Description:
BACKGROUND
1. Field of Invention
The present invention relates generally to flow control of medical fluids and more particularly to a novel pinch valve assembly and manifold for selectively controlling flow of medical fluid, together with related methods.
2. Prior Art
In the past, medical valves and valve networks have been unduly expensive. Complete and repeated sterilization has been needed to assure absence of contamination, often because medical fluid was allowed to come in contact with the valve itself. Fluid flow has been difficult to ascertain. Occasionally ports, seals or sliding members of prior art valves and valve networks have tended to clog, damage or entrap fluid or permit leakage. Selective fluid flow control has been less than precise and substantial amounts of time have been lost while a given used valve network was being conditioned for subsequent utilization.
BRIEF SUMMARY AND OBJECTS OF THE PRESENT INVENTION
The present invention provides an economical novel medical pinch valve assembly or manifold, together with related methods, the assembly comprising a non-sterile body having grooves or channels receiving sterile tubing in a readily removable fashion. One or more actuators in selected locations are selectively controlled to occlude or not occlude the tubing at one or more predetermined sites to control flow of medical fluid from source to destination sites. Used tubing can be speedily removed and replaced by additional sterile tubing of like type and configuration without need for sterilizing the assembly per se. Fluid flow is easily determined, no fluid contact with valve parts occurs and seals are not required. Fluid damage and entrapment does not occur.
With the foregoing in mind, it is a primary object of the present invention to provide a novel medical pinch valve assembly or manifold and related methods.
It is a further object of considerable importance to provide a medical pinch valve assembly for selectively controlling fluid flow between source and destination sites which is economical and which accommodates prompt exchange of sterile tubing without the necessity of sterilization of the valve per se.
It is another paramount object of the present invention to provide a novel medical pinch valve manifold which selectively controls the flow of medical fluid, which flow is visible at all times.
It is an additional object of the present invention to provide a novel medical pinch valve manifold and method for accommodating selective displacement of the medical fluid without causing the fluid to contact valve components and which does not damage or entrap the medical fluid or permit leakage thereof.
These and other objects and features of the present invention will be apparent from the following detailed description, taken with the reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross-sectional view of a presently preferred medical pinch valve of assembled components in its normally closed condition;
FIG. 2 is a side cross-sectional view of the medical pinch valve assembly of FIG. 1 in its actuated, "open" condition;
FIG. 3 is a cross-sectional view of a second presently preferred medical pinch valve assembly embodiment according to the present invention;
FIG. 4 is a top plan view of a pinch valve manifold embodying three pinch valve assemblies shown in operable condition;
FIG. 5 is a top plan view similar to FIG. 4 showing the three pinch valve assemblies positioned so as to permit ready removal of the disposable tubing comprising the assembly;
FIG. 6 is a perspective representation of the manifold of FIG. 4 shown in its assembled, ready to use condition; and
FIG. 7 is an exploded perspective of the manifold of FIGS. 4 and 6.
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
Specific reference is now made to the drawings, wherein like numerals are used to designate like parts throughout. FIG. 1 illustrates one presently preferred pinch valve, generally designated 10, according to the present invention. The medical pinch valve 10 comprises a main body portion 12 and a pneumatic influent body portion 14. The body portion 14 comprises a male projection 16 having a linear passageway or actuating port 18 concentric with the axis of the medical pinch valve 10. The male projection 16 comprises external serrations 20, adapted to receive a flexible pneumatic tube whereby air under pressure is delivered to and exhausted from the valve 10.
Interposed between the main body portion 12 and the end body portion 14 is a diaphragm 22, the periphery 24 which is rigidly held in sealed relation between the portions 12 and 14 The central portion of the diaphragm 22 is permitted to flex within a counterbore recess 26 located at the base of the body portion 12. Counter bore 26 merges with intermediate counterbore 28 and intermediate counterbore 28 in turn with axial bore 30 of the body portion 12. A valve stem or plunger 32 is movably retained in sealed relation within the bore 30 so that it may appropriately axially reciprocate upon pneumatic command any may be manually rotated by use of knurled exposed end 34.
A transverse arm 36 is rigidly secured to the stem 32 at location 38 so that at all times the arm 36 moves with the stem 32. In all circumstances, the arm 36 is exposed above the body portion 12. In a normally closed position of FIG. 1, the arm rests upon the base surface 40 of a surface slot 42. In the actuated "open" position of FIG. 2 the arm is elevated completely out of the slot 42 away from the base 40 thereof.
The stem at its interior concealed end 44 is attached to a concentric disc 46, the bottom surface of which is bonded or otherwise caused to adhere to the top surface of the diaphragm 22. Thus, the disc 46 and the diaphragm 22 move together.
A return spring 50 abuts against the shoulder 52 of the intermediate counterbore 28 and against the top surface of the disc 46 exerting sufficient force so as, in the absence of pneumatic pressure on the underside of the diaphragm 22, the stem 32 and arm 36 will be held in the down, "closed" position shown in FIG. 1.
The body portion 12 at its top surface is covered by cover plate 56. The cover plate 56 is appropriately secured to the body 12 by screws or the like, not shown, so that the plate 56 may be removed as desired. A slot 58 extending through the entire thickness of the plate 56 accommodates axial reciprocation of the arm 36 as the stem 32 moves between the positions of FIGS. 1 and 2, but at the same time prhibits, in the illustrated embodiment under consideration, rotation of the arm 36. When the plate 56 is removed, the user may grip the knurled end 34 and rotate the arm 36 out of superposition over the slot 42. The need for a cover plate is eliminated if the stem travel from the closed to the open position is less than the depth of slot 42, thereby inherently preventing rotation of the stem 32.
A channel or open groove 60 exists in the top surface of the body portion 12 and extends transverse of the slot 42, crossing the slot 42 about midway along its length. A flexible pliable medical tubing 62, having memory and a diameter approximately twice the depth of the slot 60, rests in the slot 60 along the bottom or base thereof. Preferably, the plate 56 and the tubing 62 are transparent so that one may readily observe the flow of medical fluid along the tubing 62.
As can be observed from FIGS. 1 and 2, the arm when in the normally closed position compresses the tube 62 so as to fully occlude the same, but at the time does not crush or cause structural damage to the tube. In the open position of FIG. 2, the tubing 62 is shown as being fully open to accommodatefluid flow, the tube being displaced from the occluded to the open condition due to the memory of the material comprising the tubing 62 and pressure of the fluid in the tubing.
It is intended that the valve 10, with the exception of the tubing 62 be nonsterile. Initially, the tubing 62 will be sterile and, following use, may be readily replaced by merely removing the cover plate 56, manually lifting the stem by knurled end 34 and rotating it out of superposition over the tubing 62, removal of the tubing the replacement of the same with new, sterile tubing. When appropriately assembled, air under pressure is introduced from a suitable source through the passage 18 of the portion 14 causing the valve stem 32 and arm 36 to elevate to the position of FIG. 2 thereby selectively passing medical fluid through the tube 62. When pressure from the source is removed, an exhaust mode prevails and the force of spring 50 will evacuate air on the underside of the diaphragm 22 causing the pinched valve to move from the position of FIG. 2 to that of FIG. 1.
Reference is now made to a second presently preferred embodiment of the present invention illustrated in FIG. 3 and generally designated 70. The pinch valve 70 is shown on its side, but it is to be appreciated that it may be oriented in any desired fashion. The portions of the valve 70 which correspond to the valve 10 have been given identical numerals and no further description will here be presented. Only the differences will be described. The valve 70 comprises the central body portion 12', previously mentioned, the cover plate 56 and an end body portion 14'. The end portion 14' is secured to the body portion 12' by cap screws 72 or the like. A push type solenoid 74 extends into a central bore at threads 76 in portion 14' at 78 and is there secured. Thus, the portion 14' comprises a solenoid mounting plate. An armature-actuated plunger 80 projects from opening 76 into counterbore 28' of the valve body 12'. The plunger 80 contiguously engages the bottom surface 82 of a bearing plate 84 at the distal end 86. The abutment plate 84 forms an integral part of the valve stem 32'. The upper surface 88 of the plate 84 is engaged by return spring 90, which also engages and bears against shoulder 52' of counterbore 28. The operation of the embodiment 70 of FIG. 3 is fundamentally the same as the operation of the embodiment of FIGS. 1 and 2, pinch valve 70 being illustrated in its non-actuated position (normally closed) in FIG. 3. Thus, when the solenoid 74 is energized, the plugner 80 is extended, thereby displacing the stem 32' to the right and opening the medical tubing 62 for flow of medical fluid from a source to a destination site.
Reference is now made to FIGS. 4 and 5 which illustate an array of pinch valves of the type illustrated and described in connection with FIGS. 1 and 2 and/or FIG. 3. While either valve 10 or 70 could be used, for simplicity FIGS. 4 and 5 will be described in connection with valves 10. It is intended that FIGS. 4 and 5 illustrate generally how the pinch valves according to the present invention may be assembled into arrays. Obviously, many more than three valves could be used depending upon the particular type of medical fluid flow control desired. In the FIGS. 4 and 5 three pinch valves 10 are illustrated having a single one-piece cover plate 56' extending over all three as illustrated in the assembled condition of FIG. 4. Screws 80 may be used to removably hold the cover plate 56' to the three valves 10. The valves 10 comprise surface grooves 60 arranged in a T configuration, when considered as a whole. A T-shaped array of medical tubing 62' comprising branches 82, 84 and 86. Said array of tubing is disposed in the mentioned grooves 60 beneath the cover plate 56'. Each valve 10 is normally closed (see FIG. 1) and, therefore, it can be appreciated by reference to FIG. 4 that all of the valves may be "off" at any particular time thereby preventing flow of the medical fluid in any of the branches 82, 84 and 86. By the same token, the selective actuation of the plungers or stems 32 of the three valves 10 can be used to permit flow of medical fluid between any one branch to any other branch.
Again, the present invention has as an objective the provision of valve structure which does not require sterilization. Therefore, it is contemplated that only tubing 62' would be initially sterile and the valves 10 would not be subjected to sterilization processes. Thus, when the tubing 62' has been used and is no longer appropriate for continued use, the cover plate 56' is removed by removal of screws 80. When the cover plate 56' is removed, the valves 10 are exposed as illustrated in FIG. 5, following which the tubing 62' is readily pulled from the grooves 60 and replaced by like tubing.
It should be appreciated that other configurations in the form of valve assemblies or arrays may be constructed using two or more medical pinch valves in accordance with the present invention. In this way, closed loop intravenous therapy, bypass and flushing functions may be facilitated. The pinch valve bodies, cover plate or plates, diaphragms, if diaphragms are used, and other components may be of one-piece unitary construction or formed in separate pieces. In any event, the valve actuators comprising plungers or stems must be individually operable. To illustrate the foregoing, the valve network embodiment of FIGS. 6 and 7 will now be described. The valve network or manifold, generally designated 110 comprises a one-piece valve body 112. Three stepped bores 130, configurated as are stepped bores 30 of FIGS. 1 and 2, are placed in appropriate locations so as to extend parallel to the depth of the valve body 112. The illustrated top surface of the valve body 112 contains U-shaped grooves or channels 160, each having a base. Said grooves are shaped and located as groove 42 of FIGS. 1 and 2. Three slots 142 extend transversely across the adjacent groove 160 and open into the adjacent stepped bore 130 as illustrated. In the same fashion as described in connection with FIGS. 1 and 2 the channel 160 is deeper into body 112 than the associated transverse slot 142 by a distance equal to approximately the radius of the transparent medical tubing 162 which is placed in the T-shaped groove 160. As can be observed, the medical tubing 162 is T-shaped also. The described depth difference between grooves 160 and slots 142 prevents damage to the tubing 162 when engaged by the arms 136 of the pinch valve network 110. Each arm 136, in a manner previously described, is anchored non-rotatably to the associated plunger or stem 132. Each stem 132 fits snugly but displaceably within the smallest diameter portion of the stepped bore 130. Each stem is biased as earlier described by a spring 150, which abuts a shoulder of the stepped bore 130 anda disc 146, secured by a screw 147 to a threaded bore at the lower surface of the associated stem 132. A diaphragm 122 covers the enlarged, bottom opening of each stepped bore 130 and is sealed to the underside of valve body 112 by an end cap 14, identical to the end cap 14 of FIGS. 1 and 2. Each end cap 14 is secured by cap screws 123 to the underside of body member 112, the screws 126 fitting into threaded blind bores in the body 112.
The array of medical tubing 162 and the grooves 160 at the top surface of the valve body 112 are covered by one-piece transparent plate 156. The plate 156 is secured by countersunk screws 157 to the body member 112 at threaded blind bores therein disposed in the top surface. Three key-hole openings 136 in the plate 156 accommodate reciprocation of the plungers 132 while preventing rotation of the same. Removal of the cover plate 156 accommodates lifting and rotation of the plungers 132 whereby the array of medical tubing 162, following use, may be removed and replaced by a like array of tubing in sterile condition. Hence, sterilization of the network 110, exclusive of the tubing, is avoided.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.