The use of Cole-Cole plots to compare two multi-frequencybioimpedance instruments

Stroud, Daniel B.; Cornish, Bruce; Thomas, B.J.; Ward, Leigh C.

doi:10.1016/s0261-5614(95)80069-7

“…The SEAC software allowed the impedance spectrum fit according to the Cole model (semicircular locus in the R-Xc plane with suppressed center). The impedance semicircle was fitted according to nonlinear least squares fitting procedures (root mean square error of predicted vs. observed Xc, as an indicator of goodness of fit) [14,15,24]. One operator (M.G.)…”

Section: Bioimpedance Data Analysismentioning

confidence: 99%

Equivalence of information from single versus multiple frequency bioimpedance vector analysis in hemodialysis

Piccoli¹,

Pastori²,

Guizzo³

et al. 2005

Kidney International

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“…While these factors will similarly afAt the start of the testing period, each fect the reliability of MFBIA, the electronic SFB2 monitor was calibrated by one of three complexity of measuring both impedance operators according to the manufacturer inand phase over a range of frequencies may structions using a calibration box supplied adversely affect technical errors of measure-with the monitor. The calibration procedure ment (Chumlea et al, 1994; van Marken involved recording a data set of impedance Lichtenbelt et al, 1994a;Stroud et al, 1995). for each of 11 precision (0.1% tolerance) re-…”

mentioning

confidence: 99%

“…The electronic reliability of the instruments was assessed by comparison of the measured impedance parameters with the theoretically calculated where Z ϱ ϭ R i R e R i ϩ R e and T ϭ 2f (R e ϩ R i ) C values for each of the five test circuits (Stroud et al, 1995). For these analyses, The value of R i can be determined from the data for all frequencies were included and estimates of Z 0 and Z ϱ using Equation 4. no data were rejected.…”

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confidence: 99%

“…These values are independent of the Colebest fit of the data to the semicircular locus (Stroud et al, 1995). The choice of parame-Cole fitting procedure.…”

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confidence: 99%

“…While it may be generally considimpedances of such low magnitude are not observed for the whole body, impedance val-ered bad practice to exclude measured data from subsequent analysis, it is appropriate ues for body segments of a large cross-sectional area, such as the trunk, may be of the in this case to reject data obtained at high (Ͼ650 kHz) or low (Ͻ10 kHz) frequencies order of 50 ohms or less (Fuller and Elia, 1989). The decreased accuracy in extracting (Stroud et al, 1995), since these frequencies are subject to practical difficulties of mea-Z ϱ may be a result of substantial extrapolation beyond the range of measured data (4-surement. The present procedure allowing the operator to choose data rejection param-1,000 kHz).…”

mentioning

confidence: 99%

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Reliability of multiple frequency bioelectrical impedance analysis: An intermachine comparison

Ward

¹

,

Byrne

²

,

Rutter

³

et al. 1997

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The technical reliability (i.e., interinstrument and interoperator reliability) of three SEAC‐swept frequency bioimpedance monitors was assessed for both errors of measurement and associated analyses. In addition, intraoperator and intrainstrument variability was evaluated for repeat measures over a 4‐hour period. The measured impedance values from a range of resistance‐capacitance circuits were accurate to within 3% of theoretical values over a range of 50–800 ohms. Similarly, phase was measured over the range 1°–19° with a maximum deviation of 1.3° from the theoretical value. The extrapolated impedance at zero frequency was equally well determined (±3%). However, the accuracy of the extrapolated value at infinite frequency was decreased, particularly at impedances below 50 ohms (approaching the lower limit of the measurement range of the instrument). The interinstrument/operator variation for whole body measurements were recorded on human volunteers with biases of less than ±1% for measured impedance values and less than 3% for phase. The variation in the extrapolated values of impedance at zero and infinite frequencies included variations due to operator choice of the analysis parameters but was still less than ±0.5%. Am. J. Hum. Biol. 9:63–72 © 1997 Wiley‐Liss, Inc.

show abstract

Reliability of multiple frequency bioelectrical impedance analysis: An intermachine comparison

Ward¹,

Byrne²,

Rutter³

et al. 1997

View full text Add to dashboard Cite

The technical reliability (i.e., interinstrument and interoperator reliability) of three SEAC‐swept frequency bioimpedance monitors was assessed for both errors of measurement and associated analyses. In addition, intraoperator and intrainstrument variability was evaluated for repeat measures over a 4‐hour period. The measured impedance values from a range of resistance‐capacitance circuits were accurate to within 3% of theoretical values over a range of 50–800 ohms. Similarly, phase was measured over the range 1°–19° with a maximum deviation of 1.3° from the theoretical value. The extrapolated impedance at zero frequency was equally well determined (±3%). However, the accuracy of the extrapolated value at infinite frequency was decreased, particularly at impedances below 50 ohms (approaching the lower limit of the measurement range of the instrument). The interinstrument/operator variation for whole body measurements were recorded on human volunteers with biases of less than ±1% for measured impedance values and less than 3% for phase. The variation in the extrapolated values of impedance at zero and infinite frequencies included variations due to operator choice of the analysis parameters but was still less than ±0.5%. Am. J. Hum. Biol. 9:63–72 © 1997 Wiley‐Liss, Inc.

show abstract

The use of Cole-Cole plots to compare two multi-frequencybioimpedance instruments

Cited by 31 publications

References 8 publications

Equivalence of information from single versus multiple frequency bioimpedance vector analysis in hemodialysis

Equivalence of information from single versus multiple frequency bioimpedance vector analysis in hemodialysis

Reliability of multiple frequency bioelectrical impedance analysis: An intermachine comparison

Reliability of multiple frequency bioelectrical impedance analysis: An intermachine comparison

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