Valve system with removable fluid interface

VALVE SYSTEM WITH REMOVABLE FLUID INTERFACE

Background of the Invention

1. Field of the Invention

The present invention relates generally to systems for controlling fluid flow, and in particular to medical infusion technology, although other embodiments are possible.

2. Description of Related Art

Prior art systems for controlling the flow through an intravenous line typically act on the exterior of the standard intravenous tube. For instance, peristaltic pumps are used to pump intravenous flui^d. These peristaltic pumps force the fluid through the line by squeezing the intravenous tube. Similarly, in order to restrict or cut off the flow of fluid, a clamp is used to squeeze the intravenous tube.

The advantage of these systems is that the pump or the clamp is not contaminated by coming into contact with the intravenous fluid״ The intravenous fluid remains inside the intravenous line. Thus, the pump or the clamp does not need to be washed or sterilized between uses.

The disadvantage of these systems is that squeezing the standard intravenous tube is an inefficient way to control the flow through an intravenous line. It takes a great deal of force to squeeze and keep shut an intravenous tube.

Additionally, after repeated or prolonged squeezings the intravenous tube tends to lose its rounded shape and become oblong in cross-section. Thus, even when it is desired to ״ 2 have unrestricted flow through the intravenous line, a tube that has undergone prolonged or repeated squeezings nay restrict flow. Furthermore, a peristaltic pump that works on the outside of the intravenous tube cannot be used to deliver precise quantities of intravenous fluid.

summary of the Invention

The present invention provides a system for providing a valve for controlling flow of a fluid through a line (e.g., 10 an intravenous line), wherein the portion of the valve that cones into contact with the fluid being controlled can be easily removed from the rest of the system and disposed of. This disposable portion is held against a fixture, which is that part of the system that is permanent and contains a 15 control apparatus that opens and closes the valve. In certoin^mbj^^ the system nay have nore than one valve and nay further have one or more pressure conduction 1 chambers. As its name suggests, a pressure conduction ־ chamber is used to transmit pressure to the fluid. As 20 ן explained in the parent application, pressure may be applied to the fluid in order to measure the fluid flow rate. Alternatively, pressure nay be applied to the fluid simply to force the fluid through the line, i.e., pumping the fluid (which nay be done with positive or negative pressure).

Preferably, the pressure conduction chamber is used for both flow measurement and punping.

The disposable portion of the valve, i.e., the disposable conduit, contains a housing, through which a fluid path runs. The fluid path enters and exits the 30 housing through at least two ports (one input and one output), which connect to the intravenous line. Disposed in the housing in the fluid path is/at leasrt/one valving chamber. The fluid path enters and exits the valving chamber at two mouths. Preferably, at least one of the two 35 mouths in the valving chamber is located on a protuberance from the surface of the housing. A flexible impermeable membrane is disposed on the surface of the housing and forms one of the sides of the valving chamber. The membrane 16 so disposed on the housing so that the flexible membrane can cover at least one^f_the mouths when a sufficient amount of pressure is applied to the side of the membrane facing away from the valving chamber. It is therefore preferred^to locate at least one of the mouths opposite the flexible Membrane, although the mouths could be oriented differently. The housing should be rigid enough so that the covering of the mouth by the flexible membrane can be reliably effected 10 such that the membrane forms a seal over the mouth. If the housing is not rigid enough, it may be difficult to force the membrane to seal the mouth.

It may desired to use a disposable valve that would, in one mode, allow relatively unrestricted flow and, in another 15 mode, merely restrict flow through the fluid conduit without completely stopping flow. To accomplish this, the geometry of the mouth may be altered so that, when the membrane is forced against the mouth, the mouth is not completely ו sealed, thereby allowing ^{sone flow throu}9^{h the conduit}־ * 20 | disposable conduit may_containj^o IcoulT^be^UBed^t^reduc^flow, while the other could, be use£ Ito^stop^XlQW through the fluid conduit.

ץ'' in a preferred embodiment of the disposable cgnduit, the housing defines a pressure conduction chamber, located 25 in the fluid path. Valving chambers may located between the pressure conduction chamber and each of the ports. A. flexible impermeable membrane also defines one of the sides of the pressure conduction chamber. Preferably, different portions^-^?ThTsame sheet of flexible material can form the 30 flexible membranes for all the valving chambers and pressure conduction chambers, in one embodiment, the housing is disposed in a bag made of flexible material, which forms the flexible membranes over the valving chambers and pressure conduction chambers.

The fixture, that part of the valving system that is permanent, includes a mechanism for holding the disposable fluid conduit in such a way that the disposable fluid souths BO conduit My be .«־Uy and guicfcly detached fro» th. fixture (however, not 0־ easily that the disposable fluid condu (however, nov ' fixture also includes an nay be detached accidently). Th. . .

apparatus for controlling, the flow of fluid through th line.־ Wds control is accomplished by »oving th. «»brane covering the valving chamber so that th. ® _g<> alternately (i) forced against at least one0 as to prevent flow through the valving chamber«^ M forced so that flow through the valving chamber is permitted. The fixture may apply_a control flu membrane) wh־en the fixture increases control fluid, the membrane may be forced .gal־״t *1.« one of th. «״ths, and when the fixture lowers of the control fluid, the membrane may be allowed to mo_ away from th. at least o,ne mouth. Alternatively, mn actuator may be used to apply pressure to ST. actuator may include . piesoelectric benderTh. fixture may also include an apparatus for transmitting pressure to the ««branes covering the preseur. °^onduc^“ chambers. Preferably, this apparatus uses the same c ntro fluid (e.g., air) that is used to control the valve1 ־» disposable conduit for transmlttlhg the pre״־־«to th. membrane covering the pressure conduction chamber. It wil be appreciated that a microprocessor, or other electronic controller, is preferably used for regulating thepressure of the control fluid or the position of the ectuator.

prlaf Description of th. PraWihfl5

Figs. 1 and 2 show cross-sections of two different embodiments of the ,invention, Including a fixture and a ϊΠρ^Λΰ portion with one valving chamber.

־ Fig. 3 shows a plan view of the rigid housing of a disposable cartridge having tin valving chambers and two pressure conduction chambers.

... Fig. 4 shows a plan view of the disposable cartridge of Fig. 3 and its internal fluid paths.

Fig. 5 shows an end view of the disposable cartridge of

Figs. 3 and 4.

Fig. 6 Show, a plan view of the face of the fixture, or central system unit, against which the dieposable certridge of Figs. 3-5 is placed. ׳

Fig. 7 shows a plan view of an alternative disposable cartridge and its internal fluid paths. ____ ...

Fig. 8 Bhows a cross-section of^nother alternative disposable in contact with a fixture.

Fig. 9 shows a cross-section of an embodiment of the invention, including afixture using pieae-electric benders and a disposable_pertipn with one valving chamber, wherein_ ״thi valve is open. .

Fig, 10 shows a cross-section of the embodiment shown in Fig. *, wherein the valve is closed.

Fig. 11 shows a cross-section of a preferred embodiment of the dieposable conduit, wherein the rigid housing placed in a bag.

Fig. 12 shows a cross-section of the disposable conduit shown in Fig. 11 and a fixture for holding the disposable conduit.

Like reference numerals refer to like items.

npacrlptlon of &lt;W&lt;f&lt;° Embodiments

A simple embodiment of the present invention ie shown in Fig. 1, wherein a single valve is provided. The fluid path passes from ths fluid line input 51 through the valving chamber 63 to the fluid line output 62. The valving chamber 30 63 is made of a rigid material, such as molded hard plastic.

The fluid path enters the valving chamber 63 through a first mouth 64, which in this embodiment ie located on a protuberance projecting from the wall of the valving chamber opposite the flexible membrane 65. The fluid path exits the 35 valving chamber through a second mouth 67, which in this embodiment is flush with a wall of the valving chamber.

Fig. 2 .hows another embodiment, wherein both mouths, 64 and ״ 6 sides of the Bembrane needs to to effect a *eel

״. located o״ pr־t״b־ra־־־״. ^lve **“ .

Uf.rred) eabodiaent» »ay have both »״־th־״״ ־» wall of th־ valving ch.»b.r or ־ven ״־ th® valving ehanber. I״ *ha־ ־־-b־di»״־t־J* bo »or. n־xibl״־ ,־a « ¹⁸ *“^{״ 8}״^f״cult over the Bouth. orovided by a

0־״ V״־ of th־ valving ״^־ « « P״ flexible i»per»eable »־!brane _pr0vid־s a chamber 1» placed against a x u fluid _eupply control prefrably The fir.t ״״a ₆₆ to the exterior ״־rf.₆₅ ־־_BUCh south «4 i־ located with respe _lnoteasea in the »״־—.«.»״ - .x .< « -ם 1־״״ Μ -> ״ ״״״״ . - «״ urged agai־״t the »״־th «.״״£ _BMbw־ ._grlps. θη״.־־ for the »־»bra־״» » ־״* *hat W the »״־th «4 in order to prov . . _BOUth ήalternative eabodiaent, the 9«°» completely seal it, altered 0־ that th. »־»br.״ »־׳י ־״* “X^he thereby reducing, but not . ״P cutting a notch in conduit. Such a valve »ay be bui.i _ln the protuberance that th״־«־ h _loCated _oppoalte ־ eabodiaent the ״־« *״־־־־th ־ . _Qf fro» th־ flexible »־»bra־־ .״ th־t * control ״״H 1- to ־P״־ the urged again־t »״־th « . _reB8ure !, _decrea־־d until fluid path, the control flu P . uesbrane 65 the fluid pressure in the flu« _t0 fl״־ away fro» the »״־th 64,t־re _{protuber1״cea nay be} cade בה: י ::x .*—¹: “ ׳r x:^toalter at what point the »־»br.״־» ־״« ““ ^lnt° °°ⁿwith the »outh. naraite a aechanical

Th־ structure of th־־־ enbodinente per»«־ advanX ־<״ control flu« t״־d־> ־ .re ״־ .long the ״־rf־ ־־־f th. ״ diameter of the mouth 64, the fiuia .15

- ד acta on only a email area of the nenbrane «5, When the membrane is sealed against the mouth. Thus, the control fluid line pressure can produce »ore force on the »embrane than the fluid input pressure (since force is equal to 5 pressure tines orsa). The fig. 2 embodiment is useful if the output fluid »ay be highly pressurised, since the second^ m־Sth77 in the this embodiment only permit» a small_arga_ot ttTwirane to be exposes to the output fluid, when the nenbrane is sealed againet the second mouth.

r־^ Th® pressure in the control fluid supply line nay be controlled using a stepper notor enploying a can-actuated (piston or other neane known in the art. In a pieton *⁸⁸י® embodiment, a piston is used to compress the control fluid in the line, thereby increasing the control fluid pressure 15 and causing the nenbrane to seal one or two of the nouths in the valving chamber. The piston is then retracted to decrease the control fluid pressure and thereby open the valve.

In an alternative embodiment the control fluid is 20 stored in an airtight reservoir in communication with the control fluid line. A compressor is used to increase the control fluid pressure in the reservoir, and asolenoidoperated valve, is used to open a communication pathway between the reservoir and the control fluid line, thereby 25 increasing the pressure in the control line. (The foregoing ie controlled by a microprocessor.) Alternatively, the reservoir may be pressurised using a hand pump. To open the valve in the disposable conduit, the communication pathway between the reservoir and the control fluid line is closed, 30 and the control fluid line vented to ambient atmosphere.

The present invention provides numerous advantages. Primary among these advantages is the combination of mechanical reliability with low cost and ease of manufacture. The valving systems shown in Figs. 1 and 2 are 35 mechanically reliable because they have relatively few moving parts. The valving chamber 63 is fixed, as are the fluid line input 61, the fluid line output 62 and the any of be made of

Further, the flexible membrane 65 may intravenous bags.

has is in

The control fluid line 6«. The only moving pert, are the ׳control fluid pressure generating ».ana and U>־ nenbrane' 65. he discussed .hove, the control fluid preeeure generating means ay be Implemented using a ”**W “ “ end pieton. Pieton assemblies, because of the liBited g of otion involved, are aleo mechanically reliab e. e further discussed above, the control fluid preeeure generating means may •1»־ * impi«.״־*.‘ ^uein’ ^aair reservoir. The only moving part, in such an ״־<״״“ ere the valve connecting the reservoir to the control line, and the eans used to pressurise the ^re8®™“;

Further, the flexible membrane 65 may t_ _ a number of readily available, inexpensive ״»^terla^ example, the flexible plastic used to make 1.. Thia material is known to be extremelyrugg to being relatively inexpensive. Further, this plastic excellent gripping properties.

Another advantage to using e membrane-based system that there are none of the known disadvantage־ inherent valving eysteme based on squeezing an intravenous t first disadvantage in a squeezing system is that it is relatively difficult to obtain a perfect closing of the line. A relatively large amount of energy must be expended to pinoh an intravenous line closed, because of the difficulty in folding the edges of a pinched tube. A further disadvantage is cold flow. An intravenous tube ״ill, after repeated openings and closings, tend to chang shape around the pinching Bite. This in turn decreases th. mechanical reliability of the intravenous delivery system.

Kone of theee disadvantages are present in a membrane-base system. As discussed above, because of the mechanical advantage inherent in this system, relatively little energy is required to keep the valve closed. And because there is no pinching involved, cold flow does not present a significant problem.

Further, the device does not require precision molding. The valve will tolerate a broad range of manufacturing the valve chamber mouth !»perfections. For exanple, oven if « is not perfectly aligned, the nembrane w _llght1y off

.״. .«:״ ‘.« ״ .״ center, the »«.brane will still . _are that and »«־brane ell »ay be con conduction chanber.

unit that »ay also include a p _nl״tic structure

Th. »,»br.״. »ay *. .«ached to a rigid plastic stru that is sized to fit snugly onto a system unit, integral with received by a

In one embodiment of a ¹¹־*י conduction chamber and membrane-based the be the central flow control be made be . *״«natively, the valving aysten nay _a drip chanter structure, which would specially adapted fixture.

flow control system, it is contemplated to mold the pressure together with input_of plastic. The ^¹^tTnXne nay he ־־״d 0־&lt;» ־ nenhr.־״ « i־&lt;״ ״ valves end the pressure conduction ™ “°ζ.

disposable units are is

When being us.to _{8h0wn in pi9}. 5, affixed to a receiving t _ieeicted in Pigs. ³“ »» ״ u״ ״״» ».

5. The housing unit may be e _Sea1ing rings clamp, or by other means own pathways, and are provided to insure that the_{J״ this}the measurement gas pathways r θ _receiving block embodiment, it is Central flow control system would be an Integra par _de81rable arrangement, «nit It will be seen that this is a unit. It transport intravenous fluid,

The disposable unit ״_ould _{be 1Bp}״_otical to and must therefore be sterll uses The clean and sfrlliz. s־״h . ¹’*¹י »״״ ”* receiving block, on the other hand, Bust be sturdy, to

Insure a proper seal, and to Insure proper operation of the valves.

The controller (i.e., the microprocessor) nay be 5 programmed to perform a safety protocol during calibration of the device to check that all the seals are tight. During such a protocol, control fluid pressure to various valving chambers may be manipulated, and the resulting pressure changes may be monitored using the pressure transducers in 10 the central flow control system unit. Aberrant conditions would cause an alarm state to be entered into.

Not all pathways would be required for all applications of the controller unit. A universal housing unit that would embody all possible pathway configurations for various 15 situations may be designed and manufactured. The receiving block would be adapted for specific controller applications. Alternatively, the microprocessor could be programmed to valve off pathways, as required.

Fig. 3 shows one embodiment of a disposable housing 20 unit (or cartridge or cassette). This particular unit has two concave indentations 71 for pressure conduction chambers, so that two fluid control systems may function in parallel. In a preferred embodimertt, two fluid control systems are used to deliver intravenous fluid to a patient 25 in order to make the flow of fluid smoother. As one indentation 71 is dispensing, the other is filling. Thus, fluid is delivered in more closely spaced and smaller pulses, rather than larger pulses that come less frequently and that have longer periods between them.

The disposable cartridge shown in Fig. 3 also has ten valves 72 of the type depicted in Fig. 1, with the input 61 and the output 62 showing. This side of the unit has a membrane stretched across and attached to it that serves as the membrane (65 in Fig. 1) for the valves 72 and the membrane for the indentations 71. (See item 91 in Fig. 5. )

Fig. 4 shows a bottom view of the disposable cartridge showing th־ internal piping or passage״“ *״’¹*י ׳» ־/־״ inside the disposable cartridge and which cm* various valves 72, the _{and outpu}t.

various inputs and ־“ .*״*״־ ‘ _{for exanp}1־, th. top may be arranged in a variety two ports 82 and 83 may both be input₈₆ «־_fflay di־״r״־t - :־־ .:::?:ש.Pl.־ o&lt; «״ fluid fr־B the container for testing or additional ».di״־״־־ tc the J. ζ_{β flu}id shows an end view of these por ׳ _BeBbrane 91 for aide of the indentations 71 in Phant־». The the valves 72 l disposable cartridge ״־ the .«.^“ _״billows in u_ container.

Fig. 6 shows the face against which the di _ _7J and the containers 71 is attached to the and out depending on how .uch fluid is in the u. of the fl״־ control systeu unit, disposable shown in rig^{10 3-5} .־^{p aoe}.;d held by a ״־1־P19״ device. There ^a״ ״!dentations 1״־ 1־ the sy־t״ * ״״״ ״־ m indentations 71 on the disposable. These i״d־ on the systen unit can contain a BSasureB 9 on th y indentation has an aeasuring the fluid flow rate. * ״״. _Tha aperture 103, through which ueasureBent gas P־־־ ^P aas can be used to measure how such of th neasurement gas can ne the —“ . fluid flow rate, as we _ ״_nn4._a1n_er.

container, 1—

Fig. 6 also »hows 1 valves 72 and a control control fluid passes. The pressure ״״— m - &lt;«. .¹ ״ .. ..

the disposable is claaped against t y alternative disposable housing ״״« .nd to fore, fluid ״־‘ °^{£ the} ־ontalner.

receptacle־, or dl.pl־־, ^tha fluid line «6, through which the valve ! conduction chamber are

״ 12 5

3-4.

Fig. 6 shows a s housing unit flow control This disposable 2 and two connected which can and valve beveled 1_ output 62a that like the disposable housing unit in ’ container indentations 71, fluid pathways 81 and input/output port. 83-88. Th. rig. 7 ’ uses the valves 111 shown in rig. 3. .P difference and the disposable functions the same way ״ ״״״ □imple embodiment of the disposable 124 clanped against the face of the ce _ unit 135 designed for this

124 has only one pressure conduction chamber , 1 »״λ a The input 61a of valve A is valves, A and B. The inp , _{ion m}, to the intravenous line 1 by P be inserted in the intravenous tubing. Valve A ״ B are of the type depicted in rig. 3) e X 54a and 67a ״.־ be see״ i״ valve X. Th־ ד- of valve ».leads in to the left half pressure conduction chamber ״־ !. indentation 71 in th. dis * 4־ 1 ־

״.“““ .״.

the disposable, rat , . _the pressure the membrane 65a for valve A, t e me _νβ!_νβ b.

conduction chamber 3, and the membrane_ 1 ״“.״״&lt;.״״.״״.« -4*. י or which is connected to an axr j

X ; XU »act and *rth, thereby .ff״־־ng the Xi and ־Un, of valve A by P*׳״* back from the mouths 64a and 65a against mouths 64a and 67a and pushing the membrane . In this case, the air is

67a functioning as the valve control fluid.

measurement gas

Aperture 103 provides a path for tne m_______ __ (which can be ,air) from the pressure the rest of the system (including, for ־xampl־,the reservoir). The membrane 3, which, as no ' of the flexible sheet »1, ־״v־s back and forth how much fluid is in the pressure conduction 0 .

Because the pressure is changed frequently during conduction chamber 2 to

98152/2;

and 106, shown in Fig. 1. Instead of using a the fixture uses nenbrane. The_ face of !״ ״“.״׳״ .. .״.־,־ .«״״ ,.

״ ״_:—־ ״ :.ע:?״—עש״ ד ״ < ... .ר ;™״ץ ״ ־*״. . ...>. ..

־.. <«<> «< . .. «. by means of air supply ⁰ .♦׳!®nt A protusion ¹²² *’ΐ ג X. ths prop״ sealing -״־ך the events of th. disposal ^¹״“ζΧ^ΧΓ ״. disposed .round X°^X^^^״t_of the ״,s. 9 and 0 ץ־«^^^^—piTand Fig. 10 system, wherein Fig. _rt4_Bnosable portion of the shows the valve »¹״״^ disposable portion of the velve valve 7־ is very .W _{ίβ dl£feren}t.

control nuid_t0J!0ve the Jje1^£S!!_i5&lt; ״ apply. » ־ _נ£ ThTflxt״^ is »ad־ of ׳״““״“ ־

---- 421 ו״ An actuator moves the face of th yet durable, ma er^ _forceB the membrane 65 ן In the valving chamber and allows the ₆₅ to »־ve away fro» the »־uth 64. »־ bender 23 made of pie20 In Fig. 9 the bender 23 is in its normal in Fig. 10 the bender « is aotuated by an , thereby bending the bender ־״

- --, that the face of the fixture

------ »״״th 64. Conversely, the the nenbrane 66 over th -«»ו™, it forces is that in its normal position it tore ihe mouth, and when actuated by an i u.w bender pull, bach the fa־«- of the allowing the »enbrane to cove off of the fixture, so that against the mouth 64 membrane L_ shown in Figs. » “^{nd 10 uee} * electric material. position, electric potential forcing the rod 22 down so forces/— bender may be set so the membrane over Ielectric potential the fixture, thereby 1----mouth.

Conversely, the “

The bag needs at least one .»״ shows a cross-section of b preferred «*odia-nt of the disposable conduit. In thio e״bodi״ent ־ rel.tively rigid housing 34 1« placed inside e beg 35 nade 0 . flexible, impermeable material. The bag needs at least on opening trough which the ports of the housing ~y P״ ־״* be connected to the intravenous line. Preferab y, opening of the bag 1. f־״־d relatively tightly e«m»J *. ports of the housing, so that ״״id spillage 1« when the intravenous line is disconnected free the disposable conduit. Λ pressure conduction chaster 71, veil as any valving chanters (not shown) or any o e pressure conduction chambers (not shown), are oc too side of the housing 34. Fluid P»«32 ״ are formed as grooves on the underside of the housing.

yl״״»« . too side of the flUlC like fluid paths nay be placed in tn p *

--—~«2 nay be connected housing. Some groove-like fluid paths ״ay to the pressure conduction chamber 71 by means of vertical ^P,,thexn³Fig. 12 the disposable fluid conduit of Fig. ־1 ״ held .gainst a fixture 45 by means ־« . one end is hingsdly attached to th. fixture 45 .nd at the other end may held to the fixturd 4־ by ״.a־ ־״ .threaded screw and nut 44 or some other type of guick-release 4-h»♦1 ׳« able to apply sufficient force to fastening neans that is able to app y the disposable fluid conduit while holding the conduit- A gasket 41 on the fixture serves to seal the bag ar the pressure conduction chamber 71. Thus, a po ° bag forms the »״־brane on the pressure ״־**» **£ Another gasket 4־ is pl־־־d ״־ th. d.־P P־ *־ « * *^hefixture eo os to for. seals around the groove-like fluid path. ». it any groove-like fluid paths are located on the top side of the housing, the gasket on the face of the fixture ״ay he shaped .0 as to for״ β־־!β around th.. groove-lUte fluid paths. The clasping portion of t fixture^ «ust be able to exert enough force on the ״^BlTiiuld conduit, 0־ that the gasket ״ay create * effective seals. This type structure is preferred, be־.״.־ it Is much easier to aanufacture a housing 34 with groovelike fluid paths 33 on Its surface than to manufacture a housing with fluid paths encased inside the hou g the beg 35, in addition to forming the on pressure conduction chambers end the valving ^cb׳‘״*״

’.so used to seal the groov.-Uke fluid P«th. 0־ mt ״ d does not leak fro. ״״ ־״־“ P.» « ^int0 “ ^adja“^{nt ״Ui}path 32.