GB2028975A

GB2028975A - Parenteral infusion drip chamber

Info

Publication number: GB2028975A
Application number: GB7923694A
Authority: GB
Original assignee: Baxter Travenol Laboratories Inc
Current assignee: Baxter International Inc
Priority date: 1978-08-30
Filing date: 1979-07-06
Publication date: 1980-03-12
Also published as: AU526185B2; JPS5532579A; GB2028975B; DE2921531A1; BE878476A; AU4866879A; FR2434625A1; IE791258L; ES483754A1; IE48297B1; CA1130161A; IL57473A; ZA792558B

Abstract

The drip chamber 12 has a floating pressure-sensitive ball 68, which responds to priming pressure and the pressure of liquid in the administration set, and a resilient seat 62 shaped so as to provide line contact with the ball. An inwardly- turned lip 66 on the seat inwardly flexes as the ball pushes into the valve seat to maintain the line contact. <IMAGE>

Description

SPECIFICATION Parenteral infusion drip chamber This invention concerns a drip chamber for an administration set for administering parenteral liquid to a patient.

In the U.S. patent specification No. 3,886,937, it is proposed to provide a check type valve along the tubing in an administration set between the drip chamber and an injection site commonly referred to as "Y" site. In one embodiment, this check type valve is illustrated as a duckbill valve, which is positioned within a housing connected in series with the tubing. The present invention provides an improvement over the administration set disclosed in this U.S. specification.

In accordance with the present invention there is provided a drip for a parenteral administration set, the chamber having an inlet for coupling to a source of parenteral liquid and an outlet for coupling via appropriate tubing to a patient, the drip chamber outlet comprising a housing connected at the downstream end of the drip chamber, said housing including an upstream inlet portion and a downstream outlet portion, said upstream inlet portion including a valve seat defining a liquid passage therethrough and said downstream outlet portion comprising a wall defining a liquid passage; a ball located within said housing; said valve seat and wall being spaced a sufficient distance to enable said ball to be spaced from said valve seat when liquid is flowing in the upstream to downstream direction; said valve seat and ball being dimensioned and cooperative to close said liquid passage when liquid flow is in the downstream to upstream direction; and said valve seat having a resilient portion which extends axially inwardly for contact with said ball and being shaped to provide substantially line contact along the surface of the ball with the resilient portion being peripherally free to enable inward flexing thereof.

In the illustrative embodiment, the housing includes a top portion and a bottom portion and means are provided for sealing the top portion to the bottom portion. The drip chamber includes a flexible plastics casing which surrounds the top portion and is coupled to the sealing means.

In the illustrative embodiment, the valve seat comprises a symmetrical resilient member having a central bore forming the liquid passage. The resilient member also includes an annular ring facing the ball for sealing engagement therewith.

The resilient member is formed in a unitary, integral construction. The valve seat and ball are cooperatively dimensioned so that the resilient portion which contacts the ball circumscribes a segment of the ball defining an arc of about 600.

In the illustrative embodiment, tubing is connected between the outward liquid passage of the drip chamber and one of the inlets of an injection site having two inlets and an outlet.

Tubing is also connected between the injection site outlet and an inlet of a second injection site having two inlets and an outlet. In this manner, secondary liquids can be sequentially and automatically provided to the patient.

Reference is now made to the accompanying drawings, wherein:~ Figure 1 is a view of an administration set having a drip chamber according to the present invention; Figure 2 is an enlarged, fragmentary crosssectional view of the drip chamber; Figure 3 is a cross-sectional view taken along the plane of the line 3-3 of Figure 2.

Figure 4 is a greatly enlarged cross-sectional view, taken along the plane of the line 4 4 of Figure 4; Figure 5 is a view of the administration set of Figure 1 with fluid containers connected thereto and the set being hung for use with a patient; Figure 6 is an enlarged cross-sectional view of a valve seat used in the Figure 2 drip chamber; Figure 7 is a bottom plan view of the valve seat of Figure 6; and Figure 8 is a view showing the cooperation of the valve seat of Figure 6 with a ball.

Referring first to Figure 1, an administration set 10 is shown therein, including a drip chamber 12, the inlet 14 of which is connected by a suitable spike to a plastic or other glass container 1 6 containing parenteral solution. A backflow check valve 18, which is described in more detail below, forms the outlet of drip chamber 12. Tubing 20 is connected between drip chamber 12 and inlet 22 of an injection site 24. Injection site 24 is preferably of the type disclosed in U.S. Patent specification No. 4,048,995 having two inlets and an outlet. While tubing 20 is connected to inlet 22, a secondary liquid may be connected to the other inlet 26. The outlet 28 of injection site 24 is coupled to a tube 30 which is connected to the inlet 32 of a second injection site 34.Another secondary, or tertiary, source of liquid may be connected to the other inlet 3,6 of injection site 34, and the outlet 38 of injection site 34 is coupled to tubing 40 which is connected to a needle adapter 24 having a needle 44 coupled thereto. A regulator clamp 46 may be positioned along tubing 40.

Administration set 10 is formed of plastics materials and is disposable in accordance with conventional practice. Needle 44 is coupled to a patient so that the parenteral fluid from bag or bottle 16 will flow to the patient.

Referring now to Figure 2, drip chamber 12 is shown in more detail therein. The main body 48 of drip chamber 12 comprises a flexible cylindrical elongate plastics member, the top or upstream end of which is heat sealed to a prong member in the conventional manner, and the bottom of which comprises a housing. The housing includes a top portion 52 and a bottom portion 54. Top portion 52 includes a central member 56 defining an opening 58 and a downwardly depending member 60 which cooperates with central member 58 to receive a resilient valve seat 62, preferably formed of rubber.

Valve seat 62 is formed in an integral, unitary construction and defines a central bore tri4. Uhe valve seat has a downwardly depending annular portion 66 forming a ring 67 which faces a spherical ball 68forcooperation therewith. Ball 68 is preferably formed of polypropylene so as to have a specific gravity that is less than 1.0, thereby enabling the ball 68 to float, as will be described.

In prior art ball valve constructions, the proper sealing of a spherical ball has often been a serious problem. Prior art ball valves typically utilize a valve seat which contacts the ball to circumscribe a segment of the ball defining an arc of about 450 I have discovered, however, that a more efficient seal is provided when the valve seat and ball are cooperatively dimensioned so that a resilient portion of the valve seat will contact the ball and cirO#rriscribe a segment of the ball defining an arc of about 600. 1 have also discovered that a more effective seal can be provided when the valve seat maintains a line contact with the ball, thereby providing optimum pressure against the ball.To this end, valve seat 62 includes an upper portion 62a for coupling to a recess portion within the housing carrying the valve seat, and a resilient portion 62b which extends downwardly and axially inwardly to form ring 67 which is adapted for contact with the ball. As shown in Figure 2, resilient portion 62 is peripherally free to enable inward flexing thereof. By shaping the valve seat with an undercut 62c, as illustrated most clearly in Figure 6, a relatively flexible system is provided, giving the resilient portion 62 the ability to roll inwardly as the ball moves upwardly under the liquid force.By utilizing an unsupported external wall with the undercut as just described, the resilient portion 62, which is preferably formed of rubber, will roll up as the ball pushes into the valve seat and will maintain a line contact between the valve seat and the ball.

It is desirable that ring 67 be smoothly rounded. Thus if the valve seat 62 is formed in a unitary, moulded, one-piece construction, it is important that the parting line be above ring 67 so that there is no flash at the ring. In this manner, the contact of ring 67 with the spherical ball will be line contact as is desirable.

Referring to Figure 8, it is seen that when the ball 68 contacts ball valve 62, ring 67 will circumscribe a segment of the ball defining an arc of 600. As stated previously, this 600 arc has been found to be optimum in providing an effective seal.

Although no limitation is intended, as a specific example of parameters which could be utilized in forming the valve seat illustrated in Figure 6, the following dimensions are given with respect to the Figure 6 embodiment: Reference Letter (Fig. 6) Example Dimension a .48 inches b .275 inches c .15 inches d .115 inches e .325 inches f .145 inches 9 .055 inches h .087 inches .02 inch .1 inch k .01 inch .36 inch m .219 inch n .005 inch radius o .03 inch x 45 chamfer Top portion 52 also includes an external radial flange 70 which defines a groove 72 enabling the fit of main portion 48 of drip chamber 12 into groove 72. The external diameter of top portion 52 is substantially equal to the internal diameter of main portion 48 of drip chamber 12, thereby providing a frictional fit between the main portion 48 and top portion 52.

Bottom portion 54 of housing 50 is shaped generally complementary to top portion 52 and includes a mating portion 74 which cooperates with flange 70, enabling a sonic weld between the top portion 52 and bottom portion 54. Bottom portion 54 has a bottom wall 76 which defines a central opening 78 and carries a plurality of ribs 80 (see Figures 3 and 4) which ribs prevent ball 68 from engaging and closing opening 78. An outlet tube connector member 82 is formed integrally with bottom portion 54 for connecting the plastics tubing 20 to member 82.

In the operation of the device, the spike from the drip chamber inlet is pierced into an IV solution container or the like. The drip chamber is then squeezed by the operator to prime the set.

When the drip chamber is released, the liquid will enter from the top with the drip chamber being approximately one-third to one-half full.

The valve seat 62, ball 68 and ribs 80 are spaced so that the liquid will flow through the ball valve, around the ball and through outlet 78. The ball will, of course, float within the liquid. In this manner, the administration set, when coupled to a patient, will operate to feed the primary liquid to the patient.

Figure 5 shows an embodiment in which two secondary administration sets are also coupled to the patient. Referring to Figure 5, it can be seen that a secondary solution 90 is coupled to inlet 36 and another secondary solution 92 is coupled to inlet 26. Solution 90 is a higher level than solution 92 and solution 92 is at a higher level than primary solution 16. Solution 90 is connected to inlet 36 by means of a plastics tubing 94 which extends from a drip chamber 96. Solution 92 is connected to inlet 26 via plastics tubing 98 which extends from a drip chamber 12'. Drip chamber 12' is identical in construction to drip chamber 12 described above, and includes the ball check valve outlet described above.

By utilizing the system illustrated in Figure 5, a sequential administration system is achieved.

Thus secondary solution from container 90 will flow to the patient and because secondary solution 90 is at a higher level than secondary solution 92 and primary solution 16, the balls in the check valves of drip chambers 12' and 12 will be urged upwardly against the valve seats thereby preventing flow from secondary container 92 and primary container 16. Once secondary container 90 is empty, the ball in the check valve of drip chamber 12' will drop thereby allowing flow from secondary container 92 to the patient. However, the ball in the check valve of drip chamber 12 will continue to be urged upwardly against the valve seat, thereby preventing flow of the primary liquid to the patient. Once secondary container 92 is empty, however, the ball of drip chamber 1 2 will drop thereby allowing the primary solution from container 16 to flow to the patient.

By utilizing a ball valve as described, it is not necessary to provide a four-way heat seal (for example as illustrated in U.S. Patent No.

2,702,036) between the outlet of the drip chamber and the tubing connected thereto. It has been found that the ball valve operates as a very effective connector between the drip chamber and the outlet tubing.

It is preferred that housing 50 be transparent and ball 68 have a distinctive colour, so that the operator can notice the position of the ball with respect to the housing. It has been found desirable to have the ability to view the operation of the check valve during use.

Claims

1. A drip for parenteral administration set, the chamber having an inlet for coupling to a source of parenteral liquid and an outlet for coupling via appropriate tubing to a patient, the drip chamber outlet comprising a housing connected at the downstream end of the drip chamber, said housing including an upstream inlet portion and a downstream outlet portion, said upstream inlet portion including a valve seat defining a liquid passage therethrough and said downstream outlet portion comprising a wall defining a liquid passage; a ball located within said housing; said valve seat and wall being spaced a sufficient distance to enable said ball to be spaced from said valve seat when liquid is flowing in the upstream to downstream direction; said valve seat and ball being dimensioned and cooperative to close said liquid passage when liquid flow is in the downstream to upstream direction; and said valve seat having a resilient portion which extends axially inwardly for contact with said ball and being shaped to provide substantially line contact along the surface of the ball with the resilient portion being peripherally free to enable inward flexing thereof.

2. A drip chamber according to Claim 1, wherein the valve seat and ball are cooperatively dimensioned so that the resilient portion which contacts the ball circumscribes a segment of the ball defining an arc of about 600.

3. A drip chamber according to Claim 1 or 2 wherein said housing includes a top portion and a bottom portion; means sealing said top portion to said bottom portion; and a flexible plastics casiny which surrounds said top portion and is coupled to said sealing means.

4. A drip chamber according to Claim 3, wherein the casing is cylindrical and the sealing means includes a radially extending flange which receives the cylindrical casing.

5. A drip chamber according to any preceding Claim wherein said valve seat comprises a symmetrical resilient member having a central bore forming the liquid passage, and including an annular ring facing said ball for sealing engagement therewith, said resilient member being formed in a unitary, integral construction.

6. A drip chamber according to any preceding claim, wherein said wall carries a plurality of ribs for spacing the ball from the downstream liquid passage.

7. A drip chamber according to any preceding claim including plastics tubing connected at the inlet of the chamber and a heat seal connecting the tubing to the inlet.

8. A parenteral administration set incorporating a drip chamber according to any preceding claim, an injection site having two inlets and an outlet, and tubing connected between the outlet liquid passage of the drip chamber and one of the inlets of the injection site.

9. An administration set according to Claim 8, including a needle adapter and tubing connecting the outlet of the injection site to the needle adapter.

10. An administration set according to Claim 8 or 9, including a second injection site having two inlets and an outlet, and tubing connecting the outlet of the first injection site to one of the inlets of the second injection site.

11. An administration set having a drip chamber the inlet of which is adapted for coupling to a source of parenteral liquid and the outlet of which is adapted for coupling via appropriate tubing to a patient, said drip chamber outlet comprising a housing connected at the downstream end of the drip chamber, said housing including a top portion and a bottom portion, means sealing said top portion to said bottom portion, said drip chamber including a flexible plastic casing which surrounds said top portion and is coupled to said sealing means; said housing including an upstream inlet portion and a downstream outlet portion, said upstream inlet portion including a valve seat defining a liquid passage therethrough and said downstream outlet portion comprising a wall defining a liquid passage; a ball located within said housing;; said valve seat having a resilient portion which extends axially inwardly for contact with said ball and being shaped to provide substantially line contact along the surface of the ball with the resilient portion being peripherally free to enable inward flexing thereof; said valve seat comprising a symmetrical rubber member having a central bore forming the liquid passage, and including an annular ring facing said ball for sealing engagement therewith, said rubber member being formed in a unitary, integral construction; said valve seat and ball being spaced a sufficient distance to enable said ball to float within the housing when liquid is flowing in the upstream to downstream direction; said valve seat and ball being dimensioned and cooperative to close said liquid passage when liquid flows in the downstream to upstream direction; said valve seat and ball being cooperatively dimensioned so that the resilient portion which contacts the ball circumscribes a segments of the ball defining an arc of about 600; and said wall carrying a plurality of ribs for spacing said ball from said downstream liquid passage.

12. A drip chamber constructed substantially as herein described with reference to the accompanying drawings.