RecruitingDevice studyTranscranial Alternating Current Stimulation on Patients with Delirium and Critical Illness (DeliTACS)The goal of this clinical trial is to learn if transcranial alternating current stimulation can shorten the duration of delirium in intensive care setting. The main question it aims to answer: * Is it possible to shorten the duration of delirium with transcranial alternating current stimulation? Researchers will compare experimental treatment to sham. Participants will receive experimental or sham treatment on maximum of two days depending on their delirium status. Duration of delirium is recorded and reported as "days alive and free of delirium".