Abstract: Three embodiments of a metering unit (10, 140, 200) are provided for metering fluid from a container (14) for infusion into a patient. The first embodiment of the metering unit (10) includes a cassette (26) formed of halves (28, 30). The halves (28, 30) each have a concave reservoir portion (36) formed on the inner face (32) thereon. Entry and exit channels (38, 42) extend from the reservoir portions adjacent entry and exit orifices (40, 44). Entry and exit port portions (46, 50) are formed in each half (28, 30). Flexible entry and exit valves (58, 64, 86 and 88) are movable between an open position, permitting fluid to flow through the orifices, to a closed position, preventing fluid from flowing through the orifices. The halves are separated by a flexible diaphragm (70) which divides a reservoir (76) into first and second compartments (78, 80).

Abstract: A controller (34) is disclosed for use with a dual delivery system including a primary fluid container (12) and a secondary fluid container (14). The display (48) on the controller (34) presents a representation of the primary and secondary containers and prompts the operator to input the desired primary and secondary fluid flow rates and primary and secondary fluid volumes to be infused. During operation of the controller, a series of flow lines displays (118, 126, 144) represent motion of fluid from the container being drained to indicate to the operator which fluid is being infused. An alarm will be sounded upon the detection of an occlusion within the flow lines, the presence of air within the flow lines or an open door on the controller. During the flow from a particular container, the displays associated with the other container are deactivated to prevent confusion to the operator.

Abstract: A metering device is disclosed which includes a metering chamber (14) divided into two compartments (22, 24) by a pressure transmitting member in the form of a flexible diaphragm (20). Fluid flow is alternately allowed into each of the two compartments (22, 24) with each compartment filling to the volume of the metering chamber (14) when full so that periodic pulses of intravenous fluid of that precise volume are sent to the patient. The volume of the metering chamber (14) is selected to match a standard intravenous set drop size, for example one-tenth, one-fifteenth, one-twentieth, or one-sixtieth milliliter.

Abstract: An intravenous administration set assembly (10) is disclosed which is capable of introducing fluid from a plurality of sources of intravenous fluids into a patient and which allows the various sources of fluid to be easily attached and detected from the assembly without the necessity for intravening safety steps, such as purging the system, and yet without any possibility of air or bacteria being introduced through the system into the patient. An air-eliminating filter (32) is attached to a manifold formed of fittings (26) which are connected through inlet adapters (28) to the sources of intravenous fluid. The air-eliminating filter (32) ensures that air or bacteria introduced into the assembly (10) through attaching or detaching sources to the assembly does not pass to the patient and also ensures that a head pressure is maintained relative to the venous pressure of the patient to prevent a back flow of blood from the patient into the assembly.

Abstract: A system for sensing flow faults in a membrane system for intravenous fluid introduction is provided. A scanner is pulsed to generate reflected energy signals representative of the position of a membrane within a chamber. The scanner is pulsed both before and after the membrane is commanded to move within the chamber. The signals are then compared by an electronic circuit to determine the difference between them. If there exists a sufficiently large difference between the signals, this indicates that the membrane is moving in response to the command signals and the system is functioning properly. If there exists little or no difference between the signals, this indicates that there is a flow fault in the system, and an alarm is sounded.

Abstract: An improved fluid additive system is disclosed. The first embodiment of the invention is formed by a system (10) including a controller (26) which automatically delivers a preselected quantity of a secondary fluid from a secondary container (14) at a preselected rate and subsequently delivers a preselected quantity of a primary fluid from a primary container (12) at a preselected rate. Within the controller (26) are input controls (48) for operator input of the desired preselected rates and quantity of fluid to be infused. A passive metering unit (36, 36') is provided in the controller for metering a known quantity of fluid to a delivery line upon each activation thereof. A microprocessor (40) responds to the rates amd quantity input into the input controls (48) to direct a drive unit (38) to activate the metering unit (36) to achieve the desired rates and quantity of infusion of the primary and secondary fluids.

Abstract: A method and apparatus for catheter insertion (10 or 100) for inserting a flexible catheter (12 or 112) into a selected liquid-filled body cavity (144) into which the anterior end of a substantially rigid, tubular member (151) has been inserted. A containing member (22 or 122) adapted to contain a limp, flexible, substantially straight catheter (12 or 112) is attached to the posterior end of the tubular member (151) in fluid communication therewith.

Abstract: A catheter insertion device (10) is disclosed which is usable to insert a very flexible catheter (12) formed of a silicone elastomer into the blood vessel of a patient. Catheters of highly flexible material, such as silicone elastomer, are highly desirable for use as such catheters in that they do not initiate a build-up of fibrin in the blood stream as do other, more rigid, catheters. A hub member (18) is slidably received over a needle (14) carrying the catheter (12) and a semi-rigid sleeve (26) extends under the proximal end of the catheter (12) so as to aid in removing the catheter (12) from the needle (14) after the needle (14) has been inserted into the blood stream of the patient.

Abstract: A check valve is disclosed for use in blood drawing apparatus wherein it is desired to draw multiple samples from a single needle inserted into a patient's arm for use in a variety of medical tests. The check valve includes therein a valve member formed of a piece of a silicone elastomer which has a slit formed therein, the slit opening only when fluid pressure is greater in the patient than in the vessel into which the blood is being drawn. The check valve is of particularly small size so that it may be mounted within a conventionally sized double-needle fitting normally used in blood drawing apparatus.