Pseudo current density maps of electrophysiological heart, nerve or brain function and their physical basis

Wolfgang Haberkorn,Hans Koch,Uwe Steinhoff,Andreas Morguet,Martin Burghoff,Olaf Kosch

doi:10.1186/1477-044x-4-5

Abstract

BackgroundIn recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular.MethodsThe physical basis of these intuitive maps is clarified by means of analytically solvable problems.ResultsExamples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method.ConclusionHardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.

Highlights

In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular
In 1976 Cohen et al introduced in a sequence of publications a method to construct so-called pseudo current density- or arrow-maps from multichannel biomagnetic signals obtained by magnetocardiography (MCG) [1,2,3,4]
Construction of pseudo current density maps PCD-maps are obtained from magnetic field values at a number of points in space [29,30]

Summary

Introduction

In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular. The purpose was to transform the measured magnetic field values in a way that the resulting maps could be more related to the underlying current density distribution. Later this method was frequently referred to as the Hosaka-Cohen (HC) transformation and its performance was analyzed in some detail [5,6]. It did not find widespread application until recent years, when a kind of renaissance of this method occurred. For the end-user the physicians- MFMs are not very instructive, as the MFM maximum values do not occur above those positions where the generating currents are flowing

Methods

Results

Discussion

Conclusion