3.3 Taxonomy of Biosignals

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Fig. 3.29: Three-Oscillator-Model of the heart with SA, AV and HP nodes according to Figure 3.13 and

Equation 3.28 after [20]: The model includes a delay from the SA node to the AV node by τSA−AV =

0.8 and from the AV node to the HP complex by τAV−HP = 0.1. Before the respective signals arrive at

the control input of the AV node or the HP nodes, they are influenced by the coupling factors kSA−AV

= kAV−AV: = kSAAV−AV = 5 and kAV−HP = kHP−HP:= kAVHP−HP = 20 weighted. The oscillator nodes have

the same internal structure as in the two-oscillator-model comprising only the SA and AV nodes (see

Figure 3.24). The parameters were chosen as in [20], for the SA node: vSA1 = 0.2, vSA2 = −1.9, dSA =

3, eSA = 4.9, fSA = 1, αSA = 3, for the AV node: vAV1 = 0.1, vAV2 = −0.1, dAV = 3, eAV = 3, fAV =

1, αAV = 3 and for the HP-complex: vHP1 = 1, vHP2 = −1, dHP = 3, eHP = 7, fSA = 1, αHP = 5.

2.

evoked¹⁷ signals, i.e. signals excited by external stimuli, such as the Berger-effect

in visual stimulation of the brain.

Thus, in the Berger-effect, the mental and physical state of a test person influences

whether so-called α-wave can arise in the brain or whether these frequency compon-

ents are suppressed by the waking state. If the subject is in physical and mental rest

and has closed his eyes, α-waves in a frequency range of 7 to 10 Hz can be detected in

the brain waves. As soon as the subject opens his eyes, these disappear as an effect of

the visual provocation. The disappearance of the frequency components can therefore

17 from lat. evocare: to call forth, to cause.