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 4 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 and does not positively recite an ablation electrode. Therefore, when claim 4 recites additional structure of the ablation electrode, this does not further limit the structure of the system in any way. 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 1-14 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Isaacson (US 2005/0113817) in view of Strauss (US 2010/0217259).
Regarding claims 1, 2, 4-12 and 17, 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, 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.
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 in view of Strauss, further in view of Eisele (US 2007/0222458).
Regarding claims 15 and 16, the system of Isaacson does not disclose additional control circuitry in the impedance monitoring circuitry that digitizes the measured voltage. However, digitizing information for use in control processes is common in the art. Eisele, for example, discloses another system with split pad electrode monitoring and teaches that collected voltage 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.
Claims 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Isaacson in view of Strauss, further in view of Irnich (US 4,741,334).
Regarding claims 18-20, 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 there use here produces an unexpected result. The fact that Applicant has claimed mutually exclusive mechanisms of controlling an ablation source suggests the opposite, that none of the particularly claimed mechanisms for using sensed information to control the output of an ablation generator do anything other than what a person of ordinary skill in the art would expect. 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 Irnish, to produce the predictable result of avoiding harming a patient.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Preventing harm to patients in monopolar ablation systems has long been a concern and there are many prior art documents which perform exactly the same function as the claimed invention. The following documents are considered particularly relevant to the disclosed invention: figure 6 of US 2006/0224150 to Arts, figure 2B of US 2011/0204903 to Gilbert, figure 3 of US 2023/0190364 to Curran, paragraphs [0049], [0063] and [0066] of US 2008/0281309 to Dunning, figure 1 of US 5,087,257 to Farin, figure 1 of US 5,695,494 to Becker and figure 1 of US 4,416,276 to Newton. Regarding the general teaching that a return electrode may or may not be coupled to the generator through an isolation transformer, see paragraph [0050] of US 2019/0262058 to Cheng and paragraph [0033] of US 2020/0155251 to Rockrohr.
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