WO2020077388A1

WO2020077388A1 - Electrophysiology catheter and a method of fabricating thereof

Info

Publication number: WO2020077388A1
Application number: PCT/AU2019/050831
Authority: WO
Inventors: Benjamin David King; Milanjot Singh ASSI; Roman GREIFENEDER; Mitchell Kwok; Daniel Meckes
Original assignee: Cathrx Ltd
Priority date: 2018-10-18
Filing date: 2019-08-08
Publication date: 2020-04-23

Abstract

The invention discloses a flexible electrical lead for a catheter comprising: an elongate member having a first end and a second end, and defining a lumen extending from the first end to the second end; the elongate member further comprising: a first layer of non-conductive material and a second layer of resilient braided material, wherein the second layer is arranged between the first layer and the lumen, wherein the second layer is in a preformed three-dimensional shape and the second layer imparts the preformed three-dimensional shape onto the electrical lead; a plurality of electrical conductors encapsulated between the first layer and the second layer, wherein the plurality of electrical conductors extending parallel to the longitudinal axis of the lumen, wherein the first layer encapsulates the plurality of electrical conductors.

Description

ELECTROPHY SIOLOG Y CATHETER AND A METHOD OF FABRICATING

THEREOF

TECHNICAL FIELD

[0001] The present invention relates to an electrophysiological catheter. More particularly, the present disclosure relates to an electrophysiological cardiac catheter including a sensor.

BACKGROUND

[0002] Electrophysiology catheters are commonly used in medical practice for diagnosis and treatment of the hearts. Electrophysiology catheters are frequently used for sensing electrical activity within the heart. Studies such as cardiac mapping and pacing are conducted using a catheter in order to determine abnormalities in the heart.

[0003] Catheters for diagnostic procedures are well known within the art, however there are a number of problems associated with known diagnostic and sensing catheters.

[0004] US Patent Application Publication No. 20040267106, discloses an

electrophysiology catheter which includes a tube, in which the tube has a proximal end, a distal end, and a lumen therebetween. The tube preferably comprises of multiple sections of different flexibility, arranged so that the flexibility of the catheter gradually increases from the proximal end to the distal end. The electrophysiology catheter have a generally hollow electrode member at the distal end. A magnetically responsive element disposes at least partially in the hollow electrode, for aligning the distal end of the catheter with an externally applied magnetic field. The end electrode has openings for delivering irrigating fluid, and/or a sleeve which provides around the tube to create an annular space for the delivery of irrigating fluid. A temperature sensor provides control the operation of the catheter. A localization coil senses the position and orientation of the catheter.

However, US Patent Application Publication No. 20040267106 does not teach or suggest the advantages of the present disclosure, and is in generally relatively large and may be difficult to navigate.

Substitute Sheet

(Rule 26) RO/AU [0005] EP Patent No. 0879069 relates to an electrophysiology catheter (an electrode catheter) having an electromagnetic sensor designed internally into the top portion. The catheter is a size 7 French or 8 French of metal braided construction with preferably three lumens. The catheter has a deflectable tip utilizing an offset lumen with a puller wire, a non-compressible coil in the body section, and a compressible TEFLON™ sheath in the tip section. The electromagnetic sensor is mounted internally in the catheter tip by a combination of a hole drilled in the three lumen tip, and a hollow bridging that covers the electromagnetic sensor and connects the tip electrode to the catheter shaft. The tip electrode is secured to the end of the bridging tube by an etched TEFLON™ ring which mates the electrode stem to the inside of the ring. This disclosure does not teach the advantages of the present invention.

[0006] Other well-known catheters are constructed using a pull-wire which is fixed to the distal end of the catheter, however this prevents the pull-wire from being separated from the catheter. Further, using a pull-wire only imparts limited shapes to the catheter, and must be imparted to the location in which the pull-wire is fixed to the catheter. Further, catheters equipped with pull-wires generally are not capable of having a stylet to replace the pull-wire, nor is the function of a pull-wire an equivalent to that of a stylet. More particularly, the pull-wire is similar to a tendon, in which applying tension to a pull-wire causes the catheter lead attached thereto to deform. Flowever, these types of deflection means can only impart a shape at the location in which the pull-wire is attached and activated, which can cause steering problems in use.

[0007] Other well-known catheters have been previously manufactured by manually feeding individual copper wires down a lumen and then welding the copper wire to the electrode. However, manually feeding wires down a lumen is a labour intensive process and can result in defects if the wire is damaged during the feeding down process.

[0008] Other catheters have been previously manufactured by tube extrusion processes. Traditional tube extrusion is achieved with the use of a tube tip, in which the end of the tip is maintained flush with the face of the die. However, the traditional tube extrusion process may allow the molten polymeric material to flow freely onto the lead and may

Substitute Sheet

(Rule 26) RO/AU produce an uneven non-cylindrical cross-section and surface. Uneven surfaces can cause steering problems and may cause the lead to snag anatomy in use which can cause severe lesions, internal bleeding and undesired medical complications.

[0009] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

SUMMARY

[0010] PROBLEMS TO BE SOLVED

[0011] It may be advantageous to provide a more compact electrophysiological catheter for sensing diagnostic applications.

[0012] It may be an advantage to provide a flexible preformed electrical lead for an electrophysiological catheter.

[0013] It may be an advantage to provide a cheaper catheter construction with electrodes running parallel to the flexible preformed electrical lead instead of the electrodes running in a helix.

[0014] It may be an advantage to provide a faster production of the flexible preformed electrical lead with the electrodes running parallel to the flexible preformed electrical lead.

[0015] It may be an advantage to use a pressurised extrusion process to construct the flexible preformed electrical lead with a resilient braid which may maintain good torque transfer and stiffness characteristics.

[0016] It may be an advantage to define the preformed shapes of the flexible preformed lead by the resilient braided.

Substitute Sheet

(Rule 26) RO/AU [0017] It may be an advantage to provide a shapable flexible preformed lead without requiring an internal stylet or pull wire to maintain the shape.

[0018] It may be an advantage to provide electrodes running parallel to the flexible preformed electrical lead which may prevent cross connections in the laser cutting and slot filling processes during manufacturing.

[0019] It may be an advantage to provide variable braiding and/or electrode size which may give desired mechanical properties.

[0020] It may be an advantage to provide a lumen with hollow centre which may allow for stress relief when the shape of the flexible preformed lead is deformed when in use.

[0021] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0022] MEANS FOR SOLVING THE PROBLEM

[0023] A first aspect of the present invention may relate to a flexible electrical lead for a catheter comprising: an elongate member having a first end and a second end, and defining a lumen extending from the first end to the second end; the elongate member further comprising: a first layer of non-conductive material and a second layer of resilient braided material, wherein the second layer is arranged between the first layer and the lumen, wherein a preform three-dimensional shape of the second layer is in a preformed three-dimensional shape and the second layer imparts the preformed three-dimensional shape onto the electrical lead; a plurality of electrical conductors encapsulated between the first layer and the second layer, wherein the plurality of electrical conductors extending parallel to the longitudinal axis of the lumen, wherein the first layer encapsulates the plurality of electrical conductors.

Substitute Sheet

(Rule 26) RO/AU [0024] Preferably, at least one electrode comprises a first electrode and wherein the first electrode on an outer surface of the elongate member is in electrical communication with at least one of the plurality of electrical conductors through the first layer.

[0025] Preferably, the second layer is insulated from the first electrode.

[0026] Preferably, the at least one electrode is insulated by the first layer.

[0027] Preferably, the second layer is insulated from the plurality of electrical conductors by a third intermediate layer of non-conductive material, wherein the third layer may be positioned between the first layer and the second layer.

[0028] Preferably, the flexible preformed electrical lead comprising a second electrode, wherein the second electrode covers the second end of the elongate member and is in electrical communication with at least one of the plurality of electrical conductors through the first layer.

[0029] Preferably, the at least one sensing electrode is at least one selected from the group of: platinum electrode, doped conjugated organic polymer electrodes, and polymer- metal hybrid electrodes.

[0030] Preferably, a first conductive adhesive is in electrical communication with the platinum electrode and an electrical conductor of the plurality of electrical conductors.

[0031] Preferably, the first conductive adhesive is at least one selected from the group of: a conductive epoxy, and solder.

[0032] Preferably, the melting temperature of the solder is at a lower temperature than the melting temperature of the first layer.

Substitute Sheet

(Rule 26) RO/AU [0033] Preferably, the polymer of the polymer-metal hybrid electrode comprises polyurethane, and the metal of the polymer-metal hybrid electrode comprises at least one material selected from the group of: silver, and tungsten.

[0034] Preferably, the polymer-metal hybrid electrode comprises a radiopaque marking.

[0035] Preferably, the radiopaque marking is at least one selected from the group of: an arrow, and a graduated scale.

[0036] Preferably, the plurality of electrical conductors are arranged at circumferentially spaced intervals.

[0037] Preferably, the first end of the elongate member is connectable with a handle.

[0038] Preferably, the plurality of the electrical conductors are in electrical

communication with a corresponding plurality of electrical conductors in the handle, wherein the first end of the elongate member and the handle are connected.

[0039] Preferably, the connection between the first end of the elongate member and the handle is affixed by a second adhesive.

[0040] Preferably, the second adhesive is at least one selected from the group of: instant adhesive and UV cure adhesive.

[0041] Preferably, the flexible preformed electrical lead further comprising an inner non- conductive layer between the resilient braided layer and the lumen.

[0042] A second aspect of the present invention may relate to a method of fabricating a flexible preformed electrical lead for a catheter, the method comprising the steps of: providing an elongate member having a first end and a second end, and defining a lumen extending from the first end to the second end; providing the elongate member having a first layer of non-conductive material and a second layer of resilient braided material,

Substitute Sheet

(Rule 26) RO/AU wherein the second layer is arranged between the first layer and the lumen; imparting a preformed three-dimensional shape onto the electrical lead by the second layer, wherein the second layer is in the preformed three-dimensional shape; encapsulating a plurality of electrical conductors between the first layer and the second layer, wherein the plurality of electrical conductors are extending parallel to the longitudinal axis of the lumen; and whereby applying a pressurised extrusion to the flexible preformed electrical lead molds the first layer such that the first layer encapsulates the plurality of electrical conductors.

[0043] In the context of the present invention, the words“comprise”,“comprising” and the like are to be construed in their inclusive, as opposed to their exclusive, sense, that is in the sense of“including, but not limited to”.

[0044] The invention is to be interpreted with reference to the at least one of the technical problems described or affiliated with the background art. The present aims to solve or ameliorate at least one of the technical problems and this may result in one or more advantageous effects as defined by this specification and described in detail with reference to the preferred embodiments of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

[0045] Figure 1 depicts a transparent section of a flexible preformed electrical lead in accordance with a first preferred embodiment of the present invention.

[0046] Figure 2 depicts a cross-sectional view of the section of the flexible preformed electrical lead of a further preferred embodiment.

[0047] Figure 3 depicts a cross-sectional view of a section of the flexible preformed electrical lead when the lead was manufactured from traditional tube extrusion.

[0048] Figure 4 depicts a cross-sectional view of a section of the flexible preformed electrical lead of a further preferred embodiment when the lead was manufactured from pressurised tube extrusion.

Substitute Sheet

(Rule 26) RO/AU [0049] Figure 5 depicts a cross-sectional view of a section of the flexible preformed electrical lead of a further preferred embodiment when the lead was manufactured from pressurised tube extrusion.

[0050] Figure 6 depicts a side cross-sectional view of the die and pressure tip for manufacturing the flexible preformed electrical lead from pressurised tube extrusion of a further preferred embodiment.

[0051] Figure 7 depicts a side view of the various fixed curves of the flexible preformed electrical lead.

[0052] Figure 8 depicts a side cross-sectional view of the flexible preformed electrical lead of a further preferred embodiment with an electrode affixed on the electrical lead.

[0053] Figure 9 depicts a top view of the flexible preformed electrical lead of a further preferred embodiment for laser cutting a slot to the electrical lead.

[0054] Figure 10 depicts a top view of the flexible preformed electrical lead of a further preferred embodiment affixed with an electrode.

[0055] Figure 11 depicts a side view of a flexible preformed electrical lead of a further preferred embodiment with a plurality of electrodes and a tip electrode.

[0056] Figure 12 depicts a side cross-sectional view of a catheter handle with a handle jacket connected to a flexible preformed electrical lead of a further embodiment.

[0057] Figure 13 depicts a perspective cross-sectional view of a catheter handle connected to a flexible preformed electrical lead of a further embodiment.

[0058] Figure 14 depicts a side view of a catheter handle connected to a flexible preformed electrical lead of a further embodiment.

Substitute Sheet

(Rule 26) RO/AU [0059] Figure 15 depicts a perspective view of a catheter handle connected to a flexible preformed electrical lead of a further embodiment.

[0060] Figure 16 depicts a perspective view of a catheter handle with a handle jacket showing the steering of the flexible preformed catheter lead.

[0061] Figure 17 depicts a top view of the resilient braided layers used with a flexible performed electrical lead of a further embodiment.

[0062] Figure 18A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with metal braid with parallel wires in the braided layer.

[0063] Figure 18B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 18 A.

[0064] Figure 19A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with metal with other wires forming the braid in the braided layer.

[0065] Figure 19B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 19 A.

[0066] Figure 20A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with braided metal ribbon in the braided layer.

[0067] Figure 20B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 20A.

[0068] Figure 21 depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with metal and other specialized wires forming the braid in the braided layer.

Substitute Sheet

(Rule 26) RO/AU [0069] Figure 22A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with braided metal with specialized wires running parallel in the inner layer.

[0070] Figure 22B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 22A.

[0071] Figure 23 A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with braided metal with specialized wires running parallel in the outer layer.

[0072] Figure 23B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 22A.

[0073] Figure 24A depicts a perspective view of a flexible performed electrical lead of a further preferred embodiment with braided metal with specialized wires running parallel in-between the braid in the braided layer.

[0074] Figure 24B depicts a front cross-sectional view of the flexible preformed electrical lead of Figure 24A.

DESCRIPTION OF THE INVENTION

[0075] Preferred embodiments of the invention will now be described with reference to the accompanying drawings and non-limiting examples.

[0076] As illustrated in Figure 1, reference numeral 10 generally designates an embodiment of a flexible preformed electrical lead for an electrophysiological catheter made in accordance with a process for manufacturing a flexible preformed electrical lead as described below. The flexible preformed electrical lead 10 for a catheter may comprise an elongate member 12 having a first end 14 and a second end 16, and the

Substitute Sheet

(Rule 26) RO/AU elongate member 12 may define a lumen 18 extending from the first end 14 to the second end 16. At least one sensing electrode 120 may be arranged on the electrical lead 10 at the second end 16 of the electrical lead 10. The size of the empty lumen 18 can be changed to tune the stiffness properties. The elongate member 12 may further comprise a layer of non-conductive material and a resilient braided layer 22, wherein the shape of the flexible preformed lead 10 may be defined by the resilient braided layer 22. The resilient braided layer 22 and the electrical conductors 24 may assist in maintaining the shape of the flexible preformed electrical lead 10. An advantage of having a tip or end electrode 130 as a sensing electrode 120 may be that the resilient braided layer 22 can extend all the way to the tip electrode 130 of the flexible preformed electrical lead 10. A plurality of electrical conductors 24 may be encapsulated between the layer 20 and the resilient braided layer 22, wherein the plurality of electrical conductors 24 may extend parallel to the longitudinal axis of the lumen 18, wherein the first layer 20 may envelop the plurality of electrical conductors 24. As the plurality of electrical conductors 24 may be extending parallel to the longitudinal axis of the lumen 18, the resilient braided layer 22 may also extend under the sensing electrodes 120 and may provide beneficial torque and stiffness characteristics to the tip of the flexible preformed electrical lead and to the sensing electrodes 120.

[0077] As shown in Figure 1, the flexible preformed electrical lead 10 may have at least one layer of non-conductive material 20 and a resilient braided layer 22, wherein the resilient braided layer 22 may be positioned between the layer of non-conductive material 20 and the lumen 18, wherein the shape of the flexible preformed electrical lead 10 may be defined by the resilient braided layer 22. The cross-section of the flexible preformed electrical lead 10 is shown in Figure 2. The resilient braided layer 22 may have a thin coating of non-conductive material 19 such as polytetrafluoroethylene (PTFE or

Teflon™) or polyethylene or poly ether block amide (PEBAX™) between the resilient braided layer 22 and the lumen 18. The grade of PEBAX™ may be from 25 Duro (2533 SA 01 MED grade) to 74 Duro (7433 SA 01 MED grade).

Substitute Sheet

(Rule 26) RO/AU [0078] The elongate member 12 may be tubular and it may be formed by extruding a thin layer of the non-conductive material 19 or an inner layer of non-conductive material 19 such as polytetrafluoroethylene (PTFE or Teflon™) or polyethylene or polyether block amide (PEBAX™) over a die 60 with a pressure tip 70. This thin coating of non- conductive material 19 may provide a substrate for the resilient braided layer 22 to be applied. The resilient braided layer 22 may be formed of stainless steel wire on the thin coating of non-conductive material 19. The resilient braid 22 may provide desirable rotational torque and bending stiffness characteristics to the flexible preformed electrical lead 10 whilst preventing or minimising any kinking or other adverse bending of the flexible preformed electrical lead 10.

[0079] Rotational torque and bending stiffness of the resilient braid 22 may be altered by the type of braid used. As illustrated in Figures 17A to 17C, for example, braiding designs may be the Regular braided pattern (2 over 2 under, using 16 wires) (Figure 17A), Full load Diamond braided pattern (1 over 1 under, using 16 wires) (Figure 17B), Half load Diamond braided pattern (1 over 1 under, using 8 wires) (Figure 17C). When the picks-per-inch (PPI) parameter may be the same, the ranking of torque transfer of the resilient braid 22 from highest to lowest torque transfer may be ranked as follows: Full load Diamond braided pattern (Figure 17B), Half load Diamond braided pattern (Figure 17C), followed by the Regular braided pattern (Figure 17A). The 1 over 1 under arrangement of the Half load Diamond braided pattern may provide a relatively higher torque transfer compared to the 2 over 2 under Regular braided pattern with the same PPI. The relatively higher torque transfer between these two braided patterns may be because the geometry of the 1 over 1 under arrangement may allow for less flexibility of the braided wires compared to the 2 over 2 under arrangement and may provide for higher torque capabilities. With the same pitch/PPI, the Full load Diamond braided pattern may exhibit the highest torque capabilities as the same 1 over 1 under arrangement may be reinforced with an additional eight wires.

[0080] The resilient braid 22 may be coated with at least one layer of non-conductive material of a suitable polymer such as polytetrafluoroethylene (PTFE or Teflon™) or

Substitute Sheet

(Rule 26) RO/AU polyethylene or poly ether block amide (PEBAX™). In a preferred embodiment, the resilient braid 22 may be coated with an intermediate layer of non-conductive material 21 and an outer layer of non-conductive material 20. The layer of non-conductive material 20 may overlay the intermediate layer of non-conductive material 21. At least one electrical conductor 24 may be encapsulated between an outer non-conductive layer of a suitable polymer 20 such as polytetrafluoroethylene (PTFE or Teflon™) or polyethylene or polyether block amide (PEBAX™) and the resilient braided layer 22, wherein the at least one of electrical conductor 24 may be extending parallel to the longitudinal axis of the lumen 18. The layers of non-conductive material 20, 21 between the resilient braid 22 and the electrical conductors 24 may insulate the resilient braid 22 from electrical short circuits and may provide protection to the electrical conductor insulation layer 26 by preventing cross-connection between the resilient braid 22 and the electrical conductors 24. The electrical conductors 24 may be metal wires that are insulated by a non-conducting polymeric material 26 such as Nylon, polyurethane, or a nylon- polyurethane co-polymer. This non-conducting polymeric material 26 may provide an additional layer of insulation in which the electrical conductors 24 may insulate the resilient braid 22 from electrical short circuits. The polymeric material 26 may have a predetermined thickness for achieving better insulation. The diameter of the electrical conductors 24 may be such that the overall electrical resistance may be as low as possible. It may be appreciated that any number of electrical conductors 24 may be used with the flexible preformed electrical lead 10. For illustrative purposes, the embodiments of the flexible preformed electrical lead 10 are shown with four electrical conductors 24. It may be appreciated that twenty electrical conductors 24 may be used and may be running parallel to the longitudinal axis of the lumen 18. It may also be appreciated that depending on the purpose, any number of electrical conductors 24 may be used. A possible advantage of the electrical conductors 24 may be running parallel to the longitudinal axis of the lumen 18 may be such that the winding time may be reduced compared to if the electrical conductors 24 were wound around the longitudinal axis of the lumen 18. Another possible advantage of the electrical conductors 24 running parallel to the longitudinal axis of the lumen 18 may be such that it uses less copper and may produce a cheaper or more economical flexible preformed electrical lead 10.

Substitute Sheet

(Rule 26) RO/AU Preferably, the electrical conductors 24 may be spaced equally away relatively from each other. Some of the electrical conductors 24 may be used for providing an electrical path for one or more sensing electrodes 120.

[0081] In another preferred embodiment, the resilient braid 22 may not be coated with the intermediate layer of non-conductive material 21 and may be coated with the outer layer of non-conductive material 20. In this embodiment, at least one electrical conductor 24 may be encapsulated between an outer non-conductive layer of a suitable polymer 22 such as polytetrafluoroethylene (PTFE or Teflon™) or polyethylene or polyether block amide (PEBAX™) and the resilient braided layer 22, wherein the at least one of electrical conductor 24 may be extending parallel to the longitudinal axis of the lumen 18. The plurality of electrical conductors 24 may be metal wires that may be insulated by a non conducting polymeric material 26 such as Nylon, polyurethane, or a nylon-polyurethane co-polymer. This non-conducting polymeric material 26 may provide a layer of insulation in which the electrical conductors 24 may insulate the resilient braid 22 from electrical short circuits. The polymeric material 26 may have a predetermined thickness for achieving better insulation. The polymeric material 26 of the electrical conductors 24 may have a predetermined thickness thicker than the embodiment of the resilient braid 22 coated with the intermediate layer of non-conductive material 21. The diameter of the electrical conductors may be such that the overall electrical resistance is as low as possible. It may be appreciated that any number of electrical conductors 24 may be used with the flexible preformed electrical lead 10. For illustrative purposes, the embodiments of the flexible preformed electrical lead 10 are shown with four electrical conductors 24. Preferably, up to twenty electrical conductors 24 may be used and may be running parallel to the longitudinal axis of the lumen 18. Preferably, the electrical conductors 24 are spaced equally away relatively from each other. Some of the electrical conductors 24 may be used for providing an electrical path for one or more sensing electrodes 120.

[0082] In Figure 6, the outer layer of polymeric material 20 may be formed, for example by using a pressurised extrusion apparatus comprising a pressure tip 70 and a die 60. The pressure tip 70 may have a first end 76 and a second end 78, and the die 60 may have a

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(Rule 26) RO/AU first end 66 and the second end 68. The first end 76 of the pressure tip 70 may have a smaller pressure tip opening 74 compared to the second end 78 of the pressure tip 70. Similarly, the first end of the die 66 may have a smaller opening 64 compared to the second end of the die 68. The pressure tip 70 and the die 60 may be arranged in such a way that the opening of the pressure tip 74 may be located between the first end of the die 66 and the second end of the die 68. The tip 72 of the pressure tip 70 may be offset back from the tip 62 of the die 60 at 1.75mm and it may be appreciated that the tip 72 of the pressure tip 70 may be offset back from the tip 62 of the die 60 at a range between 0mm to 6.25mm. The pressure of the extrusion process in this offset arrangement may be increased compared to when there may be no offset between the opening of the die 64 and the opening of the pressure tip 74. The elongate member 12 may be fed through the pressurised extrusion apparatus in the direction of second end of the pressure tip 78 to the first end of the pressure tip 78, in which the elongate member 12 may exit the opening of the pressure tip 74 before the elongate member exiting the opening of the die 64. There may be a channel 71 between the pressure tip 70 and the die 60, in which the channel 71 may provide for the molten non-conductive polymeric material such as PEBAX^{1 M} to flow onto the elongate member 12 between the opening of the pressure tip 74 and the opening of the die 64 when the elongate member 12 exits the opening of the pressure tip 74.

[0083] As illustrated in Figure 3, the flexible preformed electrical lead 10 manufactured from the extrusion process where the opening of the pressure tip 74 is not offset from the opening of the die 64 may result in undesirable gaps 6 being produced. These undesirable gaps 6 may produce a non-cylindrical cross-section and may produce an uneven surface. Uneven surfaces may cause steering problems and may cause the electrical lead 10 to snag anatomy in use which can cause severe lesions, internal bleeding and undesired medical complications.

[0084] Whereas in contrast, as illustrated in Figures 4 and 5, the flexible preformed electrical lead 10 may be manufactured from a pressurised extrusion process where the opening of the pressure tip 74 is offset from the opening of the die 64 may have an

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(Rule 26) RO/AU increased pressure that may force the molten non-conductive polymeric material such as PEBAX™ into the undesirable gaps 6 to fill the undesirable gaps, as indicated in filled area 8. This pressurised extrusion process may produce a filled area 8 flexible preformed electrical lead embodiment compared to the illustration in Figure 3 where the flexible preformed electrical lead 10 manufactured from the extrusion process where the opening of the pressure tip 74 is not offset from the opening of the die 64. As illustrated in Figures 4 and 5, the pressurised extrusion process may produce a cylindrical cross-section and may produce a smoother and even surface. The smoother cylindrical cross-section may minimise steering problems and may prevent the flexible preformed electrical lead 10 from snagging anatomy in use.

[0085] The pressurised extrusion process settings for forming the polymeric layer and the non-conductive layers of PEBAX^{1 M} may use the following parameters:

Preferably, the pressurised extrusion process settings for forming the polymeric layer and the non-conductive layers of PEBAX may use the following parameters:

Substitute Sheet

(Rule 26) RO/AU

The pressured extrusion apparatus may have a pressure tip dimension in the range between 1.0 to 2.0 mm, and the die dimension may be in the range between 1.94 to 2.02 mm. It may be appreciated that these settings may be different if a polymeric material other than PEBAX™ is being used or a larger industrial grade extruder is being used.

[0086] The manufacturing steps of manufacturing the flexible preformed electrical lead with an intermediate layer of non-conductive material 21 may consist of the following steps:

1) Tube extrusion of the inner jacket of a polymeric material such as PEBAX ^GM onto a PD-slick^1M mandrel. The mandrel acts as a support structure while the flexible preformed electrical lead is being manufactured.

2) A resilient braided layer 22 of any braid type may be applied over the inner jacket of a polymeric material 19.

3) An intermediate non-conductive layer 21 of PEBAX™ may be pressure extruded onto the resilient braided layer 22 with the above manufacturing parameters.

Substitute Sheet

(Rule 26) RO/AU 4) Electrical conductors 24 encapsulated with the polymeric material insulator 26 may be fed directly into the pressurised extrusion head at the same rate as the pressure extrusion line speed using a conductor feeding system.

5) An outer non-conductive layer 20 of REBAC^GM may be pressure extruded onto the electrical conductors 24.

6) Once the outer non-conductive layer 20 may have been applied and set, the

flexible preformed electrical lead 10 may then be cut into a predetermined length.

7) Removal of the PD-Slick^rM mandrel by stretching and pulling out from the inner jacket.

[0087] The manufacturing steps of manufacturing the flexible preformed electrical lead without an intermediate layer of non-conductive material 21 may consist of the following steps:

1) Tube extrusion of the inner jacket of a polymeric material such as PEBAX™ onto a PD-slick™ mandrel. The mandrel acts as a support structure while the flexible preformed electrical lead is being manufactured.

2) A resilient braided layer 22 of a braid type may be applied over the inner jacket of a polymeric material 19.

3) Electrical conductors 24 encapsulated with the polymeric material insulator 26 may be fed directly into the pressurised extrusion head at the same rate as the pressure extrusion line speed using a conductor feeding system.

4) An outer non-conductive layer 20 of PEBAX™ may be pressure extruded onto the electrical conductors.

Substitute Sheet

(Rule 26) RO/AU 5) Once the outer non-conductive layer 20 may have been applied and set, the flexible preformed electrical lead 10 may then be cut into a predetermined length.

6) Removal of the PD-Slick™ mandrel by stretching and pulled out from the inner jacket.

A possible advantage of manufacturing the flexible preformed electrical lead 10 without an intermediate layer of non-conductive material 21 may reduce time and cost in manufacturing the flexible preformed electrical lead 10 compared to manufacturing the flexible preformed electrical lead 10 with an intermediate layer of non-conductive material 21.

[0088] As illustrated in Figures 8 and 9, one or more sensing electrodes 120 may be formed onto the flexible preformed electrical lead 10 by laser cutting a portion of the outer polymeric layer 20 and the laser cutting may also strip the insulation off the electrical conductor 26 inside the outer polymeric layer 20 to expose the electrical conductor 24. Laser cutting may be accurate and may provide a suitable method of removing a portion of the outer polymeric layer 20 with ease to produce a laser cut slot 115. The slot 115 from the laser cutting may then be filled with an electrically conductive paste or adhesive 1 10 such as a low temperature solder or conductive epoxy until the paste or adhesive 110 may be substantially flush with the surface of the flexible preformed electrical lead to produce a smooth surface. The electrically conductive paste or adhesive 1 10 may be overlaid with a conductive bio-compatible material such as a metal electrode 120, which may be an inert metal electrode such as a platinum electrode; or that the conductive bio-compatible material may be a plastic electrode 120. The metal electrode 120 or the plastic electrode may be affixed onto the outside of the flexible preformed electrical lead 10.

[0089] The low temperature solders which may be used for filling the slot 115, may be at least one selected from the group of: Indalloy #13, Indalloy #41, and Indalloy #83.

Indalloy #13 may have an elemental composition (% by Mass): 70% Indium: 15% Tin: 9.6% Lead: and 5.4% Cadmium; and Indalloy #13 may have a liquidus temperature of

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(Rule 26) RO/AU 125°C. Indalloy #41 may have an elemental composition (% by Mass): 50% Bismuth: 28% Lead: and 22% Tin; and lndalloy #41 may have a liquidus temperature of 100°C and a solidus temperature of 100°C. Indalloy #83 may have an elemental composition (% by Mass): 38.4% Lead: 30.8% Bismuth: and 30.8% Tin; and Indalloy #83 may have a liquidus temperature of 139°C and a solidus temperature of 96°C. It may be appreciated that other low temperature solders with a similar liquidus and solidus temperatures may also be applicable.

[0090] The grades of PEBAX™ which may be used for the outer layer of non-conductive material 20 suitable for use with the low temperature solders as listed above may be any one of the following:

[0091] The plastic electrode 120 may be a doped conjugated organic polymer material to create a conducting or semiconducting material such that the plastic electrode is conductive or the plastic electrode may be a polymer-metal hybrid. Preferably, the plastic electrode may be a polymer-metal hybrid comprising polyurethane as the carrier material, silver as the conductive material and tungsten may be used as the radio opaque material. The ratio of the polymer metal hybrid material polyurethane : silver : tungsten can be tuned to achieve the optimal electrical conductivity and contrast under X-rays. The polymer-metal hybrid may be radio opaque or the polymer-metal hybrid may comprise a

Substitute Sheet

(Rule 26) RO/AU radio opaque marking. The radio opaque marking may have an arrow shape with the arrow head pointing in the direction from the first end 14 of the elongate member 12 to the second end 16 of the elongate member 12. The arrow shape may assist the user the direction of movement of the electrophysiological cardiac catheter as the catheter progresses in the heart as part of the diagnosis. Further, the radio opaque material may have centimetre or millimetre markings in the form of a graduated scale which may allow for the user to know the length at which the place of the heart may have been sensed.

[0092] The platinum electrode 120 or plastic electrode 120 may be a sensing electrode or any type of electrode used for electrophysiological applications. The platinum electrode 120 may be a platinum ring. The affixation of the platinum electrode 120 onto the outside of the flexible preformed electrical lead may be by swaging or crimping. Preferably, the platinum electrode may be swaged using a machine followed by applying fillets or band of adhesive 122, as illustrated in Figure 10, such that a smooth surface between the swaged platinum electrode 120 and outer non-conductive layer 20 may be formed.

[0093] When a plastic electrode 120 may be affixed onto the outside of the flexible preformed electrical lead 10, the plastic electrode 120 may be heated such that the plastic electrode 120 may be melted into the outer non-conductive layer 20 of the flexible preformed electrical lead 10 in which the plastic electrode 120 may be part of the outer surface 13 of the outer non-conductive layer 20 of the flexible preformed electrical lead 10. The plastic electrode 120 may be melted in a range between 80 to 200 °C.

Preferably, the preferred temperature range may be between 120 to 170 °C depending on the grade of polyurethane the plastic electrodes are manufactured from. This may provide a smooth surface between the plastic electrode 120 and the outer non-conductive layer 20. It may be advantageous to create a smooth affixation between the plastic electrode 120 and the outer non-conductive layer 20 without the need to apply adhesive fillets 122 or bands 122 compared to the affixing the platinum electrode 120.

[0094] There may be provided an end electrode 130 at the end or tip of the flexible preformed electrical lead 10 as illustrated in Figure 11. The end electrode 130 may be a further sensing electrode. The end electrode 130 may be formed in a similar manner to

Substitute Sheet

(Rule 26) RO/AU the sensing electrodes. The electrical conductor 24 may be exposed by laser cutting a portion of the outer polymeric layer close to the tip of the flexible preformed catheter lead 10. The laser cutting may also strip the insulation 26 off the electrical conductor 24 inside the outer polymeric layer 20. Laser cutting may be accurate and may provide a suitable method of removing a portion of the outer polymeric layer with ease to produce a laser cut slot 1 15. The slot 115 from the laser cutting may then be filled with an electrically conductive paste or adhesive 110 such as a low temperature solder or conductive epoxy and then an end electrode may be placed over the exposed electrical conductor 24 to seal the tip of the flexible preformed electrical lead 10.

[0095] Figure 7 shows the different shapes and curves of the flexible preformed electrical lead 10 for a catheter. The second end of the flexible preformed electrical lead 10 may be heatset to the desired shape after all the electrical conductors 24 have been assembled on the cable. It may be essential to attach the electrical conductors 24 before forming any shape as the electrodes cannot be pushed onto a curved tube due to geometry constraints. Heatsetting may involve the following steps:

1) Insert the end of the flexible preformed electrical lead 10 into a stainless steel tube which may have the desired end shape.

2) Heat the stainless steel tube inside an oven, which may use a temperature between 80 to 140 °C for 10 mins to 2 hours, and a cooling time up to 15 mins at room temperature which may allow for a slow controlled cooling cycle.

3) Removing the flexible preformed electrode lead 10 from the stainless steel tube to provide the pre-determined shape of the catheter.

It may be appreciated that this process may be applied to any fixed catheter shapes. The PEBAX^rM non-conductive layer, the stainless steel braided layer 22, and the electrical conductors 24 may all contribute together in maintaining this shape in use. A possible advantage of this method of shape setting may ensure that as the catheter may be heated to body temperature, no change in shape occurs.

Substitute Sheet

(Rule 26) RO/AU [0096] The flexible preformed electrical lead 10 may have a pre-shaped curve designed to better access certain cardiac structures. For example, the A curve, Josephson type curve 82 may have a relatively smaller curve for accessing smaller areas in the High Right Atrium and in the Right Ventricular Apical. The D curve, Damato type curve 84 may have a relatively larger curve for accessing and sensing in the ventricle. The F curve, Coumand type curve 86 may have a relatively longer curve that may be suitable for accessing and sensing in the bundle of HIS or HIS bundle of the heart. The Coumand type curve 86 may measure the electrical impulse of the heart as the F curve 86 travels through the atrioventricular (AV) node. The G curve 88, may have a curve suitable for accessing and sensing the inferior vena cava, and the P curve 90, may have a curve suitable for accessing and sensing the superior vena cava. The S curve 92 or a straight formable curve may be used for accessing and sensing the inferior vena cava. The Y curve 94 may have curves suitable for accessing and sensing the bundle of HIS or HIS bundle of the heart.

[0097] As illustrated in Figure 12, the first end 14 of the flexible preformed electrical lead 10 may be releasably connectable with the second end 154 of the handle 150. The first end 14 of the flexible preformed electrical lead 10 may engage with an electrical lead holder portion 162. The handle 150 may have an outer jacket 151 which may be suitable for providing additional protection to the electrical lead and electrical conductors therein of the inner handle compartment 157, and the outer jacket 151 may have gripping means to allow a user to comfortably move and steer the electrical lead 10 via the movement of the handle 150. The inner handle compartment 157 may have a receiver housing 158 which may be releasably engageable to the inner handle compartment 157. The receiver housing 158 may house a plurality of electrical conductor receivers 159 in which each electrical conductor receiver 159 may be adapted for receiving a corresponding electrical conductor 25. The corresponding electrical conductor 25 may extend into the electrical conductor receiver 159. The electrical conductor 24 of the flexible preformed electrical lead 10 may be adapted to be in electrical communication with the corresponding electrical conductor 25. It may be appreciated that the receiver housing 158 may be selected with the same number of electrical conductor receivers 159 for receiving the

Substitute Sheet

(Rule 26) RO/AU same number of electrical conductors 24 of the flexible preformed electrical lead 10. For each corresponding electrical conductor 25 to engage with the respective electrical conductors 24 of the flexible preformed electrical lead 10, there may be a respective conductor connector 156 for electrically connecting the electrical conductor 24 and the corresponding electrical conductor 25. The respective conductor connector 156 may be an electrically conductive curved portion for electrically connecting between the electrical conductors 24 and the corresponding electrical conductors 25. It may be appreciated that the connection of the first end 14 of the flexible preformed electrical lead 10 to the handle 10 at the electrical lead holder portion 162 may not allow the plurality of electrical conductors 24 to extend directly in a straight line into the electrical conductor receiver 159. As illustrated in Figures 12 and 13, there may have an electrically conductive curved portion 156 between the electrical conductors 24 and the

corresponding electrical conductors 25 within the handle 150 which may allow the corresponding electrical conductors 25 to be received in the electrical conductor receiver 159. Without the curved portion 156, the electrical conductors 24 may not be optimally received in the electrical conductor receiver 159. As such, the curved portion 156 or the conductor connector 156 may advantageously provide greater flexibility as well as reducing strain on the electrical conductors 24 and/or the corresponding electrical conductors 25. It may be appreciated a conductor connector or the curved portion 156 may be used to electrically connect the electrical conductor 24 and the corresponding electrical conductor 25.

[0098] The electrical conductor receiver 159 may be a non-conducting material or a conducting material. In a preferred embodiment, when the electrical conductor receiver 159 may be manufactured from a non-conducting material, the corresponding electrical conductor 25 may extend therein to the first end of the electrical conductor receiver 160. An electrical source and electrical apparatus may be adapted to engage in electrical connection to the corresponding electrical conductor 25 via the first end of the electrical conductor receiver 160 to supply power to the flexible preformed electrical lead 10.

Substitute Sheet

(Rule 26) RO/AU [0099] In another preferred embodiment, when the electrical conductor receiver 159 may be manufactured from a conducting material, the corresponding electrical conductor 25 may not extend therein to the first end of the electrical conductor receiver 160. The corresponding electrical conductor 25 may be engaged in electrical communication with the second end of the electrical conductor receiver 161. The engagement may be via a conductive adhesive. As the electrical conductor receiver 159 is electrically conducting, where an electrical source and electrical apparatus may be adapted to engage in electrical connection to the first end of the electrical conductor receiver 160 to supply power to the flexible preformed electrical lead 10.

[00100] As shown in Figures 14 and 15, the inner handle compartment 157 may comprise a releasably connectable inner handle compartment cover 185. As also shown in Figure 13, the inner handle compartment 157 may have protruding blocks 174 disposed on the surface 176 of the inner handle compartment 157. The protruding blocks 174 disposed on the surface 176, as shown in Figure 15, may be considered a male engaging portion. This male engaging portion may releasably engage with a

corresponding female engaging portion on the inner handle compartment cover 185 (not shown).

[00101] The releasably connectable inner handle compartment cover 185 can be released from the inner handle compartment 157 which may allow for the ease of access by a user to electrically connect the electrically conductive curved portion 156 between the electrical conductors 24 and the corresponding electrical conductors 25 within the handle 150 when the first end 14 of the elongate member 12 may engage with the second end 162 of the handle 150. The second end of the handle 150 may have a cavity 182 at which the first end 14 of the elongate member 12 may situate. The first end 14 of the elongate member 12 of a predetermined curve may be fixed to the second end 162 of the handle 150. An adhesive which may be an instant adhesive or a UV cure adhesive may be applied at a handle portion 180 between the cavity 182 and the opening of the second end 163 of the handle 150 which may fix the first end 14 of the elongate member 12 and the second end 162 of the handle 150. The instant adhesive may be at least one selected

Substitute Sheet

(Rule 26) RO/AU from the group of: Locitite - 4013, Locitite 4014, Locitite - 4306, and Locitite - 4307. It may be appreciated that any adhesive with similar properties to the listed Locitite products may also work. A possible advantage of using UV cure adhesive may solidify upon exposure to the appropriate wavelength and intensity of ultraviolet (UV) light, and offer a number of processing benefits over other adhesive cure methods including: cure on demand and fast solidification when exposed to the appropriate wavelength and intensity of U V light.

[00102] The electrical conductors 24 of the elongate member 12 may be electrically connected to the electrically conductive curved portion 156 via solder and similarly, the corresponding electrical conductors 25 of the elongate member 12 may be electrically connected to the electrically conductive curved portion 156 via solder such that the electrical conductors 24 are in electrical connection to the corresponding electrical conductors 25.

[00103] The releasably connectable inner handle compartment cover 185 can be released from the inner handle compartment 157 for also the ease of access by a user to electrically connect the corresponding electrical conductor 25 to the electrical conductor receiver 159.

[00104] As shown in Figure 16, the handle 150 may have an outer jacket 151 covering the inner handle compartment 157 for the ease of the user to steer the assembled catheter forwards and backwards 192 as indicated as well as turning 190 as indicated.

The outer jacket 151 may have an outer jacket sealing tip 165 for preventing the ingress of fluid from the first end 14 of the elongate member 12 when the catheter is in use to the inner handle compartment 157.

[00105] In another preferred embodiment, it may be appreciated that the flexible preformed electrical lead 10 may be manufactured such that the electrical conductors may be integrally consisting of the length of the electrical conductor 24, the electrically conductive curved portion 156 and the corresponding electrical conductor 25. In this

Substitute Sheet

(Rule 26) RO/AU preferred embodiment, the electrically conductive curved portion 156 of the electrical conductor may have stress relief means for increased flexibility and increased durability.

[00106] It may be an advantage of the described embodiments that the

electrophysiological catheter may be provided of a substantially smaller diameter than other conventional sensing catheters. This may be beneficial for the clinician to easily steer the electrophysiological catheter.

[00107] In another preferred embodiment, as shown in Figures 18A and 18B, the braided copper wires 22 may be woven about the parallel copper wires 23. A braiding machine may be used such that parallel wires may be fed through the braiding machine whilst the braid wires 22 may be woven around the parallel wires. To achieve this, the braiding machine allows parallel wires to be passed through the centre of the horn gears of the braiding machine during operation. This braiding woven around the parallel wires configuration may advantageously allow for an even greater number of copper wires to be incorporated into the flexible preformed electrical lead or cable 10 whilst maintaining the characteristics of braided tubing. For example, a 16 wire braided cable can include up to 8 parallel wires, which may bring the total number of conductive wires to 24. The parallel copper wires 23 are in the same layer as the braided copper wires 22.

[00108] In another preferred embodiment, as shown in Figures 19A and 19B, the braided wires 22 may be braided with any configuration of copper wires with other type of wire material such as constantan alloy, which may be a copper-nickel alloy. The copper wire 28 may be helically wound such that the copper wire 28 may be adjacent to the other type of wire material 29 as shown in Figure 19A. This embodiment may be an alternative to a complete copper wire braid. The braided copper with other material configuration may advantageously allow for greater flexibility in mechanical properties depending on the suitability of use. The method of producing a braid of copper wires with other type of wire materials may use a braiding machine carrier loaded with the desired alternate materials.

Substitute Sheet

(Rule 26) RO/AU [00109] In another preferred embodiment, as shown in Figures 20A and 20B, a variation of the braided copper cable may be to use a braided ribbon wire. Replacing single strands with multi-strand ribbon wire may provide more conductive wires and therefore may have a higher number of electrodes whilst maintaining the same braid configuration and desirable mechanical characteristics. This embodiment of the cable 10 may be produced by a braiding machine carrier loaded with multi-strand copper wire ribbon in place of single copper magnet wires.

[001 10] In another preferred embodiment, as shown in Figure 21, the braided copper wires 22 may be accompanied with specialised wires. A standard braid construction may incorporate specialty wires, such thermocouple wires, along with the copper wires. This may advantageously allow for the desirable properties of a braided tube to be maintained without requiring additional layers in the cable design. Production of this cable may be performed using the same braiding machine carrier, in which braiding is still performed in the same configuration but with one or more of the copper wires in braiding may be substituted with specialty wires and/or Litz wires.

[00111] In another preferred embodiment in which the specialised wires 23 are in the inner layer, as shown in Figures 22A and 22B, the braided copper wires 22 may be with specialised wircs/cables 23 running parallel with respect to each other. The specialised wires/cables 23 may be fibre optic cables or cables which may be suitable for using in force sensing. The advantages of this combination of copper braid with parallel wires may allow for the implementation of the copper braid concept whilst also incorporating specialty wires that may mechanically should be maintained in the cable such as fibre optic cables or cables which may be suitable for using in force sensing.

This type of preformed electrical lead 10 may be produced by tube extruding an inner layer first followed by the parallel specialty wires 23 may then be passed through the tube extruder during a pressure extrusion process. After the parallel specialty wires 23 have been pressure extruded, the parallel specialty wires 23 may become encapsulated by the polymer. The copper wires may then be braided onto the cable and a final layer of

Substitute Sheet

(Rule 26) RO/AU polymer such as PEBAX^rM may be extruded on top as the outer layer of non-conductive material 20.

[001 12] In another preferred embodiment in which the specialised wires 23 are in the outer layer, as shown in Figures 23A and 23B, the braided copper wires 22 may be with specialised wires/cables 23 running parallel with respect to each other. The specialised wires/cables 23 may be fibre optic cables or cables which may be suitable for using in force sensing. The advantages of this combination of copper braid with parallel wires may allow for the implementation of the copper braid concept whilst also incorporating specialty wires that may mechanically should be maintained in the cable such as fibre optic cables or cables which may be suitable for using in force sensing.

This type of preformed electrical lead 10 may be produced by producing a three-layered braided copper cable first. Following this, parallel specialty wires 23 may then be passed through the tube extruder during a pressure extrusion process. After the parallel specialty wires 23 have been pressure extruded, the parallel specialty wires 23 may become encapsulated by the polymer on top of the braided layer.

[00113] In another preferred embodiment in which the specialised wires 23 are in the braided layer, as shown in Figures 24A and 24B, the braided copper wires 22 may be with specialised wires/cables 23 running parallel in between the braid. The specialised wires/cables 23 may be parallel with respect to each other. The specialised wires/cables 23 may be fibre optic cables or cables which may be suitable for using in force sensing. The advantages of this combination of copper braid with parallel wires may allow for the implementation of the copper braid concept whilst also incorporating specialty wires that may mechanically should be maintained in the cable such as fibre optic cables or cables which may be suitable for using in force sensing. This type of preformed electrical lead 10 may be produced by feeding the parallel specialty wires onto the cable 10 through the braiding process, in which the parallel wires may be passed through the centre of the horn gears during operation of the braiding machine.

[003 14] In another preferred embodiment, the braiding material may be a plastic braiding material, more particularly, thermoplastic material such as Liquid Crystal

Substitute Sheet

(Rule 26) RO/AU Polymers (LCP) or Polyether Ether Ketone (PEEK) or silicone polymer. The

thermoplastic braids may allow the catheter lead 10 to be compatible with MRI applications. Besides the compatibility with MRI applications, the plastic braiding may also be advantageously used for insulative purposes. For example, the plastic braiding may isolate a fixed voltage between 100 to 1000V to a metallic electrode and/or series of metallic electrodes. Furthermore, plastic braiding may have lower flexural rigidity when compared to a metal braid. This may be beneficial where a lower flexural rigidity is required. For the variable loop sheath example, the loop may require a lower flexural rigidity but may benefit from radial movement with a braided tube which may overcome a potential perforation from the stylet. In this example, a plastic braid may be a better option than the metal braided embodiment. For the irrigated ablation catheter example, the irrigated ablator may have an internal irrigation lumen 18. The combination of rigid plastic, pressurized saline and helically wound cable/metal braid 22 may make the catheter too rigid and may therefore risk cardiac perforation. The lack of helically wound cables and/or metal braid might cause the catheter to be too soft and may compromise manoeuvrability. While the plastic braid may be required for MRI applications, this plastic braid feature may not be required in irreversible electroporation (EP) or pulsed frequency ablation procedures for the treatment of arrythmias. Those procedures may require the delivery of high voltages such as 100 to 1000Y, which may be high enough to induce apoptosis and cell death.

[00115] The benefits of using the LCP or PEEK as the braiding material may be at least one of: decreased flexural rigidity compared to metal braids and helically wound cable; increased torque, axial rigidity, and radial stiffness compared to standard plastic tubes; improved buckling for example, less likely to perforate heart muscle; and electrically insulative. The LCP or PEEK as the braiding material may be suitably used for radiofrequency ablation catheters, pulsed frequency ablation catheters, or

electrophysiology catheters. The method of producing the plastic braiding will be similar in method to metal braiding.

Substitute Sheet

(Rule 26) RO/AU [00116] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms, in keeping with the broad principles and the spirit of the invention described herein.

[00117] The present invention and the described preferred embodiments specifically include at least one feature that is industrial applicable.

Substitute Sheet

(Rule 26) RO/AU

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A flexible electrical lead for a catheter comprising:

an elongate member having a first end and a second end, and defining a lumen extending from the first end to the second end;

the elongate member further comprising:

a first layer of non- conductive material and a second layer of resilient braided material, wherein the second layer is arranged between the first layer and the lumen, wherein the second layer is in a preformed three-dimensional shape and the second layer imparts the preformed three-dimensional shape onto the electrical lead;

a plurality of electrical conductors encapsulated between the first layer and the second layer, wherein the plurality of electrical conductors extending parallel to the longitudinal axis of the lumen, wherein the first layer encapsulates the plurality of electrical conductors.

2. The electrical lead as claimed in claim 1, wherein at least one electrode comprises a first electrode and wherein the first electrode on an outer surface of the elongate member is in electrical communication with at least one of the plurality of electrical conductors through the first layer.

3. The electrical lead as claimed in claim 2, wherein the second layer is insulated from the first electrode.

Substitute Sheet

(Rule 26) RO/AU

4. The electrical lead as claimed in any one of the preceding claims, wherein the at least one electrode is insulated by the first layer.

5. The electrical lead as claimed in claim 4, wherein the second layer is insulated from the plurality of electrical conductors by a third layer of non-conductive material, wherein the third layer is positioned between the first layer and the second layer.

6. The electrical lead as claimed in any one of claims 2 to 5, comprises a second electrode, wherein the second electrode covers the second end of the elongate member and is in electrical communication with at least one of the plurality of electrical conductors through the first layer.

7. The electrical lead as claimed in claim 5 or claim 6, wherein the at least one sensing electrode is at least one selected from the group of: platinum electrode, doped conjugated organic polymer electrodes, and polymer-metal hybrid electrodes.

8. The electrical lead as claimed in claim 7, wherein a first conductive adhesive is in electrical communication with the platinum electrode and an electrical conductor of the plurality of electrical conductors.

9. The electrical lead as claimed in claim 8, wherein the first conductive adhesive is at least one selected from the group of: a conductive epoxy, and solder.

Substitute Sheet

(Rule 26) RO/AU

10. The electrical lead as claimed in claim 9, wherein the melting temperature of the solder is at a lower temperature than the melting temperature of the first layer.

11. The electrical lead as claimed in claim 7, wherein the polymer of the polymer- metal hybrid electrode comprises polyurethane, and the metal of the polymer- metal hybrid electrode comprises silver, and tungsten.

12. The electrical lead as claimed in claim 1 1 , wherein the polymer-metal hybrid electrode comprises a radiopaque marking.

13. The electrical lead as claimed in claim 12, wherein the radiopaque marking is at least one selected from the group of: an arrow, and a graduated scale.

14. The electrical lead as claimed in any one of the preceding claims, wherein the plurality of electrical conductors are arranged at circumferentially spaced intervals.

15. The electrical lead as claimed in any one of the preceding claims, wherein the first end of the elongate member is connectable with a handle.

16. The electrical lead as claimed in Claim 15, wherein the plurality of the electrical conductors are in electrical communication with a corresponding plurality of

Substitute Sheet

(Rule 26) RO/AU electrical conductors in the handle, wherein the first end of the elongate member and the handle are connected.

17. The electrical lead as claimed in Claim 15 and Claim 16, wherein the connection between the first end of the elongate member and the handle is affixed by a second adhesive.

18. The electrical lead as claimed in Claim 17, wherein the second adhesive is at least one selected from the group of: instant adhesive and UY cure adhesive.

19. The electrical lead as claimed in any one of the preceding claims, further comprising an inner non-conductive layer between the resilient braided layer and the lumen.

20. A method of fabricating a flexible electrical lead for a catheter, the method comprising the steps of:

providing an elongate member having a first end and a second end, and defining a lumen extending from the first end to the second end;

providing the elongate member having a first layer of non-conductive material and a second layer of resilient braided material, wherein the second layer is arranged between the first layer and the lumen;

imparting a preformed three-dimensional shape onto the electrical lead by the second layer, wherein the second layer is in the preformed three-dimensional shape;

Substitute Sheet

(Rule 26) RO/AU encapsulating a plurality of electrical conductors between the first layer and the second layer, wherein the plurality of electrical conductors are extending parallel to the longitudinal axis of the lumen; and whereby

applying a pressurised extrusion to the flexible preformed electrical lead molds the first layer such that the first layer encapsulates the plurality of electrical conductors.

Substitute Sheet

(Rule 26) RO/AU