Abstract: A peristaltic infusion pump is disclosed herein and includes a continuous tubular arrangement adapted to pass intravenous fluids therethrough and a peristaltic pump head mounted for rotation about a fixed axis. This pump head includes a plurality of innerconnected, circumferentially spaced tube engaging members adapted to successively engage the tubular arrangement during rotation for peristaltically pumping fluid therethrough. In a preferred embodiment, the pump includes a stepping motor which is energized in a particular way for rotating the pump head and which is also used to sense occlusion in the tubular arrangement. This preferred pump also includes a particular arrangement for detecting the index of refraction of the intravenous fluid for detecting the presence of air bubbles or the like.

Abstract: A disposable cassette for use in a peristaltic infusion pump is disclosed herein and includes a continuous tubular arrangement which is adapted to pass intravenous fluids therethrough. The disposable cassette also includes a cassette body which fixedly supports a predetermined tubular section of this tubular arrangement in a readily accessible position from outside the body. A peristaltic infusion pump is also disclosed herein and includes a first arrangement for supporting the disposable cassette for movement between an inoperative position and a spaced apart operative position, and a second arrangement which cooperates with the accessible section of the continuous tubular arrangement when the cassette is in its operative position for peristaltically pumping fluid through the tubular arrangement.

Abstract: A self-sealed hypodermic syringe uses Louis Pasteur's principle of the "tortuous path" to maintain a sterile condition within a medicament chamber contained within the syringe barrel without using airtight seals. A double walled stem cooperates with the barrel to form a rear tortuous path. A needle and hub assembly cooperates with a front bore in the barrel together with an overlying needle sheath and front cap to form a front tortuous path. The front and rear tortuous paths are maintained by a breakable bond between the cap and the stem until the syringe is to be used. Another embodiment includes a pin on the front cap which cooperates with the front barrel bore in place of the needle and hub assembly.