阅读说明：本技术 用于分叉末端导管的柔性电路末端 (Flexible circuit tip for bifurcated tip catheter ) 是由 A·饶 C·T·贝克勒 R·彭肯迪 K·达塔 于 2019-07-25 设计创作，主要内容包括：本发明公开了一种导管末端,所述导管末端可例如经由光刻被制造为平面柔性电路,所述平面柔性电路具有第一平面区段和第二平面区段,所述第一平面区段和所述第二平面区段在彼此绝缘的不同的区上包括各种电极。所述末端可变形以具有非平面构型,例如圆柱形,然后组装到导管上。所述导管可用于监测ECG信号和温度,并且用于经由所述各种电极将消融能量精确地递送到组织。当消融能量被递送到一个区时,可针对另一个区监测ECG信号和温度。(A catheter tip that can be fabricated, for example via photolithography, as a planar flexible circuit having a first planar section and a second planar section that include various electrodes on different regions that are insulated from each other. The tip may be deformed to have a non-planar configuration, such as a cylindrical shape, and then assembled to the catheter. The catheter can be used to monitor ECG signals and temperature, and to accurately deliver ablation energy to tissue via the various electrodes. As ablation energy is delivered to one zone, ECG signals and temperature may be monitored for another zone.)

1. A flexible circuit, comprising:

a first planar section and a second planar section, the second planar section including a plurality of flush ports disposed therethrough,

the second planar section further comprises

A first layer comprising a substrate,

a second layer comprising at least a first temperature sensor, a second temperature sensor and a conductor element, an

A third layer comprising an insulator.

2. The flexible circuit of claim 1, wherein the second planar section comprises a first zone and a second zone, the first zone having the first temperature sensor and the second temperature sensor, and the second zone having a third temperature sensor and a fourth temperature sensor.

3. The flexible circuit of claim 2, wherein the second planar section further comprises a third zone having a fifth temperature sensor and a sixth temperature sensor.

4. The flexible circuit of claim 3, wherein the conductor element comprises a trace connected to an ablation electrode.

5. The flexible circuit of claim 4, wherein the first, second, and third regions each comprise a respective pad having a first contact operatively coupled to a respective thermocouple, a second contact operatively coupled to another respective thermocouple, and a third contact operatively coupled to a respective electrode.

6. The flexible circuit of claim 5, wherein the first planar section comprises a first section base and a first section insulator.

7. The flexible circuit of claim 6, wherein the first planar section further comprises a first section temperature sensor.

8. The flexible circuit of claim 7, wherein the first planar section further comprises a first section electrode.

9. The flexible circuit of claim 1, wherein the insulator comprises a polyamide, a polyimide, a liquid crystal polymer, or a polyurethane.

10. The flexible circuit of claim 8, further comprising a first space between the second layer of the first zone and the second layer of the second zone, and a second space between the second layer of the second zone and the second layer of the third zone.

11. The flexible circuit of claim 10, further comprising a first insulating material disposed within the first space and the second space.

12. The flexible circuit of claim 11, wherein the first insulating material comprises a high temperature epoxy.

13. The flexible circuit of claim 1, wherein the second planar section includes a first region having the first temperature sensor, the second temperature sensor, and an ablation electrode, and a second region covered in an insulating material.

14. The flexible circuit of claim 13, wherein the second planar section comprises a third region covered in an insulating material.

15. The flexible circuit of claim 14, wherein the insulating material is ceramic.

16. A catheter, comprising:

an elongate catheter body having a distal end and at least two lumens disposed longitudinally therethrough; and

a flexible circuit tip connected to the distal end, the flexible circuit tip comprising:

a first section and a second section, the second section including a plurality of flush ports disposed therethrough, the second section further including:

a first layer comprising a substrate,

a second layer comprising at least a first temperature sensor, a second temperature sensor and a conductor element, an

A third layer comprising an insulator.

17. The catheter of claim 16, further comprising a core attached to the distal end of the catheter, at least a portion of the core being disposed within the second section of the flexible circuit tip.

18. The catheter of claim 17, wherein the core comprises an insulating material.

19. The catheter of claim 17, wherein the insulating material comprises polycarbonate.

20. The catheter of claim 17, wherein the core comprises a lumen oriented transverse to a longitudinal axis of the core.

21. The catheter of claim 17, further comprising a second insulating material disposed between the second section and the core.

22. The catheter of claim 17, wherein the core is in communication with a first lumen of the at least two lumens of the catheter body.

23. The catheter of claim 22, further comprising a plurality of wires disposed within at least a second of the at least two lumens, the plurality of wires electrically connected to the flexible circuit tip.

24. The catheter of claim 23, wherein the second section comprises a first zone and a second zone, the first zone having the first temperature sensor and the second temperature sensor, and the second zone having a third temperature sensor and a fourth temperature sensor.

25. The catheter of claim 23, wherein the second section further comprises a third zone having a fifth temperature sensor and a sixth temperature sensor.

26. The catheter of claim 25, wherein the conductor element comprises a trace connected to an electrode.

27. The catheter of claim 26, wherein the first, second, and third zones each comprise a respective pad having a first contact operatively coupled to a respective thermocouple, a second contact operatively coupled to another respective thermocouple, and a third contact operatively coupled to a respective electrode.

28. The catheter of claim 25, wherein the first section comprises a first section base and a first section insulator.

29. The catheter of claim 28, wherein the first section further comprises a first section temperature sensor.

30. The catheter of claim 29, wherein the first planar section further comprises a first section electrode.

31. The catheter of claim 29, wherein the insulator comprises polyamide, polyimide, liquid crystal polymer, or polyurethane.

32. The catheter of claim 31, further comprising a first space between the second layer of the first zone and the second layer of the second zone, and a second space between the second layer of the second zone and the second layer of the third zone.

33. The catheter of claim 32, further comprising a first insulating material disposed within the first space and the second space.

34. The catheter of claim 33, wherein the first insulating material comprises a high temperature epoxy.

35. A method of assembling a catheter, comprising:

receiving a catheter body including a distal end,

receiving a flexible circuit tip, the flexible circuit tip comprising

A first section and a second section, the second section having a planar configuration and comprising a plurality of irrigation ports disposed therethrough,

the second planar section further comprises

A first layer comprising a substrate,

a second layer comprising a conductor element,

a third layer comprising an insulator; and

a first zone having a first temperature sensor and a second temperature sensor, a second zone having a third temperature sensor and a fourth temperature sensor, and a third zone having a fifth temperature sensor and a sixth temperature sensor;

changing the planar configuration of the second section to a non-planar configuration; and

connecting the second segment in the non-planar configuration to the distal end of the catheter body.

36. The method of claim 35, wherein the insulator comprises a polyamide, a polyimide, a liquid crystal polymer, or a polyurethane.

37. The method of claim 35, wherein the non-planar configuration comprises a cylindrical configuration.

38. The method of claim 35, wherein the conductor element comprises a trace connected to an ablation electrode.

39. The method of claim 38, further comprising connecting the conductor element to an electrode.

40. The method of claim 39, wherein the first, second, and third regions each comprise a respective pad having a first contact operatively coupled to a respective thermocouple, a second contact operatively coupled to another respective thermocouple, and a third contact operatively coupled to a respective electrode.

41. The method of claim 40, further comprising connecting leads to the first, second, and third contacts of each of the first, second, and third regions.

42. The method of claim 35, wherein the second section further comprises a first space between the first zone and the second zone, a second space between the second zone and the third zone, and a third space between the third zone and the first zone.

43. The method of claim 42, wherein the second section in the non-planar configuration comprises a third space between the third zone and the first zone.

44. The method of claim 43, further comprising disposing a first insulating material in the first space, the second space, and the third space.

45. The method of claim 43, further comprising:

a receiving core;

attaching the core to the distal end of the catheter body;

disposing the core within a portion of the second section of the flexible circuit end in the cylindrical configuration; and

attaching the flexible circuit end to the core.

46. The method of claim 45, further comprising disposing a second insulating material between the second section and the core.

47. A method of ablating tissue comprising

Inserting a catheter into a subject, the catheter comprising a force sensor and a tip, the tip having at least a first, second and third tip regions, each of the first, second and third tip regions comprising an electrode and a temperature sensor, and being electrically and thermally insulated from the other tip regions;

contacting at least one of the first end region, the second end region, and the third end region with cardiac tissue;

receiving, at a processor, a signal from the force sensor, an ECG signal from the first zone, an ECG signal from the second zone, an ECG signal from the third zone, and temperature data; and

providing ablative energy to at least one of the first end region, the second end region, and the third end region.

48. The method of claim 47, further comprising determining that the first end region contacts tissue.

49. The method of claim 48, wherein the signal from the force sensor is used to determine that the first end region contacts tissue.

50. The method of claim 48, further comprising determining that the second end region contacts tissue.

51. The method of claim 50, wherein the signal from the force sensor is used to determine that the second end region contacts tissue.

52. The method of claim 50, further comprising determining that the third end region contacts tissue.

53. The method of claim 52, wherein the signal from the force sensor is used to determine that the third end region contacts tissue.

54. The method of claim 52, further comprising providing ablation energy to the first end region upon receiving an ECG signal from the second end region at the processor.

55. The method of claim 54, further comprising providing ablation energy to the first end region upon receiving an ECG signal from the third end region at the processor.

56. The method according to claim 54, further comprising providing ablation energy to the second end region upon receiving an ECG signal at the processor from the third end region.

57. The method according to claim 56, further comprising providing ablation energy to the second end region upon receipt of ECG signals from the first end region at the processor.

58. The method according to claim 56, further comprising providing ablation energy to the third end region upon receiving an ECG signal from the first end region at the processor.

59. The method of claim 58, further comprising providing ablation energy to the third end region upon receiving an ECG signal at the processor from the second end region.

60. The method according to claim 56, further comprising simultaneously providing ablation energy to at least two of the first end region, the second end region, and the third end region.

61. The method of claim 56, further comprising ablating a portion of tissue in contact with the first end region and then ablating a portion of tissue in contact with the second end region without moving the tip.

62. The method of claim 61, wherein ablating comprises delivering a first amount of power to the first end region and delivering a second amount of power different from the first amount of power to the second end region.

63. The method of claim 62, wherein the step of ablating comprises delivering a third amount of power to the third end region that is different from the first and second amounts of power.

64. The method of claim 62, wherein the ablating step comprises delivering different amounts of power to different end regions such that the temperature measured for each end region is substantially the same for all of the end regions.

Technical Field

The subject matter disclosed herein relates to electrophysiology catheters, and more particularly, to flexible circuit tips of bifurcated tip catheters for use in cardiac electrical ablation and mapping procedures.

Background

When a region of cardiac tissue abnormally conducts electrical signals to adjacent tissue, an arrhythmia, such as atrial fibrillation, occurs, disrupting the normal cardiac cycle and causing an arrhythmia.

Protocols for treating cardiac arrhythmias include surgically disrupting the source of the signal causing the arrhythmia, as well as disrupting the conduction pathway for such signals. By applying energy through a catheter to selectively ablate cardiac tissue, it is sometimes possible to prevent or alter the propagation of unwanted electrical signals from one part of the heart to another. The ablation method breaks the unwanted electrical path by forming a non-conductive ablation lesion.

Disclosure of Invention

Ablation, particularly ablation of cardiac tissue, depends on accurate delivery of ablation energy while avoiding negative side effects such as thrombosis from providing ablation energy to the blood. The present invention discloses a catheter having a tip divided into three sections for these purposes. The tip can be fabricated, for example via photolithography, as a planar flexible circuit having a first planar section and a second planar section. The second planar section may include a plurality of flush ports disposed therethrough. The second planar section may further comprise a first layer having a substrate, a second layer having at least a first temperature sensor, a second temperature sensor and a conductor element, and a third layer having an insulator (e.g. a polyamide, polyimide or polyurethane material). Additionally, the second planar section may include a first zone having a first temperature sensor and a second zone having a third temperature sensor and a fourth temperature sensor. The second planar section may also include a third zone having a fifth temperature sensor and a sixth temperature sensor. In any of these embodiments, the conductor element may include a trace connected to the ablation electrode. In addition, the first, second, and third regions may each include a respective pad having a first contact operatively coupled to a respective thermocouple, a second contact operatively coupled to another respective thermocouple, and a third contact operatively coupled to a respective electrode.

Also in any of these embodiments, the first planar section may comprise a first section base and a first section insulator. Further, the first planar section may include a first section temperature sensor. The first planar section may also include a first section electrode. A first space may be provided between the second layer of the first region and the second layer of the second region, and a second space may be provided between the second layer of the second region and the second layer of the third region. The first insulating material may be disposed within the first space and, alternatively or additionally, may be disposed within the second space. The first insulating material may be a suitable insulating material, such as a biocompatible ceramic or a high temperature epoxy.

In any of the above embodiments, the tip may be included on the distal end of the catheter. The catheter may also include an elongated body having at least two lumens disposed longitudinally therethrough. A core may be attached to the distal end of the catheter, at least a portion of which may be disposed within the second section of the tip. The core may comprise an insulating material, such as polyurethane. In addition, the core may include a lumen oriented transverse to the longitudinal axis of the core. A second insulating material may be disposed between the second section and the core. The core may be in communication with a first lumen of the at least two lumens of the catheter body such that fluid may flow through one of the lumens and through the core. A plurality of wires may be disposed within at least a second of the at least two lumens, and the plurality of wires may be electrically connected to the flexible circuit tip.

In manufacture, the catheter may be assembled by first receiving the catheter body and tip in a planar configuration. By bending the tip itself and then connecting it to the distal end of the catheter body, the tip can change its planar configuration to a non-planar configuration (e.g., a cylindrical configuration). In those embodiments that include a core, the core can be received and subsequently attached to the distal end of the catheter body. The core may then be disposed within the end of the cylindrical configuration and subsequently attached thereto.

The catheter may be used according to the following methods and variations. First, a catheter may be inserted into a subject (e.g., a human subject) adjacent to the subject's heart. The tip can be manipulated into contact with tissue. The catheter may be an aspect of an ablation system that also includes a processor in communication with the tip. The first zone may monitor the ECG signal and provide the signal to the processor. The second zone may monitor the ECG signal and provide the signal to the processor. The third zone may monitor the ECG signal and provide the signal to the processor. Each of the three zones may also measure temperature and provide temperature data to the processor. Ablation energy may be provided to the tip, e.g., controlled by a processor.

In some variations of the method, the processor determines that the first end region contacts tissue. Further, the processor may determine that the second end region contacts tissue. Further, the processor may determine that the third end region contacts tissue.

ECG signals from the second end region are received at the processor, which may control the ablation energy to the first end region. This may also be performed when the processor receives the ECG signal from the third end region at the processor. Upon receiving the ECG signal from the third end region, the processor may control ablation energy to the second end region. This may also be performed when the processor receives the ECG signal from the first end region. The ECG signal from the first end region is received at the processor, which may control ablation energy to the third end region. This may also be performed when the processor receives ECG signals from the second end region. Additionally or alternatively, the processor may control the ablative energy to at least two of the first end region, the second end region, and the third end region simultaneously.

In any of these variations, a portion of the tissue in contact with the first end region may be ablated. Then, without moving the tip, a portion of the tissue in contact with the second tip region may be ablated.

As used herein, the terms "insulator," "insulating material," "insulative material," and the like each mean a material and structure comprising at least one material having properties that are generally accepted by those skilled in the art to resist heat transfer and electrical signal transmission. Such materials include, but are not limited to, polyamides, polyimides, polyurethanes, polycarbonates, ceramics, liquid crystal polymers, and high temperature epoxies.

Drawings

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter described herein, it is believed that the subject matter will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and wherein:

FIG. 1 is a diagrammatic, schematic view of a system for assessing electrical activity in a heart of a living subject and providing therapy thereto using a catheter;

FIG. 2 depicts a flexible circuit;

FIG. 3 depicts the flexible circuit of FIG. 2 formed into a flexible circuit tip and connected to the distal end of a catheter;

FIG. 4 is a representation of FIG. 3 with the flexible circuit end hidden;

FIG. 5 depicts an alternative embodiment of a catheter including a flexible circuit tip;

FIG. 6 depicts another flexible circuit;

FIG. 7 depicts the flexible circuit of FIG. 6 in a modified configuration;

FIG. 8 depicts yet another flexible circuit;

FIG. 9 depicts a spring member;

FIG. 10 depicts a distal portion of the catheter of FIG. 3 in a partially assembled configuration;

FIG. 11 depicts a distal portion of the catheter of FIG. 3 in a further partially assembled configuration; and is

Fig. 12 depicts a cross-section taken through line a-a of fig. 10.

Detailed Description

The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.

As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows the component or collection of elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ± 10% of the recited value, e.g., "about 90%" may refer to a range of values from 81% to 99%. In addition, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject and are not intended to limit the system or method to human use, but use of the subject invention in a human patient represents a preferred embodiment.

Fig. 1 is a diagrammatic, schematic view of a system 10 for assessing electrical activity on a heart 12 of a living subject and performing an ablation procedure thereon. The system includes a diagnostic/therapeutic catheter having a catheter body 14 with a distal end 15 and a tip (e.g., tip 18) disposed thereon that is percutaneously insertable by an operator 16 into a chamber or vascular structure of the heart 12 through the vascular system of the patient. An operator 16, typically a physician, brings a tip 18 of the catheter into contact with the heart wall, for example at the ablation target site. Electrical activity maps may be prepared according to the methods disclosed in U.S. Pat. nos. 6,226,542 and 6,301,496, and in commonly assigned U.S. Pat. No. 6,892,091, the disclosures of which are hereby incorporated by reference in their entirety. An article of commerce embodying elements of system 10 mayThe 3 system was purchased from Biosense Webster, inc.,33 Technology Drive, Irvine, CA, 92618.

Regions determined to be abnormal, for example, by evaluation of an electrical activity map, can be ablated by applying thermal energy, for example, by conducting radio frequency electrical current through a lead in the catheter to one or more electrodes at the tip 18, which apply radio frequency energy to the target tissue. Energy is absorbed in the tissue, heating the tissue to a point (typically above 50 ℃) where the tissue permanently loses its electrical excitability. This procedure can form nonconductive foci in cardiac tissue that can interrupt the abnormal electrical pathway that leads to the arrhythmia. Such principles may be applied to different heart chambers to diagnose and treat a variety of different arrhythmias.

The catheter generally includes a handle 20 with suitable controls thereon to enable the operator 16 to manipulate, position and orient the distal end 15 of the catheter as required for the ablation procedure.

Ablation energy and electrical signals may be transmitted back and forth between heart 12 and console 24 via cable 38 through one or more electrodes 32 located at or near distal tip 18 or including tip 18. Pacing signals and other control signals may be communicated from console 24 to heart 12 via cable 38 and electrodes 32.

A lead connection 35 couples the console 24 with the body surface electrodes 30 and other components of the positioning subsystem for measuring the position and orientation coordinates of the catheter. Processor 22 or another processor may be an element of the positioning subsystem. The electrodes 32 and body surface electrodes 30 may be used to measure tissue impedance at the ablation site as set forth in U.S. patent 7,536,218 to Govari et al, which is incorporated by reference herein in its entirety. At least one temperature sensor, typically a thermocouple or thermistor, may be included on or near each of the electrodes 32, as will be described in detail below.

The console 24 typically contains one or more ablation power generators 25. The catheter may be adapted to conduct ablation energy, such as radiofrequency energy, ultrasound energy, cryogenic energy, and laser-generated optical energy, to the heart using any known ablation technique. Such methods are disclosed in commonly assigned U.S. Pat. Nos. 6,814,733, 6,997,924, and 7,156,816, which are incorporated herein by reference in their entirety.

The positioning subsystem may also include a magnetic position tracking arrangement that determines the position and orientation of the catheter by generating magnetic fields in a predefined workspace and sensing these fields at the catheter using coils or traces disposed within the catheter (typically near the tip). The positioning subsystem is described in U.S. patent 7,756,576 and the above-mentioned U.S. patent 7,536,218, which are incorporated herein by reference in their entirety.

Operator 16 may observe and adjust the function of the catheter via console 24. The console 24 includes a processor, preferably a computer with appropriate signal processing circuitry. The processor is coupled to drive a monitor 29. The signal processing circuitry typically receives, amplifies, filters, and digitizes signals from the catheter, including signals generated by sensors (e.g., electrodes 32) such as electrical sensors and temperature sensors, as well as a plurality of location sensing coils or traces located distal to the catheter. Console 24 and the positioning system receive and use the digitized signals to calculate the position and orientation of the catheter and analyze the electrical signals received from the catheter.

The subject matter disclosed herein relates to improvements in the manufacture and function of catheter tips known in the art, such as that disclosed in U.S. patent No. 6,171,275 to Webster, which is incorporated herein by reference in its entirety. The improved conduit end can be fabricated via a photolithographic process as a planar flexible circuit 100 reflected in fig. 2. As its illustration shows, the flexible circuit 100 is flexible. Thus, the flexible circuit can be bent into various non-planar configurations. For example, the configuration may change from planar to cylindrical such that the flexible circuit 100 may change to a cylindrical flexible circuit end 200, as reflected in fig. 3. Thus, in addition to the planar configuration of the flexible circuit 100 and the non-planar configuration of the flexible circuit tip 200, it is to be understood that features described herein with respect to the flexible circuit 100 are also present in the flexible circuit tip 200, and similarly, features described herein with respect to the flexible circuit tip 200 are also present in the flexible circuit 100, even if not expressly disclosed with respect to one of these configurations. In addition, the surface of the flex circuit 100 visible in fig. 2 becomes the inner surface of the flex circuit tip 200, and thus the electronic components visible in fig. 2 are not visible in fig. 3.

The flexible circuit 100 may include various sections depending on the desired configuration of the flexible circuit ends to be formed in the sections. As seen in fig. 2, the flexible circuit 100 has two sections, a first section 102 and a second section 104. The first section 102 may have a circular shape and the second section 104 may have a rectangular shape. So constituted, the flexible circuit 100 may be formed into a cylindrical flexible circuit tip 200 reflected in fig. 3, where the first section 102 becomes the distal-most portion (base of cylinder) 202 of the tip 200, and where the section 104 becomes the side surface (wall of cylinder) 204 of the tip 200.

The first section 102 may be provided with a geared or fancy pattern including teeth or lobes 106. The space 108 between the teeth 106 may accommodate a transition region 203 between the base 202 and the wall 204. Holes may also be provided through the first section 102 such that the holes 208 will be disposed within the transition region 203. The bore 208 may house various electronic components of the catheter, such as the electrodes 32. Additional electronic components may be incorporated into the first section 102, such as a temperature sensor (e.g., thermocouple) described below.

The second section 104 may include at least two, e.g., three, portions or zones, such as a first zone 110, a second zone 112, and a third zone 114. Dashed lines are provided on the second section 104, defining boundaries between these regions. Dashed lines are also provided on the first section 102, defining portions aligned with regions 110, 112 and 114 in the flexible circuit end 200.

The first zone 110 may include two temperature sensors (e.g., thermocouples) 116 and 118 and a conductor element 120. The second region 112 may include two temperature sensors 122 and 124 and a conductor element 126. The third region 112 may include two temperature sensors 128 and 130 and a conductor element 132. The conductor elements 120, 126, and 132 may each include at least a trace. Alternatively or additionally, the conductor elements 120, 126 and 132 may additionally include or be connected to electrodes, which may be conductive portions of, for example, the first, second and third regions 110, 112 and 114, particularly the outer layer of the second section 104 that becomes the outer surface of the tip 200. In such embodiments, vias should be provided between the conductor elements 120, 126 and 132 and the outer layer. Alternatively or additionally, the conductor elements 120, 126, and 132 may be connected to an electrode (e.g., electrode 32). The electrodes (whether the outer surface of the tip 200 or the electrodes 32) may function as, for example, ablation electrodes, mapping electrodes, or a combination thereof, depending on whether the signals that the electrodes may provide to the processor 22 are signals received from the generator 25 or electrical signals detected from tissue.

The flexible circuit 100 may also include various layers formed, for example, via a photolithographic process. At least one of the layers may be a conductive material such as gold, platinum or palladium or a combination thereof. For example, the conductive material may form a layer that forms the outer surface shown in fig. 3 on the flexible circuit end 200. Additionally, the conductive material may also form another layer that includes at least some of the electronic components of fig. 2 (e.g., temperature sensors 116 and 118). The other layer may comprise a substrate, for example a thin film of non-conductive or insulating material, onto which the conductive material may be deposited. The additional layer may also include an insulator. The base layer and the insulating layer are similar and may be provided as a single layer, however, improved insulating properties may be achieved by providing such layers: this layer has the sole purpose of insulating thermal and electrical signals from one portion of the tip 200 to other portions of the tip 200, as described below.

The port 134 may be disposed through the flexible circuit 100. These ports may be used to provide irrigation of the exterior of the tip 200. Pads 136, 138, and 140 may also be disposed on the second section 104, i.e., pad 136 is disposed on the first region 110, pad 138 is disposed on the second region 112, and pad 140 is disposed on the third region 114, each of which has various contacts 142, 144, and 146 in conductive communication with (operatively coupled to) electronic components disposed on the corresponding region. That is, for example, the bonding pads 136 include various contacts that are operatively coupled to the thermocouples 116 and 118 and the conductor element 120. In this manner, electronic components on one of the three regions of the second section 104 may be controlled (e.g., to provide ablation or detect electrical signals from tissue) and monitored separately from electronic components on the other two regions of the second section 104 (e.g., to detect individual temperatures of individual temperature sensors disposed on each portion of the section 104). In addition, the temperature around the tip 200 may be accurately monitored because each of the three zones includes two different temperature sensors, for a total of six temperature sensors on the tip 200.

In further embodiments, spacing may be provided between the first region 110 and the second region 112 and between the second region 112 and the third region 114. The spacing may be set by each layer, i.e., by the entire thickness of the flexible circuit 100. However, the pitch may be provided only by a layer including a conductive material, and need not be provided in the substrate and the insulating layer including a non-conductive material. The spacing may be provided, for example, along the contour identified by dashed lines 150 and 152 in fig. 2. This spacing isolates the various zones 110, 112, and 114 from one another, e.g., to help prevent heat from being distributed from one zone to another. Accordingly, the insulating material may be disposed within the pitch.

The flexible circuit 100 may be formed as a flexible circuit tip 200 and connected to the distal end 15 of the catheter body 14. The catheter body can have at least two lumens disposed longitudinally therethrough. For example, one of the two lumens may be used to direct irrigation fluid through the catheter body and into the tip 200. The other of the two lumens may contain leads for transmitting signals (e.g., electrical signals) to and from the electrical components of the tip 200. Additional lumens may be provided, for example, to accomplish steering functions, such as by including a pull wire or for guiding a wire, as is known in the art.

Referring to fig. 4, which is the illustration of fig. 3 with the tip 200 hidden, a core 250 (fig. 4) may be attached to the distal end 15 of the catheter body 14. The core 250 may be disposed within and attached to the tip 200 such that the tip 200 may be connected to the distal end 200 via the core 250 or with the aid of the core. The core 250 may include various ports 252 therethrough such that when the core 250 is connected to the catheter body 14, the ports 252 are in fluid communication with the flush lumen of the catheter body 14. The core 250 may provide the following advantages. First, the wick may prevent flushing fluid from entering the interior of the tip 200 in the longitudinal direction, which may bias the flushing flow out of the flushing holes. Instead, the core 250 balances the flow distribution by diverting the flow into various flows that are symmetric to each other and transverse to the core. Second, the core 250 may comprise an insulating material, such as polycarbonate, which may further help prevent heat distribution between the three regions 210, 212, and 214 of the wall 204 (corresponding to the three regions 110, 112, and 114 of the second section 104 of the flexible circuit 100). In this regard, additional insulating material may be disposed in the space between the core 250 and the tip 200, such as high temperature epoxy, polyurethane, polyamide, or polyimide. Third, a portion of the core 250 may be used as a mandrel around which the flexible circuit 100 may be formed into the flexible circuit end 200.

This third advantage can be appreciated in fig. 5, which illustrates an alternative embodiment in which the flexible circuit tip 300 is transparent (except that reference lines are provided to distinguish the regions 310, 312, and 314 from one another). The cartridge 350 is shown, again transparent, but with various flush ports indicated through the cartridge. Thus, the core 350 occupies all or most of the entire interior space defined by the flexible circuit end 300. Thus, in this embodiment, the flexible circuit 100 may be molded or otherwise conform to the outer shape of the core 350. In addition, the flexible circuit may be bonded to the core, which may facilitate assembly to the catheter body 14. Various tubes, such as 360, 362, and 364, may also be disposed within the core 350 to enable coupling with the temperature sensors 316, 318, 322, 324, 328, and 330. Additional tubes (e.g., 366) may also be provided within the core to enable coupling with other electronic components (e.g., electrode 332). In various embodiments, the wicks 250 and 350 need not include any lumens therethrough, such that the wicks may not provide the flow diverting function described above.

When the flexible circuit 100 is formed into the flexible circuit end 200 (or 300), a space may be formed between the first region 210 (or 310) and the third region 214 (or 314). The space may be filled with an insulating material as described above for the space between the first region 110 and the second region 112 and between the second region 112 and the third portion 114.

Thus, the catheter body 14 equipped with the tip 200 (or 300) provides various improvements in catheter tip design. Notably, each of regions 210, 212, and 214 and its electronic components are insulated from and functionally independent of the other two regions. Such assistance system 10 measures and generates information that can be used by the system 10 or operator 16 to provide and modify ablation therapy. In a preferred embodiment, the tip is divided into three or more distinct zones, each zone having a different electrode. The electrodes on one of the zones may be activated or deactivated independently of the electrodes on each of the other zones, and they may be activated to provide different functions, such as ablation or ECG sensing. In addition, the electrical signal provided to each of the three zones (typically within the RF range of the generator) may be the same or different than the electrical signal provided to one or both of the other zones. That is, the power delivered to each end region (e.g., the amount of power expressed in watts) may be the same or different for each region. For example, the amount of power delivered to the first end region ("first amount of power" in watts) may be controlled to be different (i.e., higher or lower) than the amount of power delivered to the second end region ("second amount of power"). Likewise, the third end region may be turned off, or a third amount of power ("third amount of power") different from the first amount of power or the second amount of power may be provided to the third end region. Alternatively, the energy delivered (in joules) to each zone may be the same or different for each zone. In yet another example, the frequency of the RF signal provided to one zone may vary relative to the frequency of the signal provided to one zone or two other zones. The RF signal may be changed to any frequency within the RF band of 10kHZ to 1MHz, for example, based on suitable feedback control. Such techniques for controlling the energy or power of the tip region help control the temperature of the tip 200 or tissue being ablated, and may also help improve the accuracy of the ablation.

It should be noted that the composition of the biological tissue in contact with the end region (e.g., water content, thickness, or other tissue characteristics) may affect the resistivity, and thus the RF power delivered to the tissue by the end region. Thus, the amount of temperature rise in the end region due to energy or power delivered to such tissue may be different from other end regions in contact with the same tissue (or even different tissue) at different locations having corresponding different tissue characteristics. Thus, one advantage of embodiments herein is the ability of the system to deliver different power levels to different end zones to ensure that the temperature measured for one end zone is substantially the same for all end zones.

The tip 200 (or 300) may be in contact with tissue such that the tissue contacts at least a portion of the first zone, or at least a portion of the first zone and at least a portion of the second zone, or at least a portion of each of the three zones. The ECG signal may be evaluated separately by the various electrodes of the three zones so that a user or system may determine which zones contact tissue in order to determine which electrodes to activate for ablation. In addition, the zone-specific signals of the ECG can be used to customize the treatment. For example, when zone 210 operating as an ablation electrode provides ablation energy to tissue in contact with zone 210 (or at least a portion thereof), temperature sensors on zone 210 measure temperature data and provide it to processor 22. At the same time, some or all of the temperature sensors on the tip 200 may provide temperature data to the processor 22, while the regions 212 and 214 operating as electromagnetic sensors and not in contact with tissue, in partial contact with tissue, or in full contact with tissue may provide ECG data to the processor 22 or may be deactivated. Alternatively, one of the regions 212 or 214 may be deactivated while the other provides ECG data. That is, while the electrodes of one or both zones function as ablation electrodes, other electrodes may provide input to determine whether a nearby region should be ablated, and if so, how the treatment should be provided or customized (e.g., via power modification, activation duration, continuous or pulsed activation, etc.). Furthermore, by providing ablation energy only to those regions in contact with the tissue, ablation energy can be provided precisely directly to the tissue, so that the energy applied to the blood can be minimized, which minimizes the likelihood of thrombosis. Furthermore, when a smaller region of the anatomy (e.g., epicardium or kidney) receives energy directly, there will be a higher probability that the wrong tissue will be ablated faster and more accurately. In addition, ECG data from non-tissue contact areas can be used to detect early signs of obstruction (e.g., thrombus) while the tissue contact areas in contact with the tissue are being ablated so that remedial steps can be taken quickly.

Additionally, in certain instances, for example, when it is determined that at least a portion of all three zones are in contact with tissue, the processor 22 may control the application of ablation energy automatically or based on user input such that ablation energy may be provided to the tissue via all three zones simultaneously or continuously. When ablation energy is applied to more than one electrode in succession, one or both ablation electrodes may be activated at a time. Two exemplary consecutive activations include: 1) zone 210 may be activated and then deactivated, then zone 212 may be activated and then deactivated, and zone 214 may be activated and then deactivated; and 2) zones 210 and 212 may be activated, then zone 210 may be deactivated and zone 214 activated, then zone 212 may be deactivated and zone 210 activated. Additional successive activations in different combinations may be performed and also repeated until the desired ablation is achieved, as indicated by the ECG signal or other signals provided by the electrodes. One advantage of continuous activation is that it allows for ablation and monitoring of different portions of tissue without moving the catheter. In addition, continuous activation may be combined with simultaneous activation of all zones. Moreover, activation can be performed repeatedly, either sequentially or simultaneously.

In some epicardial applications, certain design considerations may suggest further minimizing the amount of heat generated by one zone that is detected by the thermocouple of another zone, and further minimizing the likelihood that an ECG signal detected by an electrode on one zone is also detected by the sensor of another zone. Thus, one or both of the three zones can be fabricated with greater insulating properties, but without other functions, such as temperature measurement, ablation, and sensing, and associated components, such as thermocouples and electrodes. Thus, one or both of the zones (e.g., zone 212, zone 214, or both) may incorporate a greater amount of insulating material therein than those embodiments in which the zones include a function such as ablation. Thus, for example, ceramic material may be deposited onto the flexible circuit 100 over the zones 112 and 114, which helps prevent heat from the ablated tissue from affecting the catheter tip via these zones.

As described above, the ECG signal can be evaluated by the electrodes disposed on the tip individually so that a user or system can determine which electrodes are to be activated for providing ablation therapy in those embodiments having electrodes on different tip regions, and the tip contacting tissue. Force contact sensors may also be used to determine contact with tissue, for example, as described in U.S. patent application No. 15/452,843 filed on 3/8 2017, which is incorporated herein by reference in its entirety. A contact force sensor particularly suited for use with catheters having split tips is now described and is also described in us patent application No. 16/036710 filed 2018, 7, 16, which is incorporated herein by reference in its entirety.

Fig. 6 reflects a flexible circuit 410 that may be used within a catheter, such as catheter 14, to provide signals regarding position and force to a processor in console 24. The flexible circuit 410 includes a generally planar substrate 412 having a first portion 414 of a first shape (e.g., circular or saw-tooth as shown) and a second portion 416 of a second shape (e.g., generally rectangular or polygonal as shown). The first portion 414 and the second portion 416 are generally different shapes because, as described below, the second portion 416 is assembled parallel to the longitudinal axis of the catheter such that the second portion should be elongated, while the first portion 414 is assembled transverse to the longitudinal axis of the catheter such that the first portion should conform to the inner diameter of the catheter (i.e., the first portion has a maximum width or diameter that is less than or about equal to the inner diameter of the catheter). Nonetheless, the shape of the first portion 414 and the second portion 416 may be similar. The substrate 412 may be formed of any suitable material that is electrically non-conductive and can withstand high temperatures (e.g., polyimide or polyamide).

The substrate 412 may also include additional portions, such as a third portion 430 and a fourth portion 442. Each of these portions may also include individual segments. As noted, the first portion 414 may have a clover shape. Thus, the first portion may have three sections, namely sections 460, 462 and 464. Second portion 416 may include a segment 422 and a segment 424, and at least one connecting segment, such as 426 or 450, connecting segment 422 to segment 424. Third portion 430 may have a similar structure to second portion 416, and may include a section 432 and a section 434, and at least one connecting section, such as 436 or 452, connecting section 432 to section 434. The fourth portion 442 may include at least three connecting sections 444, 446, and 448 that connect the fourth portion 442 to the first portion 414, the second portion 416, and the third portion 430.

Electronic components may be incorporated into substrate 412 and various portions and sections thereof. For example, a generally planar coil or trace for measuring a force-related signal (i.e., a force sensing coil or trace) may be incorporated on the first portion 414. Specifically, coil 418 may be combined with section 460, coil 470 may be combined with section 462, and coil 472 may be combined with section 464. The coils 418, 470, and 472 may be separate from each other, as shown, or they may each be connected to one or both of the other coils. Portions of each coil, or extensions thereof, may extend from the coil to a weld point 468 located on the fourth portion 442 and welded thereto. In the case where the three coils are separated from each other, each coil should include a respective extension (i.e., 466, 474, and 476). However, in the case of three coil connections, only one or two extensions may be required. Where the coils are separated from one another, the signal generated in each of the coils can be used to provide additional details of the force, such as an indication of the off-center or off-axis direction of the force. Further, the catheter 14 may be assembled such that the sections 460, 462, and 464 may be aligned with the zones 210, 212, and 214, respectively. Thus, processor 22 may use the signals generated in coils 418, 470, and 472 to provide a different determination of the force on each zone. As shown, each coil on the first portion 414 includes approximately five turns. However, because the signal strength is a function of the number of wire turns, the number of wire turns can be maximized based on the size of each segment and the pitch achievable by the photolithographic process.

Planar coils or traces for measuring position-related signals (i.e., position coils or traces) may also be incorporated into the second portion 416 and the third portion 430. Coil 420 may be combined with segment 422, coil 428 may be combined with segment 424, coil 438 may be combined with segment 432, and coil 440 may be combined with segment 434. Each of these coils may extend to a weld point 468 on the fourth portion 442. For example, the coil 420 may include an extension 454 connected to a weld 468 via a connection section 446, and the coil 428 may include an extension 456 connected to a weld 468 via a connection section 426, a section 422, and a connection section 446. As shown, each coil on first portion 416 and second portion 430 includes approximately five turns. However, because signal strength is a function of the number of wire turns, the number of wire turns can be maximized based on the size of the segments 422, 424, 432, and 434 and the pitch achievable by the photolithographic process.

Various symmetries are reflected in fig. 6. For example, the entire substrate is symmetrical about a center line passing through the center of the first portion 414, such that the second portion 416 is laterally disposed to one side of the first portion 414 and the fourth portion 442, and such that the third portion 430 is laterally disposed to the other side of the first portion 414 and the fourth portion 442. Thus, the fourth portion 442 is disposed between the first portion 414, the second portion 416, and the third portion 430. Further, segments 422 and 424 are mirror images of each other, and coil 420 is mirror image of coil 428 except for extension 456. The same is true for sections 432 and 434 and coils 438 and 440. Thus, and as shown, the windings of coils 420 and 432 may be clockwise (i.e., have a clockwise orientation), while the windings of coils 428 and 434 may be counterclockwise (i.e., have a counterclockwise orientation). Alternatively, the windings of coils 420 and 432 may be counter-clockwise and the windings of coils 428 and 434 may be clockwise.

The substrate 412 may be a single layer. Alternatively, it may comprise between two and ten layers, for example four layers. Each layer is identical to the other layers, including the various portions, sections, and coil shapes described above. In this way, the coil can be thickened by adding layers. However, the thickening of the layer leads to an increase in the non-linearity of the signal generation. The flexibility of flex circuit 410 provides a solution to this tradeoff. Specifically, referring to fig. 7, segment 424 may be folded on top of segment 422 to contact and overlap segment 422 by deforming or bending connector 426 and connector 450 such that coil 428 is aligned with coil 420. Similarly, by deforming or bending connector 436 and connector 452, section 434 may be folded on top of section 432 to contact and overlap section 432 such that coil 440 is aligned with coil 438. Although connectors 450 and 452 are optional, they may help align the coils with each other by reducing relative rotation between the sections. If the substrate 412 has, for example, four layers, after folding the segment 424 onto the segment 422, the coils 420 and 428 form a combined coil having eight layers. The yield of the combined coil is not affected by the non-linear increase as is the case with eight-layer coils fabricated in an eight-layer substrate.

An advantage of a thinner substrate (e.g., four layers) over a thicker substrate (e.g., eight layers) is that it is more easily deformed or bent, which facilitates assembly of the flexible circuit 410 to other catheter components and ultimately fitting it within the inner diameter envelope of the catheter, as will be described in detail below. Thus, the flex circuit 410 allows for a thick coil without increasing the nonlinearity of the signal and without increasing the stiffness of the substrate.

Fig. 8 reflects another component of the catheter 14, namely a flex circuit 480, which includes a substrate 482 and one or more coils 484. The structure of the flexible circuit 480 is similar to the structure of the first portion 414 of the flexible circuit 410. However, in various embodiments, the number or pitch of the coils may vary, and the individual coils on the three segments may be separate from each other or integral with each other.

Fig. 9 reflects another component of conduit 14, a coil spring 490 that includes a top surface 492, a bottom surface 494, and various arms 496 that may be used to assemble spring 490 to other components of conduit 14. Spring 490 has a known or predetermined spring constant that provides a correlation between distance and force according to Hooke's Law. Together, the flexible circuit 480, the first portion 414 of the flexible circuit 410, and the coil spring 490 comprise a subassembly that can receive electrical signals from the console 24 and provide electrical signals to the console that can be processed to determine the force, e.g., a force on the order of a sub-gram, applied to the tip 18 (or the tip 200 or the tip 300, as the case may be) of the catheter 14. Specifically, one or more first cables (within cable harness 498 of fig. 10 and 11) connected at one end to console 24 may also be connected at an opposite end to weld 468 of fourth portion 442 of flex circuit 410, which are connected to coils 418, 470, and 472 on segments 460, 462, and 464 of first portion 414 via coil extensions 466, 474, and 476, respectively. One or more second cables (also within cable bundle 498) connected at one end to console 24 may also be connected at an opposite end to one or more coils 484 on flex circuit 480. The electrical signal (e.g., having an RF frequency) from the console 24 may be used to power a coil on the first portion of the flexible circuit 410 or a coil on the flexible circuit 480. Whichever set of coils receives power from the console 24 may be considered a transmitter because it transmits an electromagnetic field that varies according to the frequency of the signal received from the console 24. The coil set that is not powered by the console 24 may be considered a receiver because it acts like an antenna in response to the electromagnetic field from the transmitter. Thus, the receiver generates an electrical signal that can be transmitted to console 24 for analysis. The electrical signal generated by the receiver is dependent on the distance between the receiver and the transmitter, such that the electrical signal generated by the receiver may be related to the distance between the receiver and the transmitter.

By adhering the receiver (here, the coil on the first portion 414 of the flexible circuit 410) to the top surface 492 of the spring 490 and the transmitter (here, the coil on the flexible circuit 480) to the bottom surface of the spring 480 and routing them as described above, the electrical signal generated in the receiver can be correlated to the compressive displacement in the spring (e.g., approximately 100 nanometers) and thus the force against the end 200 or 300 of the catheter 14 that causes the spring 480 to compress. In use, a console 24 having a processor 22 can process these signals and use them to confirm that contact has occurred between the tip and the tissue, and to adjust the amount of ablation energy supplied to the electrodes. For example, when the signal indicates that the spring is in a relaxed state (i.e., not compressed), this may be considered an indicator that the tip 200 or 300 is not contacting tissue, and therefore ablation energy should not be supplied to the electrode. An indicator of information (e.g., in units of force, such as newtons) may also be provided to the operator 16 on the monitor 29. This information can be used to provide directly to the operator 16 as this can help the operator 16 avoid damaging the tissue by pressing the tip against the tissue too hard.

Further, the first portion 414 of the flexible circuit 410 and each of the three portions of the clover shape of the flexible circuit 480 may be aligned with each other and with the three zones 210, 212, and 214 of the tip 200 so that the processor 22 may determine the difference in contact force of the tissue against the three zones. Thus, processor 22 may determine, for example, that zone 210 experiences the greatest contact force against the tissue, zone 212 experiences the second greatest contact force against the tissue, and zone 214 experiences the smallest contact force against the tissue. Thus, the processor 212 may use the force data alone or in combination with the ECG data from the zones to tailor the RF energy applied to each of the electrodes of the zones for ablating tissue. In addition, the user may view information about the contact force of each of the three zones on display 29 and use this information to determine which zones contact the tissue and adjust the position of tip 200 to achieve the desired contact force on the tissue.

The top surface 492 and the bottom surface 494 of the spring 490 may be parallel to each other and oriented transverse to the longitudinal axis of the spring (e.g., at an angle greater than about sixty degrees and less than ninety degrees, such as about eighty degrees). Thus, the receiver and transmitter attached to the spring are similarly oriented. However, because the non-perpendicular angle increases the sensitivity of the receiver compared to a situation where the transmitter and receiver are disposed perpendicular to the longitudinal axis of the spring and ultimately perpendicular to the longitudinal axis of the catheter, the distance between the transmitter and receiver is minimized. Such angling may also help to differentiate between the relative forces applied to the three end regions.

Fig. 10 and 11 show the catheter 14 at two different steps of catheter assembly. Fig. 12 is a cross-section of catheter 14 taken along line a-a in fig. 10, but with various components removed or simplified for clarity in discussing flex circuit 410. Fig. 10 shows the flexible circuit 410 assembled to the spring 490 and the coupling sleeve 500. Although not shown, the first portion 414 of the flexible circuit 410 is adhered to the top surface 492 of the spring 490, and the flexible circuit 480 is adhered to the bottom surface 494 of the spring 490. In fig. 11, tip 200 is shown attached to spring 490. A cable harness 498 is also shown in fig. 10 and 11. Cable harness 498 includes a set of cables that, although not visible, connect to pads 468 on fourth portion 442 of flex circuit 410, and thus to individual coils or traces on flex circuit 410, and to coils or traces 484 on flex circuit 480. As shown in fig. 10-12, the flexible circuit 410 is no longer planar. Instead, the flex circuit has been deformed to have a partially circular and partially triangular cross-section. The section 424 of the second portion 416 is the most easily visible section of the flexible circuit 410 in fig. 10 and 11. The respective sides of section 422, section 432 and section 434 and connectors 426, 436, 446, 450 and 452 are also visible in these figures. As shown, these connectors have been deformed into a curved or curved configuration to attach to the coupling sleeve 500. Specifically, section 422 is adhered to the generally planar surface 502 of the sleeve 500, and section 432 is adhered to the generally planar surface 504 of the sleeve 500. So assembled, these portions of flex circuit 410 can be considered to have a triangular cross-section. Additionally, connector 446 is adhered to circular (or arcuate) surface 506 of sleeve 500, and connector 448 is adhered to circular (or arcuate) surface 508 of sleeve 500. So assembled, these portions of flex circuit 410 can be considered to have a circular (or arcuate) cross-section. The fourth portion 442 may also be adhered to the generally planar surface 510 of the sleeve 500.

The diameter or width of the circular portion of the cross-section of the flexible circuit 410 assembled to the sleeve 500 is equal to or about equal to the diameter or maximum width of the first portion 414, which is also equal to or about equal to the maximum width (or base) of the triangular portion of the cross-section of the flexible circuit 410 assembled to the sleeve 500. Thus, when assembled, the flexible circuit 410 may be easily inserted into an outer tube or sleeve that provides the outer surface of the catheter 14 and defines an inner diameter into which components of the catheter 14 (e.g., the flexible circuit 410, the spring 480, the sleeve 500) must fit. To help prevent soft spots under the outer sleeve caused by gaps between the generally flat outer surfaces of segments 424 and 434 and portion 442 on the one hand, and the curvature of the outer sleeve on the other hand, these gaps may be filled by including additional material, such as adhesive 518 and polyimide layer 520, on segments 424 and 434 and portion 442 (of second portion 416 and third portion 430, respectively). Polyimide layers 520 may be fabricated separately from flex circuit 410 and adhered thereto, or they may be integral parts of flex circuit 410 formed during the same lithographic process as the rest of flex circuit 410. Polyimide layer 520 may be formed with a series of generally flat steps or curves with an outer sleeve inserted within the layer.

The flexible circuit 410 may be assembled into the catheter 14 as follows. First, a flexible circuit 410 may be provided. Segment 424 of second portion 416 may be folded over segment 422 of second portion 416 to overlap and contact connector 426 and connector 450 (if included) by deforming. A section 434 of the third portion 430 may be folded over a section 432 of the third portion 430 to overlap and contact the connector 436 and the connector 452 (if included) by deforming them. The first portion 414 of the flexible circuit 410 may be oriented parallel to a top surface 492 of the spring 490 that is oriented transverse (e.g., less than thirty degrees from vertical) to a longitudinal axis of the spring 490. The first portion 414 may then be adhered to the top surface 492 of the spring 490. A coupling sleeve 500 having a generally flat surface portion may be provided and oriented to align its longitudinal axis with the longitudinal axis of the spring. The second portion 416 and the third portion 430 may be oriented parallel to the respective substantially planar surface portions of the sleeve 500. The second portion 416 and the third portion 430 may then be adhered to respective substantially planar surface portions of the sleeve 500. The sleeve 500 adhered to the flexible circuit 410 may then be coupled or inserted into an outer sleeve. Finally, the tip 18 may be attached to a spring 490. As long as the tip 18 is not yet attached to the spring 490, the flexible circuit 480 may adhere to the bottom surface 494 of the spring 490 at virtually any step of the process.

With the advantages of the embodiments shown and described herein, applicants have devised a method of selectively ablating tissue along a tissue surface (e.g., a curved tissue surface) in contact with some or all of the flexible circuit ends of a diagnostic/therapeutic catheter, while using other end regions, particularly those not in contact with tissue, to provide functions other than ablation, such as monitoring electromagnetic signals (e.g., ECG signals). That is, a user may activate at least one electrode using the above-described diagnostic/therapeutic catheter or an electrophysiology system including the diagnostic/therapeutic catheter according to various methods and variations while leaving other electrodes inactive or using other electrodes to provide functions other than ablation, such as monitoring electromagnetic signals (e.g., ECG signals) while further measuring temperature using some or all of the various temperature sensors disposed on the catheter tip. One such method and variation may include the following steps. First, a user may receive a catheter. The user may then introduce the catheter into a subject (e.g., a human subject) and position the catheter near the cardiac tissue. Second, the user may contact the catheter tip against the heart tissue. Third, a processor connected to the catheter may receive temperature data, ECG signals via the catheter tip region (e.g., 210, 212, 214), and force signals via the catheter receive and transmit coils (e.g., 118 and 184). The processor may use the ECG signals, the force signals, or both to determine which end regions are in contact with tissue (at least partially in contact with tissue) and which end regions are not in contact with tissue. Fourth, the processor may then control delivery of ablation energy to only those tips that are in contact with the tissue. In those cases where multiple end regions contact tissue, the multiple end regions in contact with the tissue may receive ablation energy (as described above) simultaneously or sequentially. Similarly, these multiple end regions may monitor the ECG signal simultaneously or continuously. In an exemplary variation where all three end regions contact tissue, the end region 210 may receive ablation energy while the regions 212 and 214 provide ECG signals to the processor, then the region 210 may switch from receiving ablation energy to providing ECG signals, and the region 212 may switch from providing ECG signals to receiving ablation energy, then the region 212 may switch back to providing ECG signals, and the region 214 may switch from providing ECG signals to receiving ablation energy. In a further variation, at least the temperature sensor may provide temperature data to the processor at least when the region on which the temperature sensor is disposed receives ablation energy. However, all temperature sensors may continuously provide temperature data to the processor.

Further, a diagnostic/therapeutic catheter having the above features may be constructed according to the following method and variations thereof. First, a flexible circuit (e.g., flexible circuit 100) may be fabricated, for example, via a photolithographic process. For example, a layer of insulating material (e.g., polyamide) can be deposited, which can be a substrate for an electronic component. Next, a layer of conductive material (e.g., platinum or gold) including the electronic components (e.g., the thermocouple 118, the conductor element 126, and the contact 146) may be deposited. Next, another layer of insulating material may be deposited. Next, another layer of conductive material may be deposited. Masking layers may also be deposited to achieve specific shapes and configurations of these layers. For example, a masking layer may be used to form different sections of the flex circuit (e.g., sections 102 and 104), regions thereof (e.g., regions 110 and 114), and shape the electronic components. If no port is fabricated in the preceding step, another step of forming a port (e.g., flush port 134) through the flexible circuit (e.g., via laser drilling) may be performed.

Second, the flexible circuit 100 may be received along with other components used to construct a diagnostic/therapeutic catheter, such as the catheter body 14. Other components may also be received, for example, a core such as core 235, and electrodes such as electrode 32 that are not fabricated as an integral part of flex circuit 100. Additionally, flexible circuits 410 and 480 may be received to impart a force measurement function to the catheter.

Third, the flexible circuit 100, which may be received in a planar configuration, may have at least a second section of the flexible circuit formed into a non-planar configuration (e.g., a cylindrical configuration). In this way, the flexible circuit may be formed as a flexible circuit tip (e.g., 200). The flexible circuit tip may then be connected to the catheter body, typically through the second section. Fourth, in some variations, a conductor element (e.g., 132) may be connected to the electrode 32.

Fifth, the leads may be connected to contacts (e.g., 142) on the pads (e.g., 136) that are operatively connected to the electronic components at the end of the flex circuit and to the flex circuits 410 and 480. Sixth, the space between the various regions of the flexible circuit end may be filled with an insulating material.

In those variations that include methods of providing a core, the flexible circuit can conform to the core to change its configuration to that of the flexible circuit ends. In other variations including methods of providing a core, the flexible circuit ends may be attached to the core. Further, an insulating material may be disposed in the space between the core and the end of the flexible circuit.

Any of the examples or embodiments described herein may also include various other features in addition to or as an alternative to those described above. The teachings, expressions, embodiments, examples, etc. described herein should not be considered as independent of each other. Various suitable ways in which the teachings herein may be combined will be apparent to those skilled in the art in view of the teachings herein.

Having shown and described exemplary embodiments of the subject matter contained herein, further modifications of the methods and systems described herein can be effected, with appropriate modification, without departing from the scope of the claims. Further, where methods and steps described above represent specific events occurring in a specific order, it is intended that certain specific steps need not be performed in the order described, but may be performed in any order, so long as the steps enable the embodiment to achieve its intended purpose. Thus, if variations of the invention exist and fall within the true scope of the disclosure or equivalents thereof as may be found in the claims, then this patent is intended to cover such variations as well. Many such modifications will be apparent to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc., described above are illustrative. Thus, the claims should not be limited to the specific details of construction and operation shown in this written description and the drawings.