The Zero of Potential of the Electric Field Produced by the Heart Beat: The Problem with Reference to Homogeneous Volume Conductors

Bayley, Robert H.; Reynolds, Ernest W.; Kinard, Conrad L.; Head, John F.

doi:10.1161/01.res.2.1.4

Cited by 22 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also report the polarity of the WCT based upon the orientation of the QRS feature present in the signal. Similarly to previous studies [3,4], we noted that with "N" signals, polarity is not clearly positive or negative i.e., the positive deflection amplitude almost matches the negative deflection at the QRS feature. Reported amplitude measurements are averaged across at least five consecutive beats.…”

Section: Methodssupporting

confidence: 88%

“…Empirical confirmation of Frank's hypotheses about the amplitude and variability of the WCT came almost simultaneously when measurements of WCT (requiring the human body to be encased in a metal structure totally submerged in water for the duration of the recording), showed that Wilson's central point is non-stationary during the cardiac cycle and has a large amplitude (up to 40% of Einthoven's ECG signal amplitudes). Details of these results were published by both H.C. Burger and R. Bayley et al [3,4]. However, until now, without a valid alternative, this largely simplified hypothesis still lies at the base of modern clinical practice.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the “Zero of Potential of the Electric Field Produced by the Heart Beat”. A Machine Capable of Estimating this Underlying Persistent Error in Electrocardiography

et al. 2016

View full text Add to dashboard Cite

Modern electrocardiography (ECG) uses a constructed reference potential for the majority of leads. This reference potential, named after its inventor as the Wilson central terminal, is assumed to have negligible value and to be stationary during the cardiac cycle. However, the problem of its variability during the cardiac cycle has been known almost since the inception of 12-lead electrocardiography. Due to the cumbersomeness of the measurement system required to fully appreciate these variations, this topic has received scant research attention during the last 60 years. Taking advantage of modern electronic amplifiers' capability to detect small voltages, drawing only femtoamperes from physiological equivalent signal sources and of the right-leg connection availability, we developed a complete electrocardiography device that, aside from the eight independent signals of the standard 12-lead ECG, allows direct recording of the Wilson central terminal components. In this paper, we present details of the circuit together with its initial clinical evaluation. For this trial, we recorded data from 44 volunteer patients at Campbelltown Hospital (Campbelltown, Australia) and we found that the Wilson central terminal amplitude, as foreseen by Frank and others in the 1950s, is not negligible, its amplitude in relation to the lead II is, on average, 51.2%, and thus it may be clinically relevant.

show abstract

Section: Methodssupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

On the “Zero of Potential of the Electric Field Produced by the Heart Beat”. A Machine Capable of Estimating this Underlying Persistent Error in Electrocardiography

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Confirmation of errors and variability of the WCT during the cardiac cycle have been measured employing an “integrator electrode.” This procedure requires the entire human body to be encased in a metal structure and then immersed in water (neutral reference) during the measurement of ECG. Unfortunately, due to the cumbersomeness of the measurement process, this technique was used only for few experimental trials [ 15 , 16 ]. In recent years, the significance of the WCT and even its physical location has also been debated [ 9 , 10 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

True Unipolar ECG Machine for Wilson Central Terminal Measurements

Gargiulo

2015

BioMed Research International

View full text Add to dashboard Cite

Since its invention (more than 80 years ago), modern electrocardiography has employed a supposedly stable voltage reference (with little variation during the cardiac cycle) for half of the signals. This reference, known by the name of “Wilson Central Terminal” in honor of its inventor, is obtained by averaging the three active limb electrode voltages measured with respect to the return ground electrode. However, concerns have been raised by researchers about problems (biasing and misdiagnosis) associated with the ambiguous value and behavior of this reference voltage, which requires perfect and balanced contact of at least four electrodes to work properly. The Wilson Central Terminal has received scant research attention in the last few decades even though consideration of recent widespread medical practice (limb electrodes are repositioned closer to the torso for resting electrocardiography) has also sparkled concerns about the validity and diagnostic fitness of leads not referred to the Wilson Central Terminal. Using a true unipolar electrocardiography device capable of precisely measuring the Wilson Central Terminal, we show its unpredictable variability during the cardiac cycle and confirm that the integrity of cardinal leads is compromised as well as the Wilson Central Terminal when limb electrodes are placed close to the torso.

show abstract

“…The theory of a zero of potential on the Wilson central terminal depends in part upon the requirement that every electrode which makes a contribution to the terminal has a potential function which is that of an unweighted resultant of the cardiac dipole distribution. 1 This function is in effect that of a point dipole or doublet. 6 The objection concerning the lack of remoteness of electrodes is synonymous with that in which the cardiac distribution of dipoles requires a weighted resultant for the potential function.…”

Section: Discussionmentioning

confidence: 99%

“…N a previous report it was shown that = l id 4vR\ V JJ V. dsi = 0 (1) Wherein V p is the arbitrary-dipole function for the sphere; Si is the spherical surface of a large integrating electrode (fig. 1); and V p , the average value of V p , is independent of the position of the dipole distribution within Si and is zero.…”

mentioning

confidence: 99%

The Zero of Potential of the Electrical Field Produced by the Heart Beat

Bayley

Kinard

1954

Circulation Research

Self Cite

View full text Add to dashboard Cite

The zero of potential of the electrical field produced by the heart beat is defined and measured as the average value over the surface of a large spherical, integrating electrode which contains the subject and a homogeneous conducting medium. The zero of potential thus defined is apparently free of assumptions of any kind and is used to evaluate the error on the three-branch and the fourbranch central terminal with equal resistances. The latter may, in certain instances, be brought to zero by using unequal resistances. The potential function at its electrodes is that of an unweighted resultant vector or a point dipole. The electrodes which contribute to its potential are remote Wherein V p is the arbitrary-dipole function for the sphere; Si is the spherical surface of a large integrating electrode (fig. 1); and V p , the average value of V p , is independent of the position of the dipole distribution within Si and is zero. Si has a radius of three feet and consists of a copper screen held in the form of a spherical surface by an exterior wood frame. An electrical hoist lowers Si into a tank containing tap water. The dipole distribution consisted of a six-pole generating electrode by which one, two, or three electromotive forces were impressed upon the volume conductor and by which the field axis was rotated in three or more noncoplanar directions. The surface Si contained several nonhomogeneous structures, From the Department of Internal Medicine, University of Oklahoma School of Medicine, Oklahoma City, Okla.Presented in part at the Twenty-Fourth Annual Postgraduate Symposium of the San Francisco Heart Association, Oct. 28, 1953. These investigations were supported by grants from the National Heart Institute of the Xational Institutes of Health, Public Health Service.Received for publication July 2S, 1953. the seat suspension, breathing tubes, face mask, contact microphones, and wire leads. Equation 1 is based on the assumption that the conducting medium within Si is homogeneous and that Ri the radius of Si, is of any value that permits Si to contain the dipole distribution. The magnitude of Ri for Si was based, however, on the idea of placing the living human subject interior to Si, figure 1. Upon immersion the potential Vo of Si must assume a value sufficiently close to the zero of the potential of the field produced by the heart beat to permit accurate evaluation of the potential at electrodes on the body surface, particularly those electrodes which are utilized with a central terminal of the Wilson type.The living human subject is a nonhomogeneous volume conductor of irregular closed surface S 2 which contains an arbitrary dipole distribution. Upon immersion a homogeneous medium (tap water) exists between the body surface S 2 and the surface »Si of the spherical integrating electrode. The field of the heart beat now extends throughout the conducting medium exterior to Si. A Helmholtz double-layer on S 2 when acting alone will produce an electrical field between Si and S 2 identical to that which is act...

show abstract

The Zero of Potential of the Electric Field Produced by the Heart Beat: The Problem with Reference to Homogeneous Volume Conductors

Cited by 22 publications

References 12 publications

On the “Zero of Potential of the Electric Field Produced by the Heart Beat”. A Machine Capable of Estimating this Underlying Persistent Error in Electrocardiography

On the “Zero of Potential of the Electric Field Produced by the Heart Beat”. A Machine Capable of Estimating this Underlying Persistent Error in Electrocardiography

True Unipolar ECG Machine for Wilson Central Terminal Measurements

The Zero of Potential of the Electrical Field Produced by the Heart Beat

Contact Info

Product

Resources

About