Jouko Tervo

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The paper considers the intensity modulated radiation therapy (inverse) treatment planning. An approach to determine the trajectories of the leaves of the multileaf collimator (MLC) in order to produce the prescribed intensity distribution is developed. The paper concentrates on the multiple static delivery technique. A mathematical model for calculating(More)
A method for the stabilization of stationary and time-varying autoregressive models is presented. The method is based on the hyperstability constrained LS-problem with nonlinear constraints. The problems are solved iteratively with Gauss-Newton type algorithm that sequentially linearizes the constraints. The proposed method is applied to simulated data in(More)
The paper considers pseudo-differential boundary value control systems. The underlying operators form an algebra D with the help of which we are able to formulate typical boundary value control problems. The symbolic calculus gives tools to form e.g. compositions, formal adjoints, generalized right or left inverses and compatibility conditions. By a(More)
A methodology, called by the name parametrization, is presented here for calculating open-loop controls for linear distributed-parameter systems. It is based on the theory of certain type of pseudo-differential operators (ΨDO). These operators have features which are useful from practical and computational viewpoints. The operators form an algebra, and(More)
— A model for the inverse radiotherapy treatment planning is studied and discussed here. The dose calculation (forward problem) is based on the Boltzmann transport equation for charged particles. The required treatment optimization (inverse problem), which is always present in the real situations, is solved by the boundary control optimization theory for(More)
A new approach for the inverse treatment planning in radiation therapy with the multileaf colli-mator (MLC) technique is presented. The application of the MLC-techniques requires an algorithm for the computation of the positions or velocities of leaves as a function of time such that the prescribed dose in the patient space is obtained. First the intensity(More)
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