A Infusion Pump, Patient-controlled analgesia (PCA) is a device that is used to deliver a prescribed amount of analgesia according to a patients demand when he or she actiavtes a button. Patient-controlled analgesia (PCA) is any method of allowing a person in pain to administer their own pain relief. The most common form of patient-controlled analgesia is self-administration of over-the-counter or prescription painkillers at home. If a complaint, e.g. a headache, does not resolve with a small dose of an analgesic then more may be taken up to a maximum dose. The PCA pump was first introduced by Dr. Philip H. Sechzer in the later 1960s and described in 1971.