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 . In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 17 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 1 is directed to a system with a rectifier which, by definition, coverts AC to DC. Therefore, when claim 17 recites that the input is AC, the structure of the system is not further limited. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-3, 5-14, 17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Isaacson (US 2005/0113817) in view of Strauss (US 2010/0217259) and Irnich (US 4,741,334).
Regarding claims 1, 2, 5-12, 17, 19 and 20, Isaacson discloses an ablation system (fig. 8, [0105]-[0111]) with a first port (not numbered, left side of 130, see ablation generator 132) couplable to an ablation electrode (140, which is capable of transcutaneous insertion) and two second ports (also not numbered, right side of 130) couplable to different reference electrodes (111a-111b, via 122 and 124 respectively). Isaacson discloses generating a signal for measuring ([0110]), where whatever circuitry generates the signal can be considered a “measurement source,” and using the signal to determine impedance from current ([0110]), where whatever circuitry determines impedance can be considered “impedance monitoring circuitry.” Further, Isaacson broadly teaches that “differences in power, waveform, frequency, phase angle, or any other measurable characteristic or property of the monitoring signal can be measured, sensed, and/or tracked” as part of contact quality measuring ([0106]) which, in conjunction with the fact that no details are provided regarding the actual circuitry, is understood to establish that the level of ordinary skill in the art is very high and easily encompasses the kind of circuitry necessary to determine contact monitoring by using current and impedance. Presumably because it is not materially important, Isaacson does not specifically disclose that that the impedance is determined from the measurement current by reference to a measurement voltage, although it is also not clear how else impedance could be derived from current. In any case, the measurements of Isaacson are across the reference electrodes (fig. 8). In the interest of compact prosecution, a reference that provides more specific details about these well-known processes will be provided. Strauss discloses an ablation system very similar to Isaacson (fig. 1) and teaches that an AC measurement circuit (19) generates a measurement current (IM) that interacts with the resistance of tissue between return electrodes (11) to allow impedance monitoring circuitry (21) to generate an impedance based on a measurement voltage and the measurement current ([0042]). Strauss discloses all these elements are used for substantially the same purpose disclosed by Isaacson, namely determining the quality of contact between a patient and return electrodes (abstract). Strauss further discloses that the ablation source (3) and the measurement source are operated simultaneously such that if the measurement source indicates an issue with tissue contact, the ablation source can be adjusted to reduce or eliminate energy delivery ([0045]). Strauss also teaches that a capacitive network comprising two serially arranged capacitors with a node between them connected to the return side of the ablation generator can be provided across the two ports where the measurement current does not pass through the capacitive network (9), and that the ablation frequency which does pass through the capacitive network (350-400kHz, [0028]) is different from the frequency used by the measurement source (75kHz, [0038]). The system of Strauss further includes a resistor in series and at least physically between the measurement voltage and the measurement source (20, [0033]). It has been held that the combination of known elements according to know methods to yield predictable results is an obvious modification (MPEP 2141(III)), where in this case more specifically the fact that Isaacson does not disclose any particular circuitry is understood to be a very broad teaching that a person of ordinary skill in the art would be able to employ any other known circuitry that would predictably produce desired results. Therefore, before the application was filed, it would have been obvious to one of ordinary skill in the art to modify the system of Isaacson to include an any commonly known circuitry useful for determining the quality of tissue contact, including the various circuit elements disclosed by Strauss as discussed above, that would produce the predictable result of allowing a user to know the quality of tissue contact between the patent and the return electrodes by analyzing the impedance calculated from voltage measured across reference electrodes. The system of Isaacson as modified does not disclose exactly how the system is able to disable the ablation source if the reference electrodes are poorly connected to a patient. However, using rectifiers and comparators with reference values are very common in the art and there is no evidence that use of such common elements here produces an unexpected result (see MPEP 2141(III) regarding the combination of known elements according to known methods to yield predictable results). Irnich discloses an ablation system that employs a voltage monitoring circuit that includes an inverter and a comparator for controlling whether the generator delivers energy to the ablation electrode (fig. 1, abstract). Therefore, before the application was filed, it would have been obvious to one of ordinary skill in the art to further modify the system of Isaacson to include any commonly known control circuitry for ensuring the ablation source does not continue to operate in undesirable conditions, including the circuitry disclosed by Irnich as discussed above, to produce the predictable result of avoiding harming a patient.
Regarding claim 3, this claim is being interpreted as extremely broad rather than indefinite. The specification does not discuss in any detail what this “serial impedance” might be or how it might be calculated. The specification does mention a “series resistance” ([0020]), but this is merely based on the strictly necessary fact that the resistance measured by the system includes the serial resistances of the components in the circuit. Since the device of Isaacson does calculate the impedance/resistance of everything between the two ports, this includes the serial impedances/resistances of the electrodes (e.g. note “total effective impedance” in [0110]).
Regarding claims 13 and 14, the system of Isaacson as modified does not disclose these methods of generating a voltage measurement. However, measuring voltage is both ubiquitous and well within the level of ordinary skill in the art. Further, there is no evidence that any of these mutually exclusive species of measuring voltage produce an unexpected result (within the meaning of MPEP 716.02(a)). Therefore, before the application was filed, it would have been obvious to one of ordinary skill in the art to further modify the system of Isaacson to employ any commonly known method of generating a voltage measurement, including measuring voltage across the current source or using a sense resistor, that would produce the predictable result of allowing the system to then calculate the impedance of the reference electrodes.
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Isaacson, Strauss and Irnich, further in view of Eisele (US 2007/0222458).
Regarding claims 15 and 16, the system of Isaacson does not disclose the additional control circuitry in the impedance monitoring circuitry also digitizes the DC voltage. However, digitizing information for use in control processes is common in the art and there is no evidence that using digital over against analog signals produce an unexpected result. Eisele, for example, discloses another system with split pad electrode monitoring and teaches that collected information can be digitized for use in a control circuit ([0070]). Therefore, before the application was filed, it would have been obvious to one of ordinary skill in the art to further modify the system of Isaacson to include digitizing the voltage information prior to being processed by control circuitry, such as taught by Eisele, to produce the predictable result of a system that controls energy output based on sensed information. It is noted that the second part of claim 15 is recited in the alternative, and claim 16 only narrows that part of the claim. However, in the interest of compact prosecution, it is noted that that Isaacson ([0107]) and Strauss ([0045]) use sensed values compared to thresholds for controlling the ablation energy output, as is common in the art.
Response to Arguments
Applicant's arguments filed 20 April 2026 have been fully considered but they are not persuasive. The arguments are about a bodily incorporation of some elements from different references and do not account for the level of ordinary skill in the art. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). As an initial matter, it is noted that Applicant’s remarks regarding Isaacson are directed to an embodiment not cited in the rejection and are therefore at least largely moot. In particular, the embodiment of Isaacson cited in the rejection and not addressed in the remarks clearly shows two electrodes each coupled independently to two ports (fig. 8), contrary to Applicant’s reference to another embodiment which does not have those features (fig. 1). In the context of the cited embodiment and as noted in the rejection, Isaacson explicitly teaches that values other than phase angle (i.e. values that strictly require AC) are useful for quality of tissue contact determination ([0106]) which at the very least establishes that a person of ordinary skill in the art would know how to create the circuitry necessary for using those other values for quality of tissue contact determination, and be motivated to do so. Applicant continues in the remarks to discuss Strauss including a note that there is no rectifier. But the rejection does not state that Strauss discloses a rectifier. Finally, Applicant flatly states that Strauss is not susceptible to modification using rectification as in Irnich, simply noting that Strauss has a use for AC voltage. But, first, the rejection does not state it would be obvious to modify Strauss as taught by Irnich. Instead, the rejection states that it would be obvious to modify Issacson to have some of the elements of Strauss and Irnich useful for determining quality of tissue contact. Obviousness rejections are not based on whether every single structural element and feature can be incorporated from one reference into another. In this case, nothing is being incorporated into Strauss at all. Instead, some teachings and structural elements useful for determining quality of tissue contact are incorporated into Issacson. In particular, Strauss discloses some circuit elements that allow sensing and ablation to occur simultaneously, where a significant reason why tissue contact quality is an important measure is to prevent burns from occurring during ablation. As noted in the rejection, the measurements in Issacson are specifically across the reference electrodes such that there is no need for the transformer of Strauss (even if including such a transformer would be an obvious modification as well). Second, even if it was argued that Strauss prefers AC for the reasons discussed therein, the teaching of Issacson that it is recognized that other parameters beside phase angle can be useful for tissue contact quality determination cannot be ignored and it would be obvious to a person of ordinary skill in the art to follow the guidance provided by Issacson as much as by Strauss (where it is noted that the existence of other obvious modifications does not render one obvious modification improper). It is reiterated that Strauss is not being modified, Issacson is being modified. As illustrated in the preceding discussion, the remarks assume that a person of ordinary skill in the art would be chained to a bodily incorporation of the structures of the three references together, starting with Strauss. However, it is well established that “a person of ordinary skill in the art is also a person of ordinary creativity, not an automaton” (as discussed in MPEP 2141(II)(C)). Further, the level of ordinary skill in the art is very high as illustrated at least by Issacson which includes sweeping suggestions for various types of circuits with very little guidance (e.g. “Differences in power, waveform, frequency, phase angle, or any other measurable characteristic or property of the monitoring signal can be measured, sensed, and/or tracked to identify whether a patient (not shown) is sufficiently in contact with electrosurgical electrode 110 to prevent patent burns” [0106], emphasis added). Thus, only an automation would view the combination of all the elements of Strauss, after having been modified with the elements of Irnich, into the system of Issacson, to be the only obvious modification of Issacson such that the rejection is improper. Instead, a person of ordinary skill and thus ordinary creativity would note that Issacson measures the values across the electrodes and not across a transformer using various isolation circuitry to allow different frequencies of signals to be employed simultaneously, and would further note that Irnich uses a rectifier and a comparator for control functions by converting AC into DC. It reasonably follows that it would be obvious to modify Issacson as taught by Strauss and Irnich in a manner that produces the predictable result of preventing a generator from supplying ablation energy when tissue contact with a ground pad is insufficient for safe operation based on an AC conversion to DC used in conjunction with a comparator.
Finally, while not immediately relevant to the rejections as they are currently written, it seems of particular note that Strauss’ figure 1 is almost identical with Applicant’s figure 2B. The only significant differences are that Strauss uses an isolation transformer and Applicant performs the extra steps of using a rectifier as part of the data-analysis circuitry. On its face it seems difficult to argue that the absence of a transformer and the presence of a rectifier are grounds for patentability in the electrosurgical generator art, although there may be other meaningful differences as yet unclaimed. Because Strauss neither stresses the importance of using an isolation transformer or phase angle, while the prior art clearly discloses isolation transformers are optional (as noted in the Conclusion of the previous Action) and there are numerous other parameters useful for quality of tissue contact determination (as noted above in Issacson), where the use of all of these common circuit components is well within the level of ordinary skill in the art, it seems likely that Strauss will continue to be directly relevant to the claimed invention even where it may not be the reference being modified.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Regarding the general teaching that control systems are commonly implemented with analog or digital circuitry, which is understood to be a teaching of functional equivalence (MPEP 2144.06), see paragraph [0057] of US 2010/0130976 to Bystryak. Regarding the general teaching that data measured for control purposes can be in analog or digital form, including conversion from analog to digital, see paragraph [0036] of US 2010/0049187 to Carlton.
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 DANIEL WAYNE FOWLER whose telephone number is (571)270-3201. The examiner can normally be reached Monday-Friday (9-5).
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/DANIEL W FOWLER/Primary Examiner, Art Unit 3794
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