**Abstract.** The aim of this work is the analysis of the error of the electrical potential
calculation on the surface of the conductive cylinder, excited by surface
source inside the cylinder. The necessity îf this comparison is connected with
the solution of the inverse problem of electrocardiography − the task of
reconstruction of the source by ECG signals created by this source and recorded
at the points of electrodes placement on the body surface. As in basis of the
solution of the inverse problem is the direct calculation of surface
potentials, it is important to estimate the error of the calculation of the
potentials, associated with the discretization of the surface of equivalent electrical
source distribution. In this paper we considered the error of calculation of potentials
on the surface of the conductive cylinder with finite length excited by a distribution
of potential and its normal derivative on the inner spherical surface (a spherical
model of quasi-epicardium in ECG). As a model source producing surface potentials
we used dipole located inside the sphere of the epicardium. The electric
potential on the torso surface was calculated by the boundary element method, in
this case we compared the contribution to the error of calculation, which
yields the integration of the potential, its normal derivative on the surface
of the spherical epicardium and the integration of the potential on the
cylindrical torso surface. The impacts of the number of segmentations, type of
source and shape of the cylinder on the error of potentials calculation were analyzed.

**
Key words:** electrocardiography, electric potentials,
model of torso,
quasi-epicardium, surface sources, surface integrals.

## References

1.
Titomir L.I., Kneppo P*. Matematicheskoe modelirovanie bioelektricheskogo
generatora serdca.* [Mathematical modeling of heart's bioelectric
generator]. Moscow, Nauka
Publ. 1999. 447 p. (In Russian)

2.
Titomir L.I. *Elektricheskij generator serdca.* [Electric Heart
generator]. Moscow, Nauka
Publ. 1980. 372 p. (In Russian)

3. Rudy
Y., Messinger-Rapport B.J. The inverse problem in electrocardiography: Solutions
in terms of epicardial potentials. *CRC Crit. Rev. Biomed. Eng*. 1988, No. 16, pp. 216-268

4.
Strelkov N. O., Kramm M.N., Zhikhareva G.V., Inhomogeneous electrodynamic model
of human chest in the form of an elliptical cylinder. *Zhurnal Radioelektroniki - Journal of Radio
Electronics, *2011, Vol. 16, No. 7.* *Available at
http://jre.cplire.ru/jre/jul11/4/text.pdf. (In Russian)

5. Brebbia C., Telles J., Vroubel L., *Metody granichnyx
elementov*. [Boundary element methods], Moscow, Mir Publ. 1987. 524 p.
(In Russian)