Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3598126 A
Publication typeGrant
Publication dateAug 10, 1971
Filing dateJul 25, 1968
Priority dateApr 30, 1968
Publication numberUS 3598126 A, US 3598126A, US-A-3598126, US3598126 A, US3598126A
InventorsJosef Hoeltzenbein
Original AssigneeBaxter Laboratories Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Vascular canula for medical applications
US 3598126 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Inventor Jose! Hoeltadiein Munster, Westphalia, Germany Appl. No. 747,712 Filed July 25, 1968 Patented Aug. 10, U7] Assignee Baxter Laboratories, Inc.

Morton Grove, ll. Priority Apr. 30, 1968 Y H 62 605/30k Gh- VASCULAR CANULA FOR MEDICAL OTHER REFERENCES Dow Corning Bulletin, Vol. 8, No. 1, Jan. 1966 page 2 re lied on 128/Si1icone DIG.

Reynolds et a1. Surgery, Vol. 58, No. 6 Dec. 1965 pp. 938- 940 128-348 Primary Examiner-Dalton L. Truluck Attorneyswalter C. Kehm and Robert G. Pollock ABSTRACT: A vascular canula which is intended for insertion into a blood vessel. The canula includes a thin-walled tube made of silicone rubber. The tubing wall is reinforced with thin fibers to provide a canula which combines softness and flexibility with stability of shape.

This invention relates to a vascular canula for medical applications. In particular the invention relates to a canula for insertion into a blood vessel wherein the canula is of the silicone rubber type.

In medical technique it is often necessary to insert a thin canula or tube into a vessel such as an artery. In doing so it is customary to place a ligature around the blood vessel so that blood cannot escape along the outside of the canula. In order to prevent bulging from developing between the exterior of the canula and the interior of the blood vessel, the ligature is usually placed as close as possible to the end of the canula. The remote end of the canula may be placed connected with a suitable tube to guide the blood externally of the patient for appropriate treatment. A similar arrangement may be made for returning blood to the body.

Canulae for this purpose are now often manufactured from silicone rubber as this material is tolerated particularly well by the human body. Moreover, canulae made of silicone rubber can be made with very thin walls relative to the diameter of the tubing.

However, certain considerations should be borne in mind in the use of silicone rubber canulae. For example, thin-walled canulae of this type are often so soft that they collapse easily, that is to say they lose their inside round cross section and it may therefore not be advisable to use these thin-walled canulae directly for introduction into the blood vessel.

Another consideration in the use of a vascular canula is that the transition from the inside wall of the blood vessel into the canula should be a continuous as possible in order to avoid the development of vortices in the blood flow which could lead to fibrinous deposits and finally to thrombosis.

Additionally, it is important that the inside skin of blood vessel should not be mechanically irritated.

Summarizing, certain forms of silicone rubber canula in present use may sometimes have certain disadvantages by being either too rigid or too soft, or by creating an undesirably abrupt transition between the blood vessel and the interior of the canula. Similar disadvantages may of course also occur in the transition from the canula to the connecting tube to the exterior.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore a general object of the invention to provide a canula which obviates or minimizes problems of the type generally noted above.

It is a particular object of the invention to provide a thin walled canula formed of silicone rubber which combines very great mechanical strength and stability of shape with the customary surface smoothness of silicone rubber.

A canula constructed in accordance with a preferred embodiment of the invention, intended to accomplish at least some of the foregoing objects comprises a thin-walled silicone rubber tube reinforced by fibers extending along the tube.

In the preferred embodiment the fibers comprise glass fibers embedded into the wall of the silicone rubber canula. The fibers are statistically evenly embedded.

In further refinements of the invention, the fibers are embedded into the wall along the main axis and disposed helically therealong. In addition, the vascular canula may be axially tapered to provide a generally frustoconical leading end of the canula.

THE DRAWINGS A canula according to certain preferred embodiments of the invention is illustrated in the accompanying drawings in which;

FIG. I is a side view of a canula according to one preferred embodiment of the invention;

FIG. 2 is a cross-sectional end view of the canula shown in FIG. 1 taken along lines II-II therein;

FIG. 3 is a side view ofa second embodiment ofa canula according to the present invention;

FIG. 4 is a cross-sectional end view of the canula shown in FIG. 3 taken along lines IVIV therein; and

FIG. 5 is a side view of a third embodiment of a canula according to the present invention.

DETAILED DESCRIPTION Referring to FIG. 1 of the drawings, a canula constructed in accordance with a preferred embodiment of the invention is there shown. The canula extends along a longitudinal axis 1 and comprises an axially extending tube 2 defined by a thin wall 3 which is of very much less thickness than the extent of the tube diameter. For example, the thickness of the wall 3 may be of the order of 0.2 mm. while the diameter of the tube is of the order of 6- l 0 mm.

Embedded in the wall 3 are a plurality of glass fibers 4. The fibers extend along the tube in a generally uniform helical configuration about the tube. Distribution if the fibers along the tube is made on a statistically even basis to maintain the strength and flexibility characteristics of the canula on an axially uniform basis. In the preferred embodiment the fibers 4 are embedded along the main axis in relatively steep helical pitch 7.

However, in the second alternative embodiment shown in FIG. 3, fibers 6 disposed in a less steep helical pitch are provided.

As disclosed in FIG. 1 the canula is provided with a tapering end portion 8 of generally frustoconical form.

Additionally, the fibers may be disposed in axially extending relation (FIG. 5) in the third alternative embodiment of the invention to provide an exceptionally elongated tapering point which nevertheless retains its stability of shape to the very tip.

Although glass fibers have thus far been disclosed, other types of fiber may be utilized under certain circumstances. In particular, embedded fibers formed of extremely fine quartz filaments of a few microns of thickness may be utilized, particularly as quartz fibers gain mechanical strength in an inverse ratio in their thickness so that they are very flexible. Quartz fibers of this type can therefore be bent without tension in exceedingly small radii especially in view of the support afforded by the surrounding silicone rubber. Other fibers include metal fibers formed of capillary sliver. If it is desired to provide magnetic or electric current conductivity properties steel or iron fibers may be used. In addition, mixtures of different fiber materials may be employed.

The embedded fibers provide the canula with a combination of high bending in elasticity and high mechanical strength. If extremely high elasticity of extension is required however, then the fibers are embedded in the tube wall at an increased pitch along the tube (as disclosed in the embodiment of FIG. 3) or else extending axially along the canula (as disclosed in the embodiment of FIG. 5).

Thus, one can produce canulae depending on the characteristics desired in the individual case, which canulae are very flexible or else which have great tensile strength. Also, the longitudinal elasticity of the canulae can be influenced through the type of development of fibers.

In cross section (FIG. 2) it will be seen that the fibers do not extend into the interior of the tube which thus retains its smooth interior wall characteristics. However, under certain circumstances, it is desirable to cause the embedded fibers to project with a noticeable roughness from the inside surface of the tube. This has the advantage that during use the fibrogerminal cells of the blood settle in the rough spots of the wall surfaces to create a vascular wall within the canula which corresponds to artificial live tissue.

SUMMARY or ADVANTAGES The fibers invention provides a canula having significant advantages. Even in the case of wall thickness of 0.2 mm. and less and with correspondingly very small diameters, silicone rubber canulae provided with embedded fibers as described, combine the advantage of optimum softness with pronounced stability of shape. The tubes and canulae furthermore have the desired smooth surfaces which are peculiar to silicone rubber. Furthermore, these canulae are of wide application because of their high elasticity.

A particular advantage is afforded by the ease with which the mechanical strength as well as the degree of elasticity may be regulated within wide limits. In some cases where a high bending elasticity and where a high mechanical strength are important, the canula contains the embedded fibers in a relatively close helical pitch. If, however, increased elasticity of extension is required, then the fibers are embedded in a helical disposition of considerably increased pitch, or extending axially along the canula.

it is furthermore an advantage that one can also produce canulae having elongated tapered extreme portions which are pliable to their extremities and yet which retain their rigidity.

Although certain embodiments have been described it will be appreciated by those skilled in the art that numerous additions, deletions, substitutions, modifications, and other changes not specifically disclosed or described may be made which will fall within the purview of the appended claims.


l. A vascular canula comprising a silicone rubber tube having a wall thickness of no more than about 0.2 mm., having a nonwoven, helical fiber disposition running in a single axial helical direction, embedded in said tube wall, and running substantially the length of the tube, the fiber material being selected from the group consisting of glass, quartz, silver, steel, and iron, whereby radial expansion of said tube under internal pressure is restricted without severe reduction of the axial extensibility of said tube.

2. A vascular canula as defined in claim I wherein, the fiber material is gloss.

3. A- vascular canula as defined in claim 1 wherein, said fibers extend at least partially from said wall into the interior of said tube to make the interior of said tube noticeably rough.

4. A vascular canula as defined in claim 1 further including,

a generally frustoconical, tapered portion of relatively reduced diameter positioned at one extremity of said tube.

5. The canula of claim I in which said fiber material is steel.

6. The canula of claim 1 in which said fiber material is quartz.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2458305 *Apr 26, 1947Jan 4, 1949Sanders Richard DTubular article comprising rubberlike material
US3016748 *Jul 25, 1957Jan 16, 1962Vernet SergiusSqueeze-push power element
US3094124 *Jun 30, 1960Jun 18, 1963Davol Rubber CoArterial catheter
US3303251 *May 13, 1966Feb 7, 1967Owens Illinois IncMethod and apparatus for extruding tubing with continuous internal reenforcement members
US3416531 *Jan 2, 1964Dec 17, 1968Edwards Miles LowellCatheter
Non-Patent Citations
1 *Dow Corning Bulletin, Vol. 8, No. 1, Jan. 1966 page 2 relied on 128/Silicone DIG.
2 *Reynolds et al. - Surgery, Vol. 58, No. 6 Dec. 1965 pp. 938 940 128-348
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3687129 *Oct 2, 1970Aug 29, 1972Abcor IncContraceptive device and method of employing same
US3757768 *Apr 7, 1972Sep 11, 1973Medical Evaluation Devices AndManipulable spring guide-catheter and tube for intravenous feeding
US3905399 *Dec 21, 1973Sep 16, 1975Uniroyal LtdLiquid-conveying hose
US3921674 *Mar 18, 1974Nov 25, 1975Dayco CorpHose construction and method of making same
US3924632 *Jun 17, 1974Dec 9, 1975William A CookFiber glass reinforced catheter
US4003581 *Jan 2, 1974Jan 18, 1977Chevron Research CompanyField dressable inflatable packer
US4106967 *Dec 3, 1976Aug 15, 1978Dayco CorporationHose construction and method of making same
US4173981 *May 23, 1977Nov 13, 1979University Of UtahCannula for arterial and venous bypass cannulation
US4343788 *Jun 29, 1979Aug 10, 1982The Procter & Gamble CompanyAntimicrobial polymer compositions
US4354491 *Dec 26, 1979Oct 19, 1982Marbry Steven LFluid transfer device
US4392848 *Jun 25, 1979Jul 12, 1983The Procter & Gamble CompanyCatheterization
US4448195 *May 8, 1981May 15, 1984Leveen Harry HReinforced balloon catheter
US4479795 *Jul 27, 1982Oct 30, 1984The Procter & Gamble CompanyAntimicrobial polymer compositions
US4553959 *Jan 21, 1983Nov 19, 1985The Victoria University Of ManchesterUrethral catheter
US4571241 *Dec 16, 1983Feb 18, 1986Christopher T GrahamUrinary catheter with collapsible urethral tube
US4638803 *Nov 30, 1984Jan 27, 1987Rand Robert WMedical apparatus for inducing scar tissue formation in a body
US4886506 *Nov 10, 1988Dec 12, 1989Baxter Travenol Laboratories, Inc.Soft tip catheter
US4981478 *Sep 6, 1988Jan 1, 1991Advanced Cardiovascular SystemsComposite vascular catheter
US4990138 *Jul 18, 1989Feb 5, 1991Baxter International Inc.Catheter apparatus, and compositions useful for producing same
US4994047 *May 6, 1988Feb 19, 1991Menlo Care, Inc.Multi-layer cannula structure
US5190520 *Oct 10, 1990Mar 2, 1993Strato Medical CorporationReinforced multiple lumen catheter
US5217440 *Oct 8, 1992Jun 8, 1993C. R. Bard, Inc.Multilaminate coiled film catheter construction
US5222949 *Jul 23, 1991Jun 29, 1993Intermed, Inc.Flexible, noncollapsible catheter tube with hard and soft regions
US5364357 *Feb 7, 1994Nov 15, 1994Schneider (Usa) Inc.Small diameter dilatation catheter having wire reinforced coaxial tubular body
US5573520 *Oct 26, 1994Nov 12, 1996Mayo Foundation For Medical Education And ResearchFlexible tubular device for use in medical applications
US5695482 *Jun 15, 1994Dec 9, 1997Intermed, Inc.UV treated catheter
US5965204 *May 4, 1998Oct 12, 1999Ad Tech Holdings LimitedDeposition of silver layer on nonconducting substrate
US6053901 *Oct 2, 1996Apr 25, 2000Vasca, Inc.Subcutaneously implanted cannula and method for arterial access
US6398764Dec 27, 1999Jun 4, 2002Vasca. Inc.Subcutaneously implanted cannula and method for arterial access
US6685680 *Jul 16, 2001Feb 3, 2004Dsu Medical CorporationTapered intravenous cannula
US7276055 *Apr 3, 2003Oct 2, 2007Medtronic, Inc.Oval-shaped cardiac cannula
US7722578 *Sep 8, 2004May 25, 2010Boston Scientific Scimed, Inc.Medical devices
US7972465Feb 2, 2010Jul 5, 2011C. R. Bard, Inc.Reinforced multi-lumen catheter
US8167867Aug 16, 2007May 1, 2012Medtronic, Inc.Oval-shaped cardiac cannula
US8430988Apr 15, 2011Apr 30, 2013C. R. Bard, Inc.Reinforced multi-lumen catheter
US8894906May 25, 2010Nov 25, 2014Boston Scientific Scimed, Inc.Medical devices
US20030191447 *Apr 3, 2003Oct 9, 2003Medtronic, Inc.Oval-shaped cardiac cannula
US20060051535 *Sep 8, 2004Mar 9, 2006Arney Michael SMedical devices
US20070005003 *Dec 29, 2004Jan 4, 2007Patterson Ryan CReinforced multi-lumen catheter
US20070083161 *Sep 1, 2006Apr 12, 2007Medtronic, Inc.Oval-Shaped Cardiac Cannula
US20070208300 *Mar 1, 2007Sep 6, 2007Applied Medical Resources CorporationGas insufflation and suction/irrigation tubing
US20080033372 *Aug 16, 2007Feb 7, 2008Briscoe Roderick EOval-shaped cardiac cannula
US20100132879 *Feb 2, 2010Jun 3, 2010C.R. Bard, Inc.Reinforced multi-lumen catheter
US20100230862 *May 25, 2010Sep 16, 2010Boston Scientific Scimed, Inc.Medical devices
US20110192008 *Apr 15, 2011Aug 11, 2011C. R. Bard, Inc.Reinforced multi-lumen catheter
EP0341049A2 *May 4, 1989Nov 8, 1989Menlo Care Inc.Multi-layer cannula structure
EP0341049A3 *May 4, 1989Sep 18, 1991Menlo Care Inc.Multi-layer cannula structure
WO1998050098A1 *May 8, 1998Nov 12, 1998Microvena CorporationImproved multi-durometer catheter
U.S. Classification604/526, 138/177, 138/118
International ClassificationA61M23/00, A61M25/00
Cooperative ClassificationA61M25/005, A61M25/0012
European ClassificationA61M25/00G3, A61M25/00S2