CA1081072A - Infusion tube access site - Google Patents
Infusion tube access siteInfo
- Publication number
- CA1081072A CA1081072A CA288,165A CA288165A CA1081072A CA 1081072 A CA1081072 A CA 1081072A CA 288165 A CA288165 A CA 288165A CA 1081072 A CA1081072 A CA 1081072A
- Authority
- CA
- Canada
- Prior art keywords
- sleeve
- tube
- needle
- infusion tube
- shaped member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M39/00—Tubes, tube connectors, tube couplings, valves, access sites or the like, specially adapted for medical use
- A61M39/02—Access sites
- A61M39/04—Access sites having pierceable self-sealing members
Landscapes
- Health & Medical Sciences (AREA)
- Heart & Thoracic Surgery (AREA)
- Pulmonology (AREA)
- Engineering & Computer Science (AREA)
- Anesthesiology (AREA)
- Biomedical Technology (AREA)
- Hematology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- External Artificial Organs (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
Abstract
IMPROVED INFUSION TUBE ACCESS SITE
ABSTRACT
An extra corporeal blood tube injection site com-prising a smooth blood conduit or tube, an elongated elast-omeric sleeve surrounding a section of the tube, and a C-shaped needle-impenetrable member extending along and partially surrounding the sleeve which generates forces within the por-tion of the sleeve that is not covered by the C-shaped member sufficient to prevent air leakage into, or blood leakage from, the tube during needle penetration or after withdrawal of a needle.
ABSTRACT
An extra corporeal blood tube injection site com-prising a smooth blood conduit or tube, an elongated elast-omeric sleeve surrounding a section of the tube, and a C-shaped needle-impenetrable member extending along and partially surrounding the sleeve which generates forces within the por-tion of the sleeve that is not covered by the C-shaped member sufficient to prevent air leakage into, or blood leakage from, the tube during needle penetration or after withdrawal of a needle.
Description
'7Z
This invention relates to an improved construction of the site on a tube external of the patient to enable leak-free ~ithdrawal of fluid samples from, or the injec~ion of medicants into, a fluid flowing in the tube. The invention is parti-cularly useful in blood tube sets used for the passage of blood between the patient and an artificial kidney or a blood oxy-genator.
Commercial blood-passage tubing sets have typically provided one or more injection sites at which blood samples may be taken from, or chemicals injected into, the blood by hypodermic needle piercing the tube wall. Smooth, nontoxic tubing must be used for the blood passage for patient safety;
such tubing has relatively thin walls, little elasticity and is typically non-sealing after being pierced. In order to prevent leakage into or from blood tubing pierced with a hypo-dermic needle, eIastomeric materials having some ability to self-seal have been used in the past. The elastomeric material is so arranged with the blood tube that the needle puncture is made through the self-sealing elastomeric material before piercing the tube. However, the self-sealing characteristics of the best commercially available material, natural rubber latex, are insufficient at times to prevent leakage into the blood tube under some of the conditions of use which are periodically encountered. For example, the difficulty of self-sealing increases as the needle size increases, as the time of needle penetration increases, and as the number of repeat injections is made at a particular injection site.
Moreover, the best self-sealer, natural rubber latex, is known to have toxicity and blood clotting characteristics 3a that are less desirable than other elastomeric materials such as silicone rubber, polyurethane elastomers, etc.
"~
-1- ,~, '~ ' '' "' ~,()g~)r~
To overcome the leaka~e problem while concurrently avoiding toxicity or blood clot formation many injection site constructions have heretofore been proposed. Commercial tube sets have used a latex sleeve surrounding a section of the blood tubing and such site constructions rely on the inherent self-sealin~ of the latex sleeve to prevent leakage. To furthex insure against leakage, a similar construction sur-rounds the latex sleeve with a second thin, latex sleeve stretched over the first sleeve and extending beyond the ends 1~ of the first sleeve to also seal against the blood tube. This latter construction is shown in U. S. Patent 3,81~,137. While this construction has experienced some commercial acceptance, it is nevertheless subject to leakage under severe use con-ditions. It is further objectionable because of the hazard of piercing the holding hand of the person as the elastomeric sleeves and the tube are pierced.
A blood access site construction which purports to eliminate hazard to the needle administrator and leakage is shown in U. S. Patent 3,898,988. This construction employs 2Q a plastic tube section which is placed in the blood flow conduît. This plastic tube is a T-shaped hard plastic body having a bore extending for the length of the vertically dis-posed body portion and a diameter sufficient to receive the ends of blood tubes which are adhesively secured in the bore.
In the longitudînal central area of the tube the bore diameter equals the inner diameter of the blood tubes and the blood flows through the bore in the hard plastic tube in this area.
Injection is made through a cylindrical opening in the top surface of the T-shaped tube, which opening extends down into the bore in the tube body through which the blood is flowing;
the opening is filled with a cylindrical insert of a non-thrombogenic elastomer ~uch as a polyurethane or silicone rubber which is compressed into place in the opening. This construction has the serious defects that the lower end of the elastomer is in contact with the blood flowing through the tube and the entire cylindrical elastomer insert is subject to dislodgement as the hypodermic needle is withdrawn; dis-lodgement of the entire elastomeric inser-~ creates a channel for leakage having the same diameter as the blood tube dia-meter which is obviously unacceptable.
1~ The above discussed constructions represent the closest prior art known to applicant which also includes the references cited during their prosecution which include U.S. Patents
This invention relates to an improved construction of the site on a tube external of the patient to enable leak-free ~ithdrawal of fluid samples from, or the injec~ion of medicants into, a fluid flowing in the tube. The invention is parti-cularly useful in blood tube sets used for the passage of blood between the patient and an artificial kidney or a blood oxy-genator.
Commercial blood-passage tubing sets have typically provided one or more injection sites at which blood samples may be taken from, or chemicals injected into, the blood by hypodermic needle piercing the tube wall. Smooth, nontoxic tubing must be used for the blood passage for patient safety;
such tubing has relatively thin walls, little elasticity and is typically non-sealing after being pierced. In order to prevent leakage into or from blood tubing pierced with a hypo-dermic needle, eIastomeric materials having some ability to self-seal have been used in the past. The elastomeric material is so arranged with the blood tube that the needle puncture is made through the self-sealing elastomeric material before piercing the tube. However, the self-sealing characteristics of the best commercially available material, natural rubber latex, are insufficient at times to prevent leakage into the blood tube under some of the conditions of use which are periodically encountered. For example, the difficulty of self-sealing increases as the needle size increases, as the time of needle penetration increases, and as the number of repeat injections is made at a particular injection site.
Moreover, the best self-sealer, natural rubber latex, is known to have toxicity and blood clotting characteristics 3a that are less desirable than other elastomeric materials such as silicone rubber, polyurethane elastomers, etc.
"~
-1- ,~, '~ ' '' "' ~,()g~)r~
To overcome the leaka~e problem while concurrently avoiding toxicity or blood clot formation many injection site constructions have heretofore been proposed. Commercial tube sets have used a latex sleeve surrounding a section of the blood tubing and such site constructions rely on the inherent self-sealin~ of the latex sleeve to prevent leakage. To furthex insure against leakage, a similar construction sur-rounds the latex sleeve with a second thin, latex sleeve stretched over the first sleeve and extending beyond the ends 1~ of the first sleeve to also seal against the blood tube. This latter construction is shown in U. S. Patent 3,81~,137. While this construction has experienced some commercial acceptance, it is nevertheless subject to leakage under severe use con-ditions. It is further objectionable because of the hazard of piercing the holding hand of the person as the elastomeric sleeves and the tube are pierced.
A blood access site construction which purports to eliminate hazard to the needle administrator and leakage is shown in U. S. Patent 3,898,988. This construction employs 2Q a plastic tube section which is placed in the blood flow conduît. This plastic tube is a T-shaped hard plastic body having a bore extending for the length of the vertically dis-posed body portion and a diameter sufficient to receive the ends of blood tubes which are adhesively secured in the bore.
In the longitudînal central area of the tube the bore diameter equals the inner diameter of the blood tubes and the blood flows through the bore in the hard plastic tube in this area.
Injection is made through a cylindrical opening in the top surface of the T-shaped tube, which opening extends down into the bore in the tube body through which the blood is flowing;
the opening is filled with a cylindrical insert of a non-thrombogenic elastomer ~uch as a polyurethane or silicone rubber which is compressed into place in the opening. This construction has the serious defects that the lower end of the elastomer is in contact with the blood flowing through the tube and the entire cylindrical elastomer insert is subject to dislodgement as the hypodermic needle is withdrawn; dis-lodgement of the entire elastomeric inser-~ creates a channel for leakage having the same diameter as the blood tube dia-meter which is obviously unacceptable.
1~ The above discussed constructions represent the closest prior art known to applicant which also includes the references cited during their prosecution which include U.S. Patents
2,129,983; 2,498,831; 2,832,338; 3,030,955; 3,112,748;
3,447,570; 3,463,691; 3,853,127; 2,053,112; 2,907,351; and 3,566,868. None of the constructions known to applicant completely solve the problems of leakage into, or from, a ~
non-thrombogenic blood tu~e while simultaneously eliminating ~ -the hazard of accidental piercing of the hand of the needle administrator. `
The present invention solves both of these problems.
According to the present invention the improved infusion tube access site comprises an infusion tube, an elongated elasto- ~;
meric sleeve surrounding a portion of said infusion tube, and a needle-impenetrable C-shaped member surrounding said sleeve and extending substantially the full length and par-tially around the periphery thereof to thereby expose a portion of said sleeve between the inner extremities of the arms of said C-shaped member, said C-shaped member having an inner diameter smaller than the outer diameter of said sleeve and compressing said sleeve around said tube along the length thereof, the arm portions of said C-shaped member exerting a - , . - . . ..
itll~ 2 combination of radial and transversely directed forces within the portion of said eIastomeric sleeve not covered by said C-shaped member sufficient to prevent leaks into said tube during the time a needle pierces said sleeve and said tube, and after ~rithdrawal of said needle therefrom.
This invention prov i;desan inexpensive infusion tube access site comprising a smooth nontoxic tube having an elongated elastomeric sleeve surrounding a section of the tube that is improved and distinguishes from prior constructions by a C-shaped needle-impenetrable member substantially co-extensive in length with the sleeve and enveloping more than one-half of the periphery of the elastomeric sleeve, which C-shaped member exerts a squeezé force on the sleeve which acts through the elastomeric properties of the sleeve to effectively seal against air leakage into, or blood leak-age from, the blood tube during needle insertion or after the needle is ~ithdrawn. The site construction of this invention protects against inadvertent injury to the hand holding the needle-impenetrable C-shaped member during needle insertion, and provides a large access area for making plural insertions while facilitating every angle of needle placement for in-jecting medications and collecting blood samples. The site construction of this invention also provides improved resist-ance to leaks under much more severe conditions of use than those normally encountered in the ordinary use of blood sets for blood passing between a patient and an artificial kidney or a blood oxygenator; it is also useful in transfusing blood or other fluids, such as saline solutions, etc.
Fig. 1 is a top view of a preferred embodiment of the invention~
Fig. 2 is a view taken on the line 2-2 of Fig. 1.
. .
Fig. 3 is a view taken on the line 3-3 of Fig. 2.
Fig. 4 is a perspective view, partly broken away, showing the preferred embodiment during needle insertion.
Fig. 5 is a vie~ of the embodiment of Fig. 4, in section, showing one needle piercing the elastomeric sleeve and blood tube wall and two additional piercing locations of a needle in dotted lines.
Fig. 6 is a view illustrating a site of this invention ~hich shows t~o ~it~drawn needle locations and a third needle partially withdrawn.
Fig. 7 is an enlarged end view of the embodiment of Fig. 1.
Fig. 8 is an enlargement of the needle penetrating por-tion of Fig. 7 showing the force distribution within the elas-tomeric sleeve as a needle is withdrawn.
Fig. 9 is an enlargement of the portion of Fig. 6 surrounded by the line 9-9 showing the force distribution within the elastomeric sleeYe on a needle inserted at an angle less than 90 to the axis of the blood tube.
Referring to the drawings, the improved access site construction of this invention is shown in Fig. 1 and ~en-- erally designated 10. Site 10 consists of blood or infusion tube 12 which in normal use is a part of the blood tubing in a tube set which connects patient's artery or vein to an artificial kidney or blood oxygenator, or an organ per-fusion device. Tube 12 may be made of any of a number of commercially available nontoxic plastics, for example, poly-vinyl plastisols, polyurethane or silicone rubber and pref-erably is made of plasticized pol~vinyl chlorlde. -An elastomeric sleeve 14 surrounds a section of tube 12 at one or more locations along its length, for example, in sections abQut 1 to 2 1/2 inches long. The elastomeric properties of sleeve 14 are important to the accomplishment of the objective of elimination of leaks of the types above mentioned. The elastomer should be relatively soft and yet have sufficient elasticity and internal strength to permit needle insertion without shredding or disintegrating as the needle is înserted or withdrawn; it should exhibit maximized memory or ability to resume its original position after being stretched or deformed and maximum resistance to fatigue or lQ change of resilience with reuse or passage of time. Import-antly, the elastomer should be capable of transmitting forces, particularly compxessive forces, from the point of application to adjacent areas within the body of the elastomer. These general considerations can be employed in selecting the best elastomer for particular use conditions which may vary sub-stantially as to pressure of fluid flowing in tube 12, or the diameter of the needle used, or the time of retention of the needle during the blood sampling or during the addition of medicants to the blood tube from those conditions which are normally encountered in the use of access sites on blood sets employed in dialyzing a patient with an artificial kidney.
There are a number of types of elastomeric materials which are available from which sleeve 14 may be fabricated that will possess the appropriate degree of resiliency for a specific set of use conditions, for example, polyurethane elastomers, silicone elastomers, synthetic latex and natural rubber latex.
For use in dialysis of humans employing an artificial kidney, particularly the type of artificial kidney containing hollow fibers as the dialyzing element such as the C-DAK artificial 3~ kidney available from Cordis Dow Corp., the preferred elastomer is natural rubber latex.
The third, and key, element in the preferred access site construction of this invention is a C-shaped needle-;mpenetrable element 16, which surrounds a portion of the periphery of sleeve 14, greater than one-half of that periph-ery, and preferably about 65~ to about 90% of it. Element 16 has as its first function the prevention of inadvertent pene-tration by needle 18 completely through sleeve 14 and tube 12 and piercing the hand holding the access site as best illus-trated in phantom in FIg. 4. The second and more important function of C-shaped member 16 is to apply an amount of com-pressive force to the portion of sleeve 14 which it surrounds sufficient to enhance the inherent resiliency characteristics of that sleeve in the portion thereof which is not coverea by member 16 to cause sleeve 14 to prevent air leaks into the tube 12 during the time that needle 18 is in penetrated position extending through the upper wall portions of sleeve 14 and tube 12 as may be seen in Fig. 5. Another somewhat . .
less important function of member 16 is to continuously apply such an amount of force to and through the body of member 16 2Q to cause substantially immediate blockage of fluid leaks out-ward through the opening in tube 12 as needle 18 is drawn through the interface between the outer surface of the wall of tube 12 and the inner surface of sleeve 14, as is illustrated in Fig. 6. Momentarily later, as needle 18 is withdrawn through the body, or upper wall, portion of sleeve 14, the force applied to sleeve 14 by member 16 functions to cause leak-tight closure of the opening earlier generated by the penetration of needle 18, as shown by lines 20, 22 in Fig. 6.
This latter force is applied majorly by the portions 16A, 3Q 16B of member 16, that is, the upper arm extremities which lie above a horizontal plane tangent to the upper surface of the tu~e 12 as shown by dotted line 17 in Fig. 7.
. . . - -, ~
108~l0~2 The ~orce applied hy member 16 to sleeve 14 results from the strength of the material comprising member 16 to resist deformation from an original circular cross-section to the C-shaped cross-section it possesses when positioned around the portion of the periphery of sleeve 14 which it covers as sho~n in Figs. 3 and 7. Fig. 7 is an expanded end view of the preferred access site 10 which is drawn to scale and shows the degree to which member 16 is distorted from its original circular cross-section when the material of tube 12 la is plasticized polyvinyl chloride, elastomeric sleeve 14 is natural rub~er latex and member 16 is polypropylene. Before assembly, tube 12 had an outside diameter of 0.253" + 0.003";
latex sleeve 14 had an inner diameter of 0.219" + 0.016", a wall thickness of 0.125" + 0.010l' and a nominal outside diameter of Q.469". Sleeve 14 is mounted over tube 12 and its inner diameter is slightly stretched as it moves into position over the section of tube 12 preselected as the location for access site 10 and sleeve 14 concurrently applles a smaLl compressive force on the outer diameter of tube 12.
Similarly, prior to assembly, member 16 was an injection molded polypropylene member, circular in cross-section, having an inner diameter of 0.400" and a wall thickness of 0.0;52"-0.060" and an opening between the upper wall portions 16A and 16B of 0.125" as shown in Figs. 3 and 7. Member 16 is mounted on sleeve 14 by forcing the portions 16A and 16B
apart sufficiently to enable encirclement of the outside diameter of sleeve 14; the resistance of the polypropylene material to the spreading deformation sufficient to tightly overlie the illustrated portion of the periphery of sleeve 3a 14 results in a bulging of the portion indicated by arrow 23 of sleeve 14 which lies between the inner surfaces 24A
~ 8107~
and 24B. Due to the final position spreading of arm portions 16A and 16B during assembly the portion indicated by arrow 25 of the wall of member 16 is slightly flattened from its circular cross-section producing a slightly elongated C-section which may be seen by rotating Fig. 7 until portion 16B is at the top of the figure.
As a result of the distortion of member 16 from its initial circular cross-section a combination of multi-direc-tional forces are constantly applied to sleeve 1~ by member 16. These forces are illustrated by the arrows 26 in Fig. 8 and are related to a needle 18 which is piercing sleeve 14 perpendicularly to the longitudinal axis of tube 12. It may be seen that the forces applied, primarily by the upper wall portions 16A and 16B, comprise forces consistin~ of components directed radially inwardly toward sleeve 12 and other forces which result from the squeezing pressure of surfaces 24A, and 24B on the outer surface of sleeve 14 to cause the bulging at 23 which ha~e components which vary from the radial direction gradually upwardly to the horizontal and beyond toward the 2a axially central area of the bulge 23.
Fig. 9 specifically illustrates the distribution of forces which are additionally available to cause closure, and leak-tight sealing, of a needle inserted through sleeve 14 at ~ , an angle less than 90, and about 40 as shown, from a hori-zontal plane passing through the axis of tube 12, as indicated at 28, Fig. 6. Arrows 30 show the vertically oriented forces which bear on the upper and lower surface portions of the opening cause by needle 18 due to the angular insertion of the needle. The best sealing results are obtained with the access site construction of this invention when the needle penetration is made at an angle of approximately 45 + 10 .. ' ~"
_g_ ,, - : ' ': ' - . : , 1~81a~7~
from a horizontal plane passing through the axis of tube 12.
The access site shown in Fig. 7 and constructed from -the materials above identified represents the best form of the invention that is currently known. It is satisfactory, how-ever, to fabricate member 16 from materials other than poly-propylene. The important requirement which must be satisfied is that the substitute material possessa relatively high rigid-ity and resistance to deformation from an initial circular cross-section to a C-shaped cross-section similar to that above described for polypropylene member 16. It is desirable to select a substitute having sufficient resistance to deform-ation in a relatively thin wall section, for example, less than 0.100", to exert sufficient force to insuxe against leaks under severe use conditions. Satisfactory substitutes for polypropylene include other plastics such as synthetic polyamides available under the designation "Nylon", acetal resins available under the designation "Delrin", and ABS
resins available from many suppliers; metals such as steel, stainless steel, aluminum and magnesium may be used and are recommended for use under the most severe of use conditions.
Metal offers the advantage of ease of fabrication into initial cross-sectional forms other than circular to enable increased pressure from the upper wall portions corresponding to 16A and 16B. For example, portions 16A and 16B may be initially bent inwardly from the circular so as to exert additional downward forces to those illustrated as arrows 26 in Fig. 8.
The improvement in preventing air leaks using the preferred embodiment of this invention which has been speci-fically described above as to materials, initial and assem~led sizes in the description of Fig. 7 is illustrated 07~2 by the comparative test data se~ forth below. The preferred access site of this invention was tested in comparison with the access site construction of U.S. patent 3,814,137 which is commercially available from Travenol Laboratories, Inc.
under the designation Travenol Dialysis slood Set. Each of these constructions is especially sultable for use in blood sets employed in artificial kidney dialysis, and thus the test conditions selected for the comparison are conditions which are much more severe than the conditions encountered --in normal clinical use on actual dialysis patients. The test conditions used are shown in Table I to provide a comparison with normal conditions encountered in clinical usage during dialysis employing a hollow fiber C-DAK artifi-cial kîdney.
Table I
Selected Test Clinical Dialysis-Condition Normal Range Needle 18 gauge (0.05" diameter) 20-27 gauge (0.036-0.016" diameter) Angle of piercing 90 45 Pressure, sub-atmospheric -150 to -400 mm Hg 0 to -80 mm Hg Pressure, positive 5, lO, 15 psig 0.4 - 3.0 psig Fluid Flow Rate 200 ml/minute 100 - 300 ml/minute Temperature 37C + 1C 35 - 39 C -Fluid Water Blood ~
: ':
It will be apparent that the conditions of larger needle size, angle of piercing, pressures both negative and positive and the use of ~ater rather than blood are each sub-stantially more severe than use conditions normally encoun-tered.
I ~ .
~o~72 The test procedure used was as follows:
l. Connect blood lines to negative pressure system and warm to body temperature, 37C.
2. At water flow rate of 20Q ml/min. set pressure to -150 mm Hg, which is approximately twice the maximum negative pressure usually encountered in dialysis.
3. Using 18 gauge, Q.Q50" diameter, needle pierce through the latex sleeve and the tube at a 90 angle to a hori-zontal plane passing through the axis of the blood tubes la and hold in place for l minute, withdraw and inspect for leaks under bright light. If no leak, after 1 minute, then repeat and reinspect.
non-thrombogenic blood tu~e while simultaneously eliminating ~ -the hazard of accidental piercing of the hand of the needle administrator. `
The present invention solves both of these problems.
According to the present invention the improved infusion tube access site comprises an infusion tube, an elongated elasto- ~;
meric sleeve surrounding a portion of said infusion tube, and a needle-impenetrable C-shaped member surrounding said sleeve and extending substantially the full length and par-tially around the periphery thereof to thereby expose a portion of said sleeve between the inner extremities of the arms of said C-shaped member, said C-shaped member having an inner diameter smaller than the outer diameter of said sleeve and compressing said sleeve around said tube along the length thereof, the arm portions of said C-shaped member exerting a - , . - . . ..
itll~ 2 combination of radial and transversely directed forces within the portion of said eIastomeric sleeve not covered by said C-shaped member sufficient to prevent leaks into said tube during the time a needle pierces said sleeve and said tube, and after ~rithdrawal of said needle therefrom.
This invention prov i;desan inexpensive infusion tube access site comprising a smooth nontoxic tube having an elongated elastomeric sleeve surrounding a section of the tube that is improved and distinguishes from prior constructions by a C-shaped needle-impenetrable member substantially co-extensive in length with the sleeve and enveloping more than one-half of the periphery of the elastomeric sleeve, which C-shaped member exerts a squeezé force on the sleeve which acts through the elastomeric properties of the sleeve to effectively seal against air leakage into, or blood leak-age from, the blood tube during needle insertion or after the needle is ~ithdrawn. The site construction of this invention protects against inadvertent injury to the hand holding the needle-impenetrable C-shaped member during needle insertion, and provides a large access area for making plural insertions while facilitating every angle of needle placement for in-jecting medications and collecting blood samples. The site construction of this invention also provides improved resist-ance to leaks under much more severe conditions of use than those normally encountered in the ordinary use of blood sets for blood passing between a patient and an artificial kidney or a blood oxygenator; it is also useful in transfusing blood or other fluids, such as saline solutions, etc.
Fig. 1 is a top view of a preferred embodiment of the invention~
Fig. 2 is a view taken on the line 2-2 of Fig. 1.
. .
Fig. 3 is a view taken on the line 3-3 of Fig. 2.
Fig. 4 is a perspective view, partly broken away, showing the preferred embodiment during needle insertion.
Fig. 5 is a vie~ of the embodiment of Fig. 4, in section, showing one needle piercing the elastomeric sleeve and blood tube wall and two additional piercing locations of a needle in dotted lines.
Fig. 6 is a view illustrating a site of this invention ~hich shows t~o ~it~drawn needle locations and a third needle partially withdrawn.
Fig. 7 is an enlarged end view of the embodiment of Fig. 1.
Fig. 8 is an enlargement of the needle penetrating por-tion of Fig. 7 showing the force distribution within the elas-tomeric sleeve as a needle is withdrawn.
Fig. 9 is an enlargement of the portion of Fig. 6 surrounded by the line 9-9 showing the force distribution within the elastomeric sleeYe on a needle inserted at an angle less than 90 to the axis of the blood tube.
Referring to the drawings, the improved access site construction of this invention is shown in Fig. 1 and ~en-- erally designated 10. Site 10 consists of blood or infusion tube 12 which in normal use is a part of the blood tubing in a tube set which connects patient's artery or vein to an artificial kidney or blood oxygenator, or an organ per-fusion device. Tube 12 may be made of any of a number of commercially available nontoxic plastics, for example, poly-vinyl plastisols, polyurethane or silicone rubber and pref-erably is made of plasticized pol~vinyl chlorlde. -An elastomeric sleeve 14 surrounds a section of tube 12 at one or more locations along its length, for example, in sections abQut 1 to 2 1/2 inches long. The elastomeric properties of sleeve 14 are important to the accomplishment of the objective of elimination of leaks of the types above mentioned. The elastomer should be relatively soft and yet have sufficient elasticity and internal strength to permit needle insertion without shredding or disintegrating as the needle is înserted or withdrawn; it should exhibit maximized memory or ability to resume its original position after being stretched or deformed and maximum resistance to fatigue or lQ change of resilience with reuse or passage of time. Import-antly, the elastomer should be capable of transmitting forces, particularly compxessive forces, from the point of application to adjacent areas within the body of the elastomer. These general considerations can be employed in selecting the best elastomer for particular use conditions which may vary sub-stantially as to pressure of fluid flowing in tube 12, or the diameter of the needle used, or the time of retention of the needle during the blood sampling or during the addition of medicants to the blood tube from those conditions which are normally encountered in the use of access sites on blood sets employed in dialyzing a patient with an artificial kidney.
There are a number of types of elastomeric materials which are available from which sleeve 14 may be fabricated that will possess the appropriate degree of resiliency for a specific set of use conditions, for example, polyurethane elastomers, silicone elastomers, synthetic latex and natural rubber latex.
For use in dialysis of humans employing an artificial kidney, particularly the type of artificial kidney containing hollow fibers as the dialyzing element such as the C-DAK artificial 3~ kidney available from Cordis Dow Corp., the preferred elastomer is natural rubber latex.
The third, and key, element in the preferred access site construction of this invention is a C-shaped needle-;mpenetrable element 16, which surrounds a portion of the periphery of sleeve 14, greater than one-half of that periph-ery, and preferably about 65~ to about 90% of it. Element 16 has as its first function the prevention of inadvertent pene-tration by needle 18 completely through sleeve 14 and tube 12 and piercing the hand holding the access site as best illus-trated in phantom in FIg. 4. The second and more important function of C-shaped member 16 is to apply an amount of com-pressive force to the portion of sleeve 14 which it surrounds sufficient to enhance the inherent resiliency characteristics of that sleeve in the portion thereof which is not coverea by member 16 to cause sleeve 14 to prevent air leaks into the tube 12 during the time that needle 18 is in penetrated position extending through the upper wall portions of sleeve 14 and tube 12 as may be seen in Fig. 5. Another somewhat . .
less important function of member 16 is to continuously apply such an amount of force to and through the body of member 16 2Q to cause substantially immediate blockage of fluid leaks out-ward through the opening in tube 12 as needle 18 is drawn through the interface between the outer surface of the wall of tube 12 and the inner surface of sleeve 14, as is illustrated in Fig. 6. Momentarily later, as needle 18 is withdrawn through the body, or upper wall, portion of sleeve 14, the force applied to sleeve 14 by member 16 functions to cause leak-tight closure of the opening earlier generated by the penetration of needle 18, as shown by lines 20, 22 in Fig. 6.
This latter force is applied majorly by the portions 16A, 3Q 16B of member 16, that is, the upper arm extremities which lie above a horizontal plane tangent to the upper surface of the tu~e 12 as shown by dotted line 17 in Fig. 7.
. . . - -, ~
108~l0~2 The ~orce applied hy member 16 to sleeve 14 results from the strength of the material comprising member 16 to resist deformation from an original circular cross-section to the C-shaped cross-section it possesses when positioned around the portion of the periphery of sleeve 14 which it covers as sho~n in Figs. 3 and 7. Fig. 7 is an expanded end view of the preferred access site 10 which is drawn to scale and shows the degree to which member 16 is distorted from its original circular cross-section when the material of tube 12 la is plasticized polyvinyl chloride, elastomeric sleeve 14 is natural rub~er latex and member 16 is polypropylene. Before assembly, tube 12 had an outside diameter of 0.253" + 0.003";
latex sleeve 14 had an inner diameter of 0.219" + 0.016", a wall thickness of 0.125" + 0.010l' and a nominal outside diameter of Q.469". Sleeve 14 is mounted over tube 12 and its inner diameter is slightly stretched as it moves into position over the section of tube 12 preselected as the location for access site 10 and sleeve 14 concurrently applles a smaLl compressive force on the outer diameter of tube 12.
Similarly, prior to assembly, member 16 was an injection molded polypropylene member, circular in cross-section, having an inner diameter of 0.400" and a wall thickness of 0.0;52"-0.060" and an opening between the upper wall portions 16A and 16B of 0.125" as shown in Figs. 3 and 7. Member 16 is mounted on sleeve 14 by forcing the portions 16A and 16B
apart sufficiently to enable encirclement of the outside diameter of sleeve 14; the resistance of the polypropylene material to the spreading deformation sufficient to tightly overlie the illustrated portion of the periphery of sleeve 3a 14 results in a bulging of the portion indicated by arrow 23 of sleeve 14 which lies between the inner surfaces 24A
~ 8107~
and 24B. Due to the final position spreading of arm portions 16A and 16B during assembly the portion indicated by arrow 25 of the wall of member 16 is slightly flattened from its circular cross-section producing a slightly elongated C-section which may be seen by rotating Fig. 7 until portion 16B is at the top of the figure.
As a result of the distortion of member 16 from its initial circular cross-section a combination of multi-direc-tional forces are constantly applied to sleeve 1~ by member 16. These forces are illustrated by the arrows 26 in Fig. 8 and are related to a needle 18 which is piercing sleeve 14 perpendicularly to the longitudinal axis of tube 12. It may be seen that the forces applied, primarily by the upper wall portions 16A and 16B, comprise forces consistin~ of components directed radially inwardly toward sleeve 12 and other forces which result from the squeezing pressure of surfaces 24A, and 24B on the outer surface of sleeve 14 to cause the bulging at 23 which ha~e components which vary from the radial direction gradually upwardly to the horizontal and beyond toward the 2a axially central area of the bulge 23.
Fig. 9 specifically illustrates the distribution of forces which are additionally available to cause closure, and leak-tight sealing, of a needle inserted through sleeve 14 at ~ , an angle less than 90, and about 40 as shown, from a hori-zontal plane passing through the axis of tube 12, as indicated at 28, Fig. 6. Arrows 30 show the vertically oriented forces which bear on the upper and lower surface portions of the opening cause by needle 18 due to the angular insertion of the needle. The best sealing results are obtained with the access site construction of this invention when the needle penetration is made at an angle of approximately 45 + 10 .. ' ~"
_g_ ,, - : ' ': ' - . : , 1~81a~7~
from a horizontal plane passing through the axis of tube 12.
The access site shown in Fig. 7 and constructed from -the materials above identified represents the best form of the invention that is currently known. It is satisfactory, how-ever, to fabricate member 16 from materials other than poly-propylene. The important requirement which must be satisfied is that the substitute material possessa relatively high rigid-ity and resistance to deformation from an initial circular cross-section to a C-shaped cross-section similar to that above described for polypropylene member 16. It is desirable to select a substitute having sufficient resistance to deform-ation in a relatively thin wall section, for example, less than 0.100", to exert sufficient force to insuxe against leaks under severe use conditions. Satisfactory substitutes for polypropylene include other plastics such as synthetic polyamides available under the designation "Nylon", acetal resins available under the designation "Delrin", and ABS
resins available from many suppliers; metals such as steel, stainless steel, aluminum and magnesium may be used and are recommended for use under the most severe of use conditions.
Metal offers the advantage of ease of fabrication into initial cross-sectional forms other than circular to enable increased pressure from the upper wall portions corresponding to 16A and 16B. For example, portions 16A and 16B may be initially bent inwardly from the circular so as to exert additional downward forces to those illustrated as arrows 26 in Fig. 8.
The improvement in preventing air leaks using the preferred embodiment of this invention which has been speci-fically described above as to materials, initial and assem~led sizes in the description of Fig. 7 is illustrated 07~2 by the comparative test data se~ forth below. The preferred access site of this invention was tested in comparison with the access site construction of U.S. patent 3,814,137 which is commercially available from Travenol Laboratories, Inc.
under the designation Travenol Dialysis slood Set. Each of these constructions is especially sultable for use in blood sets employed in artificial kidney dialysis, and thus the test conditions selected for the comparison are conditions which are much more severe than the conditions encountered --in normal clinical use on actual dialysis patients. The test conditions used are shown in Table I to provide a comparison with normal conditions encountered in clinical usage during dialysis employing a hollow fiber C-DAK artifi-cial kîdney.
Table I
Selected Test Clinical Dialysis-Condition Normal Range Needle 18 gauge (0.05" diameter) 20-27 gauge (0.036-0.016" diameter) Angle of piercing 90 45 Pressure, sub-atmospheric -150 to -400 mm Hg 0 to -80 mm Hg Pressure, positive 5, lO, 15 psig 0.4 - 3.0 psig Fluid Flow Rate 200 ml/minute 100 - 300 ml/minute Temperature 37C + 1C 35 - 39 C -Fluid Water Blood ~
: ':
It will be apparent that the conditions of larger needle size, angle of piercing, pressures both negative and positive and the use of ~ater rather than blood are each sub-stantially more severe than use conditions normally encoun-tered.
I ~ .
~o~72 The test procedure used was as follows:
l. Connect blood lines to negative pressure system and warm to body temperature, 37C.
2. At water flow rate of 20Q ml/min. set pressure to -150 mm Hg, which is approximately twice the maximum negative pressure usually encountered in dialysis.
3. Using 18 gauge, Q.Q50" diameter, needle pierce through the latex sleeve and the tube at a 90 angle to a hori-zontal plane passing through the axis of the blood tubes la and hold in place for l minute, withdraw and inspect for leaks under bright light. If no leak, after 1 minute, then repeat and reinspect.
4. If no leak is visible after second inspection, raise sub-atmospheric pressure on water to -400 mm Hg. Repeat Step 3 for 2 piercings with l minute held before inspection.
5. If no leak after the four piercings of Steps 3 and 4, set pressure on water to positive 5 psig and repeat Step 3.
6. If no leak after the sixth piercing in Step 5, change pressure to positive lO psig and repeat Step 3.
7. If no leak after the eighth piercing of Step 6, change pressure to positive 15 psig and repeat Step 3. At any time a leak appeared in the form of a visible bubble or bubbles in the water in the Steps 3 or 4 or a leak around the needle or at the needle opening after withdrawal and after 1 minute of inspection time, the test was stopped and the number of piercings made before the leak occurred was recorded and the test discontinued.
-Twenty access site constructions of the type shown in Fig. 2 of U.5. Patent 3,814,137, available in the United States under the designation Travenol Dialysis Blood Set were ob-tained and tested under the selected test conditions by using the above stated test procedure in comparison to the preferred access site constructions of this invention~ specifically shown in Fig. 7 and described above as to dimensions. The results are reported as the average number of needle punctures before a leak occurred, follo~ing for each access site the la sequence of puncturing under the increasingly severe test conditions until failure occurred. The average number of punctures before a leak occurred for the access site con-structions of U.S. Patent 3,814,137 for the 20 sites tested was 5.25. The average number of punctures before a leak occurred for the preferred access site constructions of this invention for the 72 sites tested was 7.66.
To illustrate the necessity for sufficient forces to be generated by the needle-impenetrable sleeve within the body of the latex sleeve to prevent leaks, and for contrast w-ith the results obtained from the use of the preferred ;
embodiment of this invention as above shown, a further series of tests was conducted. In this series, each of the tube, the latex sleeve and the needle-impenetrable member was made of the same material as was used in the test of the preferred embodiment. The only change was the size of the latex sleeve, and it was decreased to an outside diameter of 0.438" and its inner diameter was 0.187". This change decreased the difference in diameter between the latex sleeve outside dia-meter and the impenetrable member inside diameter and con-3Q currently increased the difference in outside diameter of the tube and the inside diameter of the latex sleeve. Seventy-1~8~ 2 two access sites of this construction, tested under identical conditions and by the same procedure resulted in an average number of punctures to leak of 2.53.
t`
1` ~
'"':
-14- :
-Twenty access site constructions of the type shown in Fig. 2 of U.5. Patent 3,814,137, available in the United States under the designation Travenol Dialysis Blood Set were ob-tained and tested under the selected test conditions by using the above stated test procedure in comparison to the preferred access site constructions of this invention~ specifically shown in Fig. 7 and described above as to dimensions. The results are reported as the average number of needle punctures before a leak occurred, follo~ing for each access site the la sequence of puncturing under the increasingly severe test conditions until failure occurred. The average number of punctures before a leak occurred for the access site con-structions of U.S. Patent 3,814,137 for the 20 sites tested was 5.25. The average number of punctures before a leak occurred for the preferred access site constructions of this invention for the 72 sites tested was 7.66.
To illustrate the necessity for sufficient forces to be generated by the needle-impenetrable sleeve within the body of the latex sleeve to prevent leaks, and for contrast w-ith the results obtained from the use of the preferred ;
embodiment of this invention as above shown, a further series of tests was conducted. In this series, each of the tube, the latex sleeve and the needle-impenetrable member was made of the same material as was used in the test of the preferred embodiment. The only change was the size of the latex sleeve, and it was decreased to an outside diameter of 0.438" and its inner diameter was 0.187". This change decreased the difference in diameter between the latex sleeve outside dia-meter and the impenetrable member inside diameter and con-3Q currently increased the difference in outside diameter of the tube and the inside diameter of the latex sleeve. Seventy-1~8~ 2 two access sites of this construction, tested under identical conditions and by the same procedure resulted in an average number of punctures to leak of 2.53.
t`
1` ~
'"':
-14- :
Claims (4)
1. An infusion tube access site comprising an infusion tube, an elongated elastomeric sleeve surrounding a portion of said infusion tube, and a needle-impenetrable C-shaped member surrounding said sleeve and extending substan-tially the full length and partially around the periphery thereof to thereby expose a portion of said sleeve between the inner extremities of the arms of said C-shaped member, said C-shaped member having an inner diameter smaller than the outer diameter of said sleeve and compressing said sleeve around said tube along the length thereof, the arm portions of said C-shaped member exerting a combination of radial and transversely directed forces within the portion of said elas-tomeric sleeve not covered by said C-shaped member sufficient to prevent leaks into said tube during the time a needle pierces said sleeve and said tube, and after withdrawal of said needle therefrom.
2. An infusion tube access site as set forth in Claim 1 wherein said infusion tube is nontoxic and said C-shaped member is polypropylene.
3. An infusion tube access site as set forth in Claim 1 wherein said infusion tube is fabricated from a polyvinyl chloride polymer, and said C-shaped member is polypropylene.
4. An infusion tube access site as set forth in Claim 1 wherein said infusion tube is fabricated from a polyvinyl chloride polymer, said elastomeric sleeve is natural rubber latex and said C-shaped member is polypropylene.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72994076A | 1976-10-06 | 1976-10-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1081072A true CA1081072A (en) | 1980-07-08 |
Family
ID=24933233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA288,165A Expired CA1081072A (en) | 1976-10-06 | 1977-10-05 | Infusion tube access site |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS5854829B2 (en) |
| AU (1) | AU512689B2 (en) |
| BE (1) | BE859401A (en) |
| CA (1) | CA1081072A (en) |
| CH (1) | CH616335A5 (en) |
| DE (1) | DE2744955C3 (en) |
| DK (1) | DK440377A (en) |
| FR (1) | FR2366843A1 (en) |
| GB (1) | GB1590101A (en) |
| IT (1) | IT1090678B (en) |
| MX (1) | MX146254A (en) |
| NL (1) | NL167597C (en) |
| SE (1) | SE428874B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987004627A1 (en) * | 1986-01-29 | 1987-08-13 | Mount Sinai School Of Medicine | Coaxial double lumen anteriovenous grafting tube |
| US8029563B2 (en) | 2004-11-29 | 2011-10-04 | Gore Enterprise Holdings, Inc. | Implantable devices with reduced needle puncture site leakage |
| US9814560B2 (en) | 2013-12-05 | 2017-11-14 | W. L. Gore & Associates, Inc. | Tapered implantable device and methods for making such devices |
| JP6673942B2 (en) | 2015-06-05 | 2020-04-01 | ダブリュ．エル．ゴア アンド アソシエイツ，インコーポレイティドＷ．Ｌ． Ｇｏｒｅ ＆ Ａｓｓｏｃｉａｔｅｓ， Ｉｎｃｏｒｐｏｒａｔｅｄ | Tapered hypobleeding implantable prosthesis |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3447570A (en) * | 1967-11-01 | 1969-06-03 | Robert M Collins | Puncture pad and holder |
| JPS5414476Y2 (en) * | 1973-05-04 | 1979-06-14 | ||
| JPS51105893U (en) * | 1975-02-22 | 1976-08-24 |
-
1977
- 1977-09-22 AU AU29033/77A patent/AU512689B2/en not_active Expired
- 1977-09-23 NL NL7710423A patent/NL167597C/en not_active IP Right Cessation
- 1977-09-30 CH CH1196277A patent/CH616335A5/en not_active IP Right Cessation
- 1977-10-05 SE SE7711139A patent/SE428874B/en not_active IP Right Cessation
- 1977-10-05 BE BE181476A patent/BE859401A/en not_active IP Right Cessation
- 1977-10-05 GB GB4135677A patent/GB1590101A/en not_active Expired
- 1977-10-05 CA CA288,165A patent/CA1081072A/en not_active Expired
- 1977-10-05 IT IT5128677A patent/IT1090678B/en active
- 1977-10-05 DK DK440377A patent/DK440377A/en not_active Application Discontinuation
- 1977-10-05 FR FR7729951A patent/FR2366843A1/en active Granted
- 1977-10-06 DE DE19772744955 patent/DE2744955C3/en not_active Expired
- 1977-10-06 MX MX17082877A patent/MX146254A/en unknown
- 1977-10-06 JP JP52119552A patent/JPS5854829B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| MX146254A (en) | 1982-06-02 |
| DK440377A (en) | 1978-04-07 |
| DE2744955C3 (en) | 1980-06-04 |
| SE7711139L (en) | 1978-04-07 |
| GB1590101A (en) | 1981-05-28 |
| NL167597C (en) | 1982-01-18 |
| DE2744955A1 (en) | 1978-04-13 |
| AU2903377A (en) | 1979-03-29 |
| DE2744955B2 (en) | 1979-09-13 |
| AU512689B2 (en) | 1980-10-23 |
| JPS5854829B2 (en) | 1983-12-06 |
| SE428874B (en) | 1983-08-01 |
| CH616335A5 (en) | 1980-03-31 |
| BE859401A (en) | 1978-02-01 |
| IT1090678B (en) | 1985-06-26 |
| FR2366843A1 (en) | 1978-05-05 |
| FR2366843B1 (en) | 1984-09-28 |
| NL7710423A (en) | 1978-04-10 |
| JPS5346192A (en) | 1978-04-25 |
| NL167597B (en) | 1981-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4184489A (en) | Infusion tube access site | |
| EP0250891B1 (en) | Catheter assembly | |
| CA2229370C (en) | Catheter | |
| US4798594A (en) | Medical instrument valve | |
| US5738664A (en) | Self-healing seal for use in medical devices | |
| US3814137A (en) | Injection site for flow conduits containing biological fluids | |
| US4626245A (en) | Hemostatis valve comprising an elastomeric partition having opposed intersecting slits | |
| US4895565A (en) | Medical instrument valve | |
| US7445611B2 (en) | Hemostasis cannula | |
| US20030199850A1 (en) | Orthogonal arterial catheter | |
| WO2006086711A1 (en) | Medical instrument | |
| US3898988A (en) | Extra corporeal blood access site | |
| EP1747755B1 (en) | Backflow preventing structure of blood sampler, lure needle, blood sampling needle and blood sampling holder | |
| CA1081072A (en) | Infusion tube access site | |
| CN211132600U (en) | Peripheral intravenous catheter assembly | |
| AU650357B2 (en) | Hemostasis cannula | |
| US6610045B2 (en) | Orthogonal arterial catheter | |
| EP0868203B1 (en) | Hemostasis cannula | |
| EP0018179B1 (en) | Catheter tip for infusion | |
| JPH025431B2 (en) | ||
| US4785821A (en) | Pressure monitor and regulating device for administration of medicament | |
| WO1995021642A1 (en) | Hemostasis cannula | |
| CN213191779U (en) | Indwelling needle | |
| US20090287115A1 (en) | Butterfly needle assembly and method of use thereof | |
| CA1157719A (en) | Check valve catheter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |