Comparison of bipolar vs. tripolar concentric ring electrode Laplacian estimates

Abstract

Potentials on the body surface from the heart are of a spatial and temporal function. The 12-lead electrocardiogram (ECG) provides useful global temporal assessment, but it yields limited spatial information due to the smoothing effect caused by the volume conductor. The smoothing complicates identification of multiple simultaneous bioelectrical events. In an attempt to circumvent the smoothing problem, some researchers used a five-point method (FPM) to numerically estimate the analytical solution of the Laplacian with an array of monopolar electrodes. The FPM is generalized to develop a bi-polar concentric ring electrode system. We have developed a new Laplacian ECG sensor, a trielectrode sensor, based on a nine-point method (NPM) numerical approximation of the analytical Laplacian. For a comparison, the NPM, FPM and compact NPM were calculated over a 400 x 400 mesh with 1/400 spacing. Tri and bi-electrode sensors were also simulated and their Laplacian estimates were compared against the analytical Laplacian. We found that tri-electrode sensors have a much-improved accuracy with significantly less relative and maximum errors in estimating the Laplacian operator. Apart from the higher accuracy, our new electrode configuration will allow better localization of the electrical activity of the heart than bi-electrode configurations.

Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology

“…On the other hand, one of the main limitations of surface bioelectric recording by means of conventional disc electrodes is the poor spatial resolution, mainly originating from the blurring effect due to different conductivities of the body volume conductor [ 23 , 24 ]. To overcome this limitation, surface Laplacian potential records have been proposed [ 25 ].…”

“…To overcome this limitation, surface Laplacian potential records have been proposed [ 25 ]. Literature has confirmed that Laplacian records are able to mitigate this effect and provide enhanced spatial resolution surface potential recordings—i.e., they are able to improve the detection of the bioelectric dipole sources closest to the recording electrodes, rejecting the contribution of distant bioelectric dipole sources—when compared to bipolar records made with disk electrodes [ 24 ]. First, surface Laplacian potentials were estimated using monopolar disc electrodes and applying discretization techniques [ 26 , 27 , 28 ].…”

A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves

“…The non-invasive recording of electrophysiological signals is commonly used in several fields of applied medicine, such as electrocardiography, electroencephalography and electromyography of many other organs and muscles. Although these recordings are usually made with conventional disc electrodes, these yield poor spatial resolution, caused in part by the blurring effect of the different conductivities of the volume conductor [ 1 , 2 ].…”

“…The tripolar recording configuration is more spatially sensitive with a smaller amplitude than the bipolar. When signal amplitude is more important than spatial specificity, then the bipolar configuration appears superior [ 2 , 8 ]. Regarding electrode dimensions, it is known that the larger the electrode the wider the recording area, the deeper the sources that can be sensed and the higher the signal amplitude, but also the poorer the spatial selectivity [ 8 ].…”

Development of the Triple Ring Body Surface Laplacian Sensor and its Experimental Study

“…The space between the electrode elements is insulated and the radial distance between the insulated areas is equal. Suppose the center plate is a dot and the radius of the two concentric rings are r and 2r separately, the surface Laplacian of the sensor is [6] ) ) , 2 ( 2 . SIGNAL CONDITIONING…”