0000000000954612

AUTHOR

Tapani Lahtinen

showing 2 related works from this author

Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy.

2010

In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner’s knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden an…

MatematikMathematical optimizationOptimization problemModels StatisticalRadiological and Ultrasound TechnologyProcess (engineering)Computer scienceComputersmedicine.medical_treatmentRadiotherapy Planning Computer-AssistedBrachytherapyBrachytherapyReproducibility of ResultsUterine Cervical NeoplasmsRadiotherapy DosageAnatomyMulti-objective optimizationImaging Three-DimensionalmedicineHumansRadiology Nuclear Medicine and imagingFemaleMathematicsAlgorithmsSoftwarePhysics in medicine and biology
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A ten-fold divided total absorption Ge(Li) gamma-ray detector

1976

Abstract We have constructed a split-crystal total absorption Ge(Li) gamma-ray spectrometer and special logic electronics for rejecting Compton continuum in spectra. A 10 cm3 planar detector was divided into ten electrically separated detectors by grinding nine parallel slots on the n-surface of the detector. In operation both the n- and p-contacts are isolated from the ground. Using capacitive sharing, most of the released electrical charge is taken from the p-contact into an ordinary pulse amplifier line and analyzed. A small fraction of the charge collected at the n-strips is observed with voltage-sensitive FET-preamplifiers. The following logic electronics provides a gate pulse for the …

PhysicsSpectrum analyzerSpectrometerPhysics::Instrumentation and Detectorsbusiness.industryAmplifierDetectorCompton scatteringGeneral MedicineElectric chargeSpectral lineNuclear physicsOpticsPhase detector characteristicbusinessNuclear Instruments and Methods
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