Abstract: A fluid pump as used to distend a portion of a patient's body including a blood pressure monitor which preselects the maximum pressure for the pump at or slightly below the mean arterial pressure for the patient.

Abstract: A pneumatic controlled infusion bag comprises a double-layer infusion bag, a space defined between the layers for receiving pneumatic pressure therein to gradually squeeze the medicament inside the bag delivering into the vessel of a patient. A pneumatic fluid control assembly controllably supplies the pneumatic pressure into the infusion bag. The assembly comprises an air inlet connected to a pneumatic source, an outlet connected to the bag via a hose, a first and a second piston disposed inside the assembly for respectively controlling the open/close and the proper amount of the pneumatic pressure. A pressure release valve inside the infusion bag can automatically release the excessive pneumatic pressure out of the bag. This disclosure overcomes the resistance of the blood pressure and needs no longer to form a potential difference between the infusion bag and the human body.

Abstract: A valve and irrigator used with a suction tube has an elongate funnel with an axis through an enlarged entrance and an opposed extended exit duct of a flexible elastomer. A flow passage through the elongate funnel connects the entrance to the exit permitting fluid communication. A web across and near the enlarged entrance sealingly separates that from the exit. The web and the elongate funnel are made of silicone elastomer and are adhesively adhered to together. A portal in the web passes therethrough along the axis and is circular in shape to surround in fluid tight engagement the suction tube. A lid, proximally of the web on the enlarged entrance, has an inlet for irrigation and a pass through for the tube; the lid closes the enlarged entrance forming a chamber between the web and the lid. A slit within the web, near the portal and spaced from the axis is in the form of a closed mouth composed of a pair of sealing lips.

Abstract: A suction control regulator for use with a medical suction catheter wherein the regulator includes a rigid molded body attached to a flexible suction catheter at its front and connectable to a source of suction at its rear. An intermediate portion is located between the front and rear portions to act as a means for regulating suction. The intermediate portion includes an outwardly extending stem with an inner passage, the stem terminating in an oval-shaped contoured flange which generally conforms in shape to the contour of the user's thumb. A resilient boot is mounted on the stem and the boot includes a flat diaphragm top suspended and free floating above the stem flange when positioned in a normally open to atmosphere non-suction applied position. The diaphragm top is depressible downward by the thumb to conform to the shape of the flange to seal off the inner passage to close the passage to atmosphere to a suction applied position.

Abstract: A pressure monitoring enteral feeding system and method are disclosed including a housing having a pair of channels for receiving a pump tubing segment which connects an intake line and an output line of a delivery set, and for holding the pump tubing segment adjacent a motor unit. A pair of pressure sensors are disposed along the channels to monitor the pressure in the pump tubing segment so as to warn a user when an undesirable pressure has developed either upstream or downstream from the motor unit, and to adjust rate based on the upstream pressure. The housing may also include a lockable cover to securely hold the pump tubing segment in the channels and in firm contact with the pressure sensors. In accordance with one aspect of the invention, the pressure sensors are used to determine the actual output of the enteral feeding pump by monitoring strain in the delivery set.

Abstract: An adapter assembly for a pressure sensor. The adapter includes a sensor housing that has a first port and a second port that are both in fluid communication with an inner chamber of the housing. The assembly further includes a membrane housing that is pressed into the first port of the sensor housing and connected to a fluid line. Extending from the membrane housing is a membrane which separates the sensor housing inner chamber into a first subchamber and a second subchamber. The first subchamber is in fluid communication with the fluid line. The second subchamber is in fluid communication with a pressure transducer which is pressed into the second port of the sensor housing. Any variation of pressure within the fluid line will cause a change in the volume of the first subchamber. The change in the first subchamber volume will deflect the membrane and vary the volume of the second subchamber.

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. The first and second relief valves are disposed in a side by side configuration in a common conduit.

Abstract: A method for controlling aspiration and irrigation fluids in an eye during a surgical procedure includes placing a handpiece in an operative relationship with an eye for introducing irrigation fluid and aspiration of fluid from the eye. Irrigation is provided at diverse pressures and aspiration is controlled on the basis of vacuum levels sensed in the handpiece corresponding to an occluded condition of the handpiece. Additionally, during phacoemulsification procedures, ultrasonic power provided to the handpiece may by varied in response to the vacuum levels corresponding to an occluded condition of the handpiece. Apparatus for performing the method of the invention is also provided.

Abstract: An apparatus for infusion monitoring including a pressure transmission line branched from the infusion hose and a diaphragm connected with the infusion hose, the diaphragm being able to be connected with a pressure sensor for registering a change in curvature of the diaphragm. In order to achieve the aim of providing an apparatus of this type which renders possible on the one hand a reliable monitoring of infusion and on the other hand a way of preventing the production of a false alarm in a substantially reliable fashion, the apparatus of this type is so designed that in the infusion hose between the branch point of the pressure transmission line and the free end, adjacent to the patient, of the infusion hose a one-way valve is arranged, which permits a direction of flow to the patient.

Abstract: An infusion method and apparatus for infusing liquid into a patient, the infusion apparatus being compatible with a plurality of different types of cassettes which are adapted to be insertable into and removable from the infusion apparatus. The infusion apparatus has a housing adapted to receive a first type of cassette and a second type of cassette, a pump disposed in the housing and adapted to pump liquid through a conduit, and a cassette sensor disposed in the housing, the cassette sensor being capable of determining whether the first type of cassette is inserted into the housing or the second type of cassette is inserted into the housing. The infusion apparatus includes control means for controlling the operation of the pump which causes a first course of control action to be taken when the first type of cassette is inserted into the housing and a second course of control action to be taken when the second type of cassette is inserted into the housing.

Abstract: A process control system according to the present invention uses analog control circuitry in which a differential amplifier stage is incorporated into the feedback path rather that the feedforward path to enable the control of highly non-linear processes that may also exhibit high levels of hysteresis. Such processes often have superior performance characteristics that conventional control circuitry cannot exploit. The present invention additionally incorporates an automatic control circuit which varies the gain of various stages the control circuitry when the output of the process is within a predetermined range. An embodiment of the present invention is used to control a nonlinear proportional valve with severe hysteresis. The valve regulates the pressure within pressure-driven ophthalmic surgical instruments, which must be controlled extremely precisely to enable successful eye surgery.

Abstract: Apparatus for supplying liquid to a body cavity during an endoscopic procedure includes a feedback loop-controlled liquid supply device inherently capable of supplying liquid at a substantially constant pressure substantially independent of the flow rate of liquid delivered by the liquid supply device within a relatively wide range of flow rate. Also disclosed are a disposable plastic pump cassette having an inflow pump in a housing, and an operative cannula. The surgical procedure is performed with continuous control over the body cavity pressure, regardless of the outflow flow rate.

Abstract: An ear irrigation device has a pump communicating with a water container for pumping water through a tube to a handpiece nozzle, for discharge into a person's ear. A control circuit operated by a switch energizes a motor, for driving the pump. The control circuit generates pulses to intermittently energize the motor, and the pulses are automatically controlled so as to positively restrict pressure discharge of water from the nozzle to a low pressure on actuation of the switch and subsequently to permit an increase in the pressure of the water discharge only after a predetermined time interval.

Abstract: An apparatus for minimizing trauma to a medical fluid while transporting the medical fluid from a surgical wound by reducing the air to fluid interface during transport. The apparatus includes a suction wand for collecting medical fluid and tubing for transporting the medical fluid to a reservoir. The reservoir repeatedly accumulates the medical fluid and discharges it in a bolus when a predetermined volume is achieved. The reservoir comprises a fluid inlet, a fluid outlet, and a gas outlet. A siphon is disposed inside the reservoir for removing the bolus of medical fluid once the predetermined fluid volume is accumulated. The siphon includes a first end for suctioning the medical fluid and a second end exiting the reservoir through the fluid outlet, thereby defining an external siphon length. A pump is attached to the second siphon end to provide suction to the system.

Abstract: A blood conservation system, including a vacuum wound drainage apparatus, comprises a liquid collection reservoir for a wound to be drained and an operating unit fixed on such reservoir. The operating unit is self contained and includes a battery supply, an electric motor powered pump, a control for setting the level of vacuum desired in the reservoir and structure for operating the motor powered vacuum pump in accord with the setting of the control. The entire system is arranged to be disposed of after use by one patient.

Abstract: A fluid delivery device for delivering fluid from a fluid reservoir to a patient. The device includes an inlet channel in communication with a fluid reservoir and a dosing chamber, and an outlet channel disposed in communication with the dosing chamber. A reciprocating dosing actuator is moveable in a reciprocating motion between first and second positions for alternately (i) transporting a dose of fluid conveyed by the inlet channel into the intermediate dosing chamber, and (ii) ejecting the dose from the dosing chamber through the outlet channel to the patient, respectively.

Abstract: This invention is directed to a temperature activated infusion device for delivering a specific quantity of medication to a recipient patent. The delivery is accomplished by the use of a sealed pouch or container of an temperature expandable fluid which applies pressure to a adjacent second pouch or container of liquid medication. A medication delivery pressure regulator and fluid metering valve associated with the output of the liquid medication from the pouch or container insure proper pressure and volume of medication to the recipient patient.

Abstract: A tubing set and method for use with a system for providing pressurized fluid from a fluid source to a surgical site. The system includes a fluid source, a length of flexible tubing having one end connected to the fluid source and another end connected to a surgical instrument, and a peristaltic type pump into which a middle portion of flexible tubing is positioned so that the peristaltic type pump can pump fluid from the source to the surgical instrument by bearing on the exterior of the tubing. The improved tubing set also includes a by-pass section of tubing connected between the tubing inlet and the tubing outlet in parallel with the middle portion of the flexible tubing. The by-pass section provides pressure relief to the system so that pressure in the tubing will not build up distally of the location of the peristaltic pump.

Abstract: A vacuum regulator having a timing module that provides intermittent vacuum and is modular in design permitting easy removal and replacement without having to disassemble the entire vacuum regulator.

Abstract: A flow regulator device for intravenous tubing comprises a frame body, a notch on the frame body for attaching an intravenous tube to the frame body, and a first pressure applicator disposed on the frame body and engageable with the intravenous tube for alternately compressing and releasing the intravenous tube in a first direction of action in a first plane. A second pressure applicator is provided on the frame body for alternately compressing and releasing the intravenous tube in a second direction of action in a second plane. The second pressure applicator is disposed on the frame body in spaced relation to the first pressure applicator along a flow path of the intravenous tube and is engageable with the intravenous tube.

Abstract: A control valve assembly is disclosed having a housing defining at least one valve chamber having an elongated cylinder. A piston is partially disposed within said valve chamber and the valve assembly allows for reciprocating movement of the piston within said valve chamber. A metering device is provided for precise positioning of the piston within the valve chamber.

Abstract: An self-releasing suction and irrigation apparatus for providing surgical suction and irrigation to a body cavity such that, upon obstruction of the suction port by body tissue, the resulting increased vacuum pressure is automatically vented, thereby releasing the suction hold on the obstructing tissue. In a preferred embodiment, the suction apparatus has a soft, flexible tip made from an elastomeric material that is releasably attached to a rigid tube. The flexible tip is designed to deform under a predetermined threshold vacuum pressure. A vent through the wall of the deformable portion of the tip is substantially closed during normal operating pressures, but opens in response to the deformation of the tip at the threshold vacuum pressure, thereby venting the interior of the tip and reducing the vacuum pressure. Rounded lips form sharp channels at the suction port to maximize the flow of fluids into the port while minimizing the likelihood of tissue obstruction.

Abstract: A pressure monitoring enteral feeding system and method are disclosed including a housing having a pair of channels for receiving a pump tubing segment which connects an intake line and an output line of a delivery set, and for holding the pump tubing segment adjacent a motor unit. A pair of pressure sensors are disposed along the channels to monitor the pressure in the pump tubing segment so as to warn a user when an undesirable pressure has developed either upstream or downstream from the motor unit, and to adjust rate based on the upstream pressure. The housing may also include a lockable cover to securely hold the pump tubing segment in the channels and in firm contact with the pressure sensors.

Abstract: In a method and apparatus for determining the volume of a bellows reservoir for medication in an infusion system which is implantable in a patient, the pressure in the reservoir is measured and the corresponding volume is determined from a predetermined relationship between pressure and volume. A pressure gauge is disposed for measuring the pressure in the bellows reservoir, and a signal corresponding to the measured pressure is supplied to a memory unit wherein a corresponding volume is determined from the measured pressure value by means of the predetermined relationship between pressure and volume being stored in the memory unit.

Abstract: The invention is directed to an external pump stroke indicator for use with in an implanted medication infusion system of the type having a pump for conveying medication into the patient, an opening covered by a septum is arranged at the output of the pump. The indicator includes a cylinder composed of a transparent material and connectable via its lower end to the opening in an essentially upright attitude, the cylinder being filled with a liquid. A movable sinker member is provided in the cylinder, the movable sinker member normally resting as a result of its weight against a seat provided in the cylinder that limits the motion of the sinker member in the direction of the lower end of the cylinder. The sinker member is composed of a material that has a higher density than that of the liquid, so that the sinker member normally rests against the seat and only moves when pressure elevations that are generated by the pump strokes of the infusion system arise in the liquid.

Abstract: A medical device which is manually operable to draw a vacuum using a piston and cylinder combination may be used for creating a vacuum in the cup of a birth extraction device or to withdraw fluids from a body cavity or perform biopsies with a hollow needle. The structure includes a closed loop at the remote end of the cylinder which allows the device to be manipulated by one hand and it may include check valves to prevent any fluid withdrawn from the body from being reinjected into the body cavity or vessel by location of check valves in a withdrawal duct and a drainage port. The same device may be used for injecting fluids into a body cavity and may include structure between the loop and cylinder to apply force to the piston to discharge fluids through a needle attached to the remote end of the cylinder.

Abstract: An infant meconium aspirating and ventilating apparatus comprising a flexible one-piece transparent aspirating device, a tube for connecting the aspirating device to a vacuum source, a ventilating device; and a clamp for shutting off and admitting vacuum into the suctioning device. The one-piece aspirating device, which is a primary feature of the present invention, is formed from the same piece of flexible, transparent, non-irritating plastic material, such as polyethylene. The aspirating device has an endotracheal tube end portion, an intermediate body portion, an outlet tube end portion and a port. The length of the endotracheal tube portion is preferably fixed at 13 cm. The length of the outlet tube is preferably about 35 to 50 cm. to prevent the weight and stiffness of the tube from the wall suction device from adversely affecting the maneuverability of the aspirating device. The port is used for regulating vacuum, administering medication and attaching the ventilating device.

Abstract: The invention relates to an inflation syringe assembly, which includes a housing having a barrel portion defining an interior space; a pressure gauge mounted to the barrel portion; a plunger disposed in the barrel portion; and structure for advancing the plunger in the barrel portion, wherein the barrel portion is rotatable relative to the housing so that the barrel portion with the pressure gauge is rotatable to a desired position relative to the housing.

Abstract: The present invention relates to an apparatus and method for penetrating body tissue. The apparatus includes a handle member having a gas pressure chamber positioned therein and a shaft member having a longitudinal bore therethrough and one end connected to the handle member. The longitudinal bore in the shaft member is in cooperative alignment with the gas pressure chamber to facilitate the passage of gases therethrough. The apparatus also includes a pressure indicating system which provides a visual indication when the shaft member has penetrated the body tissue.

Abstract: An irrigation system and method for providing fluid from a source of irrigating fluid to a surgical site, in particular a surgical site access to which is provided by a small incision or a natural orifice of the body. The irrigation system includes a control unit that is used with a cassette. The control unit includes a motor under the control of a controller, a sensor for sensing the flow of fluid in the cassette, a sensor for sensing pressure in the cassette, and a user control panel. The cassette includes a fluid flow passageway having an inlet connected to the source of irrigating fluid and an outlet for providing fluid to the surgical site. A pump located in the cassette is driven by the motor. The pump has limited efficiency when presented with back pressure to thereby limit to a safe level an amount of pressure that can be delivered to the surgical site. The system may be used to irrigate or distend a surgical site.

Abstract: A suction catheter assembly has an aspirating catheter that is enclosed along its length within a protective sleeve. The catheter extends from a vacuum connecting member, which can be connected to a suction source, and a patient connecting member which has a coupling for connection to a tracheal tube and two side ports for connection to ventilation equipment. A one-way valve in the patient connecting member forms a sliding seal with the catheter and allows trapped gas in the sleeve to escape into the patient connecting member when the catheter is advanced.

Abstract: The present invention relates to a trocar and method for penetrating body tissue. The trocar includes an obturator assembly and a cannula assembly. The obturator assembly has an obturator shaft with a distal end portion adapted to penetrate body tissue and at least one channel extending between a proximal end portion of the shaft and the distal end portion. A pressure indicating system is positioned at the proximal end of the shaft and is provided to respond to the passage of gases through the channel and provide a visual indication when the distal end has penetrated the body tissue. A safety system is associated with the obturator shaft and responsive to gas pressure to shield the distal end portion of the shaft after penetration of the body tissue.

Abstract: A portable, patient assignable, medical suction apparatus usable especially in the medical evacuation field. The suction apparatus includes self contained battery energy sourcing in addition to capability of operation and battery charging from a variety of alternating and direct current energy sources as are commonly available in transportation vehicles and ground based medical facilities. The disclosed apparatus includes provisions for suction canister usage, electromagnetic interference reduction, mounting on an existing aircraft stanchion and shelf and hand carriage to a patient's bedside. Military usage and possible civilian usage are also disclosed.

Abstract: A composite suction and irrigation probe is provided for performing the functions of irrigation and suction alone or simultaneously with the use of a single trumpet valve. The probe consist of an inner cannula and an outer cannula. In the first embodiment the inner cannula is attached to one probe mount end of the valve body while the outer cannula is attached to a second and opposite probe mount end. The inner cannula is inserted through a common channel of the valve body and the outer cannula. In the second embodiment, the inner cannula is attached to the outer cannula prior to attaching the probe to the valve body. The designated suction and irrigation ports located within the common channel of the valve body are isolated from each other to provide discrete and dedicated ports.

Abstract: A collection chamber for fluids and a vacuum control device for drainage of the thorax is described. The collection chamber is provided with ports for the attachment of tubing extending from the chest cavity and for connection to a vacuum pump. Instead of using a water level control vacuum regulator this collection chamber uses a system of calibrated holes in the chamber. The vacuum is controlled by calibrating the size of the holes and selectively opening the holes in the chamber to control the force of the vacuum.

Abstract: A medical pump drive for automatically displaying not only the flow rate of circulating blood but also blood flow rate per surface area of the body of a patient in a medical treatment such as extracorporeal circulation includes at least a pump driving circuit, an ultrasonic transceiver and ultrasonic oscillator for measuring flow rate of the blood conveyed by a pump, a CPU, to which values of height and weight of a patient are entered, for calculating the body surface area of the patient as well as the blood flow rate per body surface area of the patient based upon the blood flow rate and body surface area obtained, an LCD for displaying the calculated blood flow rate per body surface area, and an LED for displaying the blood flow rate obtained.

Abstract: A self priming tubing set for infusing a medical solution from an infusion device to a patient includes a supply tube, an air/particle filter, and a restrictor tube. The air/particle filter is adapted to remove air, particularly air contained in the supply tube at the initiation of fluid flow. The air/particle filter also removes particles from the medical solution. The restrictor tube is adapted to reduce the pressure of the medical solution from the delivery pressure of the infusion device to about a mean venous pressure of the patient. The length and inside diameter of the restrictor tube are calibrated to achieve a desired pressure drop dependent on design criteria of the system. The tubing set also includes a slide clamp for closing fluid flow from the supply tube and a connector for connection to a patient interface such as a hypodermic needle or cannula.

Abstract: A medico-surgical suction system has a container with an outlet connected to a vacuum pump and an inlet connected to a suction catheter via a dual-lumen tube assembly one end of which is connected to the container and the other end of which is has a suction control and a coupling for the catheter. A valve located in the outlet of the container is connected to the suction control via a minor lumen of the tube. A side lumen enables the vacuum pump to apply reduced pressure to one end of the valve which holds the valve off against the action of a spring. Actuation of the suction control allows air to flow to the valve via the minor lumen so that the effect of the reduced pressure is overcome and the spring opens the valve.

Abstract: An apparatus for minimally invasive tissue removal contemplates a system including a tissue cutting tool having a motor driven cut-ting blade reciprocating within a percutaneously introducable cannula. In accordance with one method of the invention, the frequency of reciprocation of the cutting blade is tuned to a characteristic frequency of the target tissue to be excised, which frequency is a function of certain properties of the target tissue and the surrounding tissue. Cutting at the characteristic frequency of the target tissue not only enhances the speed and efficiency of the tissue excision, but also minimizes the risk of cutting surrounding tissue. Another aspect of the system includes feedback control of both aspiration and irrigation circuits of the system. With the feedback control, coupled with user settable inputs, the surgeon can control the system to "tease" tissue into the cutting opening to provide more manageable bite sizes of the excised tissue.

Abstract: An irrigation system including a pump that regulates the supply of fluid to an endoscopic surgical site, and a tubing set for supplying the fluid. The tubing set comprises an inflow line for supplying fluid to the surgical site, and an outflow line for draining fluid from the surgical site. At least one of the inflow and outflow lines includes an expandable compliant tubing segment that expands to accommodate changes in the rate of fluid flow through the surgical site to reduce variations in fluid pressure in the surgical site. The fluid volume within the compliant tubing segment increases in response to increasing fluid pressure within the compliant tubing segment. The system is particularly designed for use in small joint arthroscopy (e.g., of the wrist) where the fluid volume in the surgical site is relatively small.

Abstract: A method and a device designed to suck and to convey various types of liquids through a suction hose (45) and at the same time does (4) an additive to the liquid in an accurate proportion to the amount of the sucked liquid. A liquid or a liquid/air/gas mixture is sucked by means of a suction nozzle (2,45), which is influenced by a certain pressure P2 with a moderate suction action, and is passed through the suction hose (45). A dosage device (4), which includes a flexible dosage container (20), which is enclosed in a rigid casing (21), and which is influenced by a certain relatively lower pressure P3 (providing a stronger suction action) than the pressure in the suction hose (45), is connected directly to the suction hose (45).

Abstract: A cassette for use in combination with a surgical handpiece and a control console for controlling irrigation and/or aspiration fluid flows in the handpiece having a housing with an external surface and an interface adapted to be held in operative association with the control console, an inlet coupling, a pump tube having an inlet and a discharge line in fluid communication with a waste container and a fluid flow passage in fluid communication with the inlet coupling and the pump inlet consisting of an open channel formed in the external surface and a gasket adhered to the external surface to seal the channel fluid-tight.

Abstract: An apparatus for locating a body cavity having a fluctuating fluid pressure by signaling the fluctuating pressure when the cavity is entered and then transporting fluid either into or out of the cavity.

Abstract: Apparatus for regulating pressure in and for controllably pressurizing infusion devices includes a flow-through pressure gauge for indicating and regulating the pressures within such infusion devices between minimum and maximum desirable pressures. Such apparatus includes a gauge, coupled between a fluid source and the bladder portion of the pressure infusion device. The gauge receives pressurized fluid from the fluid source, provides fluid to the bladder, indicates a range of fluid pressures in the bladder and maintains the pressure of fluid in the bladder between minimum and maximum pressures. The gauge includes a telescopingly coupled member to indicate a range of pressures in the bladder. A first valve permits the passage of fluid through the gauge and into the bladder when the fluid pressure exceeds a minimum pressure. A second valve prevents the passage of fluid through the gauge and into the bladder when the fluid pressure exceeds a maximum pressure.

Abstract: A portable, closed circuit, disposable device for post operatory surgical suction which comprised a bellows-shaped body receptacle for suctioned fluids, a threaded neck located on the upper surface of said bellows-shaped body suitable to receive a threaded cap; said cap being provided with a suction tube system connected through said cap into the bellows-shaped body, and said system of tubes is provided with a check-valve, wherein said bellows-shaped body is provided with a cannula in its lower surface, having a nearly rectangular longitudinal section, having a lower end wall, wherein the side wall of said cannula is provided with at least one opening located in a position close to said lower end wall of said cannula; where an elastic tube, with a longer extension than said cannula, is introduced under pressure in said cannula in order to close the at least one opening of said cannula, and wherein a tube of rigid or semi-rigid material is introduced in said cannula, fixing the elastic tube between its interio

Abstract: A method of manufacturing flexible thick-wall capillary tubing, comprising the steps of extruding a plastics sheath around a filament of uniform diameter, and withdrawing the filament from the sheath to form a length of tubing having a capillary bore which has been defined by the filament. The method enables the manufacture of fine-bore capillary tubing having a tightly controlled bore diameter.The invention also provides a method of low flow rate metering of a liquid by utilising a length of such tubing as a flow restriction, and apparatus for carrying out the method. This method and apparatus are particularly suited to controlling very low rates of flow of drugs or other injectable liquids to a patient over a prolonged period, in an arrangement which can readily be carried on the patient's arm to alow the patient mobility while being injected.

Abstract: The present invention provides a casing having a plurality of sources of pressurized liquid. The sources of pressurized liquid are preferably contained in at least one elastomeric bladder. Housing is provided to establish fluid communication between the sources of pressurized liquid. Additionally, at least one flow restrictor is provided to regulate the flow of pressurized liquid. A single or a plurality of flow restrictors can be used to regulate the flow of liquid between the sources of pressurized liquid. The plurality of sources of pressurized liquid can be contained under different pressures which can be provided by varying the size of the elastomeric storage area. The casing further contains an inlet port and an exit port in fluid communication with the sources of pressurized liquid to provide for filling and dispensing of the fluid.

Abstract: A closed ventilation and suction catheter system for aspirating or suctioning the bronchial tree or trachea of a patient including a dual lumen catheter, the proximal end of the catheter is connected to a dual valve assembly which is connected to separate irrigation fluid and suction pressure sources and the distal end of the catheter is adapted to be slidably positioned in communication with the bronchial tree of a patient. A transparent and flexible envelope surrounds the catheter to protect the catheter from direct exposure to the atmosphere. The catheter is slidable from the inside of the envelope through an adaptor and a tracheal tube to communicate with the bronchial tree or trachea of the patient. A ventilator is connected to the adaptor near the distal end of the catheter to provide for the artificial ventilation of the patient.

Abstract: A valve arrangement for controlling a suction stream in a dental suction system, wherein the valve controlling the flow contains a closure element that defines a valve space on one side and a control space on the opposite side. The closure element, such as a membrane, is urged closed when the pressure in the control space is greater than the pressure in the valve space and the movement of the closure element is obtained by actuation of various control valves which control flow in effective lines extending to the control space, which lines have different effective cross sections so as to control the amount of movement of the closure element toward the closed position.

Abstract: A medical suction tube which is opened at the distal end thereof and connected at the proximal end thereof to a suction means. A linear cut is made in the intermediate portion of the tube so as to extend obliquely from the proximal end side toward the distal end side of the tube so that, when the tube is bent, the cut is opened and ambient air is sucked into the tube through the cut, whereas, when the tube is straightened, the cut is closed and suction is performed through the distal end opening. A suction control apparatus for an endoscope utilizes the above-described medical suction tube.