US3525357A - Pump valve apparatus - Google Patents

Description

United States Patent [72] lnve ntor William R. Koreski Rochester, Minnesota [21] Appl. No. 776,345

[22] Filed Nov. 18, 1968 [45] Patented Aug. 25, 1970 [73] Assignee The Waters Company Rochester, Minnesota a corporation of Minnesota [54] PUMP VALVE APPARATUS 13 Claims, 7 Drawing Figs.

[52] U.S.Cl ..l37/5l6.11, 137/525.137/608.251/7 [51] lnt.Cl Fl6k 15/14 [50] Field ofSearch ..l37/516.l1. 516.13,516.15,525; 251/7 [56] References Cited UNITED STATES PATENTS 603,941 5/1898 Cartwright 137/525X 700,403 5/1902 Block 137/525X Primary Examiner- Samuel Scott Attorney-Dugger, Peterson, Johnson and Westman ABSTRACT: Pump valve apparatus including a pump for cyclically forcing liquid through lines and tricuspid type valves mounted in the lines for restricting flow through a line in one direction. Each valve is made of flexible plastic material and has a somewhat conical section extending forwardly of the tubular section in the direction of desired flow. Each conical section has a plurality of circumferentially spaced slits elongated in a direction toward the tip and an interior thickened portion adjacent each slit to provide a sturdy base against which the thin wall portion that in part defines the slit rests in a valve closed position.

Patented Aug. 25, 1970 3,525,357

IA 'VENTOR. Alla/0M R. konzsx/ Q 4770mm):

PUMP VALVE APPARATUS BACKGROUND OF THE INVENTION A tricuspid type valve made of a flexible plastic material and having a plurality of slits that open when fluid under pressure acts thereagainst in the desired direction of flow.

In the prior art, there has been provided a blood pump of the roller type which has a roller or rollers compressing soft tubing pushing perfusate (blood or plasma) ahead of the compressing roller. Also in the prior art there is a leaflet valve like a duck bill which is more pulsatile than the roller type pumps. but causes damage to liquids such as blood due to the flutter action of the two leaves during opening and closing. A third prior art type valving is the ball valve which has a rather large back flow or insufficiency. Problems associated with the above type pump and valves include a high hemolysis level resulting from compression oflarge surface areas and which is unacceptable for long term bypass for organs and/or whole body perfusion. vortexes and turbulence resulting from fluttering portions, high filling pressures required, and insufficiency on closing. In order to overcome problems of the above mentioned nature, this valve has been made.

SUMMARY OF THE INVENTION A tricuspid type valve of flexible plastic material having a cylindrical portion and a conical portion with interior thickened portions against which the thin wall portion that in part defines a slit rests when the valve is in a closed position. The conical portion has a plurality of slits that open when liquid is forced under pressure in one direction but closes when the back pressure is greater.

One of the objects of this invention is to provide a new and novel valve for creating a directional flow from each of three slits in a helical fashion to expend the energy present in moving blood cells far away from the valve rather than creating turbulence adjacent the valve. Another object of the invention is to provide a new and novel tricuspid type valve having a thin wall leaf portion in part defining a slit to overlap a thickened portion of the valve to insure complete closure after each pressurizing stroke urging liquid to move in the desired direction through the valve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a profusion pump, and somewhat diagrammatically shows the connections between the pump, an oxygenator and a patient;

FIG. 2 is a fragmentary longitudinal cross sectional view illustrating the mounting of the valve of this invention in a line for conducting fluid such as blood, the valve portion of said view being generally taken along the line and in the direction of the arrows 22 of FIG. 3;

FIG. 3 is a front end view of the valve of this invention with no pressure being exerted on the valve, said view being generally taken along the line and in the direction of the arrows 33 of FIG. 2;

FIG. 4 is a back end view of the structure of FIG. 3, said view being generally taken along the line and in the direction of the arrows 44 of FIG. 2 and showing only the valve;

FIG. 5 is a front end view of the valve of this invention, said view being the same as that of FIG. 3 other than it is illustrated in a condition with pressure on the valve in the desired direction of flow;

FIG. 6 is an enlarged fragmentary view of a slitted portion in FIG. 5 to more clearly show the valve open condition; and

FIG. 7 is a cross sectional view of a valve of this invention, said view being generally taken along the line and in the direction of the arrows 7-7 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is illustrated a profusion pump generally designated 10 having a pair of vertically spaced, adjustably positionable back up plates 11,12; a pressure plate 13 that is translatable toward and away from plate 11 for squeezing a portion of a flexible line 14 that extends between plates 11.13; and a second pressure plate 15 that is translatable toward and away from plate 12 for squeezing the portion of a flexible tube 16 which extends between plates 12,15. A driven cam 17 is eccentrically mounted on a drive shaft 18, the cam as it is being driven moving plate 13 to squeeze tube 14 while plate 15 moves away from plate 12: and plate 15 to squeeze tube 16 while plate 13 moves away from plate 11. The pump includes clamp members 19 and 20 for retaining tubes 14,16 in positions to extend between the respective pair of plates as above indicated. Since the pump is of conventional construction, it will not be further described.

One of the valves of this invention, generally designated 25. is mounted by the adjacent ends of lines 14,29 so that liquid under pressure can flow only in the direction of the arrow 31 to line 29 and thence therethrough to, for example. an oxygenator. A return line 26 is connected at one end to the oxygenator while the opposite end of line 26 and the adjacent end ofline 16 mount a valve 25 to permit liquid flow from line 26 to line 16 only in the direction ofthe arrow 32. Likewise. a third valve 25 is mounted by the opposite end of line 16 and the adjacent end of line 28 to permit liquid flow only in the direction of arrow 32. the opposite end of line 28 being connected to the patient or organ to be perfused. The return line 27 from the patient or organ and the adjacent end of line 14 mount a fourth valve 25 to permit liquid flow only in the direction of arrow 31.

The valve 25 is constructed of a flexible plastic material such as vinyl, if it is to be disposable, or silicone. An advantage of using the silicone type plastic is that the valve would have a longer life and be more acceptable for use with blood. Further the valve is self-supporting, i.e. will not collapse under its own weight when placed on a supporting surface.

The valve 25 has a circular tubular portion 35 and a somewhat conical shape section 36 that has an annular edge integrally joined to section 35 and a tipped end 36a opposite section 35 and aligned with the extension of the central axis of tubular section 35. Opening into the hollow interior of the conical section are three equally circumferentially spaced, elongated slits 37. Each slit at one end terminates rearwardly of the tip 36a and at the opposite end terminates forwardly of the juncture of the conical section with the tubular section. Other than for the above mentioned slits, the conical section is not cut or perforated. i.e. the conical section has an imperforated tipped end.

Each slit is elongated in a direction in a plane of the center axis of the valve, the conical section being at an angle to provide a slit lip portion 37a and a slit lip portion 37b. As may be noted from FIG. 7, in cross section, the edge of lip portion 370 forms an included obtuse angle with a plane that is tangential to the exterior surface at the point of intersection of the plane with said edge. Further, the edge of lip portion 3712 forms an included acute angle with said plane and abuttingly fits with the edge of lip portion 37:: when the valve is in a relaxed condition. Thus the slit edges are cut so that lip 37a serves to prevent lip 37b moving to a position radially more closely adjacent the valve central axis than lip 3711.

For each slit provided, the conical section has a thickened portion (base) 38 that is elongated in the same direction as the adjacent slit 37, is approximately the same or is slightly greater length than the adjacent slit and has a surface portion radially intermediate the central axis of the valve and the slit. The base portions 38 are equally circumferentially spaced, are predominately located offset from the respective slit in the same angular direction and are joined to lip portion 37a such as shown in the drawings. Thus, in the valve closed position the edges 36a,37a defining the slit abut; and when pressure is exerted against the valve in the direction opposite the desired direction of the flow, the base 38 serves as a rest to aid in preventing the lip portion 37b moving inwardly to a position that would permit leakage through the slit. Advantageously, the cross sectional area of the base may be greater at its rearward end than its forward end.

In using the valves ofthis invention. they are mounted in the lines with their tip end pointing in the direction that is desired to have fluid under pressure flow. Referring to FIG. 2 and assuming that the lines which the valve is mounted on are lines 29,14 the line 14 is extended into the cylindrical tubular section 35 to abut against the shoulder 35a formed in the section 35. An appropriate solvent is provided on the adjacent surfaces of tube 14 and section 35 to result in a bonding between said surfacesv On the exterior surface of the tubular section 35 that is radially opposite tube 14 there is provided a suitable solvent and the one end portion of the tube 29 extended thereover to form a bonding between the valve and line 29. Thus, the conical section is located within line 29 and is not bonded or attached to line 29.

When the pressure ofliquid exerted on both the interior and exterior surfaces of the conical section is the same. the lips 37a,37b of the slit remain in a closed condition due to the resiliency and memory of the valve material. At the time the pressure on the exterior surface of the conical section is greater than on the interior surface. lip 37b cannot move radially inwardly relative to lip 37a due to it being pressed into firmer engagement with the base 38. Further, the base serves as a reinforcing to prevent lip 37a moving inwardly. Accordingly, lips 37a,37b are forced into greater sealing engagement when the liquid pressure on the exterior surface of the conical section is greater than that on the interior surface.

When the pressure on the interior surface of the conical section is greater than that on the exterior surface (see FIG. 6). due to the resiliency of the material of which the valve is made, the lip 37b billows outwardly of lip 37a to provide a path for liquid flow through the valve. This billowing effect in part takes place due to the thickened portion 38 extending along lip 37a preventing the lip portion expanding (stretching) as much as that of lip 37b. Further, due to a provision of the thickened portions 38, the fact that the slit is elongated in a direction that the slit generally tapers toward the extension of central axis of the valve, and the lip is not cut or perforated, the liquid passing through the valve moves away therefrom in a helical fashion. Upon the pressure in the interior surface decreasing to or below that exerted on the exterior surface, the lip 37b rapidly moves to close the opening through the slit to minimize the insufficiency of the valve.

Thus in using the valve of this invention, when the pressure plate 13 moves toward plate 11 the tube 14 is squeezed whereby the liquid (blood) in a tube forces the valve at the adjacent ends of line 14, 29 to open to permit flow in the direction of the arrow 31 while the liquid under pressure acts on the valve in adjacent ends lines 14, 27 to close that valve. At the time plate 13 moves away from plate 11, the tube 14,

due to its resiliency, expands (resumes) to its rounded condition. Accordingly, the pressure on the interior surface of the valve at the adjacent ends of lines 14, 29 is below that acting against the exterior surface whereby the last mentioned valve closes. At the same time, the pressure on the exterior surface of the valve at the adjacent ends of lines 14, 27 is below that acting on the interior surface and accordingly liquid moves through this valve into line 14. Likewise, the plate 15 in moving towards and away from plate 12 causes liquid in line 16 to move through the valves at the adjacent ends of said lines in the direction of the arrow 32. While pumping with valves of this invention, the pulse wave form is essentially identical to the human normal pulse pressure curve including the dicrotic notch.

As an example of the valve of this invention and not otherwise as a limitation, the valve has been tested and will pump against 45 psi, pull 10 inches Hg and create less than 2 milligram percent of free hemoglobin per hour when operated against 100 mm of Hg pressure flowing at 1,000 cc/min. of bovine blood recirculated for a ten hour period. Additionally, the valve has been tested with flows up to 6,000 cc/minute, and a back flow or insufficiency of less than 1 cc per stroke.

Not previously mentioned is the fact that the thickness of the base (thickened portion) 38 determines the back pressure the valve may be operated against. That is, with a base of greater thickness 1, the valve may be utilized where there is higher back pressure than with a base having a smaller thickness.

lclaim:

1. A valve comprising a tubular portion having a first annular edge and a hollow generally conical portion having a second annular edge joined to said first annular edge. a tip remote from said second annular edge, and a generally conical wall extending between the tip and second annular edge. said wall having an outer surface, an inner surface. and lip portions intermediate the second annular edge and the tip defining a slit. and a thickened base joined to one lip portion to protrude into the interior of the conical section. said valve being made ofa flexible plastic material of sufficient rigidity to be self-supporting.

2. The valve of claim 1 further characterized in that it has a central axis and that said slit is elongated generally in a plane ofthe central axis.

3. The valve of claim 2 further characterized in that said conical section has lip portions defining a second and a third slit, said slits being about equally circumferentially spaced. and a base portion joined to one lip portion of each of second and third slits to protrude into the interior of the conical portion.

4. The valve of claim 3 further characterized in that each base in part underlies the lip portion of the respective slit and is of about the same length as said respective slit.

5. The valve of claim 4 further characterized in that each base is of a circumferential width and joined to the conical wall at a location predominately angularly offset from the respective slit.

6. The valve of claim 5 further characterized in that said one lip portion has a first lip edge inclined to form an angle substantially greater than with a plane tangential to the conical wall outer surface at the intersection of the last mentioned plane with said first lip edge.

7. A valve mountable in a liquid conducting line to permit liquid flow in one direction and restrict liquid flow in the op posite direction and having a generally conical section made ofa flexible plastic material of sufficient rigidity to be self-supporting, said conical section having an interior surface defining a generally conical chamber and having an annular edge, a tip remote from said annular edge and a wall extending between the annular edge and the tip, said wall having first and second wall portions defining a slit, said first wall portion having a first slit edge and the second wall portion having a second slit edge abuttable against the first slit edge to block passage of fluid through the slit, said first wall portion being of a substantially greater rigidity than the second wall portion, the first slit edge being inclined at an angle and the second slit edge being inclined at an angle substantially less than the corresponding angle of inclination of the first slit edge whereby a greater liquid pressure on the exterior surface than the interior surface will retain the slit edges in abutting relationship to block flow of liquid therebetween, and means joined to the annular edge for mounting the conical section in the line.

8. The valve of claim 7 further characterized in that said conical section has a central axis passing through the tip and that said slit is elongated predominately in a direction to intersect said axis.

9. The valve of claim 7 further characterized in that the conical section has a central axis and that the first wall portion has a thickened portion extending along at least the part of the length of the slit, protrudes into the interior of the conical section, and is closely adjacent the first slit edge to retain the first slit edge generally more closely adjacent the central axis than the second slit edge when a greater liquid pressure is exerted against the interior surface than the exterior surface.

10. The valve of claim 9 further characterized in that the conical section has a third wall portion and a fourth wall portion defining a second slit and a fifth wall portion and a sixth wall portion defining a third slit, said third and fifth wall portions being of substantially the same construction as the first wall portion, and said fourth and sixth wall portions being of substantially the same construction as the second wall portion.

11. The valve of claim further characterized in that said slits are substantially equally spaced and are elongated in the direction of taper of the conical section.

12. The valve of claim 11 further characterized in that the tip is aligned with the central axis of the conical section and is imperforated whereby a helical flow pattern is obtained in the liquid passing through the valve.

13. For mounting in the line of a perfusion pump. a valve made of flexible plastic material and having a tubular section that includes a first annular edge and a hollow tapered section that includes a second annular edge joined to said first annular edge, a tip remote from said second annular edge and the tubular section and joined to said tapered section, said tapered section having an enclosed chamber opening to said tubular section and three spaced. elongated slitted portions opening to said chamber to permit passage of perfusate through the tapered section. said slitted portions being intermediate the second annular edge and the tip and being elongated in a direction toward the tip, each slitted portion having a first slit edge and a second slit edge and a base portion for each slitted portionjoined to the tapered section adjacent the first edge of the respective slitted portion to protrude inwardly into the chamber to serve as a rest for the adjacent second slit edge to retain the adjacent first and second slit edges in abutting relationship when the liquid pressure acting against the taper section exterior of the chamber is greater than the liquid pressure in the chamber acting against the tapered section.

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