US 3595232 A
Description (OCR text may contain errors)
72] Inventor Saul Leibinsohn 7 l1 Hagardom Street. Rishon Lezion. Israel  Appl. No. 753,405
 Filed Aug. 19. 1968  Patented July 27,1971
 NONGRAVIIATIONAL INFUSION ASSEMBLY 17 Claims, 18 Drawing Figs.
52] U.S.,C,1. 128/214, 128/272  Int. Cl A6lm 5/00  Field of Search 128/214,
213, 216,272, DIG. 12
 References Cited UNITED STATES PATENTS United States Patent 2,842,123 7/1958 Rundhaug 3,151,616 10/1964 Selfon 128/214 3,384,080 5/1968 Mu11er..... 128/214 3,451,393 6/1969 Sarnoff 128/214 Primary Examiner-Warner H. Camp Attorney-Ostrolenk, Faber, Gerb and Soffen ABSTRACT: A combined container-and fluid dispensing assembly housing a compressible bag of fluid. A slidably mounted pressure bar under control of suitable biasing means is caused to bear against the compressible bag of fluid to provide a substantially constant pressure upon the bag, causing the fluid to be dispensed at a substantially constant pressure throughout the infusion operation. In the inactive state, the housing protects the compressible bag of fluid against any possible damage and further provides additional storage space for the infusion set. No observation or control need be exerted upon the device during an infusion operation in order to maintain fluid flow at a constant rate.-
PATENTEO JUL27 Ian sum 2 or 2 particularly to a novel apparatus for dispensing fluids wherein the fluid to be dispensed is urged out of a compressible fluid container at a substantially constant rate over the entire infusion operation.
Infusion apparatus is commonly used in the medical field. For example, when it is desired to infuse blood or other sterile fluids into the body of a patient being treated, the common method employed is one in which the fluid to be introduced into the body is provided within a suitable container (i.e., a rigid glass or plastic bottle). The container is supported a predetermined distance above the height or level of the body, causing infusion to be controlled by gravity. In field applications such as, for example, applications wherein a subject is being transported by stretcher, carried by two men, a third man is needed to hold the fluid container a predetermined distance above the subject upon the stretcher in order to provide for gravitational infusion of the fluid. In such extreme applications it is very much preferred that the infusion operation be capable of being performed and that the third person necessary for supporting the fluid container be eliminated. One possible method of eliminating the necessity for a person 7 supportingthe fluid container would be to provide a structure mounted to the stretcher which would support the fluid container a predetermined distance above the level of the injured person receiving the fluid. In most cases this approach is either awkward or impossible and it thereby becomes extremely necessary to provide suitable alternative means for carrying out such infusion while, at the same time, eliminating the need for a person accompanying the stretcher bearers to support the fluid container and thereby allow for gravitational infusion. v
The present invention provides an apparatus which may be readily and simply attached to a stretcher or any other support or surface which need not be elevated above the person but, in fact, may be suspended from the stretcher (or other support) and which further provides for infusion of a fluid into the person being treated at a substantially controlled and constant rate. I
The present invention is comprised of a combined container and fluid dispensingapparatus which, in turn, includes a hollow housing which encloses a compressible fluid container. A slidable arm is mounted along one side of the housing which is further provided with an elongated slot for guiding a first end of the pressure bar and an opening for slidably receiving the opposite end of the pressure bar. An elastic member is secured to the housing near said opening and is stretched around the exterior of the housing for mounting upon a suitable notch provided upon the end of the pressure bar projecting beyond said elongated slot for urging the pressure bar downwardly against the compressible fluid container. The configuration of the housing is such that the angle between the pressure bar and elastic member at their juncture point is continbously increasing as the engaging surface of the pressure bar with the compressible bag is decreasing and as the elastic member tension is being released resulting in a substantially constant pressure being applied to the fluid urged out of the compressible bag to provide a structure which operates substantially independent of gravity in urging fluid out ofthe compressible container at a substantially constant rate.
When not in use, the rugged design of the housing protects the compressible bag against being ruptured or otherwise damaged and its substantially flat and compact configuration greatly facilitates both storage and handlingof the apparatus. Additional interior space is available within the housing interior for storing an infusion set which may include the elastic member, roller assembly, suitable tubing, drop chamber and a hypodermic needle for introducing the fluid into the patient. Additional drugs and/or syringes may also be stored in the additional interior space. The housing is designed to protect these components, as well, from damage during storage and handling. Whereas the present invention has been described as being advantageous for use in the medical field, it should be ,understood that the invention may be utilized in any application wherein it is desired to urge fluid out of a container under a substantially constant pressure.
It is therefore one object of the present invention to provide a combined enclosure and infusion apparatus for compressible fluid containers which operate substantially independently of gravity and which applies substantially constant pressure upon the compressible bag throughout the infusion operation.
Another object of the present invention is to provide a novel infusion apparatus for compressible fluid containers including a housing enclosing the fluid container and a pressure bar urged by an elastic biasing member downwardly against the compressible container whereby the angle between the pressure bar and the elastic member and the surface contact area between the compressible bag and the pressure bar is continuously changing as the elastic member releases its stored energy so as to maintain a substantially constant pressure upon the compressible container.
These as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:
FIGS. Ia- 1d show side, top, front and back views, respectively, of one preferred embodiment of the present invention.
FIG. 2 shows a perspective view of the preferred embodiment of FIGS. lald.
FIGS. 3a and 3b are top and side views, respectively, of the pressure bar of FIGS. la2.
FIG. 4 is a perspective view showing the roller assembly employed in the embodiment ofFIG. la.
FIG. 5 is an elevational view of the invention similar to that shown in FIG. 1a, wherein analternative biasing means is employed.
FIG. 5a is a sectional view looking in the direction of arrows 5-5 of FIG. 4 and showing one elastic assembly which may be employed for the purpose of eliminating the roller assembly of FIG. 4.
FIG. 5b is an elevational view showing an alternative arrangement for a portion of the housing of FIG. In.
FIG. 5c is a perspective view showing another alternative arrangement for a portion ofthe housing of FIG. 1a.
FIG. 6 is an elevational view of the housing showing a measurement scale which may be employed in the present invention.
FIG. 6a is a top plan view showing two housings of the type shown in FIG. la.
FIG. 6b is an elevational view of the housing incorporating an alternative pressure bar.
FIG. 6c is an elevational view of a modified collapsible bag which may be used with the invention.
FIG. 6d is a sectional view of FIG. 60 looking in the direction of arrows 6d-6d of FIG. 6c.
FIG. 6e is a view showing an elastic band mounting clip which may be employed in the instant invention.
The infusion set 10 of the present invention is comprised of a hollow container 11 having two truncated triangular-shaped shaped sides I2 and 13 which are joined along their lower ends by a yoke portion IS. The vertical edges of side plates 12 and 13 are bent inwardly to form flanges l6 and 17 which define an elongated guideway or slot 18 therebetween. The front end of the housing is provided with a pair of inwardly bent flanges l9 and 20 which, together with the left-hand end of yoke portion 15 form a slot or guideway 21 which slidably receives the lower end of an elongated pressure bar 22, shown best in the top and side views of FIGS. 3a and 3b, respectively. The pressure bar 22 (in one preferred embodiment) is a flat elongated substantially rigid member preferably formed of a suitable plastic material. The pressure bar 22 is provided with a pair of notches 23 and 24 arranged near the upper end thereof for slidably receiving the inwardly bent flanges I6 and 17 of the housing in the manner shown best in FIG. 1a. The.
topmost edge of the pressure bar 22 is provided with a pair of notches and 26 for receiving a portion ofa biasing member which may, in one embodiment, be either a closed loop elastic member or an elongated elastic member such as the rubber band 27 shown in FlGS. 1a and 2. The rubber band is looped around the upper edge of pressure bar 22, passes through notches 25 and 26 (see FIG. 1b) and extends around the vertical and horizontal sides of the housing 11 (relative to FIG. la) where it is again looped around a portion of the yoke 15 which is similarly provided with a pair of notches 28 and 29 for firmly receiving and holding the elastic member.
The upper truncated portion of the housing is provided with a bracing member secured to the interior surfaces of sides 12 and 13. Bracing member 30, together with yoke portion 15, rigidly maintains the sides 12 and 13 in spaced parallel fashion in the manner shown best in FIGS. lb and 1c.
The pressure bar 22 is normally stored within the housing as shown best in solid line fashion in FIG. 1a wherein the lower edge thereof passes through the guideway or opening 21 defined by yoke 15 and inwardly bent flanges 19 and 20. The upper end thereof protrudes through the upper truncated portion of the housing between the right-hand edge of bracing member 30 and the inwardly bent elongated flanges 16 and 17 so that the upper shoulders 22a and 22b (see FIG. 3a) of notches 23 and 24 rest upon the upper edges 12a and 13a of sides 12 and 13, respectively. The pressure bar may be restrained from moving to the operative position by means of a pin 47 seated within notches 48 provided in side plates 12 and 13 (see FlG. 1a). The removal of the pin allows movement of the pressure bar to the operative position.
The top surface of crosspiece 30 is provided with a suitable opening 31 for receiving one end 320 ofa hook 32 which may be employed to hook or otherwise suspend the housing upon a suitable support such as, for example, one edge or side of a stretcher, in field applications. Obviously, any other support may be employed for suspending the device.
The hollow interior region of the housing is triangular in shape and is defined by pressure bar 22 which lies along the hypotenuse of the triangle with the sides of the triangle being defined by elongated flanges 16-17 and by yoke 15, respectively. This hollow triangular-shaped interior region houses a compressible or collapsible container 33 which may, for example, be a plastic bag. The plastic may, for example, be a polyvinyl chloride material. The plastic bag is filled with a fluid which may, for example, be blood plasma or a saline solution. Obviously, the bag may be filled with any other fluid which is to be injected into the body of a patient or alternatively which is to be supplied to some other object wherein it is desired to supply the fluid to such object at a substantially constant rate. An outlet port is provided at the corner of the bag which is opposite the hypotenuse of the above defined triangular configuration. The outlet port may be integrally joined with a section of hollow tubing 34 which, in turn, may be coupled to a hollow hypodermic needle or other suitable appliance for introducing the fluid into the body of a patient or for otherwise introducing the fluid into an object which is to receive the fluid at a substantially constant rate.
The bag 33 which may preferably have a triangular shape or any other shape (i.e. rectangular) capable of assuming a triangular configuration may be introduced into the hollow interior region simply by extracting the pressure bar from the housing. This is done by lifting the pressure bar out of the housing in the direction shown by arrow 35 thereby allowing an empty bag to be removed from between sideplates 12 and 13 and likewise providing suitable access to allow for the insertion of a filled compressible container which may be inserted into the housing interior in the direction shown by arrow 36. After a filled compressible container is inserted into the housing. the pressure bar may be replaced by sliding its lower edge 22c (see FIG. 3a) through the top open region defined by sideplates 12 and 13 and flanges 16 and 17 through the guideway 21. The infusion set which may comprise a hypodermic needle, plastic tubing, a drop chamber and/or drugs and a syringe, may be stored in the interior region 81 of the housing above the pressure bar 22 when being stored and/or shipped. One or more adhesive coated Mylar strips 82 (shown in dotted fashion) may be placed across the space between the diagonally aligned edges of sideplates 12-13 to retain the infusion set within the interior region 81. The Mylar strips may simply be peeled of to gain access to the infusion set.
The infusion apparatus may be placed in the operating state by taking the closed loop elastic member (which may, for example by a rubber band) and sliding a portion of the loop through the notches 28 and 29 provided in yoke 15. The elastic member is then extended from the left-hand end of yoke 15 (relative to FIG. 1a) beyond yoke 15 and up the vertical sides of the housing defined by flanges 16 and 17 where it is then looped around notches 25 and 26 provided at the upper end of pressure bar 22. It should be noted that when pressure bar 22 is maintained in the solid line position, shown in FIG. 1a, with its shoulders 22a and 22b resting upon the edges 12a and 13a of sides 12 and 13, that the pressure bar will be prevented from moving, due to pin 47. Release of the pressure bar (by removing pin 47) and movement of the pressure bar downwardly in the direction shown by arrow 37 (under control of the elastic member) is initiated by moving the pressure bar in the direction shown by arrow 38 so as to lift the shoulders 22a and 22b away from edges 12a and 13a to the point where the notches 23 and 24 (defined by the diagonally aligned shoulders 2211-2211) are slidably received by elongated flanges 16 and 17.
In one embodiment of the pressure bar 22, the elongated flanges 16-17 and the yoke 15 define an isosceles triangle wherein the sides of the triangle are equal in length. The elastic member which extends between the pair of notches 2829 and 2526 and which is under tension due to its stretching, has a length equal to twice the length of either of the sides defining the isosceles triangle. As soon as the pressure bar is released to move under the force of the tensioned elastic member, the pressure bar is caused to move downwardly from the solid line position 22, shown in FIG. la, wherein it ultimately reaches the dotted line position 22", at which time the pressure bar is aligned substantially parallel to yoke 15. 1n the initial position 22, it should be noted that the lower edge 22c of pressure bar 22 protrudes slightly beyond the guideway 21 which also acts as a sliding pivot for pressure bar 22. In moving downwardly substantially the entire surface area of pressure bar 22 bears against the diagonally aligned side 33a of the triangular-shaped collapsible container 33 applying substantially constant pressure over the entire diagonally aligned surface 33a of the collapsible container. The magnitude of the pressure may be represented by the component 37a of the force vector 37 which represents the downward vertical force applied to the pressure bar by elastic member 27. The pressure bar is urged downwardly from the solid line position 22 through the intermediate position 22' until it reaches the final position 22", at which time the notches 23 and 24 of the pressure bar are guided downwardly by the elongated flanges 16 and 17 of the housing. As the pressure bar moves downwardly its lower edge 22c moves further and further away from the guideway 21 causing a constantly decreasing surface area of the pressure bar 22 to make contact with the diagonally aligned surface 33a of the triangularshaped collapsible bag. As the area of surface contact between pressure bar 22 and bag surface 33 continually decreases, the vector 37 which originally forms an angle of 45 with pressure bar 22, continuously forms a larger and larger angle until ultimately the force vector forms an angle of with pressure bar 22 at the time that the pressure bar reaches the horizontal position 22". This means that the component 37a of vector 37 continually increases in magnitude proportionally to the magnitude of the vector 37 until vector 37 and vector component 37:: are equal in magnitude when pressure bar 22 reaches position 22". The unique result which the triangular shape of the infusion assembly provides can best be understood from the following example:
Let it be assumed that the two equal length sides of the isosceles triangle (defined by the infusion set) are each centimeters in length. As soon as the pressure bar is released to be urged downwardly under control of the elastic member its length is approximately 14.14 centimeters. Let it be assumed that the elastic band which is selected provides a downward vertical force of 2 kilograms when stretched to a length of centimeters and which provides a force of 1 kilogram when stretched to a length of 10 centimeters. The component of force which is normal to the surface of the pressure bar is equal to the cosine of the 45 angle formed between the downward vector and the pressure bar which is cos (45) or 0.707. Thus the normal component of force is equal to 1.414 kilograms. Dividing this quantity by the lengthof the pressure bar (14.14 centimeters) indicates that a force per unit length of 0.1 kilograms per centimeter is applied against the diagonal surface 33a of the collapsible bag 33.
At the time that the pressure bar reaches the bottom most position 22" the elastic band has its length reduced by onehalf (i.e'. from 20 centimeters down to 10 centimeters) thereby exerting a force upon the pressure bar of l kilogram (it being understood that the force of a stretched elastic member is substantially proportional to its length). At this time the force vector of l kilogram being normal to the pressure bar constitutes the normal force applied to the pressure bar. Due to the fat that the lower edge of the pressure bar has been passing out of the guideway 21, only that portion of the length of the pressure bar which is equal in length to the length of the yoke 15 makes surface contact with the collapsible bag, which length at this time is equal to the length of yoke 15 or 10 centimeter. Thus the force per unit length at this time is equal to 0.1 kilograms per centimeter.
It can be seen from the above description that the pressure applied to the collapsible bag by the pressure bar remains substantially constant throughout the infusion operation as the pressure bar moves from the starting position 22 to the final position 22".
Although the isosceles triangle configuration is one preferred embodiment, it should be understood that any other triangular configuration may be employed wherein the length of the vertical side may be either longer or shorter than the length of the horizontal side and/or wherein the angle formed between the horizontal and vertical sides of the triangular configuration (relative to FIG. 1a) may be greater than 90", so long as the diagonally aligned side, defined by pressure bar 22, is the longest side of the triangle.
In order to be assured that the force applied to the pressure bar 22 by elastic member 27 remains constant throughout the infusion operation, means must be provided for preventing the elastic member from frictionally grabbing the housing at the right-hand edge of yoke 15 (relative to FIG. 1a), which grabbing would result in unequal forces existing between the section of the elastic member along the yoke 15 and the section of the elastic member extending along the elongated flanges 16--17. To prevent such grabbing, a roller assembly 40 is positioned in the region of the notch 39 defined by the right-hand edge of yoke 15 and the lower edges of flanges 16-17.
The roller assembly 40, which is shown best in FIG. 4, is comprised of an elongated roller 41 having a hollow interior for receiving the inwardly directed ends 43 and 44 of a metallic clip 45. The central portion 46 of clip 45 is bent in a U- shaped configuration and bears against the surface of roller 41. The roller assembly 40 is mounted in the manner shown in FIG. 1a and is retained within the notch 39 by the tensioned elastic member which is entrained around the roller 41 in the manner shown best in FIG. 4 so that the two portions 270 and 27b of elastic member 27 are separated from one another by the U-shaped central portion 46 of the metallic clip 45. Although the surface of roller 41 engages the edges of yoke 15 and flanges 16--17, it has been found that the roller is still nevertheless free to experience rotation within the notch 39 as the tension of the elastic member continuously changes so as to insure equalization of the forces along the horizontal and vertically aligned sections of the elastic member.
Whereas the preferred embodiment has been described as employing a closed loop elastic member (i.e. a rubber band) it should be understood that a helical spring may be employed. The helical spring 60, as shown in FIG. 5 may have a first end mounted to the left-hand end of yoke 15 and a second 'end secured to one end ofa wire 61 extending around a portion of the yoke 15 and the vertical side of the housing and having its opposite end secured to the upper end of pressure bar 22. The spring 60 should be chosen so that even when stretched, it will not extend around the corner formed by the horizontal and vertical sides of the housing. The wire 61 will not experience any frictional grabbing at the lower right-hand corner of the housing (relative to FIG. 5) and for this reason the roller assembly 40 is not necessary in this embodiment. The biasing means of FIG. 5 may be comprised of either a single spring means 60 and wire 61 or may be comprised of a pair of springs whose left-hand ends are coupled to the left-hand edge of yoke 15 and whose right-hand ends are coupled to the ends of a section of wire arranged in a loop fashion wherein the loop portion of the wire may be inserted within the notches 2526 of pressure bar 22 in the same manner as was previously described with regard to the elastic member.
In an alternative embodiment the roller assembly 40 of FIG. 4 may be eliminated by providing a closed loop elastic assembly shown in cross section in FIG. 5a. The elastic member of FIG. 5a is a cross-sectional view of the assembly looking in the direction of arrows 5-5 of FIG. 4 and is comprised of an elastic member (i.e., a rubber band, for example) 51 mounted within a stretchable woven plastic or woven textile sleeve 52. Although the sleeve 52 may frictionally engage the right-hand edge of yoke 15 and the lower edges of flanges 16-17 the interior elastic member 51 will nevertheless be free to slide relative to sleeve 52 so as to equalize the forces along the horizontal and vertically aligned sections of the elastic member to thereby assure the application of substantially equal pressure upon the triangular-shaped bag by pressure bar 22. The sleeve may be a closed loop sleeve which completely surrounds elastic member 51 or may surround only a portion of the elastic member 51 and be of a length sufficient to extend around the lower right-hand corner of the housing.
The inwardly directed flanges 19 and 20 which, together with the left-hand edge of yoke 15 define a guideway for the lower end of pressure bar 22, may be replaced by a single pin 53, as shown best in FIG. 5b. The pin 53 may be secured to sideplates 12 and 13 by suitable fastening means 54. This alternative arrangement simplifies the molding of sideplates 12 and 13. As another alternative arrangement (shown in FIG. 50) the flanges 19 and 20 may be eliminated and replaced by a channel-shaped clip 55 having inwardly directed projections 55a, a pair of which are each provided along the interior opposing surfaces of the channel. Cooperating with projections 55a there is provided a pair of keyhole"-shaped notches 56 in each of the sideplates l2 and 13 which are designed to slidably receive the projections 55a by pushing the projections 55a of the channel clip 55 in the direction shown by arrow 55c so as to snap-fit the channel clip to the sideplates 12 and 13. The lower edge 55b of channel clip 55 will now serve together with the left-hand edge of yoke 15 in defining the guide slot for the lower edge of pressure bar 22.
The exterior surfaces of elongated flanges 16 and 17 may be provided with graduations 57 which define a scale for the purpose of both determining and controlling the amount of fluid to be infused. For example, if the fluid bag contains 500 cc. of a fluid and it is desired to infuse 200 cc. of the fluid into the subject, allowing the pressure bar to move from the 500 cc. reading on the scale down to the 300 cc. reading and then stopping the pressure bar manually, assures accurate control over the amount of fluid infused. The graduations of the scale may be wrapped around the flanges 16-17 on to the sideplates 12-13 to facilitate reading of the scale. The housing may preferably be formed of a transparent plastic to simplify the observation of the pressure bar relative to the graduations of the scale.
An alternative arrangement may be used in which the graduations are provided along the length of the pressure bar and upon its upper surface. These graduations may be observed relative to the guide opening 21 to control the amount of fluid infused in substantially the same manner as was previously described with reference to the graduations provided upon the flanges 16-17.
The end view of the housing shown in FIG. 6 details an alternative arrangement for the pressure bar 22 and sideplates l6'l7' of the assembly wherein a configuration is provided for preventing the return of fluid from the object receiving the fluid back to the bag. As one example, let it be assumed that the biasing means is urging the fluid out of the compressible bag 33 (see FIG. la) and into the object receiving the fluid. As the pressure bar moves downwardly along the guide slot 18', defined by flanges l6 and 17', let it be assumed that the spring biasing means becomes broken or torn. The pressure within the object receiving the fluid may be greater than atmospheric pressure at this time, causing the fluid within the object to be returned to the compressible bag 33. In order to prevent the fluid from being so returned without the need for constant surveillance of the infusion assembly, the arrangement of FIG. 6 may be employed. As shown therein, the flanges l6 and 17' are each provided with a plurality of notches horizontally aligned relative to the associated notch provided on the opposite flange. Each notch, for example, notch 65, is defined by a first inclined surface 66 forming a small acute angle with the vertical and a second inclined surface 67 forming a much larger acute angle with the vertical. The neck portion 22f(see FIGS. 34 and 3b) of the pressure bar 22 is provided with the configuration shown in FIG. 6 wherein the arrangement of the neck portion of FIG. 6 represents a cross-sectional view of the neck portion 22f, looking in the direction of arrows 6-6' of FIG. 30. It can be seen that the neck portion 22fis provided with inclined sides 68 and 69 which form a small acute angle with the vertical and which are joined at their upper ends by inclined surfaces 70 and 71, respectively, forming a larger acute angle with the vertical.
The pressure bar 22, in moving downwardly through guideway 18 in the direction shown by arrow 72, is caused to pass substantially freely between the notches provided along the interior edges of flanges I6 and 17'. However, due to a rupture or breaking of the biasing member, if the pressure bar 22 is caused to move in the upward vertical direction due to expansion of the compressible bag, one of the diagonal surfaces 70 or 71 of the pressure bar neck portion 22/ will be caused to move beneath one of the surfaces 67 closest to the pressure bar as it moves upwardly, preventing any further upward movement of the pressure bar and hence preventing expansion of the compressible bag 33. Since the arrangement of FIG. 6 renders it difficult, if not impossible, to lift the pressure bar upwardly once it has traveled downwardly to any extent through guide slot I8, an additional opening 73 of sufficient width is provided at the bottom of the housing between the lower edges of side plates 16 and 17' and yoke 15 to enable the pressure bar to be slid out of the housing. Under normal operation, there is no danger ofthe pressure bar being slid into the housing due to the force exerted upon the upper end of pressure bar 22 (relative to FIG. 3a).
The arrangement of FIG. 6a shows the manner in which the unique triangular shape of the assemblies I and I0 allows a large number of assemblies to be stacked and stored within a minimum amount of space. As shown in FIG. 6a, the diagonally inclined edges of the housings l0 and are aligned in engaging relationship so as to occupy a minimum of space when being stored. The maximum thickness of each housing is no greater than the distance between the exterior surfaces of sideplates I2 and 13, thereby greatly simplifying the stacking ofsuch assemblies one upon the other.
Whereas the preferred embodiment has been described as being comprised of a pressure bar which is a substantially straight elongated member, it should be understood that the pressure bar may have a curve or linear configuration, as shown best in the embodiment of FIG. 6b. Numeral 92 shows the topmost position of the curve or linear pressure bar while numeral 92" indicates the terminal position of the curve d or linear shaped pressure bar.
As was previously mentioned, the compressible container which has a substantially triangular shaped configuration, may preferably be formed ofa polyvinyl chloride material. In order to prevent the bag from entering into the region between the edges of pressure bar 22 and the interior surfaces ofsideplates l2 and 13 as the pressure bar is moved downwardly (which might cause ajamming of the pressure bar) the collapsible bag 33 may be sealed at spaced intervals along its interior surface. This arrangement is shown best in FIG. 60 wherein the interior seals 75, which may be formed by a heat-sealing process, provide the collapsible bag with a configuration, shown best in FIG. 6d, which is a cross-sectional view of the bag 33' looking in the direction of arrows 6d-6d'. This arrangement will prevent the bag, as it collapses, from becoming jammed between the edges of the pressure bar and the interior surfaces of sideplates l2 and 13.
FIG. 6e shows an arrangement wherein the mounting of the elastic member upon the housing and pressure bar may be greatly facilitated. A wire assembly 76 which has a substantially U-shaped configuration, has the free ends of its arms wrapped or otherwise bent around the elastic member 27. The lower end of elastic member 27 (relative to FIG. 6a) is positioned within the notches 28 and 29 provided in yoke 15 (see FIG. lb). The wire assembly 76 is then gripped by the fingers and pulled in order to pull the elastic member around the horizontal and vertical sides of the housing. The wire assembly 76 is then pulled slightly beyond the upper edge of pressure bar 22 until the section of the elastic member extending between the arms 77 and 78 of the assembly 76 lies above the top edge of the pressure bar. The vertically aligned sections of the elastic member are then guided into the notches 25 and 26 provided in the pressure bar. This assembly eliminates the clumsy and tedious operation of handling the elastic member with the fingers whereby both the pulling force and the guiding operation of the elastic member into the notches 25 and 26 must both be performed simultaneously by the fingers.
As was mentioned previously, the compressible bag may contain any one ofa variety ofsolutions or fluids. One possible solution which the bag may contain is a saline solution. Since the bag, in its preferred form, may be polyvinyl chloride material, the porosity of such bags will cause a certain amount of evaporation of the fluid within the bag, thereby changing the percentage concentration of the solution. In an effort to reduce the amount of surface area of the bag exposed to the atmosphere and thereby in order to substantially eliminate evaporation, adhesive nonporous plastic material strips 82 such as Mylar (see FIG. 1b) may be placed over the entire opening defined by the diagonal edges of the housing as well as over the guideway 18 between flanges l6 and 17. These Mylar strips will seal a substantially major portion of the opened areas of the housing to significantly reduce the evaporation of the solution. In use, the Mylar strips may simply be peeled off to gain access to the infusion set stored within the housing and to permit the elastic member to be mounted to the housing and pressure bar for commencing the operation.
It can be seen from the foregoing description that the present invention teaches a novel infusion assembly in which fluid contained within a collapsible container may be dispensed from the container at a substantially constant rate through the creation of substantially constant pressure upon the collapsible container. The container is quite simple in design, is quite easy to use and is not dependent upon gravity for dispensing fluid for infusion into an object. Thus, the need for a support to mount the infusion set a predetermined distance above an object, (as required in conventional structures) is completely eliminated. Although the infusion set employs a collapsible container or bag which might otherwise be vulnerable to damage or puncturing the unique design of the housing which completely surrounds the collapsible bag protects the collapsible bag from being damaged during either storage, transportation, handling or use.
Although the invention has been described above with respect to its preferred embodiments, it will be understood that many variations and modifications will be obvious to those skilled in the art. It is preferred therefore that the scope of the invention be limited not by the specific disclosure herein but only by the appended claims.
In the claims 1. Means for urging fluid from the outlet port of a compressible container at a substantially constant pressure comprising:
a housing having a hollow interior for receiving said compressible container;
an elongated pressure bar;
a first elongated guideway provided along a first side of said housing for guiding a first end of said pressure bar along said first side;
an opening being provided in a second side of said housing located a spaced distance from said elongated guideway, said opening being adapted to receive the second end of said pressure bar;
biasing means coupled between the housing and the first end of said pressure bar for urging said pressure bar to move through the hollow interior of the housing and against said collapsible container;
the second end of said pressure bar being adapted to slide through said opening and be pivoted about said opening as the first end of said pressure bar is urged along said guideway by said biasing means;
said pressure bar first end including guide means for cooperating with said guideway for retaining said pressure bar within said guideway as the pressure bar is moved therealong.
2. The means ofclaim 1 wherein said container is a collapsible plastic bag containing a fluid to be dispensed, said bag being positioned with the-region defined by said pressure bar and a wall of the housing lying between said guideway and said opening for undergoing compression by said pressure bar.
3. The means ofclaim 2 wherein said housing first side, said housing wall and said pressure bar form a triangular-shaped interior region for housing said compressible bag.
4. The means of claim 3 wherein said collapsible bag has a triangular configuration generally conforming to said triangular-shaped interior region enclosing said bag.
5. The means ofclaim 4 wherein said biasing means is a tensioned elastic member stretched between a point on said housing adjacent said opening and the first end of said pressure bar for urging the first end of said pressure bar in a first direction along said guideway.
6. The means of claim 5 wherein the housing first side and wall intersect to form a corner;
said elastic member extending around said corner;
said corner being notched;
a roller assembly being positioned within said notched corner so that said elastic member is entrained around the exposed curved periphery of said roller assembly for equalizing the tension along the length of the stretched elastic member.
7. The means of claim 5 wherein said housing first side and wall are joined to form a corner;
said elastic member extending around the outside of said corner;
said elastic member being contained within a hollow elongated sleeve at least one portion of which engages said corner to enable free sliding of said elastic member within said sleeve to equalize the tension along the length of said stretched elastic member.
8. The device of claim 4 wherein said biasing means is a tensioned elastic member stretched between a point on said housing adjacent said second opening and the first end of said pressure bar for urging the first end of said pressure bar downwardly along said guideway.
9. The means of claim 1 further comprising hook means secured to said housing for suspending said means from a suitable support.
10. The means of claim 1 wherein said biasing means is a tensioned elastic member stretched between a point on said housing adjacent said opening and the first end of said pres sure bar for urging the first end of said pressure bar in a first direction along said guideway.
11. The means of claim 1 wherein said housing is provided with a pair of notches adjacent a first end of said guideway;
a pin being releaseably inserted within said notches and across the path of movement of said pressure bar first end for preventing movement of said pressure bar from said first end of said guideway to the opposite end thereof;
the removal of said pin enabling movement of said pressure bar in a first direction along said guideway.
12. A device for dispensing fluids at a substantially constant pressure comprising:
a hollow housing defined by a pair of flat spaced parallel face plates, each of said plates having a substantially triangular-shaped configuration truncated at the corners, said plates being joined along a first side by a continuous sideplate;
a flat bracing member located at a first one of the truncated corners opposite said sideplate for maintaining said face plates in spaced parallel alignment in conjunction with said continuous sideplate;
a first opening being provided in said housing and being defined by one edge of said bracing member and the interior surfaces of said face plates adjacent said bracing member;
a second opening being provided in the remaining truncated corners of the face plates and being defined by said face plates and said sideplate;
each of said face plates being provided with inwardly bent flanges directed towards one another along the sides of said face plates adjacent said first truncated corners forming an elongated guideway communicating with said first opening;
an elongated substantially rigid pressure bar having a first end extending through said first opening and a second end extending through said second opening;
said pressure bar being provided with a pair of notches near said first end forming a narrow neck portion;
said notches being adapted to be slidably received and guided by said flanges;
biasing means being stretched around the outer surfaces of said continuous sideplate and said flanges and having a first end coupled to said sideplate adjacent the said remaining truncated corners and a second end coupled to the first end of said pressure bar for urging said pressure bar along said guideway toward the corner formed by the juncture of said sideplate and said flanges;
a collapsible plastic bag containing a fluid and being adapted to assume a triangular shape generally conforming to the triangular shape of said face plates, said bag being positioned within the interior space defined by said housing and said pressure bar;
said bag having an outlet port located adjacent one end of said sideplate for emitting the fluid contained therein as said pressure bar is urged along said guideway by said biasing means.
13. The device of claim 12 wherein the housing is provided with a notch in said corner at which said sideplate and said flanges are joined;
a roller assembly being positioned in said notch for slidably guiding said stretched biasing means around said notched corner for equalizing the tension along the length of the stretched biasing means.
transparent to facilitate observation of the scale reading and the pressure bar.
17. The device of claim 12 further comprising an infusion set for coupling the outlet port of the bag to an object to receive said fluid;
the interior region of the housing on the side of said pressure bar opposite said collapsible bag being provided for storing said infusion set.