WO2019059914A2

WO2019059914A2 - Methods for manufacturing electrosurgical fabrics

Info

Publication number: WO2019059914A2
Application number: PCT/US2017/052812
Authority: WO
Inventors: Sam Boong PARK
Original assignee: Park Sam Boong
Priority date: 2017-09-21
Filing date: 2017-09-21
Publication date: 2019-03-28
Also published as: WO2019059914A3; CN109528293A

Abstract

Systems and devices for tissue ablation and methods for their manufacture are disclosed. Ablation devices described herein include an expandable ablation member having conductive regions separated by at least one non-conductive region that is less stretchable. The non-conductive region comprises non-conductive yarns that are at least double layered to increase tensile strength. The expandable ablation member can include top and bottom layers separated by the expandable cavity of the ablation member. The top and bottom layers have conductive outer surfaces. One or more of the top and bottom layers have non-conductive inner surfaces; and, this layer or layers is made up of conductive and non-conductive yarns double-layered and oriented so that one side is conductive and the other is non-conductive. Alternatively or in combination, the expandable ablation member can include a non-conductive middle layer, with the edges of the top, middle, and bottom layers being coupled.

Description

METHODS FOR MANUFACTURING ELECTROSURGICAL FABRICS

CROSS-REFERENCE

[0001] The subject matter of this application is related to that of co-pending PCT Application No. PCT/US2017/043805, filed July 25, 2017 (Attorney Docket No. 52271-703.601), the contents of which are incorporated herein by reference.

STATEMENT AS TO FEDERALLY SPONSORED RESEARCH

[0002] N/A

BACKGROUND

[0003] The present disclosure relates to medical devices, systems, and methods. In particular, the present disclosure relates to medical devices for therapeutically ablating tissue, such as endometrial tissue, and methods for their manufacture.

[0004] Menorrhagia, otherwise known as heavy menstrual bleeding, is a condition which affects many adult women and can be indicative of more serious conditions such as uterine cancer, uterine fibroids, endometrial polyps, or uterine infection. There are many ways to treat menorrhagia, including hormonal medication or other drugs, endometrial ablation or the ablation of the uterine lining, myomectomy or the surgical removal of uterine fibroids, or in the most serious cases, hysterectomy, or the complete removal of the uterus.

[0005] Endometrial ablation has been an increasingly prevalent treatment because it can be an outpatient procedure and can have relatively high success rates. In at least some cases, however, current systems, devices, and method for endometrial ablation can be less than ideal.

[0006] In many cases, a uterine cavity is treated by an ablation probe with an expandable ablation member advanced into the uterine cavity. In many cases, the tissue is ablated with radiofrequency (RF) energy, which will typically be bipolar. Hence, the expandable ablation member will typically include two or more conductive regions and one or more non-conductive regions to prevent short circuits between the two or more conductive regions. U.S. Patent No. 6,508,815 discloses a bi-polar, RF ablation probe with an expandable ablation member that includes multiple conductive and non-conductive regions, for example.

[0007] The uniformity or quality of the tissue ablation generally depends from the power level applied and the uniform separation of the opposing poles. The expandable ablation member, however, typically has a non-uniform shape such as in the shape of a cone or triangle rather than a circle, rectangle, or square, for instance. In the case of a cone or funnel shaped expandable ablation member, the distal portion of the expandable ablation member will typically be wider and will often stretch more than the proximal portion. Additionally, the expandable ablation member may typically comprise stretchable fabrics of different conductive and non-conductive materials that may experience uneven stretching and expansion. Hence, in at least some cases, the expansion of the expandable ablation member is not as uniform as would be ideal and hence the separation between conductive regions as the ablation member shifts between collapsed and expanded configurations can be less than ideal.

[0008] In many cases, an expandable ablation member with multiple conductive and non- conductive regions will have multiple sides, such as a top side and a bottom side separated by a side wall. Both top and bottom sides may include conductive regions. To prevent short circuits between the conductive regions of the top and bottom sides within the body of the expandable ablation member, an insulating layer may be provided within the body of the expandable ablation member. In at least some cases, however, providing an insulating layer, a third layer between the layers of the top and bottom sides leads to the expandable ablation member in the collapsed configuration having a greater thickness than would be ideal.

[0009] For at least these reasons, improved systems, devices, and methods for ablating tissue, particularly endometrial tissue, and improved methods of manufacturing ablation devices are desired.

[0010] References that may be of interest include: U.S. Patents Nos. 4,815,299, 5,769,880, 6,508,815, 6,554,780, 8,443,634, 8,476, 172, 9,474,566, 9,554,853, and U.S. Publications Nos. 2002/0022870 and 2016/0095648.

SUMMARY

[0011] The present disclosure relates to systems and devices for tissue ablation and methods for their manufacture, which overcome at least some of the aforementioned drawbacks. Exemplary tissue ablation devices described herein may include an expandable ablation member comprising a plurality of conductive regions separated from one another by at least one non-conductive region. The at least one non-conductive region will typically be less stretchable than the plurality of conductive regions such that the separation distance between the conductive regions has improved uniformity as the expandable ablation member expands between its collapsed and expanded configurations. As ablation energy levels are typically a function of the separation distance between the conductive regions, the devices described herein can provide improved and more uniform tissue ablations. [0012] To provide the reduced stretchability, the non-conductive regions may comprise non- conductive yarns that are at least double-layered before being knit or double knitted such that tensile strength is increased or such that stretchability is reduced. For example, the non- conductive region may comprise double-layered yarns knit with non-conductive yarns common to both the conductive and non-conductive regions, and the conductive region may comprise single-layered yarns knit with the common yarns. Alternatively or in combination with being double-knit, the yarns at the non-conductive region may be thicker than those at the conductive regions.

[0013] Exemplary tissue ablation devices described herein may also include an expandable ablation member comprising top and bottom layers, each with outer conductive surfaces and at least one of the top or bottom layers having an inner non-conductive surface to prevent shorting. Providing the inner non-conductive surface can eliminate the need for a third, non-conductive layer between the top and bottom layers, thereby reducing the thickness of the expandable ablation member, particularly when in the collapsed configuration. To manufacture the layers with distinct conductive and non-conductive sides, conductive and non-conductive yarns may be double-layered with the conductive yarn facing one direction and the non-conductive yarn facing the other direction. The layer is then formed by knitting the double-layered yarns. Alternatively or in combination, the middle non-conductive layer may be knit concurrently with the outer top and bottom layers to eliminate the need for manual or subsequent insertion of the middle, non- conductive layer.

[0014] Aspects of the present disclosure provide tissue ablation apparatuses for ablating an inner wall of a bodily organ. An exemplary tissue ablation apparatus may comprise a shaft assembly having a distal end and an expandable ablation member at the distal end of the shaft assembly. The expandable ablation member may have a collapsed configuration and an expanded configuration. The expandable ablation member may comprise a plurality of conductive regions and one or more non-conductive regions. The one or more non-conductive regions may separate the conductive regions from one another with one or more predetermined separation distances, for example, between about 2 mm to about 12 mm. The one or more non- conductive regions may be less stretchable than the plurality of conductive regions.

[0015] The plurality of conductive regions may comprise a plurality of first yarns having a first yarn size. The one or more non-conductive regions may comprise a plurality of second yarns having a second yarn size. The second yarn size may be less than the first yarn size. The second yarn size may be greater than the first yarn size. The second yarns may be less stretchable than the first yarns. The plurality of second yarns may be at least double-layered and may be knit together such that plurality of second yarns have greater tensile strength or are less stretchable than the plurality of first yarns and the one or more non-conductive regions are less stretchable than the plurality of conductive regions. The plurality of second yarns may be triple layered. The plurality of first yarns may be single layered. The plurality of second yarns may comprise a plurality of non-conductive yarns. The plurality of first yarns may comprise a plurality of conductive yarns. The plurality of first yarns may comprise a plurality of non-conductive yarns interwoven with the plurality of conductive yarns.

[0016] The plurality of conductive regions may comprise a first conductive region on a first lateral side of the expandable ablation member and a second conductive region on a second lateral side of the expandable ablation member. The one or more non-conductive regions may comprise a longitudinal non-conductive strip separating the first and second conductive regions with the one or more predetermined separation distances, for example, between about 2 mm to about 12 mm.

[0017] The expandable ablation member may have a width of about 5 mm to about 9 mm in the collapsed configuration. The expandable ablation member may have a width of about 20 mm to about 70 mm in the expanded configuration. The expandable ablation member may have a cone or funnel shape in the expanded configuration.

[0018] Further aspects of the present disclosure provide tissue ablation apparatuses for ablating an inner wall of a bodily organ. An exemplary tissue ablation apparatus may comprise a shaft assembly having a distal end and an expandable ablation member at the distal end of the shaft assembly. The expandable ablation member may have a collapsed configuration and an expanded configuration. The expandable ablation member may comprise a top layer comprising a first conductive outer surface and a bottom layer comprising a second conductive outer surface. The top and bottom layers may define an expandable cavity therebetween. One or more of the top or bottom layers may comprise a non-conductive inner surface separating the first and second conductive outer surfaces within the expandable cavity.

[0019] One or more of the top or bottom layers may comprise the conductive outer surface which may comprise a plurality of conductive yarns and a plurality of non-conductive yarns. The conductive and non-conductive yarns may be at least double layered together, and the at least double layered conductive and non-conductive yarns may be knit such that the plurality of conductive yarns face away from the expandable cavity and the plurality of non-conductive yarns face toward the expandable cavity. The top layer may comprise the first conductive outer surface and the non-conductive inner surface. The bottom layer may comprise the first conductive outer surface and the non-conductive inner surface. Both the top and bottom layers may comprise non-conductive inner surfaces.

[0020] One or more of the top or bottom layers may comprise a plurality of conductive regions and at least one non-conductive region separating the conductive regions from one another at one or more predetermined separation distances, for example, between about 2 mm to about 12 mm. The expandable ablation member may have a width of about 5 mm to about 9 mm in the collapsed configuration. The expandable ablation member may have a width of about 20 mm to about 70 mm in the expanded configuration. The expandable ablation member may have a cone or funnel shape in the expanded configuration.

[0021] Further aspects of the present disclosure provide tissue ablation apparatuses for ablating an inner wall of a bodily organ. The apparatus may comprise a shaft assembly having a distal end and an expandable ablation member at the distal end of the shaft assembly. The expandable ablation member may have a collapsed configuration and an expanded configuration. The expandable ablation member may comprises a top layer comprising a first conductive outer surface, a bottom layer comprising a second conductive outer surface, the top and bottom layers defining an expandable cavity therebetween, and a middle non-conductive layer disposed between the top and middle layers to separate the first and second conductive outer surfaces within the expandable cavity. Edges of the middle non-conductive layer may be interwoven with edges of one or more of the top or bottom conductive layers.

[0022] One or more of the top or bottom layers may comprise a plurality of conductive yarns and a plurality of non-conductive yarns. One or more of the top or bottom layers may comprise a plurality of conductive regions and at least one non-conductive region separating the conductive regions from one another at one or more predetermined separation distances.

[0023] The expandable ablation member may have a width of about 5 mm to about 9 mm in the collapsed configuration. The expandable ablation member may have a width of about 20 mm to about 70 mm in the expanded configuration. The expandable ablation member may have a cone or funnel shape in the expanded configuration.

[0024] Further aspects of the present disclosure provide methods of manufacturing an expandable ablation member of a tissue ablation apparatus. At least one first conductive yarn may be knit to form a first conductive region of the expandable ablation member. At least one non-conductive yarn may be knit to form a non-conductive region of the expandable ablation member. The non-conductive region may be less stretchable than the first conductive region. The first conductive region and the non-conductive region may be coupled together. [0025] The first conductive region and the non-conductive region may be coupled together by providing at least one common non-conductive yarn for both the first conductive region and the non-conductive region. The at least one first conductive yarn may be knit to form the first conductive region by interweaving the at least one first conductive yarn with the at least one common non-conductive yarn. The at least one non-conductive yarn may be knit to form the non-conductive region by interweaving the at least one non-conductive yarn with the at least one common non-conductive yarn. The at least one first conductive yarn may be more stretchable than the at least one non-conductive yarn.

[0026] The at least one first conductive yarn may have a first yarn size. The at least one non- conductive yarn may have a second yarn size. The second yard size may be less than the first year size. The second yard size may be greater than the first year size. The at least one non- conductive yarn may be knit to form the non-conductive region by at least double layering the at least one non-conductive yarn such that the double-layered non-conductive yarns have a greater tensile strength or lesser stretchability than the at least one first conductive yarn and the non- conductive region is less stretchable than the first conductive region. The at least one non- conductive yarn may be at least double layered by triple layering the at least one non-conductive yarn. The at least one conductive region may comprise single-layered yarns.

[0027] The at least one second conductive yarn may be further knit to form a second conductive region of the expandable ablation member, and the second conductive region and the non-conductive region may be coupled together. The first conductive region, the second conductive region, and the non-conductive region may be coupled together such that the non- conductive region separates the first and second conductive regions from one another with one or more pre-determined separation distances, for example, between about 2 mm to about 12 mm.

[0028] The first conductive region may be disposed on a first lateral side of the expandable ablation member and the second conductive region may be disposed on a second lateral side of the expandable ablation member. The non-conductive region may comprise a longitudinal non- conductive strip separating the first and second conductive regions with the one or more predetermined separation distances.

[0029] Further aspects of the present disclosure also provide methods of manufacturing an expandable ablation member of a tissue ablation apparatus. At least one first conductive yarn and at least one first non-conductive yarn may be double layered such that the at least one first conductive yarn faces a first side and the at least one first non-conductive yarn faces a second side opposite the first side. The double layered at least one first conductive yarn and the at least one first non-conductive yarn may be knit to form a first layer of the expandable ablation member. The first layer of the expandable ablation member may have a conductive surface and a non-conductive surface opposite the conductive surface.

[0030] The at least one second conductive yarn and at least one second non-conductive yarn may be double layered such that the at least one second conductive yarn faces a third side and the at least one first non-conductive yarn faces a fourth side opposite the third side. The double- layered at least one second conductive yarn and at least one second non-conductive yarn may be knit to form a second layer of the expandable ablation member. The second layer of the expandable ablation member may have a conductive surface and a non-conductive surface opposite the conductive surface. The first and second layers may be coupled together such that the non-conductive surfaces of the first and second layers face inwardly toward one another and the conductive surfaces of the first and second layers face outwardly away from one another.

[0031] The first layer of the expandable ablation member may comprise a top layer and the second layer of the expandable ablation member may comprise a bottom layer of the expandable ablation member. One or more of the first or second layers may be knit such that the conductive surfaces thereof comprise a plurality of conductive regions separated by at least one non- conductive region. The first and second layers may define an expandable cavity therebetween. The first and second layers may be coupled together by at least partially joining edges of the first and second layers to one another.

[0032] At least one second conductive yarn may be knit to form a second layer of the expandable ablation member. The second layer of the expandable ablation member may have a conductive surface. The first and second layers may be coupled together such that the non- conductive surface of the first layer faces inwardly toward the second layer and the conductive surfaces of the first and second layers face outwardly away from one another. The first layer of the expandable ablation member may comprise a top layer and the second layer of the expandable ablation member may comprise a bottom layer of the expandable ablation member. One or more of the first or second layers may be knit such that the conductive surfaces thereof comprise a plurality of conductive regions separated by at least one non-conductive region. The first and second layers may define an expandable cavity therebetween. The first and second layers may be coupled together by at least partially joining edges of the first and second layers to one another.

[0033] Further aspects of the present disclosure may provide methods of manufacturing an expandable ablation member of a tissue ablation apparatus. At least one first conductive yarn may be knit to form a first conductive layer. At least one second conductive yarn may be knit to form a second conductive layer. At least one non-conductive yarn may be knit to form a non- conductive layer. The first conductive layer, the second conductive layer, and the non- conductive layer may be coupled together such that the first and second conductive layers form an expandable cavity therebetween. The non-conductive layer may be disposed between the first and second conductive layers. Edges of the non-conductive and insulating layer may be interwoven with edges of one or more of the first or second conductive layers.

[0034] One or more of the first or second conductive layers may comprise a plurality of conductive yarns and a plurality of non-conductive yarns. The non-conductive layer may comprise a plurality of non-conductive yarns. The first conductive layer may comprise a top layer having a first outer conductive surface, and the second conductive layer may comprise a bottom layer having a second outer conductive surface. One or more of the first or second conductive layers may comprise a plurality of conductive regions and at least one non- conductive region may separate the conductive regions from one another at one or more predetermined separation distances.

INCORPORATION BY REFERENCE

[0035] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The novel features of the present disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the present disclosure are utilized, and the

accompanying drawings of which:

[0037] FIG. 1 A is a side view of an ablation controller and an ablation probe coupled to one another for use to treat a bodily organ, according to many embodiments.

[0038] FIG. IB is a top view of the distal end of the ablation probe of FIG. 1 A, including the expandable ablation member.

[0039] FIG. 1C is a perspective view of the expandable ablation member of the ablation probe of FIG. 1A.

[0040] FIG. ID is a front view of the expandable ablation member of the ablation probe of FIG. 1A.

[0041] FIG. 2A is a schematic view of the expandable ablation member of the ablation probe of

FIG. 1 A showing its constituent yarns, according to many embodiments. [0042] FIG. 2B is a magnified view of an exemplary knitting pattern for the conductive and non-conductive regions of the expandable ablation member of the ablation probe of FIG. 1A, according to many embodiments.

[0043] FIG. 2C is a section view of the knitting pattern of FIG. 2B.

[0044] FIG. 2D is a magnified view of another exemplary knitting pattern for the conductive and non-conductive regions of the expandable ablation member of the ablation probe of FIG. 1A, according to many embodiments.

[0045] FIG. 2E is a section view of the knitting pattern of FIG. 2B.

[0046] FIG. 3 is a section view of an exemplary expandable ablation member of the ablation probe of FIG. 1 A, showing conductive and non-conductive layers, according to many

embodiments.

[0047] FIG. 4A is a section view of another exemplary expandable ablation member of the ablation probe of FIG. 1 A, showing its top and bottom layers, each with outwardly facing conductive surfaces and inwardly facing non-conductive surfaces, according to many

embodiments.

[0048] FIG. 4B is a section view of another exemplary expandable ablation member of the ablation probe of FIG. 1 A, showing its top and bottom layers, the top layer having an outwardly facing conductive surface and an inwardly facing non-conductive surface, and the bottom layer being conductive on its inner and outer surfaces, according to many embodiments.

[0049] FIG. 4C is a section view of another exemplary expandable ablation member of the ablation probe of FIG. 1 A, showing its top and bottom layers, the top layer being conductive on its inner and outer surfaces, and the bottom layer having an outwardly facing conductive surface and an inwardly facing non-conductive surface, according to many embodiments.

[0050] FIG. 4D is a section view of another exemplary expandable ablation member of the ablation probe of FIG. 1 A, showing its conductive top and bottom layers and a non-conductive middle layer, according to many embodiments.

[0051] FIG. 4E shows a section view of exemplary layer of the expandable ablation member as in FIGS. 4A-4D, the layer having a conductive surface and an opposite non-conductive surface.

DETAILED DESCRIPTION

[0052] FIG. 1A shows an ablation control unit 100 coupled to an ablation probe 150. In use, the ablation probe 150 may be advanced into the cavity of a bodily organ, and the ablation control unit 100 may include an ablation energy generator such as a radiofrequency (RF) generator. Typically, the bodily organ ORG will be the uterus of a subject, but the ablation probe 150 may be suitable for use with other organs such as the bladder, the heart, the stomach, the small intestines, the large intestines, the colon, to name a few. Similar ablation control units and ablation members are described in co-pending PCT application no. PCT/US2017/043805, filed July 25, 2017 (Attorney Docket No. 52271-703.601) and U.S. Patent No. 6,508,815, the contents of which are incorporated by reference.

[0053] The ablation probe 150 may comprise an expandable ablation energy applicator or ablation member 153. The ablation probe 150 may be advanced into the bodily organ such that the expandable ablation member 153 is positioned within its cavity in a collapsed configuration. The expandable ablation member 153 may then be expanded to appose the inner wall of the cavity to apply ablation energy thereto. The expandable ablation member 153 may have a maximum width of 5 to 9 mm in its collapsed configuration and a maximum width of 20 to 70 mm in its expanded configuration, for example, a maximum width of 6 to 8 mm in its collapsed configuration and a maximum width of 55 to 60 mm in the expanded configuration. The expandable ablation member 153 may have different dimensions as well such as for different anatomical targets. For example, the maximum width may be as much as 300 mm for an expandable ablation member suitable for use in the intestines. In some embodiments, the expandable ablation member 153 may be at least partially disposable while the remainder of the ablation probe 150 may be reusable. In some embodiments, the ablation probe 150 is entirely disposable or reusable. The ablation probe 150 may further comprise a shaft assembly 156 which has a distal end coupled to the expandable ablation member 153 and a proximal end coupled to a handle assembly 159.

[0054] The ablation probe 150 may comprise a handle assembly 159 which may comprise a handle 162 which the user can operate to expand the expandable ablation member 153 at the distal end of the shaft assembly 156. The handle assembly 159 may further comprise calibration circuitry 165 which may store various calibration parameters for the ablation probe 150. The calibration circuitry 165 may store one or more calibration parameters such than every individual ablation probe 150 may be custom calibrated. The handle assembly 159 may further comprise a transmitter 168 which may be coupled to the calibration circuitry 165 as well as one or more sensors of the ablation probe 150. Alternatively or in combination, one or more of the calibration circuitry 165 or the transmitter 168 may be separate from the ablation probe 150, such as by being removably coupled thereto. The transmitter 168 may couple to the ablation control unit 100 and its receiver to transmit one or more of measurement, calibration, ablation, or other data through a wired or a wireless connection. In some embodiments, one or more sensors of the ablation probe 150 are directly connected to the transmitter 168 and bypass the calibration circuitry to transmit data to the ablation control unit. For instance, ablation data may be measured directly from the power wires that deliver energy to the probe 150 at the control unit 100. Various wireless communications protocols that may be appropriate for use with the ablation probe transmitter 168 may include, but are not limited to, BlueTooth, BlueTooth LE, WiFi, Near-Field Communication (NFC), infrared wireless, radio wave, micro-wave, WiMax, Femtocell, Zigbee, 3G, 4G, 5G, to name a few. In some embodiments, the transmitter 168 may comprise a two-way communications unit and include a receiver configured to receive control instructions, calibration data, and/or other data, such as from the control unit 100.

[0055] The onboard calibration circuitry 165 may allow the customization of each ablation probe 150 and its onboard sensors to their optimal operating parameters and the storing of such customization information on the calibration circuitry 165 for use with the ablation control unit 100. In some embodiments, once the calibration and customization information is provided on the calibration circuitry 165 during the manufacturing of the ablation probe 150, further recalibration or altering of this information is disabled to prevent a user from mal-calibrating the ablation probe 150. Alternatively, further recalibration or alteration of the calibration and customization information may be enabled.

[0056] FIG. IB shows the distal end of the ablation probe 150, including the expandable ablation member 153 in its expanded configuration. In the expanded configuration, the expandable ablation member 153 may assume a bicornual shape suitable for intrauterine ablation, including lateral horn regions to extend toward the fallopian tubes when placed within the uterus. The expanded configuration may have other geometries suitable for different bodily organs as well.

[0057] The expandable ablation member 153 may extend from the distal end of a length of an inner shaft 108 of the shaft assembly 156, the inner shaft 108 being slidably disposed within an outer shaft. The expandable ablation member 153 may include an external electrode array 103a and an internal deflecting mechanism 103b used to expand the array for positioning into contact with the tissue.

[0058] The RF electrode array 103a may be formed of a stretchable metallized fabric mesh which is preferably knitted from a nylon and spandex knit plated with gold or other conductive material. Insulating and non-conductive regions 140 (FIGS. 1C, ID) may be formed on the expandable ablation member 153 to divide the mesh into electrode regions. The non-conductive regions 140 may be formed using yarn knitting techniques to form the non-conductive regions 140 from non-conductive yarns as described further herein. [0059] The array may be divided by the non-conductive regions 140 into a variety of electrode configurations. As shown in FIG. 1C, for example, the non-conductive regions 140 divide the applicator head into four electrodes or conductive regions 142a-142d by creating two electrodes on each of the broad faces 134. To create this four-electrode pattern, the non-conductive regions 140 may be formed longitudinally along each of the broad faces 134 as well as along the length of each of the faces 136, 138. The conductive regions 142a-142d may be used for ablation and, if desired, to measure tissue impedance during use. The conductive regions 142a-142b may be formed using yarn knitting techniques to form the conductive regions 142a- 142b from

conductive yarns and optionally in combination with non-conductive yarns, at least some of which may be in common with the non-conductive regions.

[0060] Deflecting mechanism 103b and its deployment structure may be enclosed within the electrode array 103a. Referring to FIG. IB, an external hypotube 109 may extends from the inner shaft 108 and an internal hypotube 110 may be slidably and co-axially disposed within hypotube 109. Flexures 112 may extend from the tubing 108 on opposite sides of hypotube 109. A plurality of longitudinally spaced apertures (not shown) may be formed in each flexure 112. During use, these apertures allow moisture to pass through the flexures and to be drawn into exposed distal end of hypotube 109 using a vacuum source 140 fluidly coupled to hypotube 109 at vacuum port 138.

[0061] Internal flexures 116 may extend laterally and longitudinally from the exterior surface of hypotube 110 and may each be connected to a corresponding one of the flexures 112. A transverse ribbon 118 may extend between the distal portions of the internal flexures 116.

Transverse ribbon 118 may be preferably pre-shaped such that when in the relaxed condition the ribbon assumes the corrugated configuration shown in FIG. IB and such that when in a compressed condition it is folded along the plurality of creases 120 that extend along its length.

[0062] The deflecting mechanism 103b formed by the flexures 112, 116, and ribbon 118 may shape the array 103a into the substantially triangular shape shown in FIG. IB, which is particularly adaptable to most uterine shapes. During use, distal and proximal grips which form a device handle may be squeezed towards one another to deploy the array. This action may result in relative rearward motion of the hypotube 109 and relative forward motion of the hypotube 110. The relative motion between the hypotubes may cause deflection in flexures 112, 116 which deploys and tensions the electrode array 103a.

[0063] Flexures 112, 116 and ribbon may be made from an insulated spring material such as heat treated 17-7 PH stainless steel. Each flexure 112 may preferably include conductive regions that are electrically coupled to the array for delivery of RF energy to the body tissue. Strands of thread 145 (which may be nylon) may be sewn through the array 103 and around the flexures 112 in order to prevent the conductive regions 132 from slipping out of alignment with the electrodes 142a-142d.

[0064] The RF generator system may utilize an ablation power that is selected based on the surface area of the target ablation tissue. For uterine ablation, the RF power is calculated using the measured length and width of the uterus. These measurements may be made using conventional intrauterine measurement devices. Alternatively or in combination, mechanical or electrical sensors may be coupled to one or more components of the ablation probe 150 to make the measurements.

[0065] FIG. 2A is a schematic view of the expandable ablation member 153 showing its constituent yarns. Conductive regions 142a and 142b as separated by non-conductive regions 140 are shown. The conductive regions 142a and 142b may comprise one or more conductive yarns particularly on the outer surface, while the non-conductive regions 140 may entirely be comprised of non-conductive yarns, particularly on the outer surface. One of the non-conductive regions 140 may laterally separate the conductive regions 142a and 142b at a pre-determined lateral separation distance from one another such that ablation power levels can be predictable, uniform, and/or consistent. The non-conductive regions 140 may also separate conductive regions at the lateral sides of the expandable ablation member 153 and at the distal end of the expandable ablation member 153. The separation distances may range from about 2 mm to about 12 mm.

[0066] It may be desired for the non-conductive region 140 to be less stretchable distally than proximally, such as to provide improved electrode separation distance consistency and hence improved ablation power level consistency. The expandable ablation member 153 may comprise a distal region 153a and a narrower proximal region 153b. When expanded, the distal region 153a may expand more than the proximal region 153b. To provide a more uniform ablation, it may be desired that the lateral separation distance between the conductive regions 142a and 142b at the distal region 153a and at the proximal region 153b be uniform and consistent. Hence, the non-conductive region 140 at the distal region 153a may be less stretchable than the non- conductive region 140 at the proximal region 153b. The non-conductive region 140 at the distal region 153a may be knit with double-layered, non-conductive yarns to provide the reduced stretchability, while the non-conductive region 140 at the proximal region 153b may be knit with single-layered, non-conductive yarns, such as shown in FIG. 2A-2E.

[0067] FIG. 2B is a magnified view of an exemplary knitting pattern for the conductive region

142a and the non-conductive region 140 at the proximal region 153b, showing in particular the transition between the two regions. FIG. 2C shows the knitting pattern in a section view. The single-layered conductive yarns 201 of the conductive region 142a may be intarsia knit with the single-layered non-conductive yarns 211 of the non-conductive region 140 such that the respective yarns are seamlessly interwoven with one another.

[0068] FIG. 2D is a magnified view of an exemplary knitting pattern for the conductive region 142a and the non-conductive region 140 at the distal region 153a, showing in particular the transition between the two regions. FIG. 2E shows the knitting pattern in a section view. The single-layered conductive yarns 201 of the conductive region 142a may be intarsia knit with the double-layered non-conductive yarns 21 1 of the non-conductive region 140 such that the respective yarns are seamlessly interwoven with one another. In some embodiments, each non- conductive yarn 211 may be thinner and/or more stretchable than each conductive yarn 201, but as double-layered, the non-conductive yarns 211 may be thicker and/or less stretchable. While intarsia knitting is shown in FIGS. 2B and 2D, other knitting patterns to interweave the conductive yarns 201 and the non-conductive yarns 211 with one another may be used. For example, plating techniques, wedge knitting, weft knitting, Jersey knitting, gore knitting, gore stitching, and other fabric manufacturing techniques may be used, such as to generate contiguous conductive and non-conductive regions, regions of different dimensions, etc.

[0069] In some embodiments, the non-conductive region 140 at the distal region 153a may be knit with non-conductive yarns that are layered more than those at the non-conductive region 140 at the proximal region 153b. For example, the non-conductive region 140 at the proximal region 153b may be knit with double-layered, non-conductive yarns while the non-conductive region 140 at the distal region 153a may be knit with triple-layered, non-conductive yarns. In some embodiments, there may be gradient of less and less stretchability in the distal direction. For example, the non-conductive region 140 at the proximal region 153b may be knit with single-layered, non-conductive yarns, the non-conductive region 140 at a region between the proximal region 153b and the distal region 153a may be knit with double-layered, non- conductive yarns, and the non-conductive region 140 at the distal region 153a may be knit with triple-layered, non-conductive yarns.

[0070] It may be desired for the non-conductive regions 140 to be less stretchable than the conductive regions. The constituent yarns of the non-conductive regions 140 may comprise a less stretchable material than the yarns of the conductive regions 142a-142d, may be thicker than the yarns of the conductive regions 142a-142d, and/or may be layered more than the yarns of the conductive regions 142a-142d. The constituent yarns of the non-conductive regions 140 may be thinner, thicker, and/or the same diameter as the constituent yarns of the conductive regions 142a-142d. Different yarn types with different properties may make up the expandable ablation member 153 at different regions and portions. For example, the yarns may be layered more in areas where stretching forces are concentrated or where less stretching is desired and may be layered less in other areas.

[0071] FIG. 3 is a section view of the expandable ablation member 153. As shown in FIG. 3, the conductive region 142a may be a portion of the conductive top layer of the expandable ablation member 153 and the conductive region 142d may be a portion of the conductive bottom layer of the expandable ablation member 153. The inward facing surfaces of the top and bottom layers may both be conductive, so to minimize the risk of short circuit, a non-conductive middle layer 144 may be provided. In the collapsed configuration of the expandable ablation member 153, the non-conductive middle layer 144 may add to the thickness of the expandable ablation member 153 in addition to the top and bottom layers. The yarns used herein may range from 30 Denier to 180 Denier in linear mass density. Exemplary yarn materials that may be used may include Spandex and/or Nylon, such as a Spandex and Nylon composite. For example, Spandex could be 20 Denier to 180 Denier, with an elasticity of 150% to 400%, and Nylon could be 5 Denier could be 50 Denier, and while Nylon has low elasticity, it could be formed into a helix which can unwind to increase elasticity. Non-composite yarns may be used as well. Yarns which are selected to be conductive may have less than 100 Ohms of electrical resistance.

[0072] In at least some cases, it may be desired to omit the non-conductive middle layer 144 to reduce the thickness of the expandable ablation member 153 in the collapsed configuration while continuing to minimize the risk of short circuit. In one example as shown in FIG. 4A, both the top layer (including the conductive region 142a) and the bottom layer (including the conductive region 142d) have conductive outer surfaces and non-conductive inner surfaces. In another example as shown in FIG. 4B, the top layer (including the conductive region 142a) has a conductive outer surface and a non-conductive inner surface and the bottom layer (including the conductive region 142d) has conductive outer and inner surfaces. In another example as shown in FIG. 4C, the bottom layer (including the conductive region 142d) has a conductive outer surface and a non-conductive inner surface and the top layer (including the conductive region 142a) has conductive outer and inner surfaces. To provide the layer(s) with outer and inner surfaces of different conductivities, the layer(s) may be knit with double-layered yarns, with one yarn being a conductive yarn 201 and the other being a non-conductive yarn 211. The yarns are knit such that the conductive yarns 201 exclusively face one side while the non-conductive yarns 211 exclusively face the other side. The conductive layer with the conductive outer and inner surfaces may be knit with conductive yarns, which may single-layered, double-layered, or more than double-layered.

[0073] In at least some cases, the non-conductive middle layer 144 may be retained and the reduced thickness of the expandable ablation member 153 may be provided by reducing the thickness of the conductive top layer (including the conductive region 142a), the non-conductive middle layer 144, and the conductive bottom layer (including the conductive region 142d). For example, the constituent yarns of the layers may be selected to be thinner than in devices currently available on the market. The non-conductive layers and conductive layer may be knit so that they seamlessly transition into one another at the edges of the expandable ablation member 153, such as shown in FIG. 4D.

[0074] The various embodiments of the expandable ablation member 153 described herein may be automatically knit with conductive yarns 201 and non-conductive yarns 211 to be configured as described by using various automated knitting machines as fed by the different yarns. For example, an automated knitting machine may select one or more conductive yarns to knit the conductive regions 142a- 142b before selecting one or more non-conductive yarns to knit the non-conductive regions 140 and de-selecting the conductive yarns; multiple yarns may be placed at the same location concurrently with multiple working needles; and, the knitting and yarn selection can be varied and repeated until the expandable member 153 is completely knit.

Exemplary knitting machines that may be used include those commercially available from H. Stoll AG & Co. KG of Reutlingen, Germany or Shima Seiki Mfg. Ltd. of Wakayama, Japan.

[0075] While preferred embodiments of the present disclosure have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

WHAT IS CLAIMED IS:

1. A tissue ablation apparatus for ablating an inner wall of a bodily organ, the apparatus comprising:

a shaft assembly having a distal end; and

an expandable ablation member at the distal end of the shaft assembly, the expandable ablation member having a collapsed configuration and an expanded configuration, and the expandable ablation member comprising:

(i) a plurality of conductive regions, and

(ii) one or more non-conductive regions separating the conductive regions from one another with one or more predetermined separation distances, the one or more non-conductive regions being less stretchable than the plurality of conductive regions.

2. The tissue ablation apparatus of claim 1, wherein the one or more predetermined separation distances are in a range between about 2 mm to about 12 mm.

3. The tissue ablation apparatus of either claim 1 or 2, wherein the plurality of conductive regions comprises a plurality of first yarns having a first yarn size.

4. The tissue ablation apparatus of any of claims 1 to 3, wherein the one or more non-conductive regions comprises a plurality of second yarns having a second yarn size.

5. The tissue ablation apparatus of claim 4, wherein the second yarn size is less than the first yarn size.

6. The tissue ablation apparatus of either claim 4 or 5, wherein the second yarn size is greater than the first yarn size.

7. The tissue ablation apparatus of claim any of claims 4 to 6, wherein the second yarns are less stretchable than the first yarns.

8. The tissue ablation apparatus of claim any of claims 4 to 7, wherein the plurality of second yarns are at least double-layered and knit together such that plurality of second yarns have greater tensile strength or are less stretchable than the plurality of first yarns and the one or more non-conductive regions are less stretchable than the plurality of conductive regions.

9. The tissue ablation apparatus of claim 8, wherein the plurality of second yarns are triple layered.

10. The tissue ablation apparatus of either claim 8 or 9, wherein the plurality of first yarns are single layered.

11. The tissue ablation apparatus of any of claims 3 to 10, wherein the plurality of second yarns comprises a plurality of non-conductive yarns.

12. The tissue ablation apparatus of any of claims 3 to 10, wherein the plurality of first yarns comprises a plurality of conductive yarns.

13. The tissue ablation apparatus of claim 12, wherein the plurality of first yarns comprises a plurality of non-conductive yarns interwoven with the plurality of conductive yarns.

14. The tissue ablation apparatus of any of claims 1 to 13, wherein the plurality of conductive regions comprises a first conductive region on a first lateral side of the expandable ablation member and a second conductive region on a second lateral side of the expandable ablation member.

15. The tissue ablation apparatus of claim 14, wherein the one or more non- conductive regions comprises a longitudinal non-conductive strip separating the first and second conductive regions with the one or more predetermined separation distances.

16. The tissue ablation apparatus of claim 15, wherein the one or more predetermined separation distances are between about 2 mm to about 12 mm.

17. The tissue ablation apparatus of any of claims 1 to 16, wherein the expandable ablation member has a width of about 5 mm to about 9 mm in the collapsed configuration.

18. The tissue ablation apparatus of any of claims 1 to 17, wherein the expandable ablation member has a width of about 20 mm to about 70 mm in the expanded configuration.

19. The tissue ablation apparatus of any of claims 1 to 19, wherein the expandable ablation member has a cone or funnel shape in the expanded configuration.

20. A tissue ablation apparatus for ablating an inner wall of a bodily organ, the apparatus comprising:

a shaft assembly having a distal end; and

(i) a top layer comprising a first conductive outer surface, and

(ii) a bottom layer comprising a second conductive outer surface, the top and bottom layers defining an expandable cavity therebetween, and one or more of the top or bottom layers comprising a non-conductive inner surface separating the first and second conductive outer surfaces within the expandable cavity.

21. The tissue ablation apparatus of claim 20, wherein the one or more of the top or bottom layers comprising the conductive outer surface comprises a plurality of conductive yarns and a plurality of non-conductive yarns.

22. The tissue ablation apparatus of claim 21, wherein the conductive and non-conductive yarns are at least double layered together, and wherein the at least double layered conductive and non-conductive yarns are knit such that the plurality of conductive yarns face away from the expandable cavity and the plurality of non-conductive yarns face toward the expandable cavity.

23. The tissue ablation apparatus of any of claims 20 to 22, wherein the top layer comprises the first conductive outer surface and the non-conductive inner surface.

24. The tissue ablation apparatus of any of claims 20 to 23, wherein the bottom layer comprises the first conductive outer surface and the non-conductive inner surface.

25. The tissue ablation apparatus of any of claims 20 to 24, wherein the both the top and bottom layers comprise non-conductive inner surfaces.

26. The tissue ablation apparatus of any of claims 20 to 25, wherein the one or more of the top or bottom layers comprise a plurality of conductive regions and at least one non- conductive region separating the conductive regions from one another at one or more

predetermined separation distances.

27. The tissue ablation apparatus of claim 26, wherein the one or more predetermined separation distances are between about 2 mm to about 12 mm.

28. The tissue ablation apparatus of any of claims 20 to 27, wherein the expandable ablation member has a width of about 5 mm to about 9 mm in the collapsed configuration.

29. The tissue ablation apparatus of any of claims 20 to 28, wherein the expandable ablation member has a width of about 20 mm to about 70 mm in the expanded configuration.

30. The tissue ablation apparatus of any of claims 20 to 29, wherein the expandable ablation member has a cone or funnel shape in the expanded configuration.

31. A tissue ablation apparatus for ablating an inner wall of a bodily organ, the apparatus comprising:

a shaft assembly having a distal end; and an expandable ablation member at the distal end of the shaft assembly, the expandable ablation member having a collapsed configuration and an expanded configuration, and the expandable ablation member comprising:

(i) a top layer comprising a first conductive outer surface,

(ii) a bottom layer comprising a second conductive outer surface, the top and bottom layers defining an expandable cavity therebetween, and

(iii) a middle non-conductive layer disposed between the top and middle layers to separate the first and second conductive outer surfaces within the expandable cavity, wherein edges of the middle non-conductive layer are interwoven with edges of one or more of the top or bottom conductive layers.

32. The tissue ablation apparatus of claim 31, wherein one or more of the top or bottom layers comprises a plurality of conductive yarns and a plurality of non-conductive yarns.

33. The tissue ablation apparatus of either claim 31 or 32, wherein one or more of the top or bottom layers comprises a plurality of conductive regions and at least one non-conductive region separating the conductive regions from one another at one or more predetermined separation distances.

34. The tissue ablation apparatus of any of claims 31 to 33, wherein the expandable ablation member has a width of about 5 mm to about 9 mm in the collapsed configuration.

35. The tissue ablation apparatus of any of claims 31 to 34, wherein the expandable ablation member has a width of about 20 mm to about 70 mm in the expanded configuration.

36. The tissue ablation apparatus of any of claims 31 to 35, wherein the expandable ablation member has a cone or funnel shape in the expanded configuration.

37. A method of manufacturing an expandable ablation member of a tissue ablation apparatus, the method comprising:

knitting at least one first conductive yarn to form a first conductive region of the expandable ablation member;

knitting at least one non-conductive yarn to form a non-conductive region of the expandable ablation member, the non-conductive region being less stretchable than the first conductive region; and

coupling the first conductive region and the non- conductive region together.

38. The method of claim 37, wherein coupling the first conductive region and the non-conductive region together comprises providing at least one common non-conductive yarn for both the first conductive region and the non-conductive region.

39. The method of claim 38, wherein knitting the at least one first conductive yarn to form the first conductive region comprises interweaving the at least one first conductive yarn with the at least one common non-conductive yarn.

40. The method of either claim 38 or 39, wherein knitting the at least one non- conductive yarn to form the non-conductive region comprises interweaving the at least one non- conductive yarn with the at least one common non-conductive yarn.

41. The method of any of claims 37 to 40, wherein the at least one first conductive yarn is more stretchable than the at least one non-conductive yarn.

42. The method of any of claims 37 to 41, wherein the at least one first conductive yarn has a first yarn size, and wherein the at least one non-conductive yarn has a second yarn size.

43. The method of claim 42, wherein the second yard size is less than the first year size.

44. The method of either claim 42 or 43, wherein the second yard size is greater than the first year size.

45. The method of any of claims 42 or 44, wherein knitting the at least one non-conductive yarn to form the non-conductive region comprises at least double layering the at least one non-conductive yarn such that the double-layered non-conductive yarns have a greater tensile strength or lesser stretchability than the at least one first conductive yarn and the non- conductive region is less stretchable than the first conductive region.

46. The method of claim 45, wherein at least double layering the at least one non-conductive yarn comprises triple layering the at least one non-conductive yarn.

47. The method of either claim 45 or 46, wherein the at least one conductive region comprises single-layered yarns.

48. The method of any of claims 37 to 47, further comprising knitting at least one second conductive yarn to form a second conductive region of the expandable ablation member and coupling the second conductive region and the non-conductive region together.

49. The method of claim 48, wherein the first conductive region, the second conductive region, and the non-conductive region are coupled together such that the non- conductive region separates the first and second conductive regions from one another with one or more pre-determined separation distances.

50. The method of claim 49, wherein the one or more pre-determined separation distances are between about 2 mm to about 12 mm.

51. The method of either claim 49 or 50, wherein the first conductive region is disposed on a first lateral side of the expandable ablation member and the second conductive region is disposed on a second lateral side of the expandable ablation member.

52. The method of claim 51, wherein the non-conductive region comprises a longitudinal non-conductive strip separating the first and second conductive regions with the one or more predetermined separation distances.

53. A method of manufacturing an expandable ablation member of a tissue ablation apparatus, the method comprising:

double layering at least one first conductive yarn and at least one first non- conductive yarn such that the at least one first conductive yarn faces a first side and the at least one first non-conductive yarn faces a second side opposite the first side; and

knitting the double layered at least one first conductive yarn and the at least one first non-conductive yarn to form a first layer of the expandable ablation member, the first layer of the expandable ablation member having a conductive surface and a non-conductive surface opposite the conductive surface.

54. The method of claim 53 further comprising:

double layering at least one second conductive yarn and at least one second non- conductive yarn such that the at least one second conductive yarn faces a third side and the at least one first non-conductive yarn faces a fourth side opposite the third side;

knitting the double-layered at least one second conductive yarn and at least one second non-conductive yarn to form a second layer of the expandable ablation member, the second layer of the expandable ablation member having a conductive surface and a non- conductive surface opposite the conductive surface; and

coupling the first and second layers together such that the non-conductive surfaces of the first and second layers face inwardly toward one another and the conductive surfaces of the first and second layers face outwardly away from one another.

55. The method of claim 54, wherein the first layer of the expandable ablation member comprises a top layer and the second layer of the expandable ablation member comprises a bottom layer of the expandable ablation member.

56. The method of either claim 54 or 55, wherein one or more of the first or second layers are knit such that the conductive surfaces thereof comprise a plurality of conductive regions separated by at least one non-conductive region.

57. The method of any of claims 54 to 56, wherein the first and second layers define an expandable cavity therebetween.

58. The method of any of claims 54 to 57, wherein coupling the first and second layers together comprises at least partially joining edges of the first and second layers to one another.

59. The method of any of claims 53 to 58 further comprising: knitting at least one second conductive yarn to form a second layer of the expandable ablation member, the second layer of the expandable ablation member having a conductive surface; and

coupling the first and second layers together such that the non-conductive surface of the first layer faces inwardly toward the second layer and the conductive surfaces of the first and second layers face outwardly away from one another.

60. The method of claim 59, wherein the first layer of the expandable ablation member comprises a top layer and the second layer of the expandable ablation member comprises a bottom layer of the expandable ablation member.

61. The method of either claim 59 or 60, wherein one or more of the first or second layers are knit such that the conductive surfaces thereof comprise a plurality of conductive regions separated by at least one non-conductive region.

62. The method of any of claims 59 to 61, wherein the first and second layers define an expandable cavity therebetween.

63. The method of any of claims 59 to 62, wherein coupling the first and second layers together comprises at least partially joining edges of the first and second layers to one another.

64. A method of manufacturing an expandable ablation member of a tissue ablation apparatus, the method comprising:

knitting at least one first conductive yarn to form a first conductive layer;

knitting at least one second conductive yarn to form a second conductive layer; knitting at least one non-conductive yarn to form a non-conductive layer; and coupling the first conductive layer, the second conductive layer, and the non- conductive layer together such that the first and second conductive layers form an expandable cavity therebetween and the non-conductive layer is disposed between the first and second conductive layers, wherein edges of the non-conductive and insulating layer are interwoven with edges of one or more of the first or second conductive layers.

65. The method of claim 64, wherein one or more of the first or second conductive layers comprises a plurality of conductive yarns and a plurality of non-conductive yarns.

66. The method of either claim 64 or 65, wherein the non-conductive layer comprises a plurality of non-conductive yarns.

67. The method of any of claims 64 to 66, wherein the first conductive layer comprises a top layer having a first outer conductive surface, and wherein the second conductive layer comprises a bottom layer having a second outer conductive surface.

68. The method of any of claims 64 to 67, wherein one or more of the first or second conductive layers comprises a plurality of conductive regions and at least one non- conductive region separating the conductive regions from one another at one or more predetermined separation distances.