Abstract: An assembly for connecting needles and catheters in I.V. applications, chemical analysis, etc., includes a leak proof, sterile, self-sealing septum from which the needle is inserted. When the needle is retracted from the septum, the septum will reseal and thus maintain a leak-proof, sterile seal. The assembly is therefore reuseable, and this represents a considerable cost saving for patients who require continuous therapy such as with diabetics, cancer patients, and the like.The assembly includes a distal end having an outlet bore through which a catheter is inserted. The proximal end of the assembly is connected to an external adaptor to which is attached a needle. The septum is positioned between the distal end and the proximal end to provide a self-sealing seal between the needle and the catheter. This external adaptor with needle may be part of a syringe or shaped to accommodate any standard connector such as a luer lock.

Abstract: A small size cannula having internal grooves is produced by pre-splitting the proximal end of the cannula along the grooves, and mounting the split ends into plastic, breakaway wings. By means of the split ends, mounting of the cannula into the wings is greatly facilitated. The process also permits the grooves to be formed along the barrel of the cannula in a random fashion, which entails less manufacturing expense.Following insertion of the cannula into a patient, the catheter is fed through the cannula into the patient, and the cannula is withdrawn. The pre-split cannula is then broken or split away from the catheter using the wings. Since less force is required to initiate splitting of the cannula, shallower grooves can be used, and this results in a greater structural integrity for cannula of smaller sizes.

Abstract: A catheter is provided having a larger size than the cannula through which it is introduced into a puncture site, such as a vein.The oversized catheter is preferably elliptical shaped, and, prior to introduction into the cannula, the catheter is folded to reduce its overall cross sectional area. The catheter is then advanced through the smaller cannula either manually, or by advancing roller drives, and then inserted into the patient.Use of an oversized catheter reduces the possibility of it slipping out from a vein, and its elliptical configuration is useful in conforming to a vein shape for improved retention therein and laminar blood flow.

Abstract: A cannula needle for a catheter is provided from flat metal sheet blank stock. A groove of controlled depth is formed on the metal sheet which is then rolled to produce a hollow barrel having a slit parallel to the longitudinal axis; the barrel is then cut into individual needles. Gripping wings are then welded to each needle on either side of the slit in a separate operation.In use, when the wings are flexed, the needle will easily split in half along the groove. This enables the cannula to be separated from the catheter.

Abstract: An oxygenator for blood employs a unique and inexpensive, tubular, finned heat exchanger, one type utilizing a spirally wound plate attached to the tube, and another type comprising longitudinal fins. The oxygenator provides a fairly uniform oxygen saturation which permits better control over the oxygen content in a patient's blood. Also, elevated inlet oxygen pressures can be reduced, and this lessens the possibility of embolii due to cavitation effects when CO.sub.2 is released by the blood following oxygenation.A preferred form of a sparger for inlet oxygen to the blood is made of a porous, hydrophobic plastic material such as high density polyethylene.

Abstract: A process for making a removable cannula using a laser to make a longitudinal cut and a longitudinal score line in the cannula wall and the cannula made thereby.