Abstract: A method of removing obstructions lodged in the pharnyx and/or larnyx of a victim, including the steps of providing a suction device incorporating a rigid hollow tongue depressor having suction means at a free end thereof; inserting said tongue depressor to a point wherein the free end is adjacent an area in which the obstruction is located; applying suction to the free end to dislodge the obstruction and retain it on the free end, and maintaining the suction while withdrawing the tongue depressor and the obstruction engaged thereon.

Abstract: A device for monitoring and limiting the fluid pressure during parenteral or intravenous administration of medication to a patient. The device includes a manometer tube connected at its lower end via a stopcock to the tubing through which the medication is administered under pressure, such as from a fluid pump. A graduated manometer bag is attached at the upper end of the manometer tube for receiving medication which overflows the manometer tube in the event excessive pressure is encountered as would happen if a blockage in the patient were to occur.

Abstract: An apparatus for draining fluids, for example, from a chest or pleural cavity, includes a collection chamber for collecting fluids through an inlet port for entry of the fluids. Also included is a dry or waterless suction control chamber in fluid communication with the collection chamber for regulating the degree of vacuum imposed in the collection chamber. If desired, a seal chamber can also be provided between the dry suction control chamber and the collection chamber so as to prevent any ambient or atmospheric air from passing into the collection chamber. The suction control chamber has a first inlet which is coupled to a suction source and a second inlet communicates with the ambient. A waterless regulator is provided for regulating the degree of suction imposed in the collection chamber at a plurality of predetermined preset levels of suction. This regulator is positioned between the suction inlet and the ambient inlet.

Abstract: A safety lock cap for use with a cardiotomy reservoir, having a passageway formed therein under control of a positive pressure relief valve and projecting axially into the reservoir beyond the outer tubular portion of the cap inserted into a port opening in the reservoir vessel. Under positive pressure, the cardiotomy reservoir is vented through the passageway so that during operation of a heart-lung machine the safety lock cap will provide a minimum amount of safe positive pressure and become a relief valve that decompresses the cardiotomy reservoir.

Abstract: A pressure regulation device utilized in an irrigation system. The pressure regulation device includes an inflatable air bladder within a housing in which a flow-through egress bladder connected to the irrigation site is placed. An operator may inflate the air bladder which is in contact with the egress bladder to restrict the flow of irrigation fluid to thereby increase the fluid pressure at the irrigation site such as a joint capsule. Once the fluid pressure in the egress bladder displaces air in the air bladder an equilibrium is reached between the air pressure in the air bladder and fluid pressure in the egress bladder and joint capsule. The operator may control the fluid pressure in the joint capsule by controlling the air pressure in the air bladder. To reduce pressure at the irrigation site, the operator deflates the air bladder to allow for increased fluid flow through the egress bladder.

Abstract: A pistol-shaped frame (26) houses a fluid distribution assembly (58), including a plunger (46) operated by a trigger (30) for discharging fluid from a reservoir (60) through an outlet check valve (68). On return of the spring-loaded trigger (30), an inlet check valve (80) allows fluid to be drawn into the reservoir (60). A thumb-operated valve assembly (96) provides a fluid passage between an output (12) of the device and the outlet check valve (68) in one position, and in another position provides a vacuum passage between a vacuum inlet port (104) and the output (12). Trigger graduations (136 ) provide a visual indication of measured amounts of fluid dispensed by the device (10).

Abstract: A blood constituent processing system uses a disposable plastic fluid flow path into which an anticoagulant must be accurately metered with respect to pumped blood flow. In a preliminary calibration phase, a closed fluid flow path is provided between the anticoagulant pump and the blood pump. One of the pumps is then controlled to inject fluid into such closed path while the other pump is controlled to withdraw fluid from that path at what is nominally an equal fluid flow rate. Changes in fluid pressure within the closed fluid flow path are then monitored and the flow rate of at least one of the pumps is changed as necessary to achieve an approximately constant fluid pressure within the closed fluid flow path. The relative pump flow control required to achieve constant pressure may then be taken as a relative flow rate calibration between the two pumps so as to permit subsequent accurate pumped metering of anticoagulant into the pumped blood flow.

Abstract: A medical infusion pump includes a housing (10), a pump assembly (30), a bubble sensor assembly (120), a pressure sensor assembly (140) and a flow control assembly (180). The pump assembly includes a ring (26) with teeth (44) and a wheel (46) mounted for eccentric rotation within the ring. The pumping action is developed by the rotation of the wheel which continuously closes a portion of tubing (36) against one or two teeth as it goes through the pumping cycle. The bubble sensor includes a pair of sensor blocks (124) defining a generally V-shaped trough for cradling a portion of the tubing. The pressure sensor assembly detects pressure variations by movement of a diaphragm (168) coupled to a magnet (162) which is operatively coupled to a Hall effect circuit (160). The flow control assembly includes a thumb wheel (196) having a cam groove (197) interacting with a valve stem (199) for controlling the fluid flow through an orifice and associated valve seat (194).

Abstract: The valve is positioned in the left ventricle drain line and includes a check valve which permits flow only away from the heart. A vent valve is located downstream of the check valve to prevent buildup of pressure. In addition, the valve includes an inwardly directed umbrella valve to limit left ventricle drain line vacuum intensity applied to the heart.

Abstract: A syringe barrel assembly includes a plurality of syringe barrels each containing a barrel portion having an open proximal end, a chamber for retaining fluid, and a tip portion extending from a distal end of the barrel portion having a passageway therethrough. The passageway is adapted to accept the hub and second cannula of the hypodermic needle assembly having a hub, a first cannula extending outwardly from a distal end of the hub and a second cannula extending outwardly from a proximal end of the hub wherein the cannulae are in fluid communication. Piercable barrier means is provided in each of said passageways for preventing fluid communication between the chamber and the passageway. A plurality of web portions extending radially outwardly from the tip portions connects the syringe barrel. The web portions are integrally formed from the same material as the syringe barrels.

Abstract: An infusion pump pressure monitor comprises a drive (26, 27, 30, 31) for an infusion pump, a pressure sensor (38) to monitor the delivery pressure downstream of the pump, and a programmed computer (34, 35). The computer (34, 35) is programmed to monitor the maximum delivery pressure that occurs during an initial operating period, and then, subsequently to monitor the delivery pressure downstream of the pump for the remainder of the delivery period of the infusion pump. The programmed computer (34, 35) is programmed to disable the drive (26, 27, 30, 31) for the infusion pump if the monitored delivery pressure differs by more than a predetermined amount from the maximum pressure monitored during the initial operating period. The infusion liquid is carried by a disposable infusion set having a pressure responsive chamber (1) located in a key-hole shaped slot (44) in the pressure monitor.

Abstract: The subject invention relates to a novel system for rapid, venous infusion of a physiologic fluid, such as blood, into a patient, comprising in combination a reservoir for the physiologic fluid having an inlet port for receiving the physiologic fluid and an outlet port for dispensing the physiologic fluid, an infusion pump to propel the physiologic fluid through the system, a heating/cooling unit to control the temperature of the physiologic fluid, a sensor to monitor the pressure of the physiologic fluid, one or move cannula for infusing the physiologic fluid into the venous system of the patient, and flexible conduits connecting the components of the system to the physiologic fluid to and from each of the components of the system.

Abstract: A laser smoke evacuation system and method for laser smoke removal from the site of laser laparoscopy in a patient cavity. The system includes a CO.sub.2 gas pump connected through a control valve, a pressure sensor, and a bacterial filter to a laparoscopic tube inserted into the patient, a return line from a second laparoscopic tube in the patient through a smoke filter, a pressure sensor, a control valve, and a fluid trap into the return of the pump, and an insufflator connected into the patient to supply CO.sub.2 gas lost by leakage and tissue absorption an to provide required distention of the patient cavity. The method includes the steps of supplying a first flow of CO.sub.2 gas into a patient cavity to the operation sites, returning the first flow of CO.sub.2 gas with removed laser smoke from the cavity, cleansing the smoke from the first flow of CO.sub.2 gas, recirculating the cleansed first flow of CO.sub.2 gas back to the patient, and providing a second makeup flow of CO.sub.

Abstract: A pressure infusion device for medical applications for applying pressure to a sealed bag of liquid, such as an I.V. bag, in which the pressure gauge is fastened directly in the pressure applying bag which presses against the I.V. bag. The gauge has a movable plunger which moves outwardly from the bag by an amount depending upon the pressure within the bag. The pressure infusion arrangement is designed to be relatively inexpensive so that it can be discarded after being used. There are two forms, one in which the I.V. bag is held against the pressure applying bag by a mesh which is secured to a fabric to form a pocket for the I.V. bag and the pressure applying bag. In the other form, the mesh is secured directly to the edge of the pressure applying bag.

Abstract: A medical underwater seal, chest drainage apparatus is provided which includes a catheter having a main lumen and an auxiliary lumen for insertion into a chest cavity to be drained of body fluid. The main lumen is connected to a drainage collection device and the auxiliary lumen is adapted to be connected to a variable setting venting valve so that an adjustable flow rate of air from the atmosphere can flow into the auxiliary lumen for venting the cavity.

Abstract: The ventricular drainage system includes an antisiphon device comprising a flow through body which has an interior chamber and which is adapted to be positioned for vertical flow therethrough. The device further includes an inflow tract at the lower end of the body, adapted to be coupled to a ventricular catheter, and an outflow tract at the upper end of said body adapted to be coupled to a drainage tubing. The device also includes a ball in the chamber which is capable of closing the inflow tract when there is no flow of fluid from the ventricular catheter, capable of allowing fluid flow through the body during normal flow of liquid from the catheter and capable of closing the outflow tract upon a rush of fluid from the catheter.

Abstract: The valve is positioned in the left ventricle drain line and includes a check valve which permits flow only away from the heart and downstream of the check valve includes a vent valve which prevents buildup of pressure. In addition, the valve includes a vacuum orifice to limit left ventricle drain line vacuum intensity applied to the heart.

Abstract: The present invention relates to an apparatus for simultaneously monitoring intrauterine pressure and delivering infusible fluids therein for relief of fetal distress during labor with ruptured membranes. The apparatus comprises a catheter assembly having a first and second catheter and a guide tube for providing passage of the catheter assembly therethrough into the uterus.

Abstract: A linking mechanism for irrigation/aspiration machines which includes a coupling member having a plug that is inserted into an opening in a receptacle on the face of the I/A machine. The plug projection is sealed in air tight relation to the wall surrounding the opening and an auxiliary prong(s) prevent rotation of the plug as well as lock the plug in the receptacle. The receptacle includes an arming switch activated responsive to proper seating of the plug in the receptacle to arm the peristaltic pump that is subsequently operated by a foot switch to generate a vacuum in the aspirant line.

Abstract: A method provided for aspirating secreted fluids from a wound by means of a drain connected to a negative pressure source with variable negative pressure, the negative pressure effective at the drain being adjusted in accordance with a selectable pressure/time diagram. Also disclosed is an apparatus for carrying out the aforementioned method consisting of a negative pressure measuring device and a regulator controlling the negative pressure source, which regulator has inputs for the actual value determined by the negative pressure measuring device and for the prescribed set point value of the negative pressure.

Abstract: A high pressure anesthetic syringe is provided for use in procedures such as intraligamentary anesthesia wherein a high pressure is generated by a drive mechanism to advance a piston rod in a direction to express liquid anesthesia from a glass carpule, wherein a pressure indicating mechanism is provided by including an elongated stem slidably mounted within the piston rod of the syringe and wherein pressure applied to the liquid anesthetic is indicated by relative movement between the elongated stem and the piston rod.

Abstract: A first balloon 11 plugs the aorta 1 during the diastole, upstream of the supraaortic arteries 2, 3. A second balloon 12 insures a propulsion of blood toward the coronaries 6,7. A pump 8 commands the inflation and deflation of the balloons from signals from an ECG and a pressure sensor 13 placed opposite the coronaries 6,7.

Abstract: Colon washing apparatus and methods wherein water flow to the colon may be by gravity flow or by pumped flow, wherein temperature control of the wash water is controlled by mixing of hot and cold water or by means of a water heater means, wherein wash water pressure is controlled by water head or by pump output pressure, and by pressure flow valve controls, wherein pulsating water flow may be used, wherein oxygen may be introduced into the wash water, wherein water penetration into the colon may be assisted by abdominal massage, wherein the nozzle may be introduced through the colon by water jet action, and wherein angular water jets from the nozzle may cause washing action ahead of the nozzle. The apparatus is fail-safe in that alternative modes of operation are available in case of power failure. The patient can control the apparatus in case of operator absence or patient discomfort.

Abstract: An overpressure safety valve assembly for use during heart surgery is disclosed. The assembly comprises an elongated tubular body portion having an inlet end, and an outlet end and an unidirectional valve disposed therebetween. A relief valve portion is joined to and in flow communication with the tubular portion. The relief valve portion includes a first relief valve configured to open if the pressure within the overpressure safety valve diminishes below a predetermined level, and a second relief valve configured to open if the pressure adjacent the outlet end exceeds a predetermined level.

Abstract: A suction drainage system for body cavities includes a suction collection container, and a disposable suction control chamber through which an essentially constant level of suction is applied to a body cavity. Drained fluids flow into the suction collection container, into the suction control chamber through an elastomeric check valve which precludes backflow of fluids to the patient. A pressure monitoring tube in the suction control chamber has a lower end communicating with ambient pressure and an upper end communicating with the interior of the suction control chamber. A ball in the tube rises to a level which is proportional to the negative pressure inside the suction control chamber. The suction control chamber can be removably mounted to the collection container.

Abstract: The present invention provides a pumping chamber to be constructed as follows:A collapsible tubing is attached to an inlet fitting and to and outlet fitting to transport a biologic fluid such as blood therethrough. An outer tubing surrounds the collapsible tubing and is secured to the outer surface of the inlet fitting and to the outer surface of the outlet fitting, forming a chamber thereby. At least a duality of ports defining passageways through the wall of the outer tubing permits communication of the chamber with ambient conditions outside the chamber. The ports are designed to accept such devices as pressure gauges, alarm systems and devices to regulate intrachamber pressure, to observe arterial pressure, and to regulate collapse and occlusion of collapsible tubing in response to inadequate blood volumes.

Abstract: A retrograde coronary sinus perfusion device provides steady state blood flow to the coronary sinus and has a balloon set back from the catheter tip to block the coronary sinus during most of diastole to maximize retrograde perfusion. A global device seals the coronary sinus at the coronary sinus valve.

Abstract: An infusion system for infusing a flowable material into a patient comprising an infusion device for delivering the flowable material in both a normal delivery pattern and a test pulse and a conduit for conducting the flowable material from the infusion device to the patient. The test pulse creates a pressure wave response in the conduit. The pressure wave response is monitored and used to detect if the infiltration has occurred.

Abstract: Automatically monitoring the volume of blood removed from a patient during the arterial phase of a control cycle of single venipuncture needle apparatus, and switching from the arterial phase to the venous phase when a predetermined stroke volume has been achieved.

Abstract: An aspirator for withdrawal of secretions from wounds has an evacuated vessel wherein the subatmospheric pressure prior to admission of secretions into its interior is maintained at a level of between about 0.8 and 1 bar. The vessel carries indicia denoting (e.g., in percent or in milliliters) the known-in-advance maximum quantity if secretions which can be sucked into the vessel by way of a cannula as well as lesser quantities which accumulate in the vessel while the pressure rises above the predetermined level as a result of admission of secretions.

Abstract: The valve is positioned in the left ventricle drain line and includes a check valve which permits flow only away from the heart and downstream of the check valve includes a vent valve which prevents buildup of pressure. In addition, the valve includes a manually adjustable vacuum control orifice whereby the surgeon can control the left ventricle drain line vacuum intensity applied to the heart.

Abstract: A medical pressure indicating injection gun for injecting fluid into a balloon catheter, with a visual indication of the balloon pressure. The injection gun includes a barrel adapted for attachment thereto the body of a syringe, and a bracketed coupling shaft for holding the syringe plunger. The coupling shaft includes pressure gauge marks thereon, and is slideable within a cylinder chamber on the end of a ratchet shaft, and in compression with a spring also in the chamber. A ratchet mechanism is employed for engaging teeth on the ratchet shaft and advancing the ratchet shaft forward, and through the spring the coupling shaft and attached syringe plunger are advanced as well. Pressure build-up in the balloon catheter causes the coupling shaft to retract into the cylinder chamber in compression with the spring and indicate by the gauge marks the balloon pressure.

Abstract: A colonic lavaging machine has a pressure switch operable by pressure in a water supply line to a speculum. The pressure switch is coupled with a valve that cyclically controls the flow of waste water from the speculum.

Abstract: A method for detecting probe penetration of human target tissue having predetermined internal pressure includes inserting a hollow probe into the human body towards the internal target tissue and gradually increasing pressure in a closed volume defined by the probe interior and a conduit communicating therewith until a moveable piston slideably resident within the conduit and having a passageway therethrough connecting the portion of the conduit interior communicating with the hollow probe with an orifice in a lateral surface of the moveable piston slideably contacting said conduit interior, moving in response to pressure within the conduit opposing predetermined bias force applied to the moveable piston, reaches a predetermined position, at which the lateral surface orifice of the moveable piston communicates with ambient air via a passageway through the wall of the conduit, corresponding to pressure in the closed volume equaling the predetermined internal pressure.

Abstract: A flow rate sensing device, particularly for use in regulating the rate of flow in a system for parenteral administration of liquids to patients. The liquid emerges from a storage reservoir and is fed into a housing through an upstream flow passage portion and then is made to pass through a narrow throat passage wherein the velocity of the liquid increases while its pressure decreases. The liquid then emerges into a downstream flow through passage and flows through an outlet from the housing. In an intravenous fluid administration system, the housing outlet is connected to a terminal tubing section and an intravenous needle. A pressure transducer, consisting of two chambers separated by a resilient deformable diaphragm, has its upstream chamber in fluid and pressure communication with the upstream flow path portion and its downstream chamber in fluid and pressure communication with the flow emerging from the throat passage.

Abstract: An externally located blood monitoring system has a single access to a patient's blood vessel for monitoring blood associated parameters. A three-position valve permits three modes of operation including flushing, blood pressure monitoring while maintaining patency of the access, and blood sampling while also permitting monitoring of other blood related parameters, such as blood temperature.

Abstract: A pressure regulated system for an irrigation system including a reservoir of irrigation fluid, a pump, catheters for providing access to and egress from the irrigation site and a pressure regulation circuit, all connected in series with one another. The pressure regulation circuit includes a flow restriction branch having a normally-open valve and a variable orifice, diaphragm-operated, restrictor and a pressure accumulation branch, having a check valve, accumulator, and a normally-closed valve. A conduit running from the pressure accumulation branch to the diaphragm controls the pressure regulator. The operator may raise the pressure by closing the normally-open valve to direct pump flow to the pressure accumulation branch and thereby restrict the orifice of the pressure regulator until the desired pressure has been reached, and then releases the valve to maintain that pressure.

Abstract: An implantable medication infusion device wherein a generally cylindrical manifold is employed having a shallow recess on one face thereof. A flexible diaphragm is positioned to form with the face of said manifold a medication reservoir. A circular cover member is positioned over the diaphragm to form with said diaphragm a pressure stabilizing chamber within which is positioned a two-phase fluid for maintaining a constant pressure on said diaphragm. A permanent magnet is positioned at the center of said diaphragm and is movable therewith. A Hall effect transducer positioned on said manifold opposite said permanent magnet is employed continuously to measure the position of said diaphragm and provide an indication of the amount of medication in said reservoir.A method of filling and sealing the pressure stabilizing chamber which insures that a small bubble of two-phase fluid is present in said chamber at all times.

Abstract: In combination with a blood reservoir, a blood volume detecting apparatus is used to ensure safe operation of the reservoir which includes a conduit in fluid communication with a lower part of said blood reservoir, a diaphragm associated with the other end of the conduit and movable by a differential hydraulic pressure applied by the blood through the conduit, and means for detecting the swelling and contracting movement of the diaphragm.

Abstract: An aortic root cannula for use in open heart surgery which combines a luer line for connection with an extracorporeal circuit outside the chest cavity with a left heart vent line and a pressure monitoring line all merging into a base unit having a single cannula for heart wall penetration. A composite base unit is formed of two parts integrated to provide the merging passages to perform the multiple functions.

Abstract: A dual-purpose catheter for performing suction or oxygen feed on a patient including two cylindrical bodies rotatably coupled together and held together by a spring which is biased to hold the bodies in a first position with respect to each other but permits rotation to a second position. One body includes first and second tubes which can be coupled to a source of suction or a source of oxygen, and the other body includes means for receiving said tubes in a tight fit and tube means for coupling either suction or oxygen to the patient, depending on the rotation state of the two bodies with respect to each other.

Abstract: An inflatable plethysmographic cuff bladder comprising interior members for preventing the trapping of an inflating medium in the bladder when the inflating medium is rapidly evacuated therefrom. The interior members comprise members which project inwardly from facing interior walls of the bladder and members which are inserted in the bladder and extend outwardly toward the facing interior walls of the bladder. In all cases, the members cooperate to form channels assisting the flow of inflating medium from the bladder when the bladder is rapidly evacuated of the inflating medium.

Abstract: A device for the aspiration of an air pocket surrounding a collapsed lung. The device includes a needle to be inserted into the cavity surrounding the collapsed lung, through the ribs of the patient. The needle is connected to a suction pump by means of a hose. A float-type flow-meter is provided to measure the air flow rate through the hose and the suction pump and to transmit an electrical signal which is indicative of the flow rate to an electronic controller which calculates and displays the total volume of the air that has flowed through the sensor. A vent line is provided between the suction pump and the flow-meter to prevent sudden increases in flow rates through the needle, and a three-way valve is provided to control flow through the vent line.

Abstract: This invention provides a system for eliminating gas bubbles from a liquid. The liquid enters a chamber through an inlet port. The chamber has two outlet ports, the first bounded by a hydrophilic filter which passes liquid but not gas, and the second bounded by a hydrophobic filter which passes gas but not liquid. Entrapped gas bubbles entering the chamber pass through the hydrophobic filter to the atmosphere. The degassed liquid passes through the hydrophilic filter into tubing leading to the desired receptacle. This apparatus and method are particularly suitable for intravenous infusions and other medical applications in which the degassed liquid passes directly into the blood vessels of a patient.

Abstract: A method for treating blood uses a tubular body fluid passageway member at least part of which is made of a flexible material, an outer tubular member which is made of a nonflexible material and contains said tubular body fluid passageway member hermetically enclosed therein, a pressure detecting member for monitoring the pressure of the flowing body fluid by means of a fluid filled in the hermetically closed space between the outside surface of said tubular body fluid passageway member and said outer tubular member without substantial contact of the body fluid with air, and a body fluid filtering member comprising a filter. The method is especially useful for non-anticoagulant hemodialysis.

Abstract: A movable blood aspiration wand, especially for use in autotransfusion, carries with it a tank for anticoagulant replenished from an anticoagulant source fixed at a high source and is connected to a blood reservoir at a low elevation. Differences in wand height relative to the source and to the blood reservoir are compensated for, so that differences in wand height and corresponding blood and anticoagulant head do not substantially vary the anticoagulant proportion added to the aspirated blood.

Abstract: A surgical instrument 10 having a normally closed valve assembly 20 at its proximal end 28 which may be manually opened to receive an implement 40 terminating in a sharp blade 46 and point 48 for puncturing the wall 82 of an anatomical cavity 84. During penetration of a cavity wall, an inner sleeve 56 or a blunt probe 354 is depressed. The depression provides a tactile signal sensible to a surgeon holding the instrument and, in conjunction with an ancilliary electronic network 110, causes a visual and aural ready signal to be emitted. Upon completion of a cavity wall puncture, the inner sleeve 56 or blunt probe 354 is released, thereby shielding interior anatomical structure from the sharp implement point 48 and providing a tactile signal while simultaneously triggering the electronic network to generate a visual and aural signal indicating completion of the puncture.

Abstract: The present invention provides an accurate method and apparatus for sensing and monitoring any buildup in the downline tubing pressure in a fluid infusion system. The initial fluid pressure as indicated by the tubing location is sensed after a delay period and is utilized as a base pressure if it is within allowable limits. The infusion tubing location or pressure is then monitored and compared with the base location or pressure. The system will alarm if a preset differential location or pressure change is exceeded.

Abstract: A medical suction device is provided in which a constant force means is utilized to create substantially constant vacuum in a chamber of the suction device, as the device progressively fills with fluid being drawn thereinto from a catheter or the like. The fluid drawn into the chamber of the suction device is selectively dischargeable therefrom into a discardable receptacle that is attached through a drain valve to the chamber. Multiple, folded, discardable receptacles, each connected through a separate drain valve, are connected to the storage chamber of the suction device. The arrangement operates to effect isolation against transmittal of infection. The multiple discardable receptacles accommodate a high volume of discardable material, while the suction device apparatus is of low bulk and is provided with means to prevent exposing the suction chamber to atmosphere, and to atmosphere-borne contamination.

Abstract: A flow regulator for use in an I.V. administration arrangement which establishes and maintains the rate of liquid flow regardless of changes in head which may occur. The regulator utilizes a diaphragm controlled orifice and a bypass with a valve to establish the flow rate. The diaphragm adjusts the effective orifice opening to maintain constant the flow selected by the valve.