Example dryers and washer-dryers having a closed process air circuit having a drum, a condenser downstream from the drum for dehumidifying warm moist air, and a thermoelectric device having a cold side arranged in the process air circuit downstream from the drum are disclosed. The method utilizes immunomagnetic methods to concentrate and localize disease-associated agents in a small region of the body. Operating parameters also include the under-lying range of contrast values and levels of brightness intensities recognized and acted upon by the vision system.