US2704544A

US2704544A - Venoclysis equipment

Info

Publication number: US2704544A
Authority: US
Priority date: 1954-07-02
Publication date: 1955-03-22
Anticipated expiration: 1972-03-22
Also published as: GB751436A

Description

March 22, 1955 ca. R. RYAN VENOCLYSIS EQUIPMENT E5 Sheets-Sheet 1 Original Filed Oct. 5, 1949 Fis. III

Inuen for George 1?. Ryan Q, MM. M

0ffown ey March 22, 1955 e. R. RYAN VENOCLYSIS EQUIPMENT 3" $heets-Sheet 2 Original Filed Oct. 5, 1949 I, Inllln ll Ialll. i. v

Invenzor George R. Egan {.9 wmw fiforneg March 22, RYAN VENOCLYSIS EQUIPMENT Original F iled Oct. 5, 1949 3 Sheets-Sheet 3 Jrm/efifor Cieoz ge R. Ryan 29 W4 2% VENOCLYSIS EQUIPMENT George R. Ryan, Waukegan Township, Lake County, Ill., assignor to Abbott Laboratories, North Chicago, III., a corporation of Illinois Continuation of applications Serial No. 119,645, October 5, 1949, and Serial No. 128,549, November 21, 1949. This application July 3, 1953, Serial No. 365,826

28 Claims. (Cl. 128-214) My invention relates to medical equipment and includes among its objects and advantages improved means for administering blood plasma and other fluids intravenously. In the accompanying drawings:

Figure I is a vertical sectional view of a device according to the invention;

Figure II is the plan view of the device of Figure I;

Figure III is a vertical sectional view of a modified device according to the invention;

Figure IV is a vertical sectional view of another modified device according to the invention;

Figure V is a vertical sectional view of still another modified deviceaccording to the invention;

Figure VI is a vertical sectional view of a drip and filter chamber according to the invention;

Figure VII is a vertical sectional view of a modified form of'the invention;

Figure VIII is a fragmentary vertical sectional view of the upper portion of the device of Figure VII indicating its configuration while it is being connected to a source of supply;

Figure IX is a fragmentary vertical sectional view of the lower end of a drip chamber indicating an alternative assembly for the bottom connections; and

Figure X is a fragmentary vertical sectional view similar to Figure IX showing another modification of the bottom assembly.

The device shown in Figure I comprises a cylindrical hollow body portion or a main tube portion 12 of resilient plastic material, and is preferably transparent, or at least translucent. A thimble or cup shaped filter screen 20 is frictionally held in the tube 12 in close proximity to the end adjacent the cup opening. The ends of the tube 12 are closed by resilient plastic annuli 16 which are cemented into place. A stiff plastic cannula is cemented into one of the annuli 16, and a length of resilient plastic tubing 14 is cemented into the other annulus. If desired a length of resilient plastic tubing can be secured in the upper annuli l6 and the cannula 10 connected to the outer end of the said length of plastic tubing. It is preferable to have the cannula 10 communicating with the cup side of the screen 20, as shown, rather than a configuration such as when the tubing 14 and the cannula 10 are reversed.

The tubing 14 is of a suitable length, for example, about 2 feet, to allow either direct transfusion from the filter cell or through a flow control apparatus, such as a Murphy drip tube. A fitting is connected to the end of the tubing 14 to allow connection of the filter cell with other apparatus, such as an injection needle. As shown, a male Luer fitting 22 is connected to the end of the tubing 14, however, other types of fittings may be used as for instance, a female Luer, a hypodermic cannula, etc.

In use, the device of Figure I can be connected directly to a transfusion bottle, containing for instance blood, by

inserting the stiff cannula 10 through a rubber stopper sealing the bottle. The filter cell is then connected directly to the patient or through a metering device through the connection 22, as for instance a needle connected to the Luer 22 into a receiving patients vein.

The main tube portion 12, being resilient, is capable of collapsing under external pressure so as to act as a pressure bulb.

This is important especially in blood transfusion where the blood frequently clots even though an anticoagulant United States Patent 0 plug the withdrawing cannula, however, using a device according to the invention, the tube portion 12 may be squeezed (indicated in dotted lines in Figure V) to exert pressure back through the cannula 10, thereby unplugging the cannula. Obviously, to prevent the pressure from entering the patients vein, the tubing 14 should be closed while collapsing the cell.

In the device of Figure III a plastic tubing 18 is sealed, completely closing one end of the tubing. The tubing 18 is punctured with a plurality of holes 32 forming a type of sieve or foraminated filter medium. The plastic tubing 18 is then inserted into the annulus 16 and cemented in place so that all the perforations are on one side of the annulus. The annulus 16 is then cemented into place in the main body 12 with the perforated tubing portion inside the main tube 12. The other end of the main tube 12 is enclosed as in Figure I with an annulus 16 cemented in place, carrying a stiff cannula 10.

The device of Figure IV has a larger diameter tubing with a sealed end 42 and perforations 44 sealed into a countersunk annulus 46. A length of tubing 14 is sealed in the annulus 46 communicating with the interior of the sieve-like portion 40. The annulus 46 is inserted into the main tube body 12 and cemented into place, having the sieve 40 inside the main tube body 12. The other end of the filter cell is enclosed by the annulus 16 with the stiff cannula 10 cemented therein.

The device in Figure V has a length of tubing 14 sealed in an annulus 16, and having one end 50 a short distance therethrough. A small woven plastic bag 52 is fastened on the end 50. The annulus 16 is cemented into the main tube body 12, with the filter bag 52 enclosed in said tube. The other end of said tube 12 is closed with an annulus 16 having a stiff cannula 10 cemented therein.

A filter cell with the filter integral with the discharge port or outlet as shown in Figures III, IV, and V may have the cannula 10 extend a short distance through the annulus 16 to the interior of tube 12, to function as a drip tube, to aid in metering the flow.

Any blood clots which form in devices having the filter integral with the discharge port, tend to settle, leaving the upper part of the foraminated tube or filter free from clots. Furthermore, with the plastic filter medium cemented in place there is little danger of displacing the filter or impairing its functions.

The material of the main tube 12 is of the type commonly referred to in the trade and in the technological literature as commercial plastics. These are solid products of polymerized organic molecules. Such plastics are suitable for use in medical work where they must contact fluids that may subsequently enter the blood stream. Of course, stainless steel, glass or other rigid materials are also suitable, but they lack the properties necessary to achieve the objects of the invention, which include flexibility and resilience combined, so that the distortion of the tube can exert a pumping action.

In the embodiment of the invention selected for illustration in Figure VI, the sight or drip chamber comprises a barrel of resilient plastic, such as a vinyl type. The main wall of the barrel is resilient and flexible but under its own weight it retains the configuration illustrated. Only slight forces are necessary to collapse it, and it can be collapsed, folded, and doubled under repeatedly without material injury or permanent distortion.

At its upper end the barrel or cylindrical hollow body of Figure VI is integrally united to a resilient end closure means comprising a reducer member 62 which reducer tapers in to define a neck 64. Bonded in the neck 64 is a relatively rigid intake cannula 66 having a sharp beveled end 68 adapted to pierce or be inserted into, a

has been used. The clots, if large enough, will seal or rubber outlet plug or seal of a suitable source of therapeutic fluid. The cannula 66 also preferably extends down inside the barrel so that the flow will fall from it and be easily seen. As delivered from the factory in sterilized condition ready for use the upper end of the cannula 66 carries a removable cover 70.

The cannula 66 is relatively rigid and of suflicient structural strength to penetrate the seal of the source of supply, but a substantial axial force is necessary to effect such penetration. Because the barrel is extremely flexible, it is easy for the user in practicing the insertion of the cannula, to pinch the sides in as indicated by the arrows 76 in Figure VIII so that a thumb and forefinger can get a firm grip directly against the cannula except for the intervening thickness of flexible material. This contributes materially to quickness and ease of Operation in assemblying the parts.

Referring again to Figure VI the barrel 60 is molded and its lower end closure means includes the bottom neck 78 enlarged at 80 to define an annular shoulder facing upward and enlarged again at 82 to merge with the side wall of the barrel forming in effect an internal rabbet. A filter 84 is inserted in the rabbet with its lower end in abutment with the annular face 80 and bonded in place. The filter 84 illustrated is a cylindrical tube of resilient plastic provided with suitable foraminations 86 to permit fiuids to pass through, while retaining blood clots or other solid bodies large enough to cause trouble farther on. Below the shoulder 80, the neck 78 receives the upper end of the delivery tube 88 which may be of desired length and ends in a terminal fitting 90 for convenient connection to a hypodermic needle or to another container.

In completing an assembly according to Figure VI the barrel 60 is bonded to the tube 88 and to filter 84 in any desired sequence. Then the cap 62 is bonded on the cannula 66; the cap 62 and the barrel 60 are bonded together; the protective cover 70 is put on; and the assembly is ready to be sterilized.

In the embodiment of Figure VII the barrel 72 and neck 74 are formed in one piece and at the lower end the bottom cap 92 which may comprise a readily flexible cup-shaped form having its concave side facing into the said barrel completes the connection to the delivery tube 96. The neck 94 is bonded to the delivery tube 96 and the delivery tube extends u through the neck and into the chamber, and supports the filter 84 which may, if desired, be identical with that in Figure VI or of a different size.

In assembling a unit according to Figure VII the cannula 66 is bonded with the barrel 72. The cap 92 is bonded on the tube 96. Then the filter 84 is bonded on the same tube 96 and finally the barrel 72 is bonded with the cap 92.

Referring now to Fi ure IX, the bottom cap 98 has a relatively long neck 100. The filter 102 may be thrust into the neck from above and bonded in place. Then the discharge tube 104 is similarly assembled. This completes an assembly ready for attachment to the barrel 72 of Figure VII.

Referring now to Figure X the bottom cap 106 has a shorter neck 108 and the filter 110 has a long neck extending down beyond the neck 108. The delivery tube 112 is telescoped over the filter tube 110 and slides up until it comes into abutment with the neck 108. This completes a bottom assembly ready for attachment to the barrel 72.

It will be obvious that the drip chamber and delivery tube of Figures VI to X is suitable for use in direct connection with a penetrable container closure or with any other source of supply connectable to the cannula 66. When using in direct connection with a container closure, the recommended procedure is to close the delivery tube at the exit end of the drip chamber and thrust the cannula 66 downward through the sealing diaphragm of the container closure to open communication with the source of supply. The parts are then inverted, but no appreciable amount of fiuid will enter the chamber because the air in the chamber prevents it. The user now contracts the chamber by squeezing it a little and a portion of the air in the chamber will rise through the cannula 66 and bubble up through the liquid above it, since the inlet cannula serving as an inlet tube has a constant effective volume less than the available variation of the chamber volume. When the pressure is released the chamber expands and an equal volume of liquid will move down into the chamber. In this way the user pumps the air out of the chamber a little at a time and replaces it with liquid until the liquid is at the level desired, which should be just above the top of the filter, leaving a substantial clearance or space between the upper surface of the liquid and the lower end of the cannula 66.

The clamp 79 or other closure in the delivery tube closely adjacent the chamber is now partly opened and a body of liquid will move down the tube and expel the air in the tube. The fitting is connected for delivery and the rate of flow can be observed by watching the liquid falling from the cannula 66 and adjusted by constricting the tube 88.

In the use of such equipment it occasionally happens that a blood clot or other obstruction blocks the inlet end of the cannula 66. With the equipment of the invention the operator merely closes the tube 88 close to the chamber 60 and squeezes the chamber to dislodge the clot. With the rigid drip chamber of the prior art, it is usual to move the bottle around vigorously to agitate the contents and try to dislodge the clot in that way. It is also possible to constrict the tube 88 remote from the chamber and collapse a considerable length of it by squeezing it in one hand to develop the pumping action but the pumping action is much more conveniently and effectively obtainable with equipment according to the invention.

It not infrequently happens, especially during somewhat prolonged administration, or as a result of manipulation to dislodge a blood clot, that the liquid level in the drip chamber gets too hi h so that the outlet of the cannula 66 is masked and it is impossible to observe the rate of flow. With the rigid drip chamber of the prior art, this condition, commonly referred to as a flooded drip chamber, usually necessitated taking the apparatus to pieces more or less and starting over again.

When a flooded drip chamber is encountered with apparatus according to the invention, the user merely closes the delivery tube close to the drip chamber and inverts the drip chamber and the bottle or other source of supply so that the chamber is above the cannula. In this position the liquid in the source of supply will move away from the lower end of the cannula 66 and an air space will surround that lower end. There will also be an air space in what is now the top of the drip chamber but none of that air will work into the delivery tube because the delivery tube is closed.

With the parts in this condition the user need only pump liquid out of the chamber by squeezing it, to have the liquid replaced by air when the pressure is released. In this way the drip chamber can be partially or completely emptied of liquid and refilled with air. Then the drip chamber and its bottle can be turned the other end up once more and if the liquid level in the drip chamber is lower than that desierd air can be pumped out of the drip chamber and the unit is again functioning correctly. All the manipulations for reconditioning a flooded drip chamber can be performed by an experienced user in less time than it takes to read this description.

The attribute described as resilience is intended to involve the capacity of sustaining great changes in shape and consequently in the volume of the resilient chamber or hollow body, such as the one illustrated in Figure VIII, without rupture or objectionable permanent alteration in the shape assumed after a momentary stress is removed, as distinguished from the amount of energy stored in the temporarily deformed shape or the force required to achieve the deformation, both of which are comparatively small in materials of the type described.

In the several embodiments of the invention illustrated it should be understood that, if desired, the filter means or the cannula means can be omitted without departing from the broad invention illustrated and described herein.

The bonding referred to is of a type generally known in this art, and per se, forms no part of this invention. Briefly, one of the parts to be united is coated or dipped in a fluid having a mild solvent action on the material of which the parts are made, and then the parts are juxtaposed in the desired position and let stand. The mechanical aspect of the operation is substantially identical with gluing, but the resulting union seems to leave practically no interface, but a substantial homogeneity extending through the mass, so that the material forming the joint is of equal strength with the rest of the material, and the joint itself even a little stronger than the rest of the assembly because of its greater thickness.

This application is a continuing application of the inventors co-pending applications Serial No. 119,645, filed October 5, 1949, and Serial No. 128,549, filed November 21, 1949, both now abandoned.

Others may readily adapt the invention for use under various conditions of service by employing one or more of the novel features disclosed or equivalents thereof.

As at present advised with respect to the apparent scope of my invention, I desire to claim the following subject matter.

1. A filter cell for venoclysis apparatus, comprising In combination: capable of being partially collapsed when external pressure is applied thereto to effect a substantial change 1n the volume of the said hollow body and returning to its original form when the pressure is released; a filter element in said body; end closure means at each end of said body having a passage therethrough; a tubular inlet means communicating with the interior of said body secured to and projecting from one of the said closure means for communication with a source of liquid; and tubular delivery means communicating with the interior of said body secured to and projecting from the other of the said closure means for discharging liquid from the said body; said body when compressed after stopping the flow of fluid in the tubular delivery means effecting a back-flow through the said tubular inlet means, thereby facilitating dislodging obstructions in the said tubular inlet means.

2. A venoclysis apparatus, comprising in combination: a deformable, cylindrical, hollow body capable of being partially collapsed when external pressure is applied thereto and returning to its original form when the pressure is released; a filter element in said body; end closure members at each end of said body having a passage therethrough; a cannula means communicating with the interior of said body through one of the closure members for communication with a source of liquid; and tubular delivery means communicating with the interior of said body secured to and projecting from the other of the said closure members for discharging liquid from the said body; said body when compressed after stopping the flow of fluid in the tubular delivery means eflecting a back-flow through the cannula, thereby facilitating dislodging obstructions in the said cannula.

3. A filter cell for venoclysis apparatus, comprising in combination: a deformable, cylindrical, hollow body capable of being partially collapsed when external pressure is applied thereto and returning to its original form when the pressure is released; end closure members at each end of the said body having a passage therethrough; a cannula communicating with the interior of said body secured to and projecting from one of the said closure members for communication with a source of liquid; and a tubular delivery means communicating with the interior of said body secured to and projected from the other of said closure members for discharging liquid from the said body; a tubular section of foraminated material extending within said body and being secured to the closure member remote from said cannula; said section being between the interior of said body and the tubular delivery means, whereby the said tubular section filters the liquid being discharged from said body; said body when compressed after stopping the flow of fluid in the tubular delivery means etfecting a back-flow through the said cannula, thereby facilitating dislodging obstructions in the said cannula.

4. A filter cell for venoclysis apparatus, comprising in combination: a deformable, cylindrical, hollow body capable of being partially collapsed when external pressure is applied thereto and returning to its original form when the pressure is released; end closure members at each end of the said body having a passage therethrough; a cannula communicating with the interior of said body secured to and projecting from one of the closure members for communication with a source of liquid; a tubular delivery means connecting the interior of said body secured to and projected from the other of said closure members for discharging liquid from the said body; and a section of foraminated material extending within said body and being secured to the closure member adjacent the said cannula; said section being interposed between the said cannula and the tubular delivery means, whereby the said tubular section filters the liquid being introduced into said body; said body when compressed after stopping the flow of fluid in the tubular delivery means effecting a back-flow through the said cannula, thereby facilitating dislodging obstructions in the said cannula.

5. A filter cell for venoclysis apparatus, comprising in combination: a deformable, cylindrical hollow body capable of being partially collapsed when external pressure is applied thereto and returning to its original form a deformable, cylindrical, hollow body when the pressure is released; end closure members at each end of the said body having a passage therethrough; a cannula communicating with the interior of said body secured to and projecting from one of the closure members for communication with a source of liquid; a tubular delivery means communicating with the interior of said body secured to and projected from the other of said closure members for discharging liquid from the said body; and a tubular section of foraminated material closed at its interior end and being coaxial with the said tubular delivery means, said section being interposed between the said cannula and the tubular delivery means, whereby the said tubular section filters the liquid being discharged from said body; said body when compressed after stopping the flow of fluid in the tubular delivery means effecting a back-flow through the said cannula, thereby facilitating dislodging obstructions in the said cannula.

6. A filter cell for venoclysis apparatus, comprising in combination: a deformable, cylindrical, hollow body capable of being partially collapsed when external pressure is applied thereto and returning to its original form when the pressure is released; end closure members at each end of the said body having a passage therethrough; a cannula communicating with the interior of said body secured to and projecting from one of the closure members for communicating with a source of liquid; and a tubular delivery means communicating with the interior of said body secured to and projecting from the other of said closure members for discharging liquid from the said body; and a filter extending inside the said body in open axial communication with the said tubular delivery means, whereby the said tubular section filters the liquid being discharged from the said body; said body when compressed after stopping the flow of fluid in the tubular delivery means effecting a back-flow through the said cannula, thereby facilitating dislodging obstructions in the said cannula.

7. A drip chamber unit for administration of fluids comprising, in combination: a chamber proper; an inlet drip tube protruding into the interior contour of said chamber, whereby, when said chamber is positioned with said inlet at the top, and contains gas from the top down to a level below the lower end of said inlet, the fall of entering liquid from said inlet affords an indication of the rate of flow of liquid through said chamber; said chamber being sufliciently transparent to permit visual observation of the falling liquid and the adjustment of the liquid level in the same chamber; and an outlet tube communicating with said chamber remote from said inlet tube; said chamber having a flexible, resilient wall for varying the eifective volume of said chamber; said inlet tube having a constant efifective volume less than the variation of the chamber volume; said outlet tube adapted to being closed adjacent said chamber; whereby, with said inlet uppermost, a fluid in said chamber of low specific gravity may be expelled through said inlet and replaced with heavier fluid, by successive contraction and expansion of said chamber, with the inlet lowermost, the same manipulation will expel a heavier fluid and replace it with a lighter one. 7

8. A drip chamber for administration of fluids, comprising, in combination: a chamber proper; an inlet drip tube protruding into the interior contour of said chamber, whereby, when said chamber is positioned with said inlet at the top, and contains gas from the top down to a level below the lower end of said inlet, the fall of entering liquid from said inlet affords an indication of the rate of flow of liquid through said chamber; said chamber being sufliciently transparent to permit visual observation of the falling liquid and the adjustment of the liquid level in the said chamber; and means defining an outlet passage of substantially smaller diameter than said chamber communicating with said chamber remote from said inlet tube and adapted to being closed adjacent said chamber; said chamber having resilient flexible walls, whereby external pressure momentarily reduces the effective volume of said chamber; said inlet tube having a constant efiective volume less than the available variation of the chamber volume; whereby fluid within said chamber is readily expelled from said chamber.

9. A drip chamber unit for intravenous administration of fluids, comprising, in combination: a flexible plastic body having a main portion of relatively large diameter, at least one end of said main portion being open; the other end of said main portion being closed by an end closure having an extending neck of relatively small diameter; a cap member having a portion telescoped with the large end of said body and an extending neck portion of relatively small diameter coaxial with the said body; said body and cap member being bonded together into an integral whole; a relatively rigid cannula integrally associated with the said cap member and projecting interiorly of the said body and exteriorly beyond said neck; the exterior end of said cannula being adapted to enter a supply container; the interior end of said cannula being spaced from said body, whereby liquid moving downwardly out of the interior end of said cannula can be visually observed; said body being sufliciently transparent to permit visual observation; and an external delivery tube associated with the said extending neck opposite said cannula.

10. A drip chamber unit for intravenous administration of fluids, comprising, in combination: a flexible plastic body having a main portion of relatively large diameter, one end of said main portion being open; the other end of said main portion being closed by an end closure having an extending neck of relatively small diameter; a cap member having a portion telescoped with the large end of said body and an extending neck of relatively small diameter coaxial with the neck of said body, said body and cap member being bonded together into an integral whole; a relatively rigid cannula integrally associated with one of said necks and projecting interiorly inside said body and exteriorly beyond said neck; the exterior end of said cannula being adapted to enter or penetrate a supply container; the interior end of said cannula being spaced from said body, whereby liquid moving downwardly out of the interior end of said cannula can be visually observed; said body being sufliciently transparent to permit visual observation; and an external delivery tube associated with the neck opposite said cannula, said body at least adjacent said cannula being sufliciently transparent to permit visual observation thereof and being sufficiently flexible to permit the operator to collapse it, and sufficiently resilient to return to substantially its original shape after temporary collapse.

A drip chamber unit for intravenous administration of fluids comprising, in combination: a flexible resilient plastic body having a main portion with a relatively large diameter; one end of said main portion being open, the other end of said main portion being closed by an end closure portion having a relatively small diameter extending neck; a cap member having a portion telescoped with the large end of said body; and an extending neck of relatively small diameter coaxial with the neck of said body; said body and cap member being bonded together into an integral whole; a relatively rigid cannula integrally associated with one of said necks and projecting interiorly of the said body and exteriorly beyond said neck; the exterior end of said cannula being adapted to enter a supply container; the interior end of said cannula being spaced from said body; said body being sufliciently transparent to permit visual observation of its interior; and an external delivery tube associated with the neck opposite said cannula.

12. A drip chamber unit for intravenous administration of fluids comprising, in combination: a flexible plastic body having a main portion of relatively large diameter; and extending end closure neck portions of relatvely small diameter at both ends; a cannula permanently bonded in one of said neck portions and projecting interiorly inside said body; an external delivery tube associated with the other of said neck portions opposite said cannula; and an interiorly extending tubular filter associated with the said other of the neck portions opposite said cannula.

13. A drip chamber unit for intravenous administration of fluids comprising, in combination: a flexible plastic body having a main portion of relatively large diameter; and extending necks of relatively small diameter at both ends; a cannula permanently bonded in one of said necks and projecting interiorly inside said body; an external delivery tube associated with the neck opposite said cannula; and an interiorly extending tubular filter associated with the neck opposite said cannula.

14. A drip chamber unit for intravenous administration of fluids, comprising, in combination: a flexible plastic body having a main portion of relatively large diameter; and extending necks of relatively small diameter at In uu both ends; a cannula permanently bonded in one of said necks and projecting interiorly inside said body; an external delivery tube associated with the neck opposite said cannula; and an interiorly extending tubular filter associated with the neck opposite said cannula; said neck being integrally bonded to said delivery tube; said delivery tube extending inside said body and being bonded to and supporting said filter.

15. A drip chamber for intravenous administration of fluids, comprising, in combination: a flexible plastic body having a main portion of relatively large diameter; and extending nccks of relatively small diameter at both ends; a cannula permanently bonded in one of said necks and projecting interiorly inside said body; an external delivery tube associated with the neck opposite said cannula; and an interiorly extending tubular filter associated with the neck opposite said cannula; said neck being integrally bonded to said filter; said filter extending through and beyond said neck; said delivery tube being telescoped with and integrally bonded to the projecting portion of said filter.

16. A drip chamber unit for intravenous administration of fluids, comprising, in combination: a flexible plastic body having a main portion of relatively large diameter; and end closures having extending necks of relatively small diameter at both ends; a cannula permanently bonded in one of said end closures and projecting interiorly inside said body; an external delivery tube associated with the other of said end closures opposite said cannula; and an interiorly extending tubular filter associated with the said other of the end closures opposite said cannula; said other of the end closures being integrally bonded to said filter.

17. In a drip tube for venoclysis equipment, comprising a resilient, elongated, hollow body, the improvement comprising; a cannula secured to and projecting from one end of said body, said cannula communicating with the interior of said body and having a sharpened end facing away from said body for insertion through a soft rubber or similar container closure element to establish communication of such container with said body, said cannula extending into said body sufliciently to be capable of being gripped between opposite wall portions of said body under compression between the fingers of a persons hand, thereby to facilitate insertion of said cannula into a container closure as aforesaid.

18. In a drip tube for venoclysis equipment, the improvement comprising; a resilient, elongated, hollow body, a cannula secured to and projecting from one end of said body, said cannula communicating with the interior of said body and having a sharpened end facing away from said body for insertion through a soft rubber or similar container closure element to establish communication of such container with said body, the end portion of said body to which said cannula is secured as aforesaid being of thin walled, readily flexible cup-shaped form having its concave side facing into said body, said cannula extending into said body sufficiently to be capable of being gripped between opposite wall portions of said end closure and the adjacent end portion of said body under compression between the fingers of a persons hand, thereby to facilitate insgrtion of said cannula into a container closure as aforesai 19. A venoclysis apparatus comprising an elongated tubular body having end closures on its opposite ends, said body being made of soft, elastic, plastic material permitting said body to be collapsed transversely, said body being sufiiciently transparent to permit visual observation of liquid flow therein, at least one of said end closures having a cap-like portion fitting telescopically with an end portion of said body, both of said end closures having openings extending therethrough for receiving inlet and outlet conduits in communication with the opposite end portions of said body and at least one of said end closures having associated therewith a cannula for connection to a fluid supply container, and at least one of said end closures embodying a wall portion which is of thickness approximating that of said body wall so as to be readily flexible and collapsible as an incident to collapsing of said body transversely as aforesaid.

20. A venoclysis apparatus comprising an elongated tubular body having end closures on its opposite ends, said body being made of soft, elastic, plastic material permitting said body to be collapsed transversely, said body being sufliciently transparent to permit visual observation of liquid flow therein, at least one of said end closures having a cap-like portion fitting telescopically with an end portion of said body, both of said end closures having openings extending therethrough for receiving inlet and outlet conduits in communication with the opposite end portions of said body and at least one of said end closures embodying a wall portion which is of thickness approximating that of said body wall so as to be readily flexible and collapsible as an incident to collapsing of said body transversely as aforesaid.

21. A drip tube for venoclysis equipment, comprising a flexible plastic tubular body having end closures provided with reduced diameter extensions at both ends, a cannula seated in one of said end closures and projecting inside said body, a delivery tube seated in the other of said end closures, and a filter member also seated in said other of said end closures and extending into said tubular body.

22. A drip tube for venoclysis equipment, comprising an elongated flexible, resilient hollow body having end closure means at the opposite ends thereof, a cannula seated in one of said end closure means extending into the inside of said body and projecting outwardly therefrom for connection to a fluid supply container, 21 delivery tube associated with the other of said end closure means and extending outwardly from said body, and a filter member extending within said body.

23. A drip tube for venoclysis equipment, comprising an elongated flexible, resilient hollow body having end closure portions, a cannula associated with one of said end closure portions for connection to a fluid supply container, a length of relatively rigid tubing extending into the inside of said body in communication with the said cannula, a filter tube associated with the other of said end closures and extending therethrough and in opposite directions into said body; and a flexible discharge tube extending outwardly from the said other of the end closures.

24. A drip tube for venoclysis equipment, comprising an elongated, flexible, resilient hollow body having end closure portions, a cannula associated with one of said end closure portions, extending into the inside of said body and projecting outwardly therefrom for connection to a fluid supply container, a filter tube associated with the other of said end closures and extending therethrough and in opposite directions into said body and outwardlv therefrom, and a discharge tube telescoped over said outwardly projecting filter tube portion.

25. A drip tube for venoclysis equipment comprising an elongated flexible resilient hollow body having end closure means at the opposite sociated with one of said end closure means extending into the inside of said body and projecting outwardly therefrom for connection to a fluid supply container, a delivery tube associating with the other of said end closure means and extending outwardly from said body, and z a filter member within said body seated on and supported by the said other of said end closure means.

26. A drip tube for venoclysis equipment, comprising, an elongated flexible resilient hollow body having end closure means at the opposite ends thereof, a relatively rigid tubular member associated with one of said end closure means extending into the inside of said body and projecting outwardly therefrom for communication with a fluid supply container, a delivery tube associated with the other of said end closure means and extending outwardly from said body, and a filter member within said ody.

27. A drip chamber unit for administration of fluids from a container having a penetrable container closure ends thereof, a cannula as comprising, in combination: a flexible resilient plastic body having a main portion with a relatively large diam eter the effective volume of which is variable upon application of external pressure thereto and capable of returning to its original volume without permanent deformation upon removal of said pressure and which has wall portions permitting the observation of the falling drops of liquid through the interior thereof and the adjustment of the liquid level therein by the application of said external pressure thereto; one end of said main portion being provided with an end closure portion having an outwardly extending cannula adapted for unobstructed communication with the interior of said container through the said penetrable closure and an inwardly projecting drip forming tube extending into and spaced from the interior of the said body, the other end of said main portion being closed by a second end closure portion having a relatively small diameter outlet passage defined thereby; and an external delivery tube associated with the said outlet passage; said body, cannula, drip tube, and end closure portions being permanently formed into an integral whole; the said cannula having together with the said drip tube a constant eflective volume less than the available variation of said body; whereby, with the said inlet uppermost, a fluid in said container of low specific gravity is expelled through said inlet and replaced with heavier fluid by successive contraction and expansion of said chamber, and with the inlet lowermost, the same manipulation will expel a heavier fluid and replace it with a lighter fluid.

28. A drip chamber for venoclysis equipment, comprising a tubular flexible resilient hollow body having end closure portions, a relatively rigid cannula member of substantially smaller diameter than the said hollow body associated with one of said end closure portions extending into the inside of said body forming a drip tube within said body and projecting outwardly therefrom for communication with a fluid supply container, and a delivery tube of substantially smaller diameter than the said hollow body having the inlet thereto spaced below the end of the said cannula associated with the other of said end closure portions and extending outwardly in the opposite direction from said body, said body being also sufficiently transparent to permit the observation of the drops formed and the adjustment of the liquid level within the said hollow body.

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