the first diagonal artery as it is shown in Fig. 2a. The infarction zone around the left ventricle wall, shown in the cross-section - Fig. 2b, was examined over a period of about four hours after which the pigs died, usually as a result of arrhythmia. The effect of the infarct on the tissue structure was examined basing on micro-histopathologic investigation as it is shown in Fig. 3. The destroyed tissue is from the left ventricle wall -this region may be seen on the left bottom side in Fig. 2b. THERMOGRAPHIC AND ELECTRICAL MEASUREMENTS FOR CA...

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In Vivo and In Situ Ischemic Tissue Characterization Using Electrical Impedance Spectroscopy^a

Cited by 98 publications

References 6 publications

Blood Impedance Characterization from Pulsatile Measurements

Blood Impedance Characterization from Pulsatile Measurements

Protective effect of gap junction uncouplers given during hypoxia against reoxygenation injury in isolated rat hearts

Thermographic and electrical measurements for cardiac surgery inspection

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