The solution for the independence of bioelectric and biomagnetic signals is confirmed.

The theoretical solution for the independence of bioelectric and biomagnetic signals rising from volume sources was published by Jaakko Malmivuo in 1995 [1]. In 2000 his research group published a clinical study on electro- and magnetocardiography which confirmed this result [2, 3]. In 2005 Iwasaki and co-workers published a clinical study on the detection of epileptic foci with electro- and magnetoencephalo-graphy [4].

Cortical potential imaging using L-curve and GCV method to choose the regularisation parameter.

Background: The electroencephalography (EEG) is an attractive and a simple technique to measure the brain activity. It is attractive due its excellent temporal resolution and simple due to its non-invasiveness and sensor design. However, the spatial resolution of EEG is reduced due to the low conducting skull.

European virtual campus for biomedical engineering EVICAB.

European Commission has funded building a curriculum on Biomedical Engineering to the Internet for European universities under the project EVICAB. EVICAB forms a curriculum which will be free access and available free of charge. Therefore, in addition to the European universities, it will be available worldwide.

Measurement of noise and impedance of dry and wet textile electrodes, and textile electrodes with hydrogel.

Textile sensors, when embedded into clothing, can provide new ways of monitoring physiological signals, and improve the usability and comfort of such monitoring systems in the areas of medical, occupational health and sports. However, good electrical and mechanical contact between the electrode and the skin is very important, as it often determines the quality of the signal. This paper introduces a study where the properties of dry textile electrodes, textile electrodes moistened with water, and textile electrodes covered with hydrogel were studied with five different electrode sizes.

Bioelectromagnetism--relative merits of electric and magnetic measurements in cardiac studies.

This lecture gives a general overview to the relationship of bioelectric and biomagnetic phenomena: The most important issue in bioelectromagnetism is: Are the biomagnetic measurements independent on bioelectric ones and do they bring new information from the source or are they only a different modality of the same phenomenon? This issue is discussed with application on cardiac studies. The three orthogonal dipolar magnetic leads (vector magnetocardiography) are equal in the sense of diagnostic performance to the three dipolar electric leads (vector electrocardiography). Therefore the VMCG has quite the same diagnostic performance as the VECG.

Effect of measurement noise and electrode density on the spatial resolution of cortical potential distribution with different resistivity values for the skull.

The purpose of the present theoretical study was to examine the spatial resolution of electroencephalography (EEG) by means of the accuracy of the inverse cortical EEG solution. The study focused on effect of the amount of measurement noise and the number of electrodes on the spatial resolution with different resistivity ratios for the scalp, skull and brain. The results show that if the relative skull resistivity is lower than earlier believed, the spatial resolution of different electrode systems is less sensitive to the measurement noise.

Effect of electrode density and measurement noise on the spatial resolution of cortical potential distribution.

The purpose of the present study was to examine the spatial resolution of electroencephalography (EEG) by means of inverse cortical EEG solution. The main interest was to study how the number of measurement electrodes and the amount of measurement noise affects the spatial resolution. A three-layer spherical head model was used to obtain the source-field relationship of cortical potentials and scalp EEG field.

Effect of skull resistivity on the spatial resolutions of EEG and MEG.

The resistivity values of the different tissues of the head affect the lead fields of electroencephalography (EEG). When the head is modeled with a concentric spherical model, the different resistivity values have no effect on the lead fields of the magnetoencephalography (MEG). Recent publications indicate that the resistivity of the skull is much lower than what was estimated by Rush and Driscoll.