RESUMO
This paper presents a multipole analysis of the QRS complex of the normal magnetocardiogram (MCG) of six normal subjects. The multipole strengths up to the octupole term were determined from the measured distribution of the z-component of the cardiac magnetic field (the component perpendicular to the frontal plane). This equivalent magnetic multipole generator was found to represent the cardiac magnetic field with a minimum error of less than 10%. The dipolar term of the expansion was found to represent the field distribution with reasonable accuracy early during ventricular activation, whereas late during activation, the higher multipole terms were clearly more significant.
Assuntos
Cardiologia/métodos , Magnetismo , Humanos , Matemática , Fatores de Tempo , VetorcardiografiaRESUMO
This paper presents a morphological study of the real-time magnetocardiogram (MCG) of normal subjects. The MCGs were obtained using a gradiometric measurement technique, and the magnetic field component perpendicular to the frontal plane (z-compenent) was studied. Forty-one healthy men and women were mapped from 51 positions on the chest, and the statistics of the waveforms of the MCG were computed. In 21 of the subjects both the MCG and the ECG were analyzed. The general behaviour of the MCGs is discussed and proposals for the standardization of the measurements are made.
Assuntos
Eletrocardiografia/métodos , Magnetismo , Adulto , Eletrocardiografia/instrumentação , Feminino , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Estatística como AssuntoRESUMO
The magnitic determination of pulmonary contamination is based on the remanent magnetization of ferromagnetic contaminating particles. The remanent field of the externally magnetized particles is proportional to their amount and shows their distribution. Although only magnetizable particles are detected with this method, the amount of the inhaled ferromagnetic substance can be used when the total dust exposure of the worker is estimated. In this work five shipyard welders were studied. First the particles disposed to the lungs were externally magnetized and then their distribution was mapped with a sensitive magnetometer. The magnitudes of the remanent fields measured from the welders differed from the fields measured from controls by several orders of magnitude. The radiographic findings showed a good correlation with the magnetic measurements, and further experiments will prove whether this method can partly replace presently used radiological investigations.