The senior doctor on the privileged Level Blue of a Dinaali hospital ship, who in 2377 comes to value the stolen Doctor's skills and is manoeuvred by him into aiding poorer patients.
Dysek appears in the seventh-season Voyager episode Critical Care, played by Gregory Itzin. He runs Level Blue of Hospital Ship 4-2, where patients judged valuable to society by the computer called the Allocator receive lavish treatment, including drugs used merely to slow ageing.
When the Doctor's program is stolen and sold to the ship's administrator Chellick, Dysek has him moved up from the neglected Level Red to work in comfort beside him. He is not cruel, but he accepts the system without question.
The Doctor exploits Dysek's fear of having his supplies cut, persuading him to order more medicine than he needs so that the surplus can be smuggled to Level Red. When the Doctor finally forces Chellick's hand, Dysek cooperates in admitting patients from the lower level.