BACKGROUND The prior art teaches numerous forms of electrode and electrode connecting cables for the conveyance of electrical signals from an electrode array to an electrocardiograph (ECG). A common form of connecting the electrodes to an ECG is by means of an array of separate cables either leading directly to input sockets on the ECG machine or to a common multi-pin connector from which a single multi-core lead connects the cable array to the ECG.

A number of systems have sought to simplify both the electrode array and the means of electrical connection to the ECG or intermediate connecting plug. For example the electrodes may be embedded as a pattern in a strip or sheet with the conductive wires also embedded. Again the cable bundle may be joined in some manner for intermediate sections along its length to avoid tangling.

In particular we may refer to US4, 328, 814 which teaches a series of six electrodes linked together by flexible strips of material. A bundle of six conductive

cables is provided, each cable being provided with a releasable connector at a first end and being connected to a common connector at a second end. Cables have lengths sequentially reaching successive electrodes in the strip.

It will be apparent that the electrode and strips assembly of US4, 328, 814 is dedicated to the system described and is of limited flexural movement. It will also be noted that the inter-electrode spacing cannot be varied to suit significant differences in the size of patient torsos.

We also refer to US5,546, 950 which teaches an electrode cable connection means in which the individual cables are joined together to form a flat strip for that portions of their lengths lying between a common connector and their intended electrode connection. At the point of departure from the common strip, each cable is provided with a short separate section leading to an electrode connector. The combining of cables into a flat strip reduces the flexibility of the cable and limits the degree of freedom of electrode positioning.

It is an object of the present invention to address or ameliorate at least one of the above disadvantages or to provide a useful alternative.

BRIEF DESCRIPTION OF INVENTION Accordingly, in one broad form of the invention there is provided an electrocardiograph (ECG) precordial cable apparatus for a twelve lead ECG system, said cable apparatus including: (a) an elongate, flexible, lightweight length of multi- core conductor cable adapted for substantially equal resistance to flexure in all directions relative to the longitudinal axis of said conductor cable ; (b) six electrode connectors distributed at substantially equal spacing along a portion of said multi-core conductor cable and disposed along the longitudinal axis of said conductor cable; (c) a distal electrode connector forming a first end of said multi-core conductor cable and core connector means forming a second end of said conductor cable; said cable apparatus arranged to conduct electrical signals derived from electrodes, connected to said electrode connectors, to said core connector means.

Preferably said electrode connectors are adapted for connection to specified precordially placed electrodes thereby to create an electrode ordering such that, in use, there is no need for cross-over of any portion of said multi-core conductor cable.

Preferably said electrode connectors are adapted to provide a"snap on"connection with commercially available types of electrodes.

Preferably said substantially equal spacing is such as to permit connection to precordially placed electrodes on any size of human patient.

Preferably the length of the multi-core conductor cable between the proximal electrode connection and the core connector means is substantially greater than the spacing between said electrode connectors.

Preferably said spacing is in the range of 15 to 20 centimeters.

Preferably said spacing is in the range of 10 to 15 centimeters.

Preferably said multi-core conductor cable includes an insulated conductor between each of said electrode connectors and said core connector means.

Preferably said insulated conductors are enclosed in a shielding sheath.

Preferably said shielding sheath is enclosed in an outer protective sheath.

Preferably the electrode connectors are integrally moulded with said outer protective sheath.

Preferably said core connector means is integrally moulded with said outer protective sheath.

Preferably each electrode connector communicates electrically with said core connector means through an insulated conductor of said multi-core conductor cable.

Preferably insulated conductors of said multi-core conductor cable are radially disposed about the longitudinal axis of said multi-core conductor cable.

In a further broad form of the invention there is provided an electrocardiograph (ECG) precordial cable apparatus for a twelve lead ECG system, said cable apparatus including: (a) an elongate, flexible, lightweight length of multi- core conductor cable adapted for substantially equal resistance to flexure in all directions relative to the longitudinal axis of said conductor cable; (b) six electrodes distributed at substantially equal spacing along a portion of said conductor cable and disposed along the longitudinal axis of said conductor cable ; (c) a distal electrode forming a first end of said conductor cable and core connector means forming a second end of said conductor cable;

said cable apparatus. arranged to conduct electrical signals derived from said electrodes to said core connector means.

Preferably said substantially equal spacing is such as to permit said electrodes to be placed precordially on any size of human patient.

Preferably the length of the conductor cable between the proximal electrode and the core connector means is substantially greater that the spacing between said electrodes.

Preferably said spacing is in the range of 15 to 20 centimeters.

Preferably said spacing is in the range of 10 to 15 centimeters.

Preferably said multi-core conductor cable includes an insulated conductor between each of said electrodes and said core connector means.

Preferably said insulated conductors are enclosed in a shielding sheath.

Preferably said shielding sheath is enclosed in an outer protective sheath.

Preferably the electrodes are integrally moulded with said enclosing sheath.

Preferably the core connector means is integrally moulded with said enclosing sheath.

Preferably each electrode communicates electrically with said core connector means through an insulated conductor of said multi-core conductor cable.

Preferably insulated conductors of said multi-core conductor cable are radially disposed about the longitudinal axis of said multi-core conductor cable.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a general view of a first embodiment according to the invention, Figure 2 is a partial side view of the embodiment of Figure 1, Figure 3 is a partial side view of a second embodiment according to the invention, Figures 4 shows a cross section of a conductor cable according to the invention.

Figure 5 is a diagrammatic representation of a conductor cable according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A first preferred embodiment of a system for a precordial cable apparatus 10 will now be described with reference to Figures 1,2 and 4.

A conductor cable 11 comprises an extruded flexible outer protective sheath 25 enclosing a number of flexible insulated conductors 26.

Integrally moulded with outer sheath 25 are six, preferably equispaced, electrode connectors, 12,13, 14, 15,16, 17 in order from distal electrode connector 12, to proximal electrode connector 17. Each of connectors 12 to 17 is centered on the longitudinal axis X-X of conductor cable 11 as shown diagrammatically in Figure 5.

Again with reference to Figure 1, at the proximal end of conductor cable 11 is an integrally moulded core connector 18.

Each electrode connector 12 to 17 is provided with electrical contacts 24 resiliently embedded in the connectors. Flexible insulated conductors 26 are sheathed in shielding 29.

A preferred arrangement of conductors 26 within outer sheath 25 and shielding 29 is shown in Figure 4. With reference to Figure 5 each electrical contact 24 is

connected by a flexible insulated conductor 26 to a designated connector element in core connector means 18.

With reference to Figure 2 electrical contacts 24 are arranged to accept studs 21 of electrodes 20 as a"snap" connection thereby securing an electrical connection between electrodes 20 and contacts 24 of connectors 12 to 17.

A second preferred embodiment of a system for a precordial cable apparatus 10 will now be described with reference to Figure 3.

In this embodiment precordial cable apparatus-10 is intended for single use only. Electrodes 20 are permanently attached to electrode connectors 12 to 17. The construction of Cable 11 and connectors 12 to 17 is in this embodiment considerably simplified. Since the apparatus is designed for single use its construction can be lightened, thus further reducing cost of manufacture.

In use, for a first preferred embodiment of the cable apparatus according to the invention, six commonly available electrodes may be placed in a preferred pattern on the torso of a patient. After connection of the distal electrode the cable is logically applied to the electrodes in the designated pattern. The path of connection is that path which does not include any cross-over of the cable.

For the second embodiment of the invention, the cable and integral electrodes may be constructed of very light weight and less durable materials allowing for single use applications. Electrodes may be attached by adhesives to a sheet of material and peeled from that sheet when required for application to a patient. Prior to use the sheet of electrodes and cable may be conveniently stored in a sealed sterile pouch.

The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope and spirit of the present invention.