Infusion pumps incorporating 'Diprifusor' for the administration of pr
opofol by target controlled infusion are now commercially available an
d are becoming more widely used. This paper considers possible future
applications of target controlled infusion and summarises results obta
ined using prototype systems as a component of other control technique
s and with other drugs. These include studies with patient-controlled
systems for the administration of analgesia or sedation and a closed l
oop control system for the administration of propofol. Among currently
available analgesic drugs, alfentanil and remifentanil are considered
to be the most suitable for administration by target controlled infus
ion, but commercial systems for these agents are not yet available.