DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
The amendment filed 03 March 2026 has been entered. Claims 1, 3, 5-12, and 15-20 are currently amended. Claim 4 and 14 are canceled. Claims 1-3, 5-13, and 15-20 are pending in the application. Applicant’s amendments to the claims have overcome each and every objection and rejection under 35 U.S.C. 112(b) previously set forth in the Non-Final Office Action mailed 03 December 2025.
Claim Objections
Claim 10 is objected to because of the following informalities: in line 3, "loFngitudinal" should read --longitudinal--. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-3, 5-9 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Levin et al. (US Patent No. 6,456,863), hereinafter Levin, in view of Couture (US PGPub No. 2008/0249527).
Regarding claims 1 and 20, Levin teaches a catheter for ablating tissue (Fig. 16: catheter 1000), the catheter comprising: an elongated body extending along a longitudinal axis and having a proximal end and a distal end (Figs. 16, 23-28: molded distal end assembly 1200 bonded to distal end of guide tube 1016);
a first electrode spaced proximally from a second electrode along the elongated body (Fig. 26: ring electrodes 1262),
each of the first and second electrodes having a transition region opposing the other electrode terminating in an edge (Fig. 26: tapered edges 1264 opposing each other);
and an insulator disposed over the electrode in the transition region and extending between the first and second electrodes, wherein, in each transition region, an electrode thickness of each electrode decreases toward the respective edge and an insulator thickness of the insulator correspondingly increases so as to maintain a generally constant combined thickness (Fig. 24: wall 1204 and corresponding wall 26 in Figs. 3-5; col 14, line 65 - col 15, line 3: “As with the previously described tapered coil electrodes (such as electrode coil 50 depicted in FIGS. 3-5) the tapered edges 1264 are molded into the sidewall of a molded catheter assembly;” examiner notes that the sidewall as best shown in Fig. 3 corresponding increases in thickness at the tapering region of each electrode such that the elongate body maintains a generally constant thickness).
Levin does not explicitly teach wherein a thickness of the insulator increases at a constant taper angle. However, in an analogous art, Couture teaches providing dielectric material with a tapered thickness having a constant taper angle at the junction between an electrode and an insulator (Fig. 5E: tapered insulative layer 140; par. 0080: “By providing insulative layers of various lengths, the thickness of the insulative layer 140 varies from top to bottom. It is envisioned that a gradient forms where the dielectric strength of the top portion 138 of insulative layer 140 (adjacent to the conductive layer) is less than the dielectric strength of the bottom portion 139 of the insulative layer 140 (adjacent to the top portion 160 of the insulating substrate 111)”), in order to reduce stray currents and flashover (0053: “one way to reduce the incidence of stray currents and flashover is to provide a gradient insulating layer between the insulating substrate, and the electrically conductive surface which effectively increases the overall distance that the electrical current must travel along the predetermined electrical path. As used herein the term "gradient" refers to a gradual change in some quantitative property over a specific distance. It is envisioned that the quantitative property of the gradient insulating layer is the dielectric strength of the at least one material of the gradient insulating layer”). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the device and method of Levin by providing a constant taper angle for the increasing thickness of the insulator, as taught by Couture, in order to reduce stray currents and flashover, as taught by Couture.
Levin teaches substantially all the limitations of the claim except that Levin teaches radiofrequency ablation (col 4, lines 60-63: “The physician then introduces radio frequency energy from a source (not shown) through the cable 20, through electrical leads in the guide tube assembly 16 to the multi-electrode assembly 12 to ablate the heart tissue”) and does not explicitly teach wherein the ablation is achieved through irreversible electroporation. However, irreversible electroporation is well known in the art as an alternative to radiofrequency for ablation, and the substitution of irreversible electroporation for radiofrequency ablation would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, since the substitution would have yielded predictable results, namely, non-thermal rather than thermal ablation.
Method claim 20 is also rejected over Levin in view of Couture as broadly reciting the steps of creating the catheter of claim 1.
Regarding claims 2 and 8, Levin teaches the device of claim 1 as described previously. Levin further teaches wherein each transition region has a substantially similar shape, and wherein the transition region comprises one or more of steps, ramps, or transitions of various geometries (Fig. 26: similar tapered edges 1264 on each electrode).
Regarding claims 3 and 7, Levin teaches the device of claim 1 as described previously. Levin further teaches wherein the transition region is configured such that when a voltage is applied to each of the electrodes, a current density in each transition region is generally constant, a tapered region of insulation on the electrode creating a gradual transition of current density from the insulator to the electrode (col 14, line 65 - col 15, line 3: “As with the previously described tapered coil electrodes (such as electrode coil 50 depicted in FIGS. 3-5) the tapered edges 1264 are molded into the sidewall of a molded catheter assembly to control the effects of the generally higher electrical power density that occurs at the electrode edges, as discussed hereabove;” see description of tapered coil electrodes in col 6, lines 18-30: “The decreased diameter may also be achieved by grinding the outer surface of coil windings 110 and 136 to make the coil wire thinner at the proximal and distal ends. The coil end windings 110 and 136 are preferably molded into the distal wall section 26 because the tissue adjacent the end windings receives a higher electrical power density than tissue adjacent the middle windings 138 of the coil electrode. The higher electrical power density can lead to uneven effects upon the tissue disposed proximate the coil electrode, and molding the end windings of the coil electrodes into the sidewall produces a more even electrical power density at the outer surface of the assembly 12 that is in contact with the tissue”).
Regarding claims 5-6, Levin teaches the device of claim 1 as described previously. Levin further teaches wherein the insulator comprises a dielectric strength of from about 15kV/mm to 60kV/mm, and wherein the dielectric strength of the insulator determines the gradient of current density (col 13, lines 54-55: “A preferred molding material is Pebax®;” examiner notes that the dielectric strength of Pebax® falls within the claimed range).
Regarding claim 9, Levin teaches the device of claim 1 as described previously. Levin further teaches further comprising a third and a fourth electrode with the insulator extending between the third and fourth electrodes, a diameter each of the third and the fourth electrode decreasing in respective transition regions toward respective edges, and the insulator increasing in diameter correspondingly such that the catheter shaft is substantially isodiametric (Fig. 26: third and fourth ring electrodes 1262 with corresponding tapered edges 1264 and molding into the insulating sidewall, as laid out in the rejection of claim 1).
Claims 10-13 and 15-19 are rejected under 35 U.S.C. 103 as being unpatentable over Levin in view of Couture and further in view of Langberg (US Patent No. 5,257,635).
Regarding claim 10, Levin teaches a catheter for ablating tissue (Fig. 16: catheter 1000), the catheter comprising: an elongated shaft extending along a longitudinal axis and having a proximal end and a distal end (Figs. 16, 23-28: molded distal end assembly 1200 bonded to distal end of guide tube 1016);
a ring electrode located proximal of and spaced apart from a tip at the distal end of the elongated shaft, the ring electrode having a distal portion (Fig. 26: ring electrodes 1262);
and an insulator disposed between the tip and the first ring electrode, wherein the distal portion of the ring electrode is tapered in the distal direction along the longitudinal axis in a transition region, such that an electrode thickness of the electrode decreases and an insulator thickness of the insulator increases to maintain a generally uniform catheter diameter (Fig. 26: tapered edges 1264; Fig. 24: wall 1204 and corresponding wall 26 in Figs. 3-5; col 14, line 65 - col 15, line 3: “As with the previously described tapered coil electrodes (such as electrode coil 50 depicted in FIGS. 3-5) the tapered edges 1264 are molded into the sidewall of a molded catheter assembly”).
Levin does not explicitly teach irreversible electroporation for ablation, but it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to substitute irreversible electroporation for radiofrequency ablation in Levin’s device, for the same reasons laid out previously in the rejection of claim 1.
Levin further does not explicitly teach wherein a thickness of the insulator increases at a constant taper angle, but Levin in view of Couture teaches this limitation for the same reasons laid out previously in the rejection of claim 1.
Levin further does not teach a tip electrode at the distal end of the elongated shaft and configured to provide ablation. However, in an analogous art, Langberg teaches that an active tip electrode at the end of a catheter and a proximal ring electrode is a known typical configuration in the ablation art (Fig. 5: proximal ring electrode 74 and distal tip electrode 76; col 2, lines 59-64: “Typical state of the art catheter heating applicators for the conductive region, such as the United States Catheter Industries (USCI) catheter shown in FIG. 1, and described in detail later, has an active electrode at the end of the catheter tube and possibly ring electrode or electrodes around the diameter of the tube”). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to provide the device of Levin with the ablating tip electrode of Langberg, since Langberg teaches that a tip electrode with a proximal ring electrode is a known configuration for ablation, and one skilled in the art could have combined these elements as claimed by known methods with no change in their respective functions, and the combination would have yielded nothing more than predictable results, namely, ablative functionality at the distal tip of the ablation catheter.
Regarding claim 11, the combination teaches the device of claim 10 as described previously. Langberg further teaches wherein the tip electrode is tapered in the proximal direction along the longitudinal axis in the transition region, such that the tip electrode thickness decreases and the insulator thickness increases to maintain a generally uniform catheter diameter (Fig. 3: electrode 20 tapered at its base 22, conductive skirt 23 with higher insulating properties than the electrode), which improves uniformity of power density at the junction of the electrode and the catheter shaft (col 5, lines 36-47: “Active electrode 20 is tapered at its base 22 with a tapered angle of 10 degrees. Conductive epoxy fills this tapered region and forms a conductive skirt 23. The contours of equal heating power density, are shown in FIG. 3 for conductive epoxy with resistivity of 150 Ω-cm. […] It can be seen that the uniformity of heating density at the junction of active electrode 20 and tube 24 is much improved when compared with the state-of-the-art catheter in FIG. 1 due to a graduated impedance, presented to the surface current flow, provided by the wedge-shaped cross section of conductive skirt 23”). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the device of the combined reference by providing a proximal tapered region for the tip electrode, as taught by Langberg, in order to improve uniformity of power density at the junction of the electrode and the catheter shaft, as taught by Langberg.
Regarding claims 12 and 18, the combination teaches the device of claim 10 as described previously. Levin further teaches the limitations of these claims for the same reasons laid out previously in the rejection of claims 2 and 8.
Regarding claims 13 and 17, the combination teaches the device of claim 10 as described previously. Levin further teaches the limitations of these claims for the same reasons laid out previously in the rejection of claims 3 and 7.
Regarding claims 15-16, the combination teaches the device of claim 10 as described previously. Levin further teaches the limitations of these claims for the same reasons laid out previously in the rejection of claims 5-6.
Regarding claim 19, the combination teaches the device of claim 10 as described previously. Levin further teaches the limitations of this claim for the same reasons laid out previously in the rejection of claim 9.
Response to Arguments
Applicant’s arguments, filed 03 March 2026, with respect to the rejection(s) of claim(s) 1, 10, and 20 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, in light of the amendments to the claims, the previous rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Couture. As described previously, Couture teaches a constant taper angle for increasing thickness of a dielectric material at the junction between an electrode and insulator.
Applicant’s argument regarding the interchangeability of pulsed frequency ablation and radiofrequency ablation has been fully considered but is not persuasive. Although the differences between these types of ablation are acknowledged, it appears to be known in the prior art that tapering insulation thickness and electrode edges would provide the same result in both types of ablation, namely, reduced current density at a junction between a dielectric and an electrode, which is desirable in either pulsed frequency or radiofrequency ablation.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Mickelsen (US PGPub No. 2017/0065339) teaches beveling or rounding electrode edges in an irreversible electroporation device in order to reduce high current density due to conductive regions with high curvature (see par. 0089).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVINA E LEE whose telephone number is (571)272-5765. The examiner can normally be reached Monday through Friday between 8:00 AM and 5:30 PM (ET).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, LINDA C DVORAK can be reached at 571-272-4764. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/LINDA C DVORAK/Primary Examiner, Art Unit 3794
/D.E.L./Examiner, Art Unit 3794
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