In the paper, the description of a heat transfer process proceeding in a one-dimensional, nonhomogeneous biological tissue domain is presented. The paper concerns imprecisely defined transient bio-heat transfer problems, when in the mathematical model the uncertain parameters are defined and treated as interval numbers. The base of mathematical model is given by the Pennes interval set of equations supplemented by the adequate boundary-initial conditions. The problem discussed is solved with

more »

... use of the interval version of the finite difference method applying classical and directed interval arithmetic rules. In the final part of the paper the examples of numerical simulations are shown, in particular the comparison of both types of interval arithmetic.