WO1990005553A1

WO1990005553A1 - Safety needle sheath in anti reflux catheter having novel valve means

Info

Publication number: WO1990005553A1
Application number: PCT/US1988/004056
Authority: WO
Inventors: Philip N. Sawyer; Joseph F. Fitzerald; Lester F. Miller
Original assignee: Interface Biomedical Laboratories Corp.
Priority date: 1988-11-14
Filing date: 1988-11-14
Publication date: 1990-05-31

Abstract

Methods for preventing needle-stick injuries to healthcare workers during intravenous or intra-arterial procedures as well as for preventing catheter-contamination and blood clotting within the tip of the catheter (16). Also, novel fluid directing means and catheters which include integral fluid flow control means for use in these methods.

Description

SAFETY NEEDLE SHEATH IN ANTI REFLUX CATHETER HAVING NOVEL VALVE MEANS

Technical Field

This invention relates to a valve, catheter and method for preventing both needle-stick injuries by possibly contaminated or infected needles and blood reflux onto the hands of healthcare workers. The invention can also be used to prevent blood from clotting within the tip of the catheter, thereby eliminating the problem of removing and replacing the catheter.

This invention also relates to a valve, catheter and method for preventing the entry of air into the vascular system of a patient during intravenous or intra-arterial procedures. The invention can also be used for preventing the reflux of fluids, such as urine, back into the body of the patient when such fluids are removed by catheter means.

Background

Procedures have long been known involving the introduction or removal of fluids into or from the vascular system or body cavity of a patient. For the introduction of fluids, these have developed to a point of employing a source of fluid for intravenous procedures and connecting such source, often via a pump, through a needle or catheter into the vascular system. The pump itself has been developed to a point that when connecting catheters are accidentally opened to ambient atmosphere, the pumping operation is terminated thereby to reduce the possibilities of air being introduced into the vascular system. This is necessary because the introduction of air will cause an air embolism which in turn may be fatal to the patient being treated. Nevertheless, the use of such a pump, which is commercially available, is not effective to prevent accidents of the aforenoted type in all cases. Thus, for example, when the intravenous tubing is coupled to a catheter situated on the downstream side of the pump, and this catheter becomes accidentally opened to ambient atmosphere, the pressure differential between ambient atmosphere and the vascular system in which the distal tip of the catheter resides (particularly in the chest and/or abdomen) is such as to cause air to be sucked through the catheter into the vascular system. Also, when the fluid is introduced by gravity flow, this problem can result from an accidental opening or separation of the catheter or the fluid supply. This accidental occurrence has been known to cause serious harm or death to the patient being treated.

A number of U.S. patents have been found which attempt to resolve problems of the aforenoted type, as well as to related systems exposed to pressure differential or the like. These patents include 2,538,662; 3,570,808; 3,559,670; 3,888,249; 4,103,686; 4,252,166; 4,324,239; and 4,335,747. Abbott in U.S. Patent 2,538,662 discloses a surgical apparatus for the intravenous administration of liquids, such as whole blood, blood plasma, dextrose solutions, and the like and is directed particularly to an expendable valve unit construction used in such surgical apparatus.

Wren in U.S. Patent 3,570,808 discloses a coupling assembly for releasably attaching an air hose to a regulator of the type used in conjunction with the face mask of an underwater diving apparatus. The coupling is readily detachable and a valve mechanism is provided so that when the air hose is decoupled from the regulator underwater, the valves provided in the regulator air inlet and in the end of the air hose are immediately biased to a closed position. Such a construction and arrangement may have utilization in connection with intravenous procedures.

Simon in U.S. Patent 3,595,228, discloses a portable alarm device attached to a coupling in a therapeutic apparatus to provide an alarm to alert hospital personnel under certain dangerous conditions as might apply to a respirator flow line or a tracheostomy tube assembly for indicating a break therebetween. 5 In U.S. Patent 3,599,670, Gurner discloses a fluid coupling with a valve means having such provision that if a maximum rate of flow through a hose is exceeded as, for example, by leakage, the coupling valve will close and prevent flow. -_Q In U.S. Patent 3,888,249, Spencer discloses a catheter for prolonged infusion of medication into an artery. The catheter is provided with a tip design employing a flap valve principle to assure uniform and steady diffusion of the medication into the blood stream and to inhibit reetrograde ₁₅ flow of blood into the catheter thereby to minimize clotting in the catheter and blockage of medication flow.

Haverland discloses in U.S. Patent 3,906,034 a pressure sensor-timer alarm for pressure sensitive devices wherein a plunger, having a magnetically mounted switch actuator, __n actuates a switch in response to pressure changes from a diaphragm. A failure to actuate the switch in either phase of the breathing cycle within a preset time causes the actuation of an alarm.

Winicki discloses in U.S. Patent 4,067,329 a warning __ device which is actuated by the disconnection of a tube from another tube such as, for example, of a respirator cannula from a patient's medical apparatus.

In U.S. Patent 4,103,686, LeFevre discloses a dual value assembly for intravenous infusions from multiple parenteral ₃₀ fluid sources. The assembly controls forward and reverse flow through a flow line and includes normally seated first and second valves mounted for movement toward and away from respective valve seats to control flow in such a manner as to prevent reverse flow through the assembly. 5 Gordon shows in U.S. Patent 4,324,239 a safety valve for preventing air embolism and hemorrhage. The safety valve disclosed is useful for catheterization procedures and is characterized by a piston having an internal flow path and so 5arranged as to be biased to a closed position<. The arrangement is such as to prevent air embolism and hemorrhage

In U.S. Patent 4,335,747, Mitsumoto et al. disclose an arrangement which is ef ective to exclude air or other undesirable gas in a connecting procedure.

J_Q None of the aforegoing patents, nor any of the other arrangements known heretofore, however, is as effective as the present invention for preventing the introduction of air into the vascular system of a patient, or for preventing the reflux of fluids back into the organ or portion of the body from

_l₅which such fluids were removed.

There is great concern among hospital personnel about the serious risks associated with the use of needles in the healthcare environment. Particularly, healthcare workers remain fearful of becoming infected with viruses such as the

--acquired immunodeficiency syndrome (AIDS) or hepatitis B as a consequence of having been exposed, directly or indirectly, to a patient's blood sample. These infectious agents are transmitted to the healthcare worker when, in the performance of his duty to collect blood from a patient, a needle stick is

__made or blood clotting develops within the tip of a previously 2b inserted catheter. Whether it is when a hospital employee is punctured with the patient's needle or when the employee is exposed to the patient's blood while removing a clot from or replacing the catheter, the effect of this occupational hazard

--appears to be the same: potential medical and psychological consequences for both the healthcare worker and his family.

Healthcare workers have identified four specific circumstances under which the risk of contracting a virus from a patient's infected blood is extremely high: (1) while

₃_ disassembling a device that has an exposed or contaminated needle; (2) while carrying exposed needles to a disposal box along with other items; (3) while storing a needle that is to be used two or more different times to collect blood from a patient; (4) while passing by another healthcare worker who is holding an exposed needle; or (5) leaving a contaminated needle in the patient's bed. In view of these circumstances, it appears that a solution to the problem is the development of a device that provides for the needle to remain unexposed when it is not being used to withdraw blood. In fact, the National Academy of Sciences Committee on Trauma Research has concluded that improvements in product design are among the most successful approaches to the prevention of injury in this area. Jagger, et al. "Rates of Needle-Stick Injury Caused By Various Devices In a University Hospital," The New England Journal of Medicine, August 4, 1988, pp. 284-87.

Accordingly, the present invention is a new and effective means for preventing needle stick injuries, blood clotting, and catheter contamination. No other arrangement known heretofore is as practical or efficient in preventing the spread of viruses from patients to healthcare workers.

Summary of the Invention

It is an object of the present invention to provide improved methods for preventing needle-stick injuries to health care workers during various intravenous or intra- arterial procedures.

Another object of the invention relates to a method for preventing blood from clotting within the catheter.

Still another object of the invention relates to a ^J method for preventing the reflux of fluids following the introduction of a catheter system into the vascular tree. Thus, the present invention relates to a method for preventing needle exposure to healthcare workers during intravenous or intra-arterial procedures which comprises providing the catheter means having fluid flow control means, the fluid flow control means comprising a tubular structure and a valve means wherein the valve means is competent in response to blood reflux but opens in responses to a positive 5 fluid pressure within the tubular structure, the catheter means also having needle-enveloping means including obturating means which is inserted into the tubular structure in order to render the valve means incompetent, needle means which is inserted into the obturating means, and a receptacle means

_1Q which is releasably secured to one end of the needle means. This method contemplates that the obturating means is made of a material which will not stick to the valve means and will facilitate insertion of the obturating means into the valve means as well as removal therefrom. This method further

₁₅ contemplates that the valve means comprises a tube having a flexible plastic disc therein. The needle means is double ended in order to permit one end thereof to pierce the vein or artery of a patient meanwhile allowing blood to collect in the receptacle means which is releasably secured to the other end

__ of the needle means. The needle means may be retracted half- 20 ² way within the obturating means before the needle means and obturating means are simultaneously withdrawn from within the tubular structure.

The invention also relates to a method for preventing blood from clotting within the catheter during intravenous or intra-arterial procedures which comprises providing the catheter means having fluid flow control means, the fluid flow control means comprising a tubular structure and a valve means wherein the valve means is competent in response to blood _- reflux but opens in response to a positive fluid pressure within the tubular structure, the catheter means also having needle-enveloping means including obturating means which is inserted into the tubular structure in order to render the valve means incompetent, needle means which is inserted into the obturating means, and a receptacle means which is releasably secured to one end of the needle means. The needle means is double-ended, one end of the needle means being inserted into a patient's blood vessel and the other end of the needle means being releasably secured to the receptacle means. The receptacle means collects blood which is directed under pressure through the needle means when the catheter means is inserted into a patient's blood vessel. The obturating means and needle means are simultaneously withdrawn from within the tubular structure after the needle means has first been retracted halfway within the obturating means so that no blood ever touches the hands of the inserting healthcare worker and any blood that refluxes up the needle means enters the receptable means. Blood collection is facilitated by a plurality of apertures located on the end of the tubular structure that is opposite to the end on which the receptacle means is releasably secured.

The methods of the invention advantageously utilize fluid flow control means comprising a tubular means with an input chamber and an output chamber and valve means located within the tubular means and having an open and closed position, the valve remaining competent in response to blood reflux but opens in response to a positive fluid pressure within the. tubular means in order to render the valve means incompetent; and needle means having a first and second end, inserted into the obturating means to insert the fluid flow control means into an organ or the pleural cavity of a patient for removal of fluid therefrom, with the needle being retracted within the obturating means when the obturating means and needle means are simultaneously withdrawn from the tubular means so that only the tubular means remains in the organ or pleural cavity of the patient and said valve remains competent in response to fluid reflux. The valve means is integral with the tubular means. Further, the needle means is enveloped by the obturating means when the needle means is retracted within the overlying obturating means so that the needle means is unexposed.

The invention also relates to a fluid flow control means comprising tubular means having open input and output bores 5 connected by channel means and operable between an open position to allow fluid flow therethrough and a closed position to prevent ambient.pressure air from passing therethrough; and obturating means located within the channel means for prestressing and maintaining a portion of the I_Q channel means i a closed position. The channel means is forceable to open position in response to a positive fluid pressure in the input or output bore of the tubular means to allow fluid flow through the channel means from the bore containing the positive pressure to the other bore. The fluid ₁₅ flow control means is capable of passing fluid in either direction depending upon which bore contains the positive pressure, while the obturating means returns the channel means to a closed position when the positive pressure is removed.

In this fluid flow control means, the obturating means is preferably disc means for maintaining the tubular means in a substantially flat configuration, and the tubular means is a silicon tube. If desired, concentric housing means for enclosing the tubular means and obturating means may be used.

The invention also relates to catheter means comprising an elongated body portion for insertion into a patient; an 2o integral hub portion adjacent to the body portion for introducing or removing fluids through the body portion; and the fluid flow control means described above.

In the catheter means, the fluid flow control means may -_ be integral with the body portion or the hub portion. Also, means to maintain the fluid flow control means in an open position to facilitate the introduction of second catheter mean, trocar means, needle means or fluid directing means, can be used if desired.

35 Alternately, the fluid flow control means may be releasably secured to the hub portion. For specific applications, two integral hub portions may be provided where each hub includes fluid flow control means located adjacent 5thereto. Thus, a first hub portion could allow the introduction of a fluid into a portion of the body of the catheter means and a second hub portion could allow a fluid to be removed from another portion of the body of the catheter means. The first hub portion may also include fluid flow

_1Qcontrol means which remains competent in response to fluid reflux or ambient air pressure but which opens in response to a positive fluid pressure above that of ambient air, while the second hub portion includes fluid flow control means which remains competent in response to fluid reflux but which opens

₁5in response to fluid pressure in the catheter body.

In either embodiment, the end of the body portion of the catheter opposite the hub portion may include a plurality of apertures to facilitate fluid collection or removal.

Another embodiment of the invention relates to a method for preventing the introduction of air into the vascular system of a patient through catheter means during intravenous or intra-arterial procedures which comprises providing catheter means with the fluid flow control means described above; introducing the catheter means into the vascular system

__ of the patient during intravenous or intra-arterial _i_ procedures; and introducing a fluid into the patient through the fluid flow control means and catheter means by directing the fluid under a positive pressure into the bore of the input means of the fluid flow control means so that the fluid flow _3ncontrol means opens in response to said positive fluid pressure to allow flow therethrough, but remains competent in response to ambient air pressure in the bore of the input means to prevent the introduction of air into the vascular system of the patient. 5 Another method of the invention relates to preventing the reflux of fluids into an organ or the pleural cavity of a patient when fluid directing means or catheter means are utilized for removal of such fluids, which method comprises providing the catheter means or fluid directing means with the fluid flow control means described above; introducing the catheter or fluid directing means into the organ or pleural cavity of the patient; and removing fluids from the organ or pleural cavity by directing the fluid under a positive pressure into the bore of the input means of the fluid flow control means to facilitate the removal of such fluids by flow therethrough while preventing reflux of such fluids back into the patient.

Brief Description of the Drawings

The nature, advantages, and various other additional features of the invention will appear more fully upon consideration of the illustrative embodiment now to be described in detail in connection with the accompanying drawing figures, whereinr

FIG. 1 is a perspective view of a catheter arrangement with fluid flow control means for removing fluids from the body;

FIG. 2 is a perspective view of a catheter with valve means for draining fluids from the body;

FIG. 3 is a cross-sectional view of a catheter arrangement with fluid flow control means;

The nature, advantages, and various other additional features of the invention will appear more fully upon consideration of the illustrative embodiments now to be described in detail in connection with the accompanying drawing figures, wherein:

FIG. 4 is a perspective view of a valve structure according to the present invention; FIG. 5 is a front cross-sectional view of the valve of FIG. 4 to illustrate the positioning of the tubular member within the housing;

FIG. 6 is a side cross-sectional view of the valve of 5 FIG. 4.

FIG. 7 is a perspective view of the valve of FIG. 4 with the exterior housing removed; and

FIGS. 8 and 9 are views of disk prestressing means in octagonal and circular configurations, respectively.

10

Detailed Description of the Preferred Embodiments

In U.S. Patent 4,684,364 there is disclosed a flow

₁₅ control device having a tubular structure with input means and output means each provided with an open bore, channel means connecting the input and output bores and operating between open and closed positions, and clip means for retaining a portion of the channel means in a prestressed condition to

_₀ obturate the channels means so as to maintain it in a closed position. The channel means is forceable to an open position in response to a positive pressure in either one of the bores to facilitate flow through the channel means from the bore containing the positive pressure to the other bore. Also, the

__ flow control device is capable of passing fluid in either direction depending upon which bore contains the positive pressure, with the clip means returning the channel means to the closed position when the positive fluid pressure is removed. This invention also includes an intravenous system

₃₀ comprising a source of intravenous fluid, first catheter means for insertion into the vascular system of a patient, a pump for performing a pumping operation and urging the fluid from the source to the first catheter means, second catheter means coupling the pump to the source, and the flow control device ₅ described above located in at least the first catheter means. In U.S. Patent 4,722,725, there is disclosed catheter means comprising an elongated body portion for insertion into a patient, at least one integral hub portion adjacent to the body portion, and at least one fluid flow control means ₅ located in either the body or hub portion or adjacent to the hub portion. The fluid flow control means may be integral with or releasably secured to its respective hub portion. Also, obturating means for rendering incompetent the fluid flow control means can be used. ₁₀ The catheter means is intended for use in the methods disclosed in that patent. Such methods include preventing the introduction of ambient air into the vascular system of a patient when the catheter means is introduced into the patient's vascular system during intravenous or intra-arterial ₁₅ procedures, preventing the reflux of blood from the vascular system of the patient during such intravenous or intra- arterial procedures, and preventing the reflux of fluids into an organ or the pleural cavity of the patient when fluid directing means or catheter means are utilized for the removal of such fluids therefrom.

In U.S. Patent 4,784,644, there is disclosed a novel valve comprising a disc member for use in a fluid flow control means. This fluid flow control means can be incorporated into a catheter and used for delivering or removing fluids from a

__ patient. 2D

To the extent that the disclosure of the specification or drawings of either of these patents is necessary for an understanding of the present invention, the disclosures of the patents are expressly incorporated herein by reference

30 ^thereto«

FIGS. 1 and 2 generally illustrate a fluid flow control means in the form of a valve arrangement 8 provided with an inlet chamber- 10 and an outlet chamber 12. The trocar portion of this arrangement 8 includes a strong sturdy needle 14. The

₃₅ catheter 16 includes a plurality of holes 18, valve 20, and compartment 22 for reception of an obturator 24 and the needle 14. In order to place the catheter 16 into the proper location in the patient's vascular system, the catheter 16, obturator 24 and needle 14 are inserted therein together. The 5 needle 14 is provided with a sharp point 26 which assists in puncturing the skin and vein or artery of the patient, and a sharp point 28 upon which a vacutainer 30 is secured, in which the blood is collected. The obturator 24 is inserted into the catheter valve 20, thus rendering it incompetent so as to

₁₀ allow blood to flow through the needle 14 and into the evacuated tube 30 or syringe (not shown) , resulting in collection of the blood in the tube 30. One skilled in the art would realize that a syringe or other blood collection device could be used instead of the evacuated tube.

₁₅ Following collection of blood in tube 30, the needle 14 is retracted into the obturator 24 and the needle 14 and obturator 24 are then simultaneously withdrawn from the catheter 16, allowing valve 20 to become competent, thus preventing blood reflux through the catheter proximal to the valbe 20, as well as needle-stick injuries because the needle

14 remains unexposed when withdrawn from the catheter 16 since it is enveloped by obturator 24, having been retracted therewithin.

FIG. 3 illustrates a cross-sectional view of the fluid flow control means in the form of a valve arrangement of FIGS. 25

1 and 2. The valve 20 is clearly shown as integral with the compartment 22 of the catheter 16.

In the present invention, FIGS. 4-7 generally illustrate a fluid flow control means in the form of a valve arrangement

100. This valve includes exterior housing 110 and inlet and outlet connectors 120 and 130, shown having leur lock connections for releasable attachment to a catheter tubing, or the like. Therefore, the valve can be connected to the catheters or intravenous systems described in either patent J „o_ referred to above. A male extension 122, 132 which extends towards the center of the valve 100, is provided on the inlet and outlet connectors, 120, 130, respectively. A flexible tubular member 102 formed of a silicon tube or the like provides a channel between the input and output connectors ₅120, 130. The ends of tubular member 102 fit over the respective male ends 122 and 132 of connectors 120 and 130. The center portion of this tube 102 includes an internal disk member 104 which prestresses the tube and maintains it in a flattened condition in the area of the disk member. FIG. 3 ₀ best illustrates the flattened condition of the tube.

FIGS. 8 and 9 show a detail of various disks 104 in an octagonal and circular configuration, respectively. By making the width or diameter of these disks wider than the opening of the input or output connectors, the disk is prevented from ₁₅ leaving the central area of the tube where it is placed during manufacture of the valve. Also, the tube is maintained in an extended position by the placement of the input and output connectors in housing 140. This also prevents kinking or binding of the tube 104.

As shown in FIGS. 5 and 6 the housing 140 includes stop means 150, 152, in the form of an inwardly extending pin or plate, which maintains the distance between the input and output connectors at a predetermined distance when the valve is assembled. Of course, the input and output connectors have a corresponding hole or groove which matches the pin or plate 25 of the housing 140.

Also to facilitate manufacture of the valve, the housing is split into two portions as best shown in FIG. 4. In the actual assembly of the valve, the disk 104 is initially placed inside the silicone tube 102 and the ends of the tube are then fitted around the male portion of the input and output connectors 120, 130. Next, top and bottom sides of housing 140 are placed around the input and output connectors and tube in a manner such that the stop means 150, 152 align properly ,_ς with the groove means of the connectors. The two halves of the housing 140 can be held together by retaining rings 160 which slide over the end connectors and onto the terminal ends of the housing. If desired, the housing can be friction welded, ultrasonically welded, or glued with a suitable 5 adhesive to create a permanent housing.

As mentioned above, the end connectors of this valve can be attached to catheters, tubing (shown in FIG. 7 as 170) , intravenous systems, or the like. Such attachment techniques and preferred arrangements are illustrated in the drawings and

_,« descriptions of the preferred embodiments of the previous patents described above.

While it is apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that numerous embodiments and

₁₅ modifications may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.

0

5

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5

Claims

What is claimed is:

5 1. Fluid flow control means comprising: tubular means having open input and output bores connected by channel means and operable between an open position to allow fluid flow therethrough and a closed position to prevent ambient pressure air from passing

.._Q therethrough; obturating means comprising disc means for maintaining said tubular means in a substantially flat configuration located within said channel means for prestressing and maintaining a portion of said channel

-_E means being forceable to said open position in response to a positive fluid pressure in said input or output bore of said tubular means to allow fluid flow through channel means from the bore containing the positive pressure to the other bore, said fluid flow control means capable of

-_ passing fluid in either direction depending upon which bore contains the positive pressure; said obturating means returning said channel means to said closed position when said positive pressure is removed;

2. The fluid flow control means of claim 1 further

25 comprising inlet and outlet connectors for insertion into said input and output bores, respectively, of the tubular means for releasable attachment of the control means to fluid directing means; and

₃_ housing means enclosing said tubular means and obturating means, and maintaining said inlet and outlet connectors at a predetermined spaced distance.

3. Catheter means comprising an elongated body ₃_ portion for insertion into a patient; an integral hub portion adjacent to the body portion for introducing or removing fluids through the body portion; and the fluid flow control means of claim 1 or 2.

5 4. The catheter means of claim 3 wherein the fluid flow control means is integral with one of said body portion or said hub portion.

5. The catheter means of claim 3 which further 1_Q comprises means to maintain the fluid flow control means in an open position to facilitate the introduction of second catheter means, trocar means, needle means or fluid directing means.

₁₅

6. Fluid flow control means comprising: tubular means having input means and output means, each provided with an open bore constituting a flow channel, valve means located between the bores of said input and output means of said tubular structure and having an open and closed position, said valve means providing for a connecting channel between said bores when said valve means is in the open position, said valve means normally being prestressed to said closed position and being forcible to said open position in response to a positive fluid pressure in the bore of either of said input or

25 output.means, said valve means being constructed and arranged so as to return to said closed position in response to a removal of said positive fluid pressure from said bore containing same; obturating means, inserted into said tubular

30 means so as to render incompetent said valve means; and needle means having a first and second end, inserted into said obturating means to insert the fluid flow control means into an organ or the pleural cavity of a

_b_ patient for removal of fluid therefrom, with the needle being retracted within the obturating means when the obturating means and needle means are simultaneously withdrawn from the tubular means, so that only the tubular means remains in the organ or pleural cavity of said 5 patient and said valve means remains competent in response to fluid reflux.

7. The fluid flow control means of claim 6 wherein said needle means comprises a first end and a second end,

10 the first end being inserted into the organ or pleural cavity of the patient, with the second end capable of releasably securing said receptacle means thereto.

8. The fluid flow control means of claim 7 wherein _.- the tubular means comprises a first end and a second end, the first end of said tubular means being inserted into the organ or pleural cavity of the patient, wherein said first end comprises a plurality of apertures to facilitate fluid collection or removal. 0

9. The fluid flow control means of claim 6 wherein said valve means is integral with said tubular means.

10. The fluid flow control means of claim 6 wherein said needle means is enveloped by said obturating means

25 when said needle means is retracted within the overlying obturating means so that the needle means is unexposed.

11. The fluid flow control means of claim 13 wherein 6said valve means includes a disc member position within a

30 flexible tube.

12. The fluid flow control means of claim 6 wherein said obturating means is a trocar which houses said needle means therein.

35 — y—

13. The fluid flow control means of claim 6 wherein said trocar includes means for preventing insertion of said needle means beyond a predetermined distance therein.

5 14. The flow control means of claim 21 wherein said inlet and outlet connectors each include leur local means to facilitate said releasable attachment.

15. A method for preventing the introduction of air _1Qor reflux of blood flow into the vascular system of a patient through catheter means during intravenous or intra-arterial procedures which comprises: providing catheter means with fluid flow control means of claim 1 or 6; ₁₅ introducing the catheter means into the vascular system of the patient during intravenous or intra-arterial procedures; and introducing a fluid into said patient through said fluid flow control means and catheter means by directing the fluid under a positive pressure into the bore of the input means of said fluid flow control means so that the fluid flow control means opens in response to said positive fluid pressure to allow fluid therethrough, but remains competent in response to ambient air pressure in

-_c the bore of said input means to prevent the introduction of __!b air into the vascular system of the patient.

16. A method for preventing the reflux of fluids into an organ or the pleural cavity of a patient when fluid

₃- directing means is utilized for removal of such fluids, which comprises: providing fluid directing means having fluid flow control means of claim 1 or 6; introducing the fluid directing means into the organ or pleural cavity of a patient; and removing fluids from said organ or plural cavity by directing said fluid under a positive pressure into the bore of the input means of said fluid flow control means to facilitate removal of said fluids by flow therethrough ₅ while preventing the reflux of fluid or the introduction of air into the organ or pleural cavity of the patient.

17. A method for preventing needle-stick injuries when catheter means is introduced into or withdrawn from _1Q the vascular system of a patient during intravenous or intra-arterial procedures as well as during disposal, storage or transportation of the catheter means which comprises: providing a catheter means having fluid flow ₁₅ control means according to claim 6; introducing the catheter means having said inserted obturating means and needle means into an organ or pleural cavity of a patient for removal of fluids therefrom; retracting the needle means within the overlying obturating means so that the obturating means envelops said needle means; and withdrawing simultaneously the retracted needle means and said obturating means with the needle means unexposed from within the tubular structure so that only said tubular structure remains in the organ or pleural cavity of said patient and said valve means remains competent in response to fluid reflux.

__n 18. A method for preventing needle stick injuries when catheter means is introduced into or withdrawn from the vascular system of a patient during intravenous or intra-arterial procedures as well as during disposal, storage or transportation of the catheter means which 3 _b_ comprises; providing a catheter means having fluid flow control means according to claim 6; introducing the catheter means with said inserted obturating means and needle means into a blood vessel of a patient for removal of blood therefrom; retracting the needle means within the overlying obturating means so that the obturating means envelops said needle means; and withdrawing simultaneously the retracted needle means and said obturating means with needle means unexposed from within the tubular structure so that only said tubular structure remains in the blood vessel of said patient and said valve means remains competent in response to blood reflux.

19. The method of claim 17 or 18 wherein the needle means is double-ended in order to permit insertion of a first end of the needle into the blood vessel of a patient with the second end capable of releasably securing the receptacle means thereto, and wherein the end of the tubular structure opposite the releasably secured receptacle means includes a plurality of apertures to facilitate blood collection or removal.

20. The method of claim 17, 18 or 19 wherein the obturating means and needle means are simultaneously withdrawn from within the tubular structure after said needle means has first been retracted half-way within the obturating means so as to avoid blood contact with the user of the catheter means.

21. The method of claim 17 wherein an intravenous system is attached to the tubular means for introduction of fluids through said tubular structure after withdrawal of the obturating means and needle means therefrom, and wherein the receptacle means includes a vacuum therein to collect blood through the needle means when the catheter means is inserted into a blood vessel of the patient.