Post-surgical anesthesia at a continuous and progressively decreasing administration rate

摘要

A method of administering post-operative anesthesia directly to the surgical site through a catheter introduced into the site during the post- operative procedure. The flow of medication into the catheter is regulated by a micro-bore cannula that insures delivery at very small rates. The plunger of a spring-loaded syringe creates the pressure that causes the medication to flow through the cannula and catheter into the wound. Because of the spring's nonlinear characteristics within the range of stroke of the plunger, the pressure exerted on the liquid gradually decreases with the expansion of the spring. By appropriately sizing the spring and the inside diameter of the cannula, a device is developed that administers the required dosages of anesthetic continuously and at decreasing rates.