US20070051409A1 - Pressure responsive fluid flow control valves - Google Patents

Abstract

In one set of embodiments a selected section of tubular stock has its ends welded together to form a pillow-like pressure sensing device with an entry tube and an exit tube each configured to facilitate insertion of the pressure sensing device into the flow path of IV infusate in an IV administration set or system. Fluid pressure in excess of a predetermined amount reconfigures the pressure sensing device from a generally oval configuration to a generally circular configuration to restrict and/or cut off fluid flow into the device while permitting fluid flow from the device to reduce the fluid pressure again reconfiguring the device back to its generally oval configuration and permitting fluid flow into and through the device. In other embodiments a fluid pressure sensing device is formed with a fluid entry chamber and a fluid exit chamber interconnected by a passageway and provided with a piston that reacts to an increase in fluid pressure above a predetermined amount to close off the interconnection between the chambers and fluid flow into the exit chamber. Continued fluid flow from the eit chamber results in a reduction of fluid therein and reopening of the fluid passageway between the chambers.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Application
• This invention relates to fluid-flow control valves, and more particularly to pressure responsive fluid-flow control valves particularly adapted for use with Intravenous (IV) infusion applications.
• 2. Background Of The Invention—Description Of Prior Art
• In the administration of blood, and other fluids, it is sometimes required to rapidly increase the flow rate through the IV set to administer a large or larger volume of IV fluid. This is usually done by applying pressure to the IV line. One very common means of doing this is by manually squeezing a bladder or bulb in the IV administration set. When that is done, especially if the needle or cannula, or the other venous access device, cannot accommodate the sudden increase in fluid-flow, the pressure in the line usually quickly rises to a large and often dangerous value. Such pressure can easily exceed 20 psi (greater than 1,000 mm Hg) for a brief period. The use of a syringe to rapidly infuse fluid in pediatric patients through a small needle can produce a similar unacceptable pressure. The generally accepted safe pressure threshold is about 300 mm Hg, or about 6 psi. If the venous access device is not seated properly, this high pressure can be applied to the patient's veins, and damage the vein and surrounding tissue. In addition, some devices in the IV line are not made to withstand such a high pressure, and can leak when subjected to this pressure. It is, therefore, desirable and necessary to protect the patient/recipient from such dangerous, and possibly damaging, high pressure.
• There are numerous examples of valves for use with IV (intravenous) administration sets and devices. However, valves, such as those shown and described in U.S. Pat. No. 4,146,055 patented on Mar. 27, 1979 to F. E. Ryder et al for “Valve Structure”; U.S. Pat. No. 4,230,300 patented on Oct. 28,1980 to H. L. Wiltse for “Flow Metering and Shut-Off Valve”; and U.S. Pat. No. 4,332,369 patented on Jan. 1, 1982 to M. Gordon et al for “Adjustable In-Line Intravenous Valve With Locking Mechanism”; require human intervention to adjust the valves which are in no way automatically, and/or otherwise, self-responsive to changes in fluid-flow pressure. While a valve such as the one shown and described in U.S. Pat. No. 5,453,097 patented on Sep. 26, 1995 to J. R. Paradis for “Control of Fluid Flow” may very well permit fluid under unacceptable and dangerous pressures to flow into and out from the valve and from there to a person receiving the fluid infusion. There are also shown and described in U.S. Pat. No. 4,256,104 patented on Mar. 17, 1981 to A. J. Muetterties et al for “Equipment Sets and System For The Sequential Administration of Medical Liquids At Dual Flow Rates”; U.S. Pat. No. 4,316,460 patented on Feb. 23,1982 to J. N. Genese et al for “Gravitational Flow System For The Sequential Administration of Medical Liquids”; and in U.S. Pat. No. 4,417,577 patented on Nov. 29, 1983 to J. N. Genese for “Gravitational Flow System For The Sequential Administration Of Medical Liquids”; but such systems are relatively complex and shut down one IV where a second one is turned on and then act to restrict air-flow when the second IV is finished.
• Other valves intended for use with IV administration sets; such as, for example, those shown and described in U.S. Pat. No. 4,515,588 patented on May 7,1985 to P. J. Amendolia for “I.V. Flow Regulator” and in U.S. Pat. No. 5,988,211 patented on Nov. 23, 1999 to W. D. Cornell for “I.V. Flow Controller” are provided for flow rate control, and in fact show, describe and teach that there are to be both inlet and outlet fluid-flow chambers and that the pressure in the outlet fluid-flow chamber has to exceed the pressure in the inlet fluid-flow chamber to permit passage of fluid to the patient and, as such, unacceptable high fluid-flow pressure entering the inlet chamber will necessitate an even higher and even more unacceptable fluid-flow pressure to the fluid recipient. On the other hand a pressure control valve, such as the one shown and described in U.S. Pat. No. 4,787,413 patented to J. M. Saggers on Nov. 29, 1988 for “Pressure Control Valve”; shows, describes and teaches the use of an intermittent on/off air-flow control that incorporates an inflatable sac that receives a bleed-off from an air duct to operate a plate that, in turn, moves a sealing device away from the opening of the air duct to permit air flow for the end use. The sac, however, when air flow pressure is reduced, returns air flow to the air duct and permits movement of the plate, under spring action, to move the sealing device back into position blocking the exit of air from the air duct and thus from the end use. The air entering the Saggers air-sac does not pass through the sac but is expelled, when expelled, through the air entry opening to the air sac. As such the valve is obviously only suitable for gasses and not for IV uses. It requires manual adjustment by a rotatable shaft and vents the air to the outside rather than confining it.
SUMMARY OF THE INVENTION
• It is therefore an object of this invention to provide new and novel pressure responsive valves.
• It is another object of this invention to provide new and novel fluid pressure responsive valves for incorporation into intravenous administration and infusion sets and systems.
• It is yet another object of this invention to provide new and novel fluid pressure responsive valves for incorporation into intravenous administration sets and systems with relative ease, within the fluid-flow path between the source of the fluid and the patient/recipient that is to receive the fluid, and permits normal fluid flow with little or no flow restriction.
• It is yet still another object of this invention to provide new and novel pressure responsive valves, primarily for IV use, which are relatively small in size and volume and which are bio-compatable.
• It is yet still another object of this invention to provide new and novel pressure responsive valves, primarily for IV use, which respond to a predetermined “critical pressure”.
• It is yet still another object of this invention to provide new and novel pressure responsive valves, primarily for IV use, which work passively without operator adjustment and facilitate a normal fluid flow in safe fluid pressures independent of pressure applied to the fluid.
• It is yet still another object of this invention to provide new and novel pressure responsive valves, primarily for IV use, which respond to pressures above a predetermined value to reduce or cut-off inflow of fluid to a pressure sensing device while maintaining uninterrupted flow to the recipient.
• It is yet still another object of this invention to provide new and novel pressure responsive valves, primarily for IV use, for incorporation into or with a fluid warmer.
• It is still another object of this invention to provide new and novel fluid pressure responsive valves, primarily for IV use, that are constructed of materials so that the fluid-flow path can be sterilized and made non-pyrogenic by conventional methods and so that single use thereof is economically feasible.
• Other objects of this invention will hereinafter become obvious from the following description of the preferred embodiments of this invention.
• The instant pressure response valve (PRV) incorporates a deformable sensor chamber. The geometry of the sensor chamber allows normal fluid-flow to proceed with very low flow restriction when the applied pressure is well below a predetermined “critical value”. When the fluid pressure is at or exceeds the “critical value” the valve functions by change of the geometric configuration of the sensing chamber with sufficient force to either overcome the input pressure seen in the chamber or by action of a valve member to crimp fluid flow tubing to the sensing chamber; or by deforming so as to activate a feature in the valve to cut off fluid flow into the sensor chamber; all without interfering with outflow from the valve to the intended use or user. The pressure in the valve is automatically reduced below the “critical value” by the continued fluid flow from the sensing chamber, or part of the chamber, to once again permit fluid inflow. The pressure responsive valve (PRV) utilizes a small number of simple plastic components to accomplish the pressure limiting function, and to maintain very small size, and small priming volume. The components contacting the fluid are relatively easily formed by injection molding or by welding or sealing tubing components, and are presumably sterilizable by conventional means. Example embodiments of simplified valves employing these mechanisms are shown in the detailed description that follows:
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings:
• FIG. 1 is a partially schematic view of an IV administration set or system incorporating and embodying the principles of and the instant invention;
• FIG. 2 is a schematic plan view of a pressure responsive valve incorporating the instant invention;
• FIG. 3 is a schematic side view of the pressure responsive valve ofFIG. 2;
• FIG. 4 is a schematic section taken on line4-4 ofFIG. 2;
• FIG. 5 is a schematic section taken on line5-5 ofFIG. 2 and showing the pressure responsive valve as it would be ready to receive fluid and/or as it would receive fluid with a pressure less then a “critical pressure” for the pressure responsive valve;
• FIG. 6 is a schematic section also taken on line5-5 ofFIG. 2 showing the pressure responsive valve as it would be responding to fluid at or above the critical pressure;
• FIG. 7 is a schematic side view of still another alternative embodiment of pressure responsive valve incorporating the instant invention;
• FIG. 8 is a schematic side view of yet another alternative embodiment of pressure responsive valve incorporating the instant invention;
• FIG. 9 is a schematic side view of yet still another alternative embodiment of pressure responsive valve incorporating the instant invention;
• FIG. 10 is a schematic side view of yet still another alternative embodiment of pressure responsive valve incorporating the instant invention;
• FIG. 11 is a schematic side view of yet still another alternative embodiment of pressure responsive valve incorporating the instant invention;
DESCRIPTION OF THE INVENTIVE EMBODIMENTS
• With reference toFIG. 1 there is generally shown at20 an intravenous IV administration set or system including areservoir22, which, by way of example, may be a pouch or fluid bag containing any of a multiple of different fluids or infusate24 appropriate for infusion into a recipient (which could be a person, animal or the like) as will be hereinafter explained. Anopening26 facilitates providing ahandle28 forreservoir22 to facilitate carrying and/or hanging of same for use. Atube40, of conventional construction, connects anoutput port42 ofreservoir22 to aninlet port44 of aconventional drip chamber46; theoutlet port48 of which is connected to a tube50. A hand pump, bladder, or squeezepump56 may be incorporated into IV set20, to facilitate increasing pressure on the flow of fluid infusate24 should that be necessary, by having its input port58 connected to tube50 and its output port60 connected to a tube62. Tube62 also connects to a conventional fluid-flow control valve orroller clamp64 which is, in turn, connected by atube66 to aninput port68 of a pressure responsive fluid-flow valve70 incorporating the instant invention. Anoutput port72 of pressureresponsive valve70 is connected by atube74 to a needle or cannula76 that is usually inserted into an arm78 of apatient80 for delivery of the potential infusate24 flowing fromreservoir22.
• Tubes40,50,62,66 and74 are of conventional construction and use; as aredrip chamber46,bladder56, and hypodermic needle76 to a patient/recipient80. A piece oftape82 may be utilized to secure needle76 in place. Thus it should be clear thattubes40,50,62 and66 anddrip chamber44,bladder56,valve64, pressureresponsive valve70,tube74 and needle76 together define a fluid-flow path84 for the delivery of IV fluid24 fromreservoir22 to a patient/recipient78. It should be understood that while the various components of IV set20 have been shown as connected and described herein that other suitable connections may be utilized and additional and/or other components may be employed for IV set orsystem20.
• Tube66 (FIGS. 1-4) extends throughinput port68 of pressureresponsive valve70 and terminates at a “T” tube90 (FIGS. 1-3,5 &6) open at itsends92 and94. Pressureresponsive valve70 is fabricated in general as a tube from the same materials astubes40,50, etc. but so as to have a somewhat larger diameter and, for purposes of this specification may be considered to have an upper wall100 (FIGS. 2-6) and a lower wall102 (FIGS. 3-6). A portion of the tube stock from whichvalve70 is to be fabricated is cut to a selected length and welds110 (FIGS. 2 & 4) and112 (FIG. 2) are fabricated at respective ends thereof to secureupper wall100 andlower wall102 together to formvalve70 into a pillow like configuration.Weld110 also securestube66 in place so that “T”tube90 is properly positioned in pressureresponsive valve70 at a pressureresponsive zone108 as shown inFIGS. 5 & 6; whileweld112 also secures tube74 (FIG. 1) in place atoutput port72 of pressureresponsive valve70.Upper wall100,lower wall102 are fabricated from plastic materials which are transparent or translucent and which posses a predetermined amount of resilience and flexibility. The sizing and configuration ofwalls100 and102 is selected so that whentubes66 and72 are in place and with “T”tube90 extending as shown frominput tube66welds110,112 are applied so thatvalve70 assumes said “pillow-like” configuration enclosing a sensing space orchamber120 within inner surfaces ofwalls100 and102 and welds110,112. It should be noted that the normal, usual or at-rest configuration forvalve70 is an oval (FIG. 5).
• When pressureresponsive valve70 is installed in IV set20 (FIG. 1) fluid-infusate24 fromreservoir22 will follow fluid-flow path84 entering pressureresponsive valve70 throughtube66, andinput port68 and “T”tube90, exitingvalve70 throughexit port72 andtube74, to its end use such as by a patient/recipient78. As long as the pressure exerted by fluid24 is below a predetermined “critical pressure”valve70 will remain in its oval configuration, with itswalls100 and102 spaced from open ends92,94 of “T”tube90. As such fluid24 will flow from ends92,94 of “T”tube90 intosensing space120 and therefrom out ofvalve70 through itsexit port72 andtube74. Should the pressure withinvalve70 rise above the predetermined “critical pressure” fluid24 withinsensing space120 will inducewalls100102 and104 ofvalve70 to assume a circular or near circular configuration as shown inFIG. 6.Walls100 and102 will approach or even touch ends92,94 of “T”tube90 and the flow of fluid24 from those ends will either stop or be curtailed. However, the fluid24 already in sensingchamber120, will continue to flow throughexit port72 and thereafter alongflow path84 to a recipient/patient78 because of the fluid pressure in the sensing chamber.
• As fluid24exits sensing space120 the fluid pressure therein will automatically and with no operator intervention be reduced below the “critical limit”.Walls100,102 and104, due to the material and fabrication thereof, will return to their oval disposition (FIG. 5) where they are spaced from ends92,94, of “T”tube90. However, the fluid24 already in sensingchamber120 will be at elevated pressure (near the critical pressure) and fluid will continue to flow out ofvalve70 throughexit port72 and therefore alongfluid path84 to a recipient/patient78.
• With reference toFIG. 7 there is shown an alternative embodiment of pressureresponsive valve150 that could be incorporated into an IV administration set orsystem152, similar to IV set20 (FIG. 1), and at a location in IV set152 similar to that of pressureresponsive valve70 of IV set20.Valve150 is disposed in a housing154 sized and configured to receive a sensing tube orchamber156, which is fabricated from materials similar to that ofsensing chamber120 of IV set20 ofFIG. 1 and withwelds160,162 proximate the ends oftube156 so thattube156 is disposed in an oval, pillow-like, configuration.Weld160 also serves to retain inflow tube orentry170 in place as an entry into sensing tube orchamber156; whileweld162 serves to retain outflow orexit tube172 in place as an exit or outflow from sensingtube156. An action lever174 is positioned in housing154 so that itsresponse arm176 is disposed in contact withsensing chamber156 and so that itspinch arm178 is disposed in contact with or proximate to a pinch orrestriction zone180 forinflow tube170 proximate where it enters sensingchamber156 butoutside sensing chamber156. Apivot182 is formed wherepinch arm178 meetsresponse arm176. The angle at which pincharm178 meetsresponse arm176, and the relative lengths and widths of same are selected to provide appropriate coaction between action lever174 and sensing tube/pillow156 and commensurate operation ofvalve150.
• Tube170 andvalve150 are incorporated into IV set152 at a suitable location so that the outflow from the IV reservoir (not shown) and IV set components that receive that outflow becomes the fluid inflow throughtube170 and intosensing chamber156. As long as the pressure exerted on, or by, such fluid remains under a selected “critical pressure limit” the flow of the IV fluid will continue throughvalve150 andoutflow tube172 and thence to the recipient of the IV infusion. Should the pressure on and exerted by the IV fluid reach the “critical limit” or be in excess thereof, the oval/pillow like configuration ofsensing chamber156 will become rounder (less oval) and that occurrence will effect a reaction ofsensing chamber156 withresponse arm176 of action lever174 to pivot action lever174 clockwise (FIG. 7) aboutpivot182 and movepinch arm178 againstinflow tube170 at pinch/restriction zone180 to thus reduce or cut-off inflow of the fluid intosensing chamber156. The flow of the fluid that is already in sensingchamber156, however, will continue, under pressure, to flow from sensingchamber156 and out through exit/outflow port172. As such the fluid pressure within and exerted by sensingchamber156 onresponse arm176 of action lever174 will diminish permitting the inflow of fluid throughinflow tube170 to urgepinch arm178 to pivot counterclockwise aboutpivot182 andresponse arm176 to followsensing chamber156 as it returns from its reactive circular configuration to its normal oval configuration.
• FIG. 8 shows another alternative embodiment of pressure responsive valve200 that could be incorporated into an IV administration set or system202, similar to IV set20 (FIG. 1), and at a location in IV set202 similar to that of pressureresponsive valve70 of IV set20. Valve200 is disposed in ahousing204 sized and configured to receive a sensing tube orchamber206, which is fabricated from materials similar to that of sensing chamber120 (FIG. 1) of IV set20 and sensing chamber156 (FIG. 7) of IV set152 and with welds210 and212 proximate the ends ofchamber206 so that sensingchamber206 is disposed in an oval/pillow-like configuration. Weld210 also serves to retain inflow tube orentry216 in place as an entry intosensing chamber206; whileweld218 serves to retain outflow orexit tube218 in place as an exit or outflow from sensingchamber206. Amovable piston220 is positioned inhousing204 in contact with anaction wall222 ofsensing chamber206 and for movement towards and away from a pinch/restriction zone224 ofinflow tube216. Apinch valve218 is carried bypiston220 for coaction withfluid inflow tube216 at pinch/restriction zone224.
• Inflow tube216 and pillow-like sensing chamber206 are incorporated into IV set202 at a suitable location so that outflow from the IV reservoir (not shown) and IV set components that receive fluid therefrom (not shown) becomes the fluid inflow throughtube216 and intosensing chamber206. As long as the pressure exerted on or by such fluid remains under a selected “critical pressure” or “critical limit” the flow of the IV fluid will continue through valve200 andoutflow tube218 and thence to the recipient of the IV infusion. Should the pressure on and exerted by the IV fluid reach the “critical pressure limit” or be in excess therof, the oval/pillow-like configuration ofsensing chamber206 becomes rounder (less oval) and that occurance will effect a reaction ofaction wall222 ofsensing chamber206 withpiston220 to move pinch valve228 against and intoinflow tube216 at pinch/restriction zone224 to thus reduce or cut-off inflow of the IV fluid intosensing chamber206. The flow of the IV fluid that is already in sensingchamber206, however, will continue, under pressure, to flow from sensingchamber206 and out through exit/outflow port218. As such the fluid pressure within and exerted by sensingchamber206 will automatically diminish allowingsensing chamber206 to return to its oval/pillow-like configuration and itsaction wall222 onpiston220 will diminish permitting the inflow of IV fluid throughinflow tube216 throughsensing chamber206 and therefrom to the recipient of the infusion.
• FIG. 9 shows another alternative embodiment of pressure responsive valve250 that could be incorporated into an IV administration set orsystem252, similar to IV set20 (FIG. 1), and at a location in IV set252 similar to that of pressureresponsive valve70 of IV set20. Valve250 is disposed in a housing254 sized and configured to receive a sensing tube or chamber266, which is fabricated from materials similar to that of sensing chamber120 (FIG. 1) of IV set20 and sensing chamber156 (FIG. 7) of IV set152 and withwelds260 and262 proximate the ends ofchamber256 so that sensingchamber256 is disposed in an oval/pillow-like configuration.Weld260 also serves to retain inflow tube or entry270 in place as an entry intosensing chamber256; whileweld262 serves to retain outflow orexit tube272 in place as an exit or outflow from sensingchamber256. A reaction device274 is positioned in housing254 so that a relativelyflexible action arm276 thereof is in contact with anaction wall278 ofsensing chamber256 and for movement towards and away from a pinch/restriction zone280 of inflow tube270. Apinch valve282 is carried byarm276 for coaction with fluid inflow tube270 at pinch/restriction zone280. Apinch piece284 extends from anotherarm286 of reaction device274 towards and for coaction withpinch valve282 at pinch/restriction zone280.
• Inflow tube270 and pillow-like sensing chamber256 are incorporated into IV set252 at a suitable location so that outflow from the IV reservoir (not shown) and IV set components that receive fluid therefrom (not shown) becomes the fluid inflow through tube270 and intosensing chamber256. As long as the pressure exerted on or by such fluid remains under a selected “critical pressure or limit” the flow of the IV fluid will continue through valve250 andoutflow tube272 and thence to the recipient of the IV infusion. Should the pressure on and exerted by the IV fluid reach the “critical pressure limit” or be in excess therof, the oval/pillow-like configuration ofsensing chamber256 becomes rounder (less oval) and that occurance will effect a reaction ofaction wall278 ofsensing chamber256 withaction arm276 to movepinch valve282 against and into inflow tube270 at pinch/restriction zone280, and in coaction withpinch piece284 to reduce or cut-off inflow of the IV fluid intosensing chamber256. The flow of the IV fluid that is already in sensingchamber256, however, will continue, under pressure, to flow from sensingchamber256 and out through exit/outflow port272. As such the fluid pressure within and exerted by sensingchamber256 will reduce allowingsensing chamber256 to return to its oval/pillow-like configuration and itsaction wall276 on piston274 will diminish permitting the inflow of IV fluid throughinflow tube272 throughsensing chamber256 and therefrom to the recipient of the infusion.
• Another embodiment of pressure responsive valve300 (FIG. 10) includes a housing ormain body302 within which there is disposed a valve operator308.Housing302 and valve operator308 may be fabricated from materials similar to those described above for the other embodiments and may be circular, square, rectangular or of any other suitable horizontal or vertical cross-section configuration. Valve operator308 includes a flexible silicone diaphragm310 with astem312 extending from its bottom wall and withstem312 terminating at a piston-like valve cap316. Diaphragm310 is seated on a rim318 that surrounds aninner wall320 ofhousing302. Avalve seat330, that surroundsvalve stem312, is supported by afirst ledge332, that extends out fromwall320 ofhousing302 and asecond ledge334 that is supported by aleg336 that extends out from a wall338 ofhousing302.First ledge332 andsecond ledge334 surround but are spaced from valve stem312 to form afluid passageway340 between a fluid entry or in-flow chamber342 forvalve302 and a fluid outflow orexit chamber344 forvalve302. A fluid inflow tube346 is utilized to connect pressureresponsive valve302 into an IV set or system, of the type described hereinabove and shown inFIG. 1, through aninput port348 of input chamber342; while afluid outflow tube350 is utilized to connect pressureresponsive valve302 into an IV set or system through anoutput port352 ofoutput chamber344 ofvalve302. A cap354, providing a cover forvalve300, includes avent hole356.
• IV fluid entering inflow chamber342, of pressureresponsive valve300, through tube346, flows throughfluid passage340 and into outflow orexit chamber344 and then throughoutflow tube350 to either other components of the IV set or system or to the intended recipient of the fluid. Should the pressure of, or exerted by, the fluid exceed a “critical limit pressure” the fluid inoutflow chamber344 will exert sufficient pressure on an underside of diaphragm310 and move valve operator308 alonginner wall320 ofhousing302 until valve cap316 seats againstvalve seat330 and closesfluid passage340 and the flow of fluid frominput chamber312 intooutput chamber344. Since there are no obstructions to fluid flow out fromchamber344 the fluid will flow fromchamber344 throughtube350 and then to other components of the IV set or system and/or then to the recipient of the fluid. As the fluid continues to so flow the pressure inchamber344 will diminish without operator intervention and diaphragm310 will move alongwall320 ofhousing302 until valve cap316 moves away fromvalve seat330 to again permit fluid flow intovalve300 and on to the recipient all automatically and without operator involvement.
• Another embodiment of pressure responsive valve400 (FIG. 11), similar to but different from the embodiment ofFIG. 10, includes a housing ormain body402 within which there is disposed avalve operator408.Housing402 andvalve operator408 may be fabricated from materials similar to those described above for the other embodiments and may be circular, square, rectangular or of any other suitable horizontal or vertical cross-section configuration.Valve operator408 includes aflexible silicone diaphragm410 with a stem412 extending from its bottom wall and with stem412 terminating at a piston-like valve cap414.
• Diaphragm410 is seated on arim418 that surrounds aninner wall420 ofhousing402. A taperedvalve seat430, that surrounds valve stem412, is formed at a lower end of afirst ledge432, that extends out fromwall420 ofhousing402 and a second ledge434 that is supported by aleg436 that extends out from awall438 ofhousing402.First ledge432 and second ledge434 surround but are spaced from valve stem412 to form afluid passageway440 between a fluid entry or in-flow chamber442 forvalve402 and a fluid outflow orexit chamber444 forvalve402.Sides445 of valve stem412 are tapered down and out for co-action with correspondingly taperedvalve seat430. A fluid inflow tube446, of the type described for previously described embodiments, is utilized to connect pressureresponsive valve402 into an IV set or system, of the type described hereinabove and shown inFIG. 1, through an input port448 ofinput chamber442; while a fluid outflow tube452 of similar size and construction is utilized to connect pressureresponsive valve402 into an IV set or system through an output port452 ofoutput chamber444 ofvalve402.
• IV fluid enteringinflow chamber442, of pressureresponsive valve400, through input port448, flows throughfluid passage440 and into outflow orexit chamber444 and then through output port tube452 to either other components of the IV set or system or to the intended recipient of the fluid. Should the pressure of, or exerted by, the fluid exceed a “critical limit pressure” the fluid inoutflow chamber444 will exert sufficient pressure on an underside ofdiaphragm410 to flexdiaphragm410 and movevalve cap416 to seat same againstvalve seat430 andclose fluid passage440 and the flow of fluid frominput chamber442 intooutput chamber444. Since there are no obstructions to fluid flow out fromchamber444 the fluid will flow fromchamber444 through port450 and then to other components of the IV set or system and/or then to the recipient of the fluid. As the fluid continues to so flow the pressure inchamber444 will diminish without operator intervention anddiaphragm410 will flex or return back untilvalve cap416 moves away fromvalve seat430 to again permit fluid flow intovalve400 and on to the recipient all automatically and without operator involvement.
• At times an IV warming device570 (FIG. 12) is employed, as a component of an IV set or system of the type shown inFIG. 1, with an inflow tube572 to receive fluid flow and an outflow tube574 to conduct the warmed IV fluid to the next component and/or the recipient of the IV fluid. Warming device570 includes a case or housing580 which, in turn, receives a warming mechanism582 into a seat584, sized and configured to receive same. The above described pressure responsive valves may be utilized for such IV sets and systems.
• The instant pressure responsive valves (PRV's) operate as a simple components of IV infusion sets and/or systems. The set must be a closed system to maintain both sterility of the infusate, and not expose workers in the field to unsafe fluids. The PRV's are constructed of materials so that the fluid path is biocompatible-compatible with blood products, and does not leach out any substance which is harmful to tissue. Its flow path is readily sterilized and rendered pyrogen free by commonly used means. It is relatively small, with small priming volume, and capable of being placed in-line in the set. It does not contain any electrical components. It operates passively, without requiring the user to make any adjustments or settings and can deliver infusate at unregulated pressures 0 to greater than 1500 mm Hg.
• The instant pressure responsive valves allow for sudden increase in flow so long as the applied pressure remains below a “critical pressure limit or value”, (in the range of about 250 to 350 mm Hg for instance). The valve has a minimal flow resistance when used at typical IV pressures of 50-100 mm Hg, as well as at increased pressures which are below the said “critical value”. The respective valves are formed to provide valves of single “critical pressure limits or values”. It being understood that valves with other “critical pressure limits or values” may be fabricated depending on proposed uses and fluids to be infused.
• The present invention can be used as a separate device in an IV set, can be built into a fluid administration set, or can be integrated into an existing device. The described PRV embodiments may, for example, be permanently bonded to the inflow tubing of a device such as the Blood Heater Disposable Set, which is one embodiment of U.S. Pat. No. 6,480,257, “Heat Exchanger Usable in Wearable Fluid Heater.” to protect the device from excessive pressure, or to protect the patient distal to the device, from excessive pressure. The disclosed PRV's may may be fabricated with luer or other fittings for insertion into an IV administration set or system.
• While only certain specific preferred embodiments of the invention have been described, it is understood that, many variations thereof are possible without departing from the principals of this invention as defined in the following claims.

Claims (20)

1. A fluid pressure responsive valve, for insertion into a predetermined fluid-flow path, and responsive to fluid pressure of a predetermined amount; comprising:

(a) deformable fluid-pressure sensing means insertable into a fluid-flow path and responsive to a predetermined fluid pressure;

(b) fluid entry means for said fluid pressure responsive means to receive fluid flow from the fluid path and direct the fluid into said fluid pressure sensing means; and

(c) fluid exit means from said fluid pressure sensing means to direct fluid from said fluid pressure sensing means back into said fluid flow path;

(d) said fluid pressure sensing means reacts to a change of fluid pressure, within said fluid pressure sensing means, in excess of said predetermined amount to restrict and/or close-off fluid flow into said fluid pressure sensing means while permitting fluid flow from said fluid pressure sensing means.

2. The fluid pressure responsive valve ofclaim 1; wherein, said fluid pressure sensing means further reacts to the flow of fluid from said fluid pressure sensing means and a resulting reduction of fluid pressure therein below said predetermined amount to permit the flow of fluid into said fluid pressure sensing means.

3. The fluid pressure responsive valve ofclaim 1; wherein, said fluid pressure sensing means is fabricated from selected materials and so as to be capable of being in a first configuration when fluid at a fluid pressure less then said predetermined amount is to pass into, through and out from said fluid pressure sensing means and of being in a second configuration when fluid at a fluid pressure at or above said predetermined amount is to be restricted and/or cut-off from entering said fluid pressure sensing means but permitted to flow from said fluid pressure sensing means.

4. The fluid pressure responsive valve ofclaim 2; wherein, said first configuration of said fluid pressure sensing means is substantially an oval pillow-like configuration and said second configuration is substantially a circular configuration.

5. The fluid pressure responsive valve ofclaim 4; wherein, said fluid pressure sensing means includes weld means proximate respective opposite ends thereof that facilitate fabrication of same into said first, oval pillow-like, configuration while also permitting said sensing means to re-configure to said second configuration.

6. The fluid pressure responsive valve of claim ofclaim 4; wherein, said fluid entry means includes a fluid flow directing means extending part way into said fluid pressure sensing means so that when said fluid pressure sensing means is in said first configuration fluid may flow there into and when said fluid pressure sensing means is reconfiguring to said second configuration fluid flow into said fluid pressure sensing means is restricted and even cut-off from entering said fluid pressure sensing means.

7. The fluid pressure responsive valve ofclaim 6; wherein, an inside wall of said fluid pressure sensing means moves towards said fluid entry means when said fluid pressure sensing means is re-configuring to said second configuration thereof.

8. The fluid pressure responsive valve ofclaim 3; including,

(a) housing means within which said fluid pressure sensing means is disposed; and

(b) action means positioned in said housing means for co-action with said fluid pressure sensing means such that upon re-configuration of said fluid pressure sensing means from said first configuration to said second configuration said fluid pressure sensing means will co-act with said action means to cut-off and/or arrest fluid flow into said fluid pressure sensing means.

9. The pressure responsive valve ofclaim 8; wherein, said action means includes a pivoting lever with a first lever arm disposed to co-act with said fluid pressure sensing means as it reconfigures between said first configuration thereof and said second configuration thereof, and a second lever arm disposed for co- action with said fluid entry means to either permit or restrict and/or cut-off fluid flow therethrough.

10. The pressure responsive valve ofclaim 3; wherein, piston means are disposed for co-action with said fluid pressure responsive means as it reconfigures between said first configuration thereof and said second configuration thereof, said piston means including pinch means disposed for co-action with said fluid entry means to either permit or restrict and/or cut-off fluid flow therethrough.

11. The pressure responsive valve ofclaim 3; wherein, reaction means are disposed for co-action with said fluid pressure responsive means as it reconfigures between said first configuration thereof and said second configuration thereof, said reaction means including first and second pinch means between which said fluid entry means is disposed and which co-act with said fluid entry means to either permit or restrict and/or cut-off fluid flow therethrough.

12. The pressure responsive valve ofclaim 2; wherein,

(a) said fluid sensing means includes a first sensing chamber disposed and configured to receive fluid flow from said fluid entry means and a second sensing chamber disposed and configured to receive fluid from said first chamber and permit fluid flow to exit said pressure sensing means through said fluid exit means and piston means disposed between said first sensing chamber and said second sensing chamber and co-acting therewith and responsive to an increase in fluid pressure to or above said predetermined pressure to restrict and/or cut-off fluid flow from said first sensing chamber to said second sensing chamber.

13. The pressure responsive valve ofclaim 12; wherein, said piston means includes a piston seat formed on wall means disposed between said first sensing chamber and said second sensing chamber.

14. The pressure responsive valve ofclaim 13; wherein, said piston seat and said piston are fabricated with corresponding tapered surfaces which co-act to restrict and/or cut-off fluid flow from said first sensing chamber to said second sensing chamber.

15. A fluid pressure responsive valve, for insertion into a predetermined infusate flow path, within an infusate heating device, and responsive to fluid pressure of said infusate of a predetermined amount; comprising:

(a) deformable infusate pressure sensing means disposed and configured to define a sensing portion of said infusate flow path and responsive to a predetermined fluid pressure;

(b) fluid entry means for said infusate pressure sensing means to receive infusate flow from the infusate flow path and direct the infusate into said infusate pressure sensing means; and

(c) fluid exit means from said infustae pressure sensing means to direct fluid from said infusate pressure sensing means back into said infusate flow path.

16. A fluid pressure responsive valve, for insertion into a predetermined fluid-flow path, and responsive to fluid pressure of a predetermined amount; comprising:

(a) a deformable fluid pressure sensing device for insertion into a fluid-flow path;

(b) a fluid entry for said fluid pressure sensing device;

(c) a fluid exit from said fluid pressure sensing device to direct fluid from said fluid pressure sensing device back into said fluid flow path;

(d) said fluid pressure sensing device being configured and constructed to react to a change of fluid pressure, within said fluid pressure sensing device, in excess of said predetermined amount to restrict and/or close-off fluid flow into said fluid pressure sensing device while permitting fluid flow from said fluid pressure sensing device.

17. The fluid pressure responsive valve ofclaim 16; wherein, said fluid pressure sensing device further reacts to the flow of fluid from said fluid pressure sensing device and a resulting reduction of fluid pressure therein below said predetermined amount to permit the flow of fluid into said fluid pressure sensing device.

18. A method of restricting and/or cutting off fluid flow through a fluid flow path in response to a predetermined fluid pressure; comprising:

(a) providing a fluid pressure sensing device for insertion into a fluid-flow path;

(b) providing a fluid entry for said fluid pressure sensing device;

(c) providing a fluid exit from said fluid pressure sensing device to direct fluid from said fluid pressure sensing device back into said fluid flow path;

(d) fabricating said fluid pressure sensing device so as to react to a change of fluid pressure, within said fluid pressure sensing device, in excess of said predetermined amount to restrict and/or close-off fluid flow into said fluid pressure sensing device while permitting fluid flow from said fluid pressure sensing device.

19. The method ofclaim 18: including, forming said fluid pressure sensing device from a selected length of flexible tubular material and welding the ends of said selected length of tubular material together to form a deformable pressure sensing device with a pillow-like configuration.

20. The method ofclaim 18; including forming said pressure sensing device with a fluid entry chamber and a fluid exit chamber connected together with a fluid passageway and providing a valve operating device responsive to a change of fluid pressure within said fluid entry chamber in excess of said predetermined amount to restrict and/or close-off fluid flow from said fluid entry chamber to said fluid exit chamber while permitting fluid flow from said fluid pressure sensing device.

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