GB2441776A

GB2441776A - Atraumatic tip

Info

Publication number: GB2441776A
Application number: GB0618150A
Authority: GB
Inventors: Mark Jessup
Original assignee: NOVAGEN Ltd
Current assignee: NOVAGEN Ltd
Priority date: 2006-09-15
Filing date: 2006-09-15
Publication date: 2008-03-19
Also published as: GB0618150D0

Abstract

A tube 2 having an atraumatic tip 3, wherein the tip 3 comprises a base layer of thermoplastic 5 fused to the tube 2, and a thermoplastic/elastomer moulding 6 bonded to the base layer 5. The thermoplastic/elastomer moulding 6 preferably has a rounded end 7 and an enlarged diameter intermediate portion 8 near the end 7 to ease insertion of the tube 2 into a patient. The thermoplastic base layer 5 may be applied to the tube 2 by powder coating or electrostatic coating.

Description

2441776

Atraumatic Tip

Field of the Invention

The present invention relates to a tip for a medical device, and in particular to a tip which is atraumatic.

Background of the Invention

Medical devices such as tubes, for example suction tubes, must be inserted into parts of the body for example the larynx, the spinal canal or the brain. One problem with tubes in current use is that their tips are blunt or flat ended. As the tube is inserted into a part of the body the tip of the tube may cause damage.

It would be desirable to provide a tip which reduces the risk of trauma in the body part into which the tube is inserted.

One attempt at providing such an "atrium tip" composes the addition of a rubber tube to the tip of the suction tube. Typically, the suction tubes to which these atraumatic tips are attached are fabncated of stainless steel. Whilst rubbers which are manufactured so as to adhere to stainless steel are known, the small diameter of the suction tubes used in healthcare is such that there is insufficient surface area of tube for the atraumatic tip attached thereto to generate good adhesion. Health professionals are sceptical about using suction tubes with such tips as they fear that the tip may become dislodged from the tube whilst in the body, with potentially severe consequences.

It would be desirable to provide an atraumatic tip which cannot be removed from the suction tube. A problem with manufacturing such a tip is that there is a functional requirement for the external suction tube diameter to be as close as possible to its internal diameter. This means that the coating must be as thin as possible.

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Another problem associated with one known atraumatic tip is that it is relatively hard, having a Shore hardness of 85.

The present invention seeks to provide an atraumatic tip which does not suffer from the drawbacks associated with known atraumatic tips.

Summary of the Invention

According to the invention there is provided a tube having an atraumatic tip as specified in

Claim 1.

The atraumatic tip of the invention provides a smooth surface for engagement with the part of the body into which the tube (for example a suction tube) provided with the tip is to be inserted. The ap is formed of a base layer which is fused to the metal of the tube and provides a surface onto which a relatively soft top layer can itself chemically bond. The atraumatic tip of the invention represents a significant step forward in the treatment of patients requiring the use of a suction tube.

Brief Description of the Drawings

In the drawings, which illustrate preferred embodiments of a suction tube having an atraumatic tip, and are by way of example:

Figure 1 is a schematic representation of a suction tube according to the invention;

Figure 2 is a schematic representation of the atraumatic tip; and

Figure 3 is a cross-sectional representation of the atraumatic tip illustrated in Figure 2.

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Detailed Description of the Preferred Embodiments

Referring now to Figure 1, there is shown a suction tube 1 having a tubular portion 2. A hand grip 4 is provided at one end of the tube, with the other end of the tube being provided with an atraumatic tip 3.

The atraumatic tip 3 comprises a base layer 5 which is formed from a thermoplastic, for example polyethylene, polypropylene or nylon, although nylon is less preferred due to its higher melting point.

Preferably, the thermoplastic is applied to the tube 2 by one of two methods, namely by powder coating either by means of electrostatic spray coating or fluidised bed dipping. I the present example the tube 2 is stainless steel although tube may be formed from and suitable metal or metal alloy.

In the fluidised bed dipping technique the method of application compnses heating the tip of the metal tube to 200 - 300 C. The heated tip is then inserted into a fluidised bed of powdered thermoplastic material. The length of time the heated tip is in the fluidised bed determines the thickness of the coating.

In the electrostatic spray coating method, the powdered thermoplastic material is charged with a positive charge and the tube to be coated with the opposite charge so the powdered thermoplastic is attracted onto the surface of the tube. The tip of the tube is then heated to melt the thermoplastic.

The melted thermoplastic base layer 5 is illustrated by broken lines in Figure 2.

It is desirable that the part of the atraumatic tip which is in contact with the body part has rounded edges and is relatively soft This is achieved by moulding a thermoplastic/elastomer 6

onto the base layer 5. The thermoplastic of the thermoplastic/elastomer moulding is selected to bond with the thermoplastic of the base layer, thereby forming a very secure attachment of the atraumatic tip to the suction tube 2.

The thermoplastic/elastomer moulding 6 is formed into a desired shape by inserting the tube with the base layer 5 applied into a mould, the shape of which corresponds to a desired shape for an atrium tip. Following removal from the mould the thermoplastic is allowed to cool and cure to form an atraumatic tip 3. As can be seen from Figure 2, the atraumatic tip 3 includes a front part 7 which presents a rounded shape to the part of the body into which the tube is to be inserted. Further, by virtue of the shape of the mould the atraumatic tip 3 includes an intermediate part 8 which is of larger diameter than both the front part 7 at its widest, and the section 6' of the tip 3 which extends rearward from the intermediate part 8 to the bare tube 2. By making the intermediate part 8 of the tip 3 wider than the diameter of the tube 3 and the section 6', insertion of the tube into a patient will be made easier.

The thickness of the tip is in the order of 0.1mm or less. The thermoplastics used in the process of the present example provide an atraumatic tip having a Shore hardness of 45 to 50.

Referring now to Figure 3, the broken line 10 indicates the extent of fusion of the thermoplastic material of the base layer 5 into the surface of the metal of the tube 2, the inner surface of which is indicated by reference numeral 9. The thermoplastic/elastomer is moulded onto the surface of the base layer 5.

The thermoplastic/elastomer may be a mixture of polypropylene and rubber.

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Claims

A tube having an atraumatic tip, wherein the tip comprises a base layer of thermoplastic fused to the tube, and a thermoplastic/elastomer moulding bonded to the base layer. A tube according to Claim 1, wherein the atraumatic tip has a hardness of forty five to fifty Shore.

A tube according to Claim 1 or 2, wherein the thickness of the coating is less than or equal to 0.1mm

A tube according to any preceding claim, wherein the thermoplastic is applied to the tube by powder coating, wherein the thermoplastic is in powder form in a fluidized bed, and an end of the tube is inserted into the fluidised bed for a period of time in the range of 0.1 to 1 second.

A tube according to any of Claims 1 to 3, wherein the thermoplastic is applied to the tube by electrostatic coating and wherein the tip region of the so coated tube is heated to a temperature of 200 to 300 C post application of the coating.

A tube according to any preceding claim, wherein the edges of the atraumatic ap are rounded.

A tube according to any preceding claim, wherein the rip includes a front portion, an intermediate portion and a rear portion, and wherein the diameter of the intermediate portion is greater than the diameter of the rear portion, and wherein the front portion has a rounded edge.

A tube according to any preceding claim, wherein the shape of the tip is formed by moulding the thermoplastic/elastomer.

A tube having an atraumatic tip substantially as shown in, and as described with reference to, the drawings.