Patients that suffer from chronic pain, metabolic disorders, diseases of the central nervous system and tumor diseases require accurately dosed medication. Here implantable medication delivery systems are used. Through the localized medication delivery, the dosage can be reduced to the required minimum. These infusion systems thus improve the quality of life of the patients. For many patients, it is only the medication delivery system that allows them to have a life outside of the clinic. Repetitive invasive, painful operations can be avoided. The risk of medication dependency and undesired side effects are reduced to a minimum. All these factors can contribute to the disease no longer being the central focus of the patient's life.