GB2418361A

GB2418361A - Intravenous catheter with flow increase

Info

Publication number: GB2418361A
Application number: GB0418099A
Authority: GB
Inventors: Don Julian De Silva; Akbar De Medici
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-13
Filing date: 2004-08-13
Publication date: 2006-03-29
Also published as: GB0418099D0

Abstract

Apparatus for intravenous catheter insertion comprising a needle 11 and a catheter 20 which are inserted into a blood vessel. Preferably the needle 11 slides within the catheter tube 20. The catheter tip may have a cone shape providing an increase in diameter 22, 23, 24. Further, the cone shaped catheter tip may be strengthened by struts (25, fig 3) with intervening gaps (26, fig 3) along its length. Ridge 21 may prevent the catheter 20 entering the skin too deeply. The varying diameter catheter may enable increased flow rate.

Description

241 8361 To

INTRAVENOUS CATHETER WITH FLOW INCREASE

DESCRIPTION

1] The present invention relates to an apparatus for intravenous catheter insertion that utilizes a cone shaped increase in catheter diameter to result in a proportional increase in cannula flow.

2] Intravenous catheters are used in the practice of medicine for intravenous administration of fluids. Infusion is proportional to catheter diameter, and is frequently a limiting factor in the administration of emergency fluid loss in life threatening trauma, or the administration of a spectrum of urgent intravenous medications. These treatments include hydrating solutions, medications, blood products, and nutrients, to a patient.

3] Intravenous catheters are frequently used in everyday medical practice for the administration of fluids. In such circumstances large diameter catheters are favoured as they may remain for a longer duration of time with a reduced risk of blockage and infection, thrombophlebitis. However large diameter catheters are more difficult to place within a blood vessel and insertion more uncomfortable.

4] This catheter has advantage over current design by utilizing advantages of both small and large catheter diameter designs. The small entry diameter catheter facilitates easy insertion into the patient's blood vessel. The catheter increases in diameter along its length such that on complete insertion into the blood vessel the catheter diameter has substantially increased. The increased diameter facilitates a marked increase in potential infusion rate. The increased diameter of the catheter once fully inserted reduces the risk of blockage or infection.

5] Prior to insertion into a patient, an intravenous catheter includes a trocar. The trocar includes a needle. The needle extends from the forward end of the styles and through the connection hub and catheter cannula. The connection hub may be removed and engages the forward end of the styles. When the needle is positioned with the cannula the tip extends beyond the tip of the cannula.

6] On inserting the catheter the tip of the needle is placed within a blood vessel of the patient, the person inserting the catheter grasps the body of the styles with one hand and pierces the skin of the patient with the needle to locate the tip of the cannula within the blood vessel. The catheter is advanced into the blood vessel and the increased diameter of the catheter which is made possible by the gentle sloping increase in cone diameter. The cone design is constructed of sloped platforms which provide both structural integrity and ease of insertion.

7] Contemporary catheter design consists of a single diameter tube. Flow rate is limited by the internal diameter of this tube. On insertion of our catheter the diameter of the catheter increases along the length of the cone structure. The maximum diameter of the catheter bore is achieved once the cone structure is fully inserted into the blood vessel. This facilitates a marked increase in flow rate.

8] Correct positioning of the tip of the needle within the desired blood vessel is o usually indicated by a flush of blood between the needle and the cannula of the catheter. After a blood return is observed, the styles is withdrawn while the doctor uses the other hand to apply light pressure upon the catheter, so that the needle can be withdrawn.

9] After the styles is withdrawn and disposed of, the catheter is taped in position at the insertion site prior to attaching an infusion line.

0] The present invention utilizes an apparatus for intravenous catheter insertion, described in claim 1.

1] Following insertion ofthe needle into the blood vessel, the catheter is inserted and the needle removed. On withdrawal of the needle a cap, which is encompassed by the catheter, slides along the needle and lock over the needle tip. At the point at which the needle is removed from the cannula the needle has already been sheathed without any further manipulation or manoeuvre.

2] The foregoing detailed description, will be best understood when read in conjunction with the attached drawings in which: FIG.I is a sectional view of a catheter insertion apparatus of the present invention.

FIG. 2 is a sectional view of a catheter insertion apparatus of FIG.I with the catheter partially removed.

FIG.3 is a perspective view of an the catheter insertion apparatus of FIG. 1.

FIG. 4 is an enlarged sectional view of the catheter of FIG.I with the catheter diameter shown in cross section.

3] Referring now to FIG.I the device 10 may be referred to as a trocar. The device includes a hollow housing with a needle 11 extending therefrom. The trocar consists of a needle tip 12 which protrudes beyond the front end of the cannula and a distal end 15 with finder ridges to aid needle withdrawal, and flush chamber 10 which indicates insertion of the catheter within a blood vessel by the pooling of blood.

4] With reference to FIG.I the catheter tip has a sequence of changes in diameter 21 to 24. The front of the catheter tip 22 fits tightly over the needle 10. The catheter diameter increases as a cone shaped structure 23 until reaching maximum diameter 24. The catheter then widens abruptly 21 to prevent further entry to the blood vessel.

5] With reference to FIG. 2 shows partial removal ofthe needle which follows complete insertion of the catheter within the blood vessel. At this point the catheter 20 is within the blood vessel. Complete insertion of the catheter results in the catheter parts 22,23 and 24 being inserted into the blood vessel and 21 stopped flush with the skin. The catheter has external wedges 27 which extend from the cone shaped structure 23. The wedges 27 enable smooth insertion of the catheter into the blood vessel and funnel the catheter edges 28 into the blood vessel. To

6] With reference to FIG. 3 the catheter tip 21 to 24 is shown enlarged with a perspective view. The narrow catheter tip 22 is shown to increase in diameter in a cone shape 23. The cone increase in diameter is supported by cylindrical struts 25.

The struts provide the catheter tip with mechanical strength. In addition gaps 26 exist between the catheter struts which following complete catheter insertion allow fluid movement. The catheter increases to its maximal diameter 24 and further entry of the catheter into the skin is limited by the casing ridge 21.

7] With reference to FIG. 4 the catheter tip is shown in section from parts 21 to 24. Beneath the sectional view is a cross section of the catheter diameter. The catheter tip 21 has the smallest diameter which facilitates entry into the blood vessel. The cone structure 23 consists of a gradual sloping increase in tube diameter. The cone is supported by struts 25 and intervening gaps 26. The widest diameter of the catheter 24 is distal to the cone and further entry into the skin is limited by the casing ridge 21.

8] It should be apparent to those skilled in the art that further additions and modifications may be made to the device as disclosed herein. Furthermore, terms and expressions which have been employed are used as terms of description and not of limitation. There is no intention in the use of such terms and expressions of excluding any equivalents ofthe features shown and described or portions thereof. It is recognized, however, that various modifications are possible within the scope of the invention as claimed.

Claims

1. An apparatus for intravenous catheter insertion, which consists of a needle and catheter that is inserted into a blood vessel.

2. An apparatus as claimed in claim I where the needle slides within the catheter tube and is supported at its front end by the catheter tip and at its distal end by the needle end.

3. An apparatus as claimed in claim I where the catheter tip has a coneshaped (22, 23, 24) increase in diameter.

4. A catheter insertion system as claimed in claim 3 in which the needle is part of a trochar which includes a flush chamber. ]

4. An apparatus as claimed in claim 3 where the catheter cone structure is strengthened by mechanical struts 25 along its length.

5. An apparatus as claimed in claim 3 where the catheter cone structure has intervening gaps 26 along its length.

6 An apparatus as claimed in claim I where the catheter diameter tip 22 increases in diameter, which equates to increased maximum flow velocity.

Amendments to the claims have been filed as follows -.. C LLIMS 1. A catheter for insertion into a blood vessel comprising a tip portion that fits tightly over a needle, a middle cone section and large diameter base section. The middle section consists of a cone-shaped structure that increases in diameter from its tip to its base such that the cross sectional area of the catheter increases along its length. The distal end of the catheter widens abruptly to prevent further entry of the catheter into a blood vessel.

2. A catheter as claimed in claim I in which the cone-shaped portion is provided with struts which extend along the length of the catheter to improve its mechanical strength. Along the cone-shaped structure are vents/ holes which perforate the cone thereby increasing the flow of liquid into the blood vessel. With traditional catheters, flow along a catheter may be limited by the diameter of the catheter tip, in this catheter, as claimed in claim 1, the holes in the cone-shaped structure provide an increase in cross-sectional area and thereby increased flow. Along the outside surface ofthe catheter are ridges, which lift the blood vessel wall offthe catheter cone structure, thus ensuring the vents/ holes remain open.

3. A catheter insertion system comprising a catheter as claimed in claim I or claim 2 and a needle, the needle being slideable/ moveable within the bore of the catheter such that the tip of the needle is capable of extending beyond the tip of the catheter to enable insertion into a blood vessel.