WO2004097994A1

WO2004097994A1 - Identification systems for compatible components and apparatus for use with such systems

Info

Publication number: WO2004097994A1
Application number: PCT/GB2004/001745
Authority: WO
Inventors: Paul Chamberlain; Peter Walters
Original assignee: Sheffield Hallam University
Priority date: 2003-04-25
Filing date: 2004-04-23
Publication date: 2004-11-11
Also published as: GB0523146D0; GB2420918A

Abstract

A set of identifier members in which at least two of said identifier members s are configured such that they can be unambiguously matched together by at least one common tactile feature.

Description

IDENTIFICATΪON SYSTEMS FOR COMPATIBLE COMPONENTS AND APPARATUS FOR USE WITH SUCH SYSTEMS

Field Of the invention

This invention relates to an identification system for compatible components, and particularly although not exclusively to an identification system for connectable components such as connectors for supply lines, in particular for connectors used for joining together tubes, pipes, cables, wires and the like. Background to the Invention

In many fields it is necessary to be able to readily connect and disconnect components and apparatus to ensure a conductive connection, such as in an electric circuit. Other connections may be required to conduct fluids through tubes, such as in the administration of drugs to patients in hospital. In the latter case this is usually facilitated using the Luer connectors, an internationally established and universal system. Figure 1 shows an example of one such system. In this particular example, specifically in the matter of the care of and treatment of patients, such connectors are used to administer a supply of anaesthetic and other drugs intravenously, intrathecally or otherwise. In certain situations, such as intensive care, for example, a plurality of drugs may be administered simultaneously or successively to a patient resulting in a plurality of connections to [luer valves] on the patient's body. It has been known for a drug to be attached to or introduced into the patient through the wrong connector which in some cases can be fatal. For example, there are some drugs which if administered intrathecally, i.e. by the spinal route, rather than intravenously invariably will cause death or severe neurological damage. The five most common drug delivery routes are intravenous, intrathecal, respiratory, cardiovascular and enteral, so it will be seen that the opportunities for misadministration are many. It is a disadvantage of universal systems of connectors that the elements of the connectors are so alike and quite easily mixed up. Various methods are currently used to avoid this, including the use of labels and or applying a colour coding to the individual lines and connectors. Where labels are employed these are normally handwritten and there is still room for error, particularly in a stressed environment. Colour is widely used as an identifier in Hospitals as well as in

Industry generally. This can lead to a conflict with existing identification schemes using colour making such a system difficult to memorise. Also, given that many people, whilst not necessarily colour blind, see and identify many colours differently, the use of colours is not necessarily foolproof. Furthermore any purely visual identifier is dependant upon there being sufficient light available to readily recognise its significance. In many cases excess light is not desirable and it may cause unnecessary discomfort to the patient.

It should be noted that the problem of misconnection is not limited to medical applications alone but may occur wherever a plurality of cables wires tubes or other conductive material is required to be connected to various appliances, power sources and the like.

One such alternative case is where there is provided a plurality of supply lines, such as cables attaching various devices to a computer, for example. Often it is necessary to identify specific cables or connectors when the connecting ends are out of sight. It can be difficult to identify the cables and connectors by touch alone, particularly where interchangeable or universal connectors are used such as those known as USB (Universal Serial Bus) connectors.

Summary of the Invention

It is an object of the present invention to provide an identification system for compatible components, which addresses various ones of the above disadvantages. Specific embodiments according to the present invention provide a new identification system which uses tactile cues, for example contrasting shapes and/ or surface textures and/or material resilience or other like material properties to match individual articles with their correct partner articles unambiguously. The identification system may combine the use of tactile and visual clues which are experienced by a user of the system to enable the user to unambiguously identify correctly matching pairs of articles. Human users of articles to which the identification system has been applied may be able to immediately and clearly identify matching sets of articles through visual or tactile senses, or by a combination of visual and tactile senses.

Examples of articles to which the identification system may be applied include but are not limited to: connectors for medical applications, for example "Luer" connectors for drug delivery to patients, electrical connectors, or optical connectors, fluid carrying pipes, and like articles.

According to a first aspect of the present invention an identification system for compatible components comprises at least two corresponding pairs of identifiers each pair having a combination of individual characteristics governing at least two of the following:

(A) shape of cross-section;

(B) at least one surface feature; (C) the material properties; and

(D) comparative size;

and wherein no two pairs in any system has the same combination of characteristics.

It is envisaged that such a system can be utilised wherever there is a need to match a pair of compatible components. Said components may be a pair of connectors, such as those used in medical applications or for any fluid supply, as described above or may be used for connecting other fluid supplies. Alternatively such connectors may be electrical connectors.

Each identifier may be formed integrally with its respective component or may be permanently or removeably attached thereto or alternatively adjacent said component.

In an alternative embodiment at least one of the characteristics of one of each pair of identifiers is represented in substantially two-dimensional form. Preferably in such an embodiment there is provided a substantially three- dimensional identifier to be used with an identifier carrying the substantially two- dimensional representation of the characteristics of said three-dimensional identifier. In such a case the system may be used to identify the cable for a device connected to the processor of a computer system. The three-dimensional identifier of a pair is attached to a cable at or adjacent its universal, e.g. USB connector and the other identifier is attached to the cable at or adjacent its associated device, or alternatively to the device itself. With such an identification system it is a reasonably simple task to match the visual representation with its corresponding "hidden" three-dimensional identifier.

Where the individual characteristics govern the shape of cross-section of corresponding identifiers said characteristics may be provided by any suitably recognisable shape such as any one of the following:

a) circular; b) semi-circular; c) square; d) triangular; e) oval; for example Likewise where the individual characteristics govern an at least one surface feature of corresponding identifiers said surface characteristic may incorporate any one taken from the following set:

5 a) at least one longitudinal rib; b) at least one transverse rib; c) at least one diagonal rib; d) at least partial knurling; e) at least one hemispherical node; 0 f) at least one elongate spine; g) substantially smooth; h) at least two transverse body segments; for example.

It will be appreciated that whilst in some applications the deployment of a 5 single longitudinal, transverse, or diagonal rib or node or spine may suffice the use of a plurality of ribs, spines or nodes in each case will improve the tactile qualities of the individual characteristic and thereby assist in identification and differentiation.

o Additionally or in the alternative said surface characteristic may incorporate any one taken from the following set:

a) substantially straight side(s); b) tapered side(s); 5 c) convex side(s); d) concave side(s); for example.

Where the individual characteristics govern the material properties of corresponding identifiers said material may have one characteristic taken from o the following set:

a) substantially resistant to external pressure; b) partially resistant to external pressure; for example.

Where the individual characteristics govern the comparative size of respective pairs of identifiers in the system any size difference shall be preferably sufficient to permit recognition thereof by sight and or by touch.

As will be further seen, the use of a combination of visual and tactile characteristics on corresponding pairs of identifiers provides an improved identification system which may be adapted to suit any number of situations either medical or non-medical. By careful selection the likelihood of confusing one combination of characteristics with another can be greatly reduced and in most cases totally eliminated.

The connectors may be made of any suitable material to give the desired degree of resilience to external pressure. Such materials may be comparatively hard, such as rigid plastics or metal, or may be comparatively soft, ductile, elastic, compliant or malleable, such as a soft plastics, rubber, or expanded/foamed elastomeric material.

In one preferred embodiment of the first aspect of the invention a set of corresponding connectors is provided wherein each pair of connectors is provided with a pair of corresponding identifiers each pair having a different combination of characteristics selected from the following:-

I. a circular cross section having longitudinal ribs, straight sides and partially resistant to external pressure;

II. a circular cross-section having transverse ribs, straight sides and substantially resistant to external pressure;

III. a circular cross-section having no ribs, concave sides and substantially resistant to external pressure;

IV. a circular cross-section having three transverse body segments and substantially resistant to external pressure; V. a triangular cross-section having no ribs, straight sides and substantially resistant to external pressure; and

VI. a square cross-section having transverse ribs, straight sides and substantially resistant to external pressure.

5

The identifiers are preferably of a shape and dimension to readily carry the variety of individual characteristics required to carry out the invention. In one embodiment each identifier has a substantially elongate body portion which carries all the required characteristics. As will be seen this arrangement allows o for the full range of individual characteristics to be deployed giving an extensive selection so as to provide an identification system capable of use with a large number of individual components at the same time.

In another embodiment each identifier is provided by a substantially flat 5 body to be readily attached to or adjacent its respective component by any suitable means, the substantially flat body being adapted to carry any combination of individual features.

According to a further aspect, there is provided an identification system for 0 identifying a plurality of first connector portions and a plurality of second connector portions, wherein each said first connector portion is paired with a corresponding respective second said connector portion, said identification system comprising:

5 a first set of identifier members, wherein each said identifier member of said first set is physically distinguishable from each other said member of said first set;

a second set of identifier members, wherein each said identifier member of said second set is physically distinguishable from each other said identifier o member of said second set; and each identifier member in said first set has a corresponding respective partner in said second set, with which said first identifier member shares common physical features which unambiguously identifies said identifier member of said first set with its corresponding respective said partner in said second set.

Preferably, the common physical features comprise features that are discernable to a human user by a sense of touch.

Preferably, the common physical features comprise features which are discernable to a human user by a sense of touch and vision.

According to a further aspect, there is provided a set of identifier members in which at least two of said identifier members are configured such that they can be unambiguously matched together by at least one common tactile feature.

According to a further aspect there is provided a pair of components configured to be connected together, each component of said pair of components comprising a first end, a second end, a length extending between said first end and said second end, an outer surface extending along a longitudinal axis of each said component, wherein said outer surface defines a longitudinal cross section;

wherein each component of said pair of components comprises:

a first set of identifier members, wherein each said identifier member of said first set is physically distinguishable from each other said member of said first set;

a second set of identifier members, wherein each said identifier member of said second set is physically distinguishable from each other said identifier member of said second set; and each identifier member in said first set has a corresponding respective partner in said second set, with which said first identifier member shares common physical features which unambiguously identifies said identifier member of said first set with its corresponding respective said partner in said second set; and

said common physical features are selected from at least two of the following:

• a shape of said cross section;

• at least one surface profiling;

• at least one material property;

• comparative size

wherein said surface profiling comprises any one of the following:

• at least one raised portion extending substantially parallel to said longitudinal axis of said component over at least a portion of said outer surface;

• at least one raised portion extending over at least a portion of said outer surface in a line substantially perpendicular to said longitudinal axis of said component;

• at least one raised portion extending in a line substantially transverse to said longitudinal axis of said component over at least a portion of said outer surface;

^β knurling extending over at least a portion of said outer surface; • at least one substantially hemispherical raised portion disposed on at least a portion of said outer surface of said component;

• a substantially smooth surface of said outer surface of said component;

• at least two body segments, each body segment being capable of being distinguished by a user's sense of touch over at least one other body segment on said component; and

wherein said material property comprises any one of the following:

• resilience;

• co-efficient of friction;

• density;

• thermal conductivity.

Specific embodiments according to the invention are not limited to connectors per se and may be used to identify particular supply lines or distinguish specific supply lines from others.

Other aspects of the invention are as recited in the claims herein.

Brief Description of the Drawings

For a better understanding of the invention and to show how the same may be carried into effect, there will be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings, in which:

Figure 1 shows one example of a known connector system;

Figure 2 shows a set of different cross-sections from which one individual characteristic may be selected;

Figure 3 shows a set of different surface characteristics from which another individual characteristic may be selected;

Figure 4 shows a set of different external characteristics from which another individual characteristic may be selected;

Figure 5 shows a pair of male/female connectors having a selection of characteristics one from each set of Figures 2 to 4;

Figure 6 shows a selection of inter-distinguishable connectors each having a different combination of characteristics one from each set of Figures 2 to 4; and

Figure 7 shows a multi layered feature model of visual and tactile cues which may be incorporated into an identifier member.

Detailed Description

Figures 2 to 4 show three sets of characteristics from which sets (including the characteristics of resilience of the material) individual characteristics may be selected to create distinctive pairs of identifiers. In these examples, the identifiers are associated with a pair of items to be connected. Each item in this example comprises an elongate body having a length, a cross-section and an outer surface. The item may be connected to further features, for example tubing or a connector for mating with the other item in the pair. Referring specifically to Figure 2 the following cross-sections are represented: - circle 10, square 12, triangle 14, and oval 16.

Where the cross-section is a circle 10, the cross-section of one item is substantially circular along at least a portion of the length of the item.

Where the cross-section is a square 12, the cross-section of one item is substantially square along at least a portion of the length of the item. The cross 0 section comprises four corners that may be partially rounded to provide a more comfortable grip for a user. The sides need not be of equal length; rectangular cross-sections can also be used.

Where the cross-section is a triangle 14, the cross-section is substantially 5 triangular along at least a portion of the length of the item. The cross-section illustrated in Figure 3 shows a substantially equilateral triangle having rounded corners, although any type of triangle may be used.

Where the cross-section is oval 16, the cross-section is substantially oval o along at least a portion of the length of the item.

Any cross-sectional shape may be used for the cross-section of the item, provided that the cross-section can be identified and differentiated from other cross-section shapes in a series by the user. 5

Figure 3 shows the various surface characteristics in the second set illustrated by way of example only on plain circular cross-sectional bodies, as follows: longitudinal ribs 18, transverse ribs 20, diagonal ribs 22, knurling 24, hemispherical nodes 26, substantially smooth surface 28, and transverse body o segments 30. The longitudinal ribs 18 illustrated in Fig. 3 comprise at least one raised portion extending in a line substantially parallel with the length of the item, substantially along the full length of the item and substantially over the surface of the item. However, the longitudinal ribs may extend only along a portion of the length of the item and/or only over a portion of the outer surface. The raised portions are ideally sufficiently spaced apart and of a suitable height over the surface of the body to be sensed by a user's sense of touch.

The transverse ribs 20 illustrated in Fig. 3 comprise at least one raised portion extending in a line substantially perpendicular to the length of the item, substantially along the full length of the item and substantially over the surface of the item. The transverse ribs 20 may extend only along a portion of the length of the item and/or only over a portion of the outer surface. The raised portions are ideally sufficiently spaced apart and of a suitable height over the surface of the body to be sensed by a user's sense of touch.

The diagonal ribs 22 comprise at least one raised portion extending in a line substantially diagonal to the length of the item. The diagonal ribs 22 may extend over a portion of the outer surface of the item, and are of a spacing and height configured to be sensed by a user's sense of touch.

The knurling 24 comprises a series of raised and depressed portions. The knurling need only be over a portion of the outer surface of the item, although it is illustrated in Fig. 3 as covering substantially the entire outer surface of the item.

The hemispherical nodes 26 comprise substantially hemispherical raised portions disposed on at least a portion of the outer surface of the item. They are illustrated in Fig. 3 as being disposed in a regular geometric pattern, although other patterns or a random disposition may also be used.

The item can have a substantially smooth surface 28, in which case no significant surface profiling is used. The body segments 30 illustrated in Fig. 3 comprise three convex bulges along the length of the item. Any number of body segments can be used, and the body segments need not all comprise the same features. For example, an item may comprise a first convex bulge, a broad ridge extending laterally around the item, and a second convex bulge. Each segment must be capable of being differentiated from an adjacent segment such that a user can identify that separate segments are present.

The surface characteristics illustrated in Fig. 3 are by way of example only.

Other surface characteristics may be used provided that they can be used to assist in identifying the item. Furthermore, whilst the above surface characteristics have been described with reference to an item having a plain circular cross-section, surface characteristics can be applied to an item having any shape of cross-section.

Figure 4 shows variations in outer wall characteristics in the third set illustrated by way of example only on plain circular cross-sectional bodies, as follows: straight sided 32, tapered 34, convex 36, and concave 38.

An item having a straight sided 32 outer wall characteristic has a uniform cross-section along the length of the item.

An item having a tapered 34 outer wall has a cross-section that has a uniform shape but at least one dimension that decreases along the length of the item.

An item having a convex 36 outer wall has a cross-section with at least one dimension that increases from a first end of the item towards the middle of the item along its length, and decreases from the middle of the item towards a second end of the item. An item having a concave 38 outer wall has a cross-section with at least one dimension that decreases from a first end of the item towards the middle of the item along its length, and increases from the middle of the item towards a second end of the item.

The outer wall characteristics illustrated in Fig. 4 are by way of example only. Other outer wall characteristics may be used provided that they can be used to assist in identifying the item. Furthermore, whilst the above outer wall characteristics have been described with reference to an item having a plain circular cross-section, outer wall characteristics can be applied to an item having any shape of cross-section.

Referring to Figure 5 there is illustrated a pair of mating connectors 40 and 42 for connecting supply lines 44 and 46, each connector 40, 42 having a body 48 with the following characteristics: a circular cross section 50, a plurality of longitudinal ribs 52 and straight sides 54. In this way, three different characteristics are combined to identify a mating connector; a cross-section characteristic comprising a plain circular cross-section 50, a surface characteristic comprising a plurality of longitudinal ribs 52 and an outer wall characteristic comprising straight sides 54.

Material properties can also be used as identifying characteristics. Material properties that may be used include resilience, co-efficient of friction, density and thermal conductivity.

A material that is resilient, or hard, does not substantially deform when pressure is applied to it. This can be an important tactile identifier. For example, an identifier comprising hemispherical nodes that are substantially resistant to compression will feel significantly different to a user compared to an identifier comprising hemispherical nodes that are partially resistant to compression.

Examples of materials that are substantially resistant to external pressure include metals, glass, hard plastics, and ceramics. Examples of materials that are partially resistant to external pressure include rubbers, silicone rubbers and some soft plastics.

A material having a high co-efficient of friction when rubbed against the skin of a user's fingers will feel substantially different to a material having a low coefficient of friction. An example of a material that has a high co-efficient of friction is rubber, and an example of a material that has a low co-efficient of friction is polytetraflouroethylene (PTFE). Materials can be selected for their co-efficient of friction to provide identifying characteristics. 0

A material can be selected for its density to provide an identifying characteristic. An item made from a material having a high density will feel heavier than an item made from a material having a low density, where the two items have the same volume. For small items, the difference in density must be 5 selected such that it is apparent to the user that one item is heavier than the other.

A material can be selected for its thermal conductivity to provide an identifying characteristic. A material with a high thermal conductivity such as a 0 metal will feel cold to the touch when it is first handled by a user, whereas a material with a low thermal conductivity such as wood will feel warm to the touch when first handled by the user.

Figure 6 shows a selection of inter-distinguishable connectors each having 5 a different combination of three characteristics one from each set of Figures 2 to 4.

Connector 56 corresponds to the connector shown in Figure 5 and has a circular cross section having a plurality of longitudinal ribs, straight sides and is o partially resistant to external pressure. Connector 58 has a circular cross-section with a plurality of transverse ribs, straight sides and is substantially resistant to external pressure.

Connector 60 has a circular cross-section, no ribs, concave sides and is substantially resistant to external pressure.

Connector 62 has a circular cross-section with three transverse body segments and is substantially resistant to external pressure;

Connector 64 has a triangular cross-section with no ribs, straight sides and is substantially resistant to external pressure.

Connector 66 has a circular cross-section with transverse ribs, straight sides and is substantially resistant to external pressure.

It will be seen that in this combination there are sufficient differences between each connector and any other connector in the selection to allow them to be readily distinguished one from another by touch as well as by sight.

In various implementations of an identification system, one connector having a specific external shape is recognisable using the sense of touch, and can be matched with another connector of a same or recognisably similar external shape. In one embodiment, a first identifier member is applied to a first connector portion, and a second identifier member is connected to a second connector portion, where the two connector portions are intended and adapted for connecting with each other. In other words, the identifier members should be matched like to like on connector portions that are to be connected together.

Some features of first and second identifier members may be interpreted as 'opposites'. For example, an identifier member with a concave surface may be interpreted as opposite to an identifier member with a convex surface. Similarly, an identifier member having iongitudinal ribs may be interpreted as being opposite to an identifier member having transverse ribs. External shapes of identifier members may be based upon geometric primitives such as a square, a circle or a triangle. Other distinguishing features of shape may include the presence or absence of small surface details such as bumps or dimples.

A further identifying characteristic that may be used for an item is the size of the item. By having pairs of items of a predetermined size, any difference in size shall be sufficient to permit recognition thereof by sight and or by touch, thereby allowing a user to discriminate between pairs of identifiers.

A further identifying characteristic that may be used for an item is the colour of the item. By having pairs of items of the same colour, in addition to other identifying characteristics, a user is provided a further indication that the two items in the pair can be matched or connected.

In various embodiments, identification members may be provided as retro- fitable members which fit around an existing connector member such as a tube connector, pipe connector, cable connector or the like. In other embodiments, the connectors themselves may have identification members applied thereto and integrated with the connector itself, for example having a shaped identifier member moulded into a connector portion.

In yet further embodiments, visually symbolic shapes may be incorporated into the design of an identification marker for a connector. The visually symbolic shapes may reflect an intended function of the connector, for example a particular clinical function. For example, a connector intended for intrathecula use may comprise an identifier that symbolically represents the spine of a person, whereas a connector intended for respiratory use may comprise an identifier that symbolically represents a set of lungs.

Individual identification members within a set of identification members may be differentiated from each other by the type of material from which they are fabricated. For example, first and second identification members of a matching pair may be made from a hard plastics material, whereas a matching pair of members comprising third and fourth members may be fabricated from a soft rubber material. A further matching plurality of identification members may be fabricated from metal.

Referring to Fig. 7 herein, there is illustrated schematically a multi layered filter model, showing how a combination of visual and tactile clues may be applied to an identification member to help prevent errors in connecting first and second connectable components.

The multi layered filter layers of Fig. 7 illustrates schematically how a person perceives a design feature of an identification member according to their strength of 'intuitive sense', of how such an identification member component might feel to touch. This intuitive sense is an example of tacit knowledge, that is, knowledge based on a previous handling experience of 3-dimensional forms and materials.

A visual clue, colour, provides a first layer of intuition. Further layers of intuition which are tactile include the size of a member, its shape, a surface texture of a member, the weight of a member, and/or connector component, the hardness of an identification members, and a thermal conductivity. Cues that are both tactile and visual include the size, shape, and surface texture of an identification member.

Claims

1. An identification system for compatible components comprising at least two corresponding pairs of identifiers each pair having a combination of individual characteristics governing at least two of the following:

(A) shape of cross-section;

(B) at least one surface feature;

(C) the material properties; and (D) comparative size;

2. An identification system for compatible components as claimed in claim 1 characterised in that said compatible components are medical connectors.

3. An identification system for compatible components as claimed in claim 1 characterised in that said compatible components are electrical connectors.

4. An identification system for compatible components as claimed in any preceding claim characterised in that at least one identifier is formed integrally with its respective component.

5. An identification system for compatible components as claimed in any one of claims 1 to 3 characterised in that at least one identifier is attachable to or adjacent its respective component.

6. An identification system for compatible components as claimed in claim 1 characterised in that at least one of the characteristics of one of each pair of identifiers is represented in substantially two-dimensional form.

7. An identification system for compatible components as claimed in claim 6 characterised in that there is provided a substantially three-dimensional identifier to be used with an identifier carrying the substantially two-dimensional representation of the characteristics of said three-dimensional identifier.

8. An identification system for compatible components as claimed in any preceding claim where the individual characteristics govern the shape of cross-section of corresponding identifiers characterised in that said characteristics are provided by any suitably recognisable shape such as any one of the following:

a) circular; b) semi-circular; c) square; d) triangular; β) oval.

9. An identification system for compatible components as claimed in any preceding claim where the individual characteristics govern an at least one surface feature of corresponding identifiers characterised in that said surface characteristic incorporates any one taken from the following set:

a) at least one longitudinal rib; b) at least one transverse rib; c) at least one diagonal rib; d) at least partial knurling; e) at least one hemispherical node; f) at least one elongate spine; g) substantially smooth; h) at least two transverse body segments.

10. An identification system for compatible components as claimed in 5 claim 9 characterised in that a plurality of ribs, spines or nodes in each case is provided.

11. An identification system for compatible components as claimed in any preceding claim characterised in that said surface characteristic incorporates l o any one taken from the following set:

a) substantially straight side(s); b) tapered side(s); c) convex side(s);

15 d) concave side(s).

12. An identification system for compatible components as claimed in any preceding claim where the individual characteristics govern the material properties of corresponding identifiers characterised in that said material has one 2 o characteristic taken from the following set:

a) substantially resistant to external pressure; b) partially resistant to external pressure.

25 13. An identification system for compatible components as claimed in any preceding claim where the individual characteristics govern the comparative size of respective pairs of identifiers in the system characterised in that any size difference shall be sufficient to permit recognition thereof by sight and or by touch.

30

14. An identification system for compatible components as claimed in claim 13 characterised in that the identifiers are made of any suitable material to give a desired degree of resilience to external pressure.

15. An identification system for compatible components comprising a set of corresponding connectors characterised in that each pair of connectors is provided with a pair of corresponding identifiers each pair having a different combination of characteristics selected from the following:-

IV. a circular cross-section having three transverse body segments and substantially resistant to external pressure;

V. a triangular cross-section having no ribs, straight sides and substantially resistant to external pressure; and VI. a square cross-section having transverse ribs, straight sides and substantially resistant to external pressure.

16. An identification system for compatible components comprising at least two corresponding pairs of identifiers each identifier being provided by a substantially flat body to be readily attached to or adjacent its respective component, the substantially flat body being adapted to carry any combination of individual features.

17. An identification system for identifying a plurality of first connector portions and a plurality of second connector portions, wherein each said first connector portion is paired with a corresponding respective second said connector portion, said identification system comprising: a first set of identifier members, wherein each said identifier member of said first set is physically distinguishable from each other said member of said first set;

a second set of identifier members, wherein each said identifier member of said second set is physically distinguishable from each other said identifier member of said second set; and

each identifier member in said first set has a corresponding respective 0 partner in said second set, with which said first identifier member shares common physical features which unambiguously identifies said identifier member of said first set with its corresponding respective said partner in said second set.

18. The identification system of claim 17, wherein said common 5 physical features comprise features which are discernable to a human user by a sense of touch.

19 The identification system of claim 17, wherein said common physical features comprise features which are discernable to a human user by a o sense of touch and vision.

20. A set of identifier members in which at least two of said identifier members are configured such that they can be unambiguously matched together by at least one common tactile feature. 5

21. A set of identifier members as claimed in claim 20, wherein said at least one common tactile feature comprises a cross-section characteristic.

22. A set of identifier members as claimed in claim 21 , wherein said o cross-section characteristic comprises any one of the following:

• a substantially circular cross-section for at ieast a portion of an item; o a substantially rectangular cross-section for at least a portion of an item;

• a substantially triangular cross-section for at least a portion of an item;

• a substantially oval cross-section for at least a portion of an item.

23. A set of identifier members as claimed in claim 20, wherein said at least one common tactile feature comprises a surface profile on at least a portion 0 of an item, said surface profiling comprising at least one raised feature on an outer surface of said item.

24. A set of identifier members as claimed in claim 23, wherein said surface profile comprises any one of the following: 5

• at least one raised portion extending substantially parallel to a length of an item;

• at least one raised portion extending substantially perpendicular to a o length of said item;

• at least one raised portion extending in a line substantially diagonal to said length of said item;

5 • knurling over at least a portion of said outer surface of said item;

• at least one substantially hemispherical raised portion disposed on said outer surface of said item;

0 © a substantially smooth outer surface of said item; • at least 2 body segments, each body segment configured to be differentiated from an adjacent body segment such that a user can identify that separate body segments are present.

25. A set of identifying members as claimed in claim 20, wherein said at least one common tactile feature comprises any one of the following:

• a uniform cross section along a length of an item;

• a cross section having at least one dimension that decreases along a length of said item;

• a convex outer wall;

• a concave outer wall;

26. A set of identifying members as claimed in claim 20, wherein said at least one common tactile feature comprises a material property selected from the following:

• resilience;

• co-efficient of friction;

• density;

• thermal conductivity

27. A set of identifying members as claimed in claim 20, wherein said at least one common tactile feature comprises a size of an item.

28. A set of identifying members in which at least two of said identifying members are configured such that they can be unambiguously matched together by at least two common tactile features, said common tactile features being selected from any one of claims 21 to 27.

29. A set of identifying members as claimed in any one of claims 20 to 28 further comprising at least one common visual feature.

30. A set of identifying members as claimed in claim 29 wherein said at least one common visual feature comprises any one of the following.

• colour;

• surface decoration;

• comparative size.

31. A pair of components configured to be connected together, each component of said pair of components comprising a first end, a second end, a 0 length extending between said first end and said second end, and a longitudinal outer surface extending between said first end and said second end;

wherein each component of said pair of components comprises:

a second set of identifier members, wherein each said identifier member of said second set is physically distinguishable from each other said identifier o member of said second set; and each identifier member in said first set has a corresponding respective partner in said second set, with which said first identifier member shares common physical features which unambiguously identifies said identifier member of said first set with its corresponding respective said partner in said second set; and

said common physical features are selected from at least two of the following:

• a shape of said cross section;

• at least one surface profiling;

• at least one material property;

• comparative size

wherein said surface profiling comprises any one of the following:

® knurling extending over at least a portion of said outer surface; • at least one substantially hemispherical raised portion disposed on at least a portion of said outer surface of said component;

• a substantially smooth surface of said outer surface of said component;

wherein said material property comprises any one of the following:

• resilience;

• co-efficient of friction;

• density;

• thermal conductivity.

32. A pair of components configured to be connected together as claimed in claim 31 , further comprising visual identifiers, said visual identifiers selected from any of the following:

• colour;

• surface decoration;

size.