AU657089B2 - Flow controllers for fluid infusion sets - Google Patents

Description

-1- FLOW CONTROLLERS FOR FLUID INFUSION SETS The present invention relates to flow controllers for administration sets for the purpose of delivering fluids into the human body. Infusing fluids into the human body is done for a variety of medical reasons and there have been many administration sets which have been developed for this purpose.

It is presently well known to provide for liquid infusion into a living body by providing a container, acting as a reservoir for holding liquid to be infused and which is connected to the body via a conduit in which pressure supplying the fluid is created by either a gravitational pressure head or by pressure generation means.

In these systems there are three main factors controlling the actual infusion rate of the liquid to be infused into a patient. The first is the height that the liquid container is held relative to the outlet and the second factor is the degree of back pressure which is experienced as the liquid enters the patient. It is a disadvantage in such a simple arrangement that the back pressure can provide significant changes in flow rate and this can be altered almost casually without intention by the patient perhaps rolling over in bed or simply changing to a more comfortable position. A third factor is the viscosity of the 20 fluid being infused. The viscosity can be changed due to temperature variation or change of fluid.

Furthermore, it is necessary on many occasions to keep the flow rate of the liquid within selected limits and this becomes either very difficult c impossible with the simple gravitationally actuated device of the type discussed.

o

J

o r o o

D

o u r Thus, in the past it has been very difficult to provide a fluid for infusion into a body at a constant flow rate and to ensure that a selected quantity of the fluid is infused into the body at any given time and with a high degree of accuracy and without the unwanted effects of back pressure. The present invention seeks to improve administration sets used for the purpose of infusing fluids into the human body by providing a flow controller which is adapted to be used as an attachment to the administration set or alternatively to be integral with an administration set.

p:\wpdocs\dys\specie\438650\ars -2- The present invention therefore comprises: a fluid flow controller for insertion in a selected position in a fluid flow line of an administration set. More particularly, the invention resides in a flow controller adapted for detachable or fixed attachment to an administration set, said flow controller essentially comprising; a housing having a chamber inside which a flow restrictor fits and which is adapted to enable attachment to the administration set or to be integral therewith, wherein when fluid flows through said administration set to a patient via said flow controller said flow restrictor thereby restricts the flow of fluid to the extent that the fluid discharged into the body of said patient takes place at a relatively constant rate largely irrespective of viscosity or fluid, body temperature or height and back pressure.

The present invention seeks to provide a convenient form of providing a controlled flow in an administration set and like infusion apparatus and to overcome the aforementioned problems.

According to one aspect of the present invention, there is provided an in line fluid flow controller for use with a fluid administration set for infusion of flfid into the body of a patient, the administration set including a means for connecting the administration set to a reservoir of fluid, said connecting means being connected to a supply line having 20 the flow controller therein, said fluid flow controller comprising: a housing; S"an inlet to and an outlet from said housing; a plurality of feed passages within said housing, said feed passages being in fluid communication with said inlet, each feed passage having a flow restrictor therein which includes at least one orifice configured to control the rate of fluid therethrough so that the fluid flow is at a predeternnined constant flow rate, an associated flow rate selector including a transfer passage, the selector being movable so that the transfer passage can be in cormmunication with one or a selected number of said feed passages, said transfer passage being in communication with the outlet and the arrangement being such that a predetermined flow rate of fluid can be selected by the number of feed passages in communication with the transfer passage as a result of movement of said selector.

,wpdocdyspci\43865\nrs -p:\wpdocs\dys\specie\43860\ars -3- Preferably the housing may include a chamber therein with the inlet and outlet being in communication with the chamber.

Preferably the feed passages open to one side of the housing for permitting each flow restrictor to be located within a respective feed passage, there further being provided a retaining element having a section receivable within respective the feed passage for retaining the flow restrictor in position, the section having a passage therethrough.

The housing may be adapted for detachable attachment to the supply line of an administration set. The housing may be resiliently deformable to enable evacuation of or priming of the supply line of the administration set.

Each of the flow restrictors may comprise a plate having at least one orifice therein. The movable selector may be rotatable such that selection of the flow rate is made by the degree of displacement of the rotatable selector. Preferably the transiLr 'g 15 passage of the moveable selector comprises at least one through passage and at least one associated groove which allow passage of fluid from a restrictor orifice which is aligned with said through passage and groove to the outlet of said housing according to the flow rate selected. The selector may enable selection of any combination of flow rates available from the flow restrictors. Preferably the chamber within the housing acts as a 20 priming chamber or fluid evacuation chamber to assist passage of fluid along or to evacuate the supply line of the administration set.

Preferably the restrictor orifices sizes fall within the range of 5 to 100 microns.

The housing may have located therein a hydrophilic filter located upstream of the restrictor plates. Preferably the flow controller is located at or near the patient end of the administration set.

As an example flows of 0.5 litres per day, 1 litre per day, 2 litres per day or 3 litres per day may be selected either by selection of a single flow restrictor or in a combination of flow restrictors. It will be recognised that the flow characteristic through the orifices in the flow restrictors is dictated by the geometry of the orifice. The subject of the orifice geometry has been made the subject of other patent applications by the Sapplicant.

S p:\wpdocs\dys\specie\438650\ars ur

OC*

U.

r' -4- The present invention will now be described in more detail and with reference to preferred but non limiting embodiments wherein: Figure 1: shows a schematic layout of a typical administration set with the fluid flow controller inserted in a pre-selected position in the fluid supply line.

Figure 2: shows an isometric view of one embodiment of the flow controller adapted for detachable attachment to the fluid supply line.

Figure 3: shows an exploded side view of the flow controller shown in figure 2.

Figure 4: shows an enlarged cross-sectional view of the flow controller of figure 2 showing the restrictor plate spanning the flow chamber.

Figure 5: shows a flow controller according to an alternative embodiment wherein the flow chamber is eccentric to the axial alignment of the inlet and outlet to the flow controller.

Figures 6a, show views of another embodiment of a flow controller adapted for b and c insertion in a fluid supply line of an administration set as shown in figure 1.

Figure 7: shows an elevational view of a longitudinal cross-section of a flow controller with a filter according to another embodiment.

Figure 8: shows a long sectional view of a multiple flow controller according to the present invention with multiple restrictor plates each with one orifice.

Figure 9: shows a plan view of a rotatable member of a flow controller according to a preferred embodiment with passages adapted to align with the channels in the circular restrictor plate of figure 8.

25 Figure 0: shows a cross section through the member of figure 9.

Figure 11: shows a long sectional view of a multiple flow controller according to one embodiment of the invention having a single plate with multiple orifices.

Figure 12: shows a plan view of a circular restrictor plate having radially disposed orifice plates.

Figure 13: shows a plan view of drainage passages overlaid by the restrictor plate of figure 12.

Figure 14: shows an elevational view of an adjustable multi-flow controller .r o p:\wpdlocs\dys\spccic\438650\urs according to one embodiment.

Figure 15: shows an elevational view of an adjustable multi flow controller according to an alternative embodiment.

Referring to figure 1 there is shown an administration set 1 comprising a fluid supply line 2 which runs between a fluid reservoir end 3 and a fluid discharge end 4.

Intermediate the said reservoir end 3 and end 4 is a flow controller 5 which may be inserted in the fluid supply line as an attachment to the administration set 1 or alternatively, as an item integral with the supply line 2.

In addition, the fluid supply line 2 is adapted with a drip chamber 6A, an injection port 6, a plastics slide clamp 7, a flash ball 8, a luer connector 9 and tip protectors 10A and 10B to form one possible configuration of administration set.

Altl- .gh the embodiment shown has a number of features in the fluid supply line, in its simplest form, an administration set may simply have a fluid flow line and a flow controller upstream of an outlet.

20 Figure 2 shows the flow controller according to one preferred embodiment of the invention. The flow controller 11 A in figure 2 comprises a housing 11B, which is adapted to house a restrictor 12 (see figure an inlet 13 and an outlet 14.

Preferably the housing 11 is comprised of a resiliently deformable but elastic 25 material which enables the priming of the fluid flow line or urging of fluid along said flow line.

o r

D

r r e r n

D

o o Figure 3 shows the flow controller of figure 2 from in a cross sectional exploded view. From figure 3 it can be seen that the housing 11 is comprised of components 16 and 17. These are separable and provide a means for enabling insertion of the restrictor 12 therein. When components 16 and 17 are joined, a priming chamber 15 is formed. As can be seen from figure 3, the inlet and outlet 13 and 14 are in alignment with each other and also in axial alignment with the priming y p:\wpdocs\dys\spccic\438650\ars -6chamber 15. The restrictor in this embodiment is shown as a single plate with a single orifice.

Figure 4 shows an assembled view of the flow controller with the components 16 and 17 of the housing 11. In doing this they secure the restrictor or orifice plate 12 such that a barrier is presented substantially normally to the axis of the fluid flow line which is in turn axially aligned to ends 13 and 14 of the housing 11 B. The orifice is adapted with a geometrically designed hole 18 which can be seen in figure 4 and this has been made the subject of a co-pending patent application by the present applicant.

In this configuration with the flow controller attached to the fluid supply line, the housing 11B receives fluid via inlet 13 axially along the passage 19 and into the chamber 15. The geometry of the hole 18 enables the fluid to be delivered at a substantially constant flow along passage 20 and via outlet 14 and distal part of the administration set into the body of a patient, The housing 11 can either be detachably affixed to the fluid supply line or moulded integral with the fluid supply line such that the inlet 13 is to be regarded as of indefinite length; so too the outlet 14. It should be noted that the shape and configuration of the housing as illustrated in figures 2 to 4 shows merely one embodiment of many different embodiments of a detachable or fixedly attached fluid flow controller for use with an administration set in a fluid supply line.

Referring to figure 5 there is shown a further embodiment of a flow controller 25 21. This particular embodiment of flow controller also adapted for detachable c fixed attachment to an administration set supply line comprises a housing 22 comprising an inlet 23 an outlet 24 and a priming chamber 25. The housing also comprises means to enable the adaption of a restrictor plate 26 and also the insertion of a hydrophyllic filter 27 therein for the purpose of filtering the fluids which flow therethrough. It is to be noted that in this embodiment the priming chamber is parallel to the inlet 23 and outlet 24.

Figures a and b show from one view a further embodiment of a flow r Figures 6a and 6b show from one view a further embodiment of a flow p:\wpdocs\dys\spcchAk438650\ars controller 28 having an axially aligned inlet and outlet 29 and 30 respectively, in addition to a priming chamber 31 to form a flow controller housing 32. The housing is adapted to receive a restrictor plate 33 for insertion in such a way that it is used in conjunction with a top seal 34 and a side seal 35. In this embodiment the housing is also adapted with a hydrophyllic filter 36 at the inlet 29 for the purpose of filtering the fluid which flows therethrough prior to passing through the restrictor 33. Figure 6c is a cross-sectional view showing the priming position of the flow controller shown in figure 6b.

Figure 7 shows an alternative embodiment of the flow controller showing an inlet passage 41 entering a housing 42 also connected to an exist passage 43. The housing 42 has therein a chamber 44, having located therein a hydrophyllic filter 45, a hydrophobic filter 46 and an orifice plate 47. The hydrophobic filter comprises a hydrophobic mesh material which allows air to escape to the atmosphere but prevents the fluid from exiting.

o :o In order to prime the flow controller in figure 7, pressure is exerted in a direction lateral or perpendicular to the axial direction of the inlet and outlet tubes.

The consequence is that it allows the fluid to by-pass the orifice plate and to prime the line prior to use.

The orifice plate stays relatively still and the sealing spigot moves away from the plate when the controller is squeezed. This occurs with the assistance of webs 100.

The above described embodiments are examples of a number of different embodiments which can be used in the present application in order to achieve a constant flow rate in a given administration set.

In attaching the fluid flow controller to the administration set, it is envisaged that the connection can be done in any one of the number of different ways including h, rs* conventional means for fitting tubing together. This would include sleeve fitting, flange mating, slot fitting, claap fitting.

Sp:\wpdocs\dys\spccie\438650\ars -8- In an alternative embodiment of the present invention, it is envisaged that the administration set may be adapted so as to deliver a predetermined liquid flow rate via a series of flow controllers linked either in series or in parallel. It is also to be understood that the present invention is not to be restricted to the delivery of fluids for administration into the human body but can also be used for delivery of fluids in a variety of different applications where fluid is to be delivered at a constant flow rate.

It will be appreciated that the present invention as broadly described herein can be varied somewhat to include a variety of different embodiments including alteration of the location of each flow controller along the supply line of an administration set, altering the configuration of the housing, altering the configuration of the chamber within which the restrictor fits, altering the relative position of the restrictor in relation the outlet and inlet of the flow control housing and providing the flow control housing as a one piece or multiple piece unit either pre-assembled or adapted for assembly at site.

Ideally, each flow control chamber would be adapted with a hydrophyllic filter in order to remove particulate matter large enough to block the orifice.

20 In one embodiment of the present invention the invention comprises an administration set with the flow controller adapted integrally therewith. In this type of embodiment and indeed in the embodiment whereby the flow controller can be detachably affixed to the fluid supply line of an administration set the fluid supply line can also be adapted with a valve which enables by-pass of fluid or release of air from the fluid supply line for the purpose of priming prior to use.

Figure 8 shows a long sectional view of a multi-flow controller 48 according to an alternative embodiment of the invention.

The controller 48 as shown in figure 8 is adapted with a series of passages 49, 51, 52 and 53. The passages are linked with a series of orifice plates 54, 55, 56, 57 and 58 respectively. The orifice plates are held in position by means of wedge 59 ,C which is adapted with a series of passages 60, 61, 62, 63 and 64 which are aligned p:\wpdocs\dys\spccc\438650\ars -9with holes in the orifice plates and the with corresponding passages, 49, 50, 51, 52 and 53. In use, fluid passes through the orifices in the array of restrictor plates 54, 56, 57 and 58 upon selection of flow rate by rotatable member 65. Figure 9 shows a side elevational view of the rotatable member 65. This member is adapted to rotate in a clockwise or anti-clockwise direction according to a selected fluid flow requirement. The rotatable member 65 is adapted with a passage 66 and grooves 67 and 68. When fluid flow is to be selected, the rotatable member 65 is rotated according to one selection such that the groove 68 as shown in figure 10 presents to passage 49 where a single flow is required. Where a combination of flows are required through more than one restrictor plate, the groove 68 is presented to one of passages 50, 51, 52 or 53. When any one of these passages are selected, fluid then flows through grooves 67 and 68, and depending upon the presentation of the groove relative to the passages 49 to 53, fluid will flow through passage 49 and one or more of passages 50 to 53. Using this method a number of different combinations of flows can be achieved depending upon which of passages 49 to 53, groove 68 of the rotatable member 65 is presented to.

V. Figure 11 shows a similar configuration of an exploded multiple flow controller this time however a single orifice plate 69 is used with a series of apertures 20 of the same or different diameters. These apertures 70, 71, 72 and 73 are presented to passages 74, 75, 76 and 77. Passage 78 is used for priming purposes or free flow of fluid. Wedge 79 is used to locate the plate in position and also to provide upstream passages for fluid to present to the apertures. In a similar manner to that described for the flow controller of figure 8, rotatable member 80 operates by rotation in either an 25 anti clockwise or clockwise direction to select fluid flow. As with the controller of figure 8, a single flow or multiple flows can be chosen according to the manner in which the groove (not shown) in rotatable member 80 which corresponds to the groove 68 of rotatable member 65 presents to either one or more of passages 74, 76, 77 and 78.

Figure 12 shows an alternative embodiment of a restrictor plate housing 81 S having radially disposed holes 82, which are located on that plate according to flow requirements. The restrictor plate housing 81 is superimposed over the rotatable p:\wpclocs\dys\spccic\438650\ars drainage facilitator 83 shown in figure 13 such that when a flow selection is made, one or more of the orifices 82 present to drainage passage array 84 in the rotatable member 83.

Figure 14 shows an elevational view of the external design of a multi-flow controller showing an external flow selector handle 85 with selection gradations 86.

Figure 15 shows an alternative embodiment of the flow controller 87 having a rotatable flow selector 88. The flow controller 87 has an inlet 89 and an outlet (not shown) which engages with a supply line in a typical administration set.

It will be recognised that it is possible to make a number of different variations to the various embodiments of the present invention described including varying the size of the orifices in the restrictor plates, the spacing between orifices, increasing the number of separate flow restrictors and consequently the number of flow through passages, varying the number of combinations of a flow rate selection by varying the number of flow through passages. The orifice sizes of the flow restrictors may fall within the range 5 microns to 100 microns. It will also be appreciated that the present invention can be utilised with gravity feed, administration sets, and administration sets which deliver fluid under induced pressure by for example elastomeric pressure 29 pumps. Furthermore, the flow controllers can be inserted virtually anywhere in the length of the supply tube associated with the administration set. It is optional whether a filter is used and where in the administration set the filter would be located. The filter may be located in the flow controller however, it is quite feasible to locate the filter above the flow controller. Where fluid under pressure is utilised in an administration set, typically the pressure would operate at between 5-10 psi but could be anywhere from 1 psi to 20 psi.

According to prior art methodology, flow restriction have previously been achieved according to one example by use of a small bore glass tube. It is considered that the present invention can be used as a substitute for and improvement on this method. The flow controller of the present invention in all of its embodiments is 1j. useful in any application where a restriction of flow is required in an infusion system, ther operated by gravity or under pressure generated by elastomeric or other p: wpdocs\dys\spcic\438650\ars 11 conventional means.

It will be recogni ~d by persons skilled in the art that numerous variations and modifications can be made to the present invention without departing from the overall spirit and scope of the invention as broadly described herein.

*0 0 *0 0 *000 ,.t0 0

S..

~004 0000 0 0*

S

0 5@ 0 SO

S

505555 0 0 0555

S

I.

*g j) ~1;4 p:\wpdocs\dys\spccic\43865O~ars

Claims (3)

12- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. An in line fluid flow controller for use with a fluid administration set for infusion of fluid into the body of a patient, the administration set including a means for connecting the administration set to a reservoir of fluid, said connecting means being connected to a supply line having the flow controller therein, said fluid flow controller comprising: a housing; an inlet to and an outlet from said housing, a plurality of feed passages within said housing, said passages being in fluid communication with said inlet, each feed passage having a flow restrictor therein which includes at least one orifice configured to control the rate of fluid therethrough so that the fluid flow is at a predetermined constant flow rate, an associated flow rate selector including a transfer passage, tie selector being movable so that the transfer passage can be in communication with one or a selected 1. number of said feed passages, said transfer passage being in communication with the outlet and the arrangement being such that a predetermined flow rate of fluid can be t; *selected by the number of feed passages in communication with the transfer passage as a result of movement of said selector. An in line flow controller according to claim 1 wherein said feed passagei- open to one side of said housing for permitting each flow restrictor to be locatei' within a respective said feed passage, there further being provided a retaining element having a section receivable within respective said feed passage for retaining the flow 25 restrictor in position, said section having a passage therethrough. 3. An in line fluid flow controller according to claim I or claim 2 wherein the said housing is adapted for detachable attachnient to the supply line of an administration set. 4. An in line fluid flow controller according to any preceding claim wherein the said housing is resiliently deformable to enable evacuation of or priming of the supply line of the administration set. p:\wpdocs\dys\spccic\438650\ars 13 An in line fluid flow controller according to any nreceding claim wherein said movable selector is rotatable such that selection of the ow rate is made by the degree of arcuate displacement of the rotatable selector. 6. An in line fluid flow controller according to any preceding claim wherein the transfer passage has at least one associated groove which allows passage of fluid from a flow restrictor to the outlet. 7. An in line fluid flow controller according to any preceding claim wherein the transfer passage of said moveable selector comprises at least one through passage and at least one associated groove which allow passage of fluid from a flow restrictor which is aligned with said through passage and groove to the outlet of said housing according to the flow rate selected. 15 8. An in line fluid flow controller according to any preceding claim wherein the selector enables selection of any combination of flow rates available from the flow restrictors. 4 6a. 9. An in line fluid flow controller according to any preceding claim including a 20 chamber within the said housing which acts as a priming chamber or fluid evacuation «*04 chamber to assist passage of fluid along or to evacuate the supply line of said administration set. 10. An in line flow controller according to any preceding claim wherein the .25 restrictor orifices sizes fall within the range of 5 to 100 microns. 11. An in line flow controller according to any preceding claim wherein the housing has located therein a hydrophilic filter located upstream of aid flow restrictors. 12. An in line flow controller according to any preceding claim wherein the flow controller is located at or near the patient end of the administration set.

13. An in line flow controller according to any preceding claim wherein the flow p:\wpdocs\dys\speclc\438650\ars E ki-0,

14- controller is inserted into an induced pressure driven set or gravity feed administration set. 14. An in line flow controller according to any preceding claim wherein the fluid of the administration set is pressurised by an elastomeric pump prior to passing through said flow controller. DATED this 5th day of December, 1994 MACNAUGHT PTY LIMITED By Its Patent Attorneys DAVIES COLLISON CAVE 9 «i a s*ee 0 oo *Sn* p:\wpdocs\dys\spccio\438650\ars