BURETTE WITH FILTER SCREEN

Abstract: An administration set including a burette (16), in which the burette chamber (36) encloses a number of equally spaced upright vanes (76) which support a screen filter (80) having a surface area that is greater than the cross-sectional area of the chamber (36). A hemisphere (84) is positioned at the top of the vanes (76) to directly underlie the inlet opening (86) to the burette chamber (36), for providing a maximum distance fall for the liquid, such as blood, which drops from the inlet opening (86). A ball valve (60) is located at the outlet of the burette (16) and includes a ball (62), a valve chamber (65) and a ball seat (64), with the bottom (77) of the vanes (76) defining the top of the ball valve chamber (65). The ball valve chamber (65) includes a number of angled flow directors (66) spaced about the inner wall (68) defining the ball valve chamber (65).

Description: Description BURETTE WITH FILTER SCREEN Background of the Invention The present invention concerns a novel burette and, 5 more particularly, a burette used in an administration set and operative to handle blood flow. It is often desirable to infuse a small precise amount of blood to a patient, such as a young child. For example, if blood samples have been withdrawn from a pre- 10 mature infant, replacement blood has to be infused very carefully and precisely. Typically, a spike is connected to a blood container and the blood flows into a burette to the selected amount, for example, 10 to 15 ml. How¬ ever, for other uses it is necessary to infuse a greater 5 amount of liquid and thus it is desirable to provide a burette that will handle relatively small and relatively large quantities of liquid. However, in providing a burette that will handle a large amount of liquid, a relatively large volume chamber is necessary, but it has 20 also been found undesirable for blood to have to drop, more than a maximum distance. It has been found that blood cells may break if the drop is a greater distance than 2-1/2 inches. In using a burette for administering blood, it is 25 also desirable that particulate matter be filtered down from the blood, yet is is necessary that the blood flow as efficiently as possible, preferably in a laminar manner. * " --- .. . . .- , - . ..- , H'CIEtΛπoi.:—•sir*' A. •• lthoug.h.τ..,-it "''~i-*so e"u-j.n.~d iceos"i ϊr~a >'bl ■e ?, it'o■ " u.s.e>. ■ • p • H_u.mcps in• it>wheΛOt.r«ans-* 30 fer of blood, often hospitals use pumps to tran'Sfe* 1 so»- iι - ' lutions and jμ.aγ also use pumps to transfer blood. , If a-, . ' ■ pump is connected,;,at the outlet of a ball valve type bu*, rette, it is possible for the pump to cause the ball tσ be sucked downward, prematurely closing the out ' let , - and '■ _ - 35 not allowing the liquid in the burette to flow. In other words, the pump may cause, the ball to act as if there were no liquid present. It is, therefore, an object of the present invention to provide a burette that is universally adaptable for the administration of relatively small and large volumes of liquid, including blood. 5 Another object of the present invention is to provide a burette which obviates the problem of blood drop which may cause the blood cells to break if the drop is a greate distance than 2-1/2 inches. A further object of the present invention is to pro- 10 vide a burette which includes a screen filter having a. relatively large surface area, and being supported in a manner which aids in providing a laminar flow for the liquid, such as blood. A still further object of the invention is to provide 15 a burette having a ball valve in a ball chamber that is operative to maintain the ball in at least a semi-floating position unless no liquid is present. Another object of the present invention is to provide an administration set including a burette that is re- 20 latively simple in construction and efficient to manu¬ facture. Other objects and advantages of the present invention will become apparent as the description proceeds. Summary of the Invention 25 In accordance with the present invention, a burette is provided having an inlet end, an outlet end and a burette chamber separating the inlet end and outlet end. An inlet opening is defined at the inlet end and an outlet opening is defined at the outlet end with a drop former 30 also present at the outlet end. A filter is provided in the burette chamber for filtering the liquid flowing therethroug . The improvement comprises the filter including a screen having a surface area that is greater than the 35 cross-sectional area of the chamber. A plurality of upright vanes support the filter, with the vanes being located above and around the outlet opening. Means di¬ rectly underlie the inlet opening for providing a maxi¬ mum distance fall for the liquid which drops from the inlet opening. In the illustrative embodiment, the underlying means comprises a hemisphere supported by the upright vanes and spaced no more than 2.5 inches from the inlet opening. The plurality of vanes comprise four vanes equally spaced about the outlet opening and operative to aid in pro¬ viding laminar flow of the liquid. In the illustrative embodiment, the burette in¬ cludes a ball valve located at the outlet end, with the ball valve including a ball, a valve chamber and a ball seat. The vanes define the top of the valve chamber and the ball seat defines the bottom of the valve chamber. The valve chamber includes a plurality of angled flow di¬ rectors spaced about the inner wall defining the valve chamber. In the illustrative embodiment, the chamber has a volume of at least 150 ml. An airway valve is carried by the inlet end of the chamber and means are provided for coupling the inlet opening to flexible tubing. A more detailed explanation of the invention is provided in the following description and claims, and is illustrated in the accompanying drawings. Brief Description of the Drawings FIGURE 1 is an elevational view, partially broken, of an administration set constructed in accordance with the principles of the present invention; FIGURE 2 is a top plan view of the burette of FIGURE 1; FIGURE 3 is a cross-sectional elevation taken along the plane of the line 3-3 of FIGURE 2; FIGURE 4 is a fragmentary enlarged view of the Q;V.PI lower portion of the burette of FIGURE 1, with portions broken and shown in cross-section for clarity; FIGURE 5 is an enlarged cross-sectional elevation taken along the plane of the line 6-6 of FIGURE 4; FIGURE 6 is a cross-sectional view, taken along the plane of the line 7-7 of FIGURE 5; and FIGURE 7 is a cross-sectional view, taken along the plane of the line 7-7 of FIGURE 5; and FIGURE 8 is a fragmentary cross-sectional eleva- tion, taken along the plane of the line 8-8 of FIGURE 5. Detailed Description of the Illustrative Embodiment Referring to FIGURE 1, an administration set con¬ structed in accordance with the principles of the pre¬ sent invention is shown therein. The administration set includes a conventional spike 10 for coupling to a blood container or a source of parenteral liquid, tubing 12 connected to main liquid inlet 14 (FIGURE 3) of a burette 16, the burette having a drip chamber 18 extending from the bottom thereof and in series with the flow line, a slide clamp 20 connected to tubing 12, a roller clamp 22 on tubing 24, an injection site 26 coupling tubing 24 to tubing 28 and to a conventional needle adapter 30. Referring now to FIGURES 1-3, burette 16 has an inlet end cap 32 and an outlet end assembly 34, with a burette chamber 36 coupling inlet end cap 32 to outlet end assembly 34. Burette chamber 36 is defined by end cap 32, outlet assembly 34, and a cellulose propionate cylinder which is preferably marked with graduations. End cap 32 includes an airway valve 38 and an in- jection site 40, and may be identical to the inlet end cap disclosed in Mittleman and Boland U.S. patent ap¬ plication Serial No. 938,063, filed August 30, 1978, and entitled "Administration Set Including Burette Kith Pivotable Air Valve". Thus referring to FIGURES 2 and - 3 in particular, end cap 32 includes an upstanding an¬ nular stationary port 38, which is formed integrally with the base 40 of end cap 32. Port 38 defines a central bore 42. Port 38 also defines a shoulder 44 which sup- ports air filter 46. Air filter 46 is preferably cir¬ cular and dimensioned so as to fit securely in a resting position on shoulder 44. As more fully disclosed in Mittleman and Boland U.S. application Serial No. 938,063, filed August 30, 1978, a manually graspable handle 48 is operable when moved to move a resilient ball 50 either into a position where it seals passageway 52 (valve in its closed posi¬ tion) or in a position wherein ball 50 is away from passageway 52 and passageway 52 is aligned with opening 54 (valve in its open position) . Inlet cap 32 also carries an injection site 56 which effectively communicates with the burette chamber via passage 5-8. Thus, if desired, medicament may be injected through injection site 56 and passageway 58 into the burette chamber. The outlet end assembly 34 of burette 16 includes a ball valve 60 comprising a ball 62, a ball seat 64, and a ball valve chamber 65. Ball valve chamber 65 has a relatively large volume and includes six radially in- wardly extending angled flow directors 66, extending from the inner wall 68 which defines the ball valve cham¬ ber. The six angled flow directors 66 are equally spaced about inner wall 68, as most clearly illustrated in FIGURE 6. The relatively large volume of ball valve chamber 65 combined with the angled flow directors 66 operate to circulate the liquid in the ball chaπber and to maintain the ball in at least a semi-floating position unless no liquid is present. This alleviates a prob¬ lem which has occurred when a pump is used to transfer solutions from a ball valve type burette, in which the pump has caused the ball to be sucked downward, pre¬ maturely closing the outlet and not allowing the liquid in the burette to flow. Ball seat 64 defines a central bore 70 and has an inlet ring 72 which is dimensioned to receive ball 62 in the manner illustrated in FIGURE 5. Ball seat 64 is preferably formed of a synthetic rubber, such as poly- isoprene, and the outlet of bore 70 may act as a blood drip pre-former. The combination ball seat and drop pre-former 64 is fitted snugly within outlet port 74 (FIGURE 5) , and the outlet port 74 includes a drop for¬ mer portion 75. The upward float limit for ball 62 is provided by the bottom of four equally spaced upright vanes 76. Vanes 76 each extend radially inwardly from an upright support member 78 which cooperates with the respective vane to support screen filter 80. Screen filter 80 is operative to filter particulate matter and preferably has a mesh or pore size of 170 microns. By utilizing the aforesaid construction screen filter 80 is formed in a generally cylindrical configuration and has a filter surface area that is significantly larger than the cross- sectional area of burette chamber 36» The bottom 77 of each of the vanes 76 is angled inwardly and upwardly to receive the floating ball 62 (FIGURE 4) , and the top of the vanes 76 and uprights 78 cooperate to support a hemisphere 84. The center of hemisphere 84 directly underlies bore 86 of inlet 14 so that liquid flowing via inlet 14, such as blood, will drip from drip former 88 (FIGURE 3) onto the hemispheri¬ cal cap 84. Cap 84 is at a relatively high level so that the liquid (i.e., blood) does not have to drop more than a predetermined amount. It is preferred that this pre¬ determined amount be a maximum of 2.5 inches because blood cells may break-if the blood drop is a greater distance than 2.5 inches. However, by using the afore¬ said construction, a relatively large burette chamber may be employed without resulting in a blood drop that is longer than 2.5 inches. By forming screen 78 around the generally cylindri¬ cal shape with vanes 76 and by positioning vanes 76 radially inwardly, a laminar flow for the blood is pro¬ vided through the screen and down to the ball valve 60. As stated above, bottom 77 of vanes 76 are located and shaped to act as a ball float stop, so that the ball cannot go higher than a predetermined amount. Further, the angled flow directors combined with the aforesaid structure, enhance the laminar flow and aid the liquid in circulating throughout the ball chamber to maintain the ball in at least a semi-floating position (unless no liquid is present) . In the operation of the system, when it is desired for liquid to flow into the burette, handle 48 is opera¬ ted so as to open the valve. Thus when the burette is used in a continuous flow mode, i.e., when the flow from the blood container or parenteral liquid container is continuously flowing into the patient, the air valve is in a closed position. However, when the burette is used in an intermittent mode, i.e., when a precise amount is to be infused to the patient, the air valve is open so that the fluid can flow properly. It can be seen that a novel administration set has been described, which includes a burette that can be used for infusing a small, precise amount of blood or can also be used for handling a large amount of liquid. The construction is such that a large screen filter may be employed and the screen filter and support members therefor operate to provide a laminar flow of the liquid through the filter and into a ball valve. The ball valve is constructed to alleviate the problem of the ball being sucked downward to close the outlet when the liquid is present and a pump is used. Although an illustrative embodiment of the invention has been shown and described, it is to be understood that various modifications and substitutions may be made by those skilled in the art without departing from the novel spirit and scope of the present invention.

Claims: What is Claimed is; 1. A burette having an inlet end, an outlet end and a burette chamber separating the inlet end and out¬ let end, an inlet opening at the inlet end, an outlet opening and a drop former at the outlet end, and a filter in the burette chamber for filtering the liquid flowing therethrough, the improvement comprising: said filter comprising a screen having a surface area that is greater than the cross-section area of the chamber; a plurality of upright vanes supporting said filter, said vanes being located above and around said outlet opening; and means directly underlying said inlet opening for providing a maximum distance fall for the liquid which drops from the inlet opening. 2. A burette as described- in Claim 1, said under¬ lying means comprising a curved surface member spaced no more than 2.5 inches from said inlet opening. 3. A burette as described in Claim 1, said chamber having a volume of at least 150 ml. 4. A burette as described in Claim 1, said screen filter having a mesh size of about 170 microns. 5. A burette as described in Claim 1, said plurality of vanes comprising at least three vanes equally spaced around said outlet opening and operative to aid in pro¬ viding laminar flow of the liquid. 'BUREA * f OΓ..PI 6. A burette as described in Claim 1, said vanes being located inwardly of the outer wall defining the burette chamber, and said underlying means being posi¬ tioned at the top of said vanes. 7. A burette as described in Claim 6, said under¬ lying means comprising a hemisphere. 8. A burette as described in Claim 1, comprising a ball valve including a ball, a valve chamber and a ball seat, said ball valve being located at said outlet end and including said outlet opening. 9. A burette as described in Claim 8, said vanes defining the top of said valve chamber and said ball seat defining the bottom of said valve chamber. 10. A burette as described in Claim 9, said ball seat comprising a pre-drop former. 11. A burette as described in Claim 1, including an airway valve carried by said inlet end and means for coupling said inlet opening to said flexible tubing. 12. A burette as described in Claim 1, said upright vanes being equally spaced and extending radially inwardly, to aid in providing a laminar flow for the liquid through the screen filter and to the outlet end. 13. A burette as described in Claim 8, said valve chamber including a plurality of angled flow directors spaced about the inner wall defining said valve chamber. 14. A burette having an inlet end, an outlet end and a burette chamber separating the inlet end and outlet end, an inlet opening at the inlet end, an outlet opening and a drop former at the outlet end, and a filter in the burette chamber for filtering the liquid flowing there¬ through, the improvement comprising: said filter comprising a screen having a surface area that is greater than the cross-sectional area of the chamber; said chamber having a volume of at least 150 ml; at least three upright vanes supporting said filter, said vanes being equally spaced above and around said out¬ let opening and operative to aid in providing laminar flow of the liquid; and a curved surface member directly underlying said in¬ let opening for providing a maximum distance fall for the liquid which drops from the inlet opening, said curved surface member spaced no more than 2.5 inches from said inlet opening. 15. A burette as described in Claim 14, said vanes being located inwardly of the outer wall defining the chamber and said underlying means being positioned at the top of said vanes, said underlying means comprising a hemisphere. 16. A burette having an inlet end, an outlet end and a burette chamber separating the inlet end and out¬ let end, an inlet opening at the inlet end, an outlet opening and a drop former at the outlet end, and a filter in the burette chamber for filtering the liquid flowing therethrough, the improvement comprising: a ball valve located at said outlet end and in¬ cluding said outlet opening, said ball valve including a ball, a valve chamber and a ball seat, said ball seat comprising a pre-drop former, said valve chamber including a plurality of angled flow directors spaced about the in¬ ner wall defining said valve chamber. 17. A burette as described in Claim 16, including a plurality of upright vanes supporting said filter, said vanes being located above and around said outlet opening, said vanes defining the top of said valve chamber and said ball seat defining the bottom of said valve chamber. 18. A burette having an inlet end, an outlet end and a burette chamber separating the inlet end and out¬ let end, an inlet opening at the inlet end, an outlet opening and a drop former at the outlet end, and a filter in the burette chamber for filtering the liquid flowing therethrough, the improvement comprising: said filter comprising a screen having a surface area that is greater than the cross-sectional area of the chamber; a plurality of upright vanes supporting said filter, said vanes being located above and around said outlet opening, said vanes being located inwardly of the outer wall defining the burette chamber; a hemisphere directly underlying said inlet opening for providing a maximum distance fall for the liquid which drops from the inlet opening, said hemisphere being positioned at the top of said vanes; and a ball valve located at said outlet end and in¬ cluding said outlet opening, said ball valve including a ball, a valve chamber and a ball seat, said vanes de¬ fining the top of said valve chamber and said ball seat defining the bottom of said valve chamber. 19. A burette as described in Claim 18, said upright vanes being equally spaced and extending radially inwardly, to aid in providing a laminar flow for the liquid through the screen filter and to the outlet end; said valve chamber including a plurality of angled flow directors spaced about the inner wall defining said valve chamber. 20. An administration set including a burette having an inlet end, an outlet end and a burette chamber separating the inlet end and outlet end, an inlet opening at the inlet end, an outlet opening and a drop former at the outlet end, and a filter in the burette chamber for filtering the liquid flowing therethrough, an air valve at the inlet end communicating with the burette chamber, and a drip chamber connected downstream of the burette chamber, the improvement comprising: said filter comprising a screen having a surface area that is greater than the cross-sectional area of the chamber; a plurality of upright vanes supporting said filter, said vanes being located above and around said outlet opening; and means directly underlying said inlet opening for providing a maximum distance fall for the liquid which drops from the inlet opening. B REAT / * O.V I 21. An administration set as described in Claim 20, said burette chamber having a volume of at least 150 ml, and said plurality of vanes comprising at least three vanes equally spaced about said outlet opening and operative to aid in providing laminar flow of the liquid. 22. An administration set as described in Claim 21, said vanes being located inwardly of the outer wall defining the chamber, and said underlying means com¬ prising a hemisphere positioned at the top of said vanes; and a ball valve located at said outlet end and including said outlet opening, said ball valve including a ball, a valve chamber and a ball seat; said vanes defining the top of said valve chamber and said ball seat defining the bottom of said valve chamber. ^ \ \K

Inventors: MITTLEMAN H
Applicants: BAXTER TRAVENOL LAB
Application year: 1981
Main classification: A61M5
IPC codes: A61M5