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 Amendments filed August 06, 2026 has been entered. Applicant’s amendments have overcome the 112(b) rejection previously set-forth in the Non-Final Office Action mailed on 04/06/2026. Currently, claims 32-33 have been amended, claim 34 has been newly added, claim 29 has been newly cancelled, and claims 1, 3-4, 6-9, 22-28, 30-34 are pending in the application.
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, 7-8, 22-28, and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Schwartz (U.S. Application No. 20180125575 A1), in view of Panescu (U.S. Patent No. 5487391 A), and further in view of Cory (U.S. Application No. 20110082383 A1).
Regarding independent claim 1, Schwartz discloses a system (100) for monitoring tissue lesion development during a medical ablation process applied to a patient (pa. 0107 & Fig. 1B), the system comprising:
a catheter ablation device (111) having at least one catheter electrode (103) (pa. 0113, 0138);
the catheter ablation device connectable via an electrical feedline to a source of electrical energy (101A) and configured to apply ablation energy to ablate tissue in a target region (pa. 0107);
a plurality of external electrodes (105) for application to the body of the patient (pa. 0117, 0138);
measurement circuitry (120A, 120B, 101B) for determining an electrical impedance of a current path between the at least one catheter electrode and the external electrodes (pa. 0107, 0117, 0140); and
an electrical controller (120) arranged to control the application of an AC current source (pa. 0004, 0115) between different combinations of the catheter electrode and the plurality of external electrodes and to measure resulting voltages (i.e., the controller 120 is capable of receiving dielectric property data, such as impedance data, from catheter electrodes 103 and/or skin patch electrodes 105, by controlling the input of AC current supplied by the field generator 101A; pa. 0107, 0115-0117), the measurement of the resulting voltages providing a measure of impedance of different electrical paths through the body of the patient between the respective electrodes (pa. 0132-0138),
wherein the measurement circuitry is able to switch between different combinations of the at least one catheter electrode and the plurality of external electrodes under control of the electrical controller (pa. 0116, 0131-0138, 0140), wherein each of the different combinations comprises a pair of connected electrodes including one catheter electrode from the at least one catheter electrode and one external electrode from the plurality of external electrodes (pa. 0132-0137).
In further detail, Schwartz specifically discloses that in order to achieve accurate results of impedance measurements, they utilize numerous vector components (for example, measurements at multiple frequencies between different combinations of multiple catheter/skin patch electrode pairs using a vector formula (pa. 0137) which uses three elements: a set of frequencies, the set of catheter electrodes, and the set of skin electrodes (pa. 0132-0135) to extract strong correlations of lesion assessment.
At step 206 (pa. 0153 & Fig. 2), after applying fields of selected frequencies between the catheter electrodes and the skin electrodes, measurements of the field (for example by field measurer 101B, which is controlled by controller 120) comprise a characteristic signal at each frequency, and for each electrode selection, which is measured at block 208 to produce the set of impedance measurements Z(t). Later, these impedance measurements can be isolated in order to further understand the contributions of just the catheter electrodes or just the skin electrodes or both (pa. 0140-0142). Therefore, the device of Schwartz is able to supply current to the different sets of catheter/skin electrodes pairs and gather impedance information from either or both of the catheter/skin electrodes.
However, Schwartz does not disclose controlling the sequential application of the AC current between the different combinations of the least one catheter electrode and one external electrode via a measurement circuitry that includes a switch matrix comprising a plurality of switches.
Panescu, in the same field of endeavor, teaches a system for measuring impedance between a catheter electrode and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1). The system comprises a plurality of adjacent catheter electrodes (E1-E7) electrically coupled to their own signal wires (W1 to W7), and one external electrode (EI) is electrically coupled to its own signal wire (WI) (Col. 9, lines 27-33 & Fig 11). The system further includes an interface (56) element electronically configured to a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51). As seen in Fig. 12, when the setting switch SM in Position A, the interface configures the switching element for operation in the unipolar mode, and the interface electronically configures each individual electrode E1 to E7 to emit current by sequentially setting the associated switch SE1 to SE7. When the selected electrode E1 to E7 is so configured, it is electronically coupled to the supply of the current generator and emits current. The external electrode receives the current sequentially emitted by the selected catheter electrode E1 to E7 (Col. 10, lines 1-15).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the interface and the switching element with its plurality of switches to the measurement circuitry of Schwartz for the purpose of providing a more efficient process that is able to render impedance measurements with high accuracy and/or repeatability.
However, Panescu only teaches the different combinations of electrodes being between at least one catheter electrode and only one external electrode, not between at least one catheter electrode and the plurality of external electrodes.
Cory, in the same field of endeavor, teaches a system and method for applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue (pa. 0143). The system comprises waveform electrodes (1), return electrodes (7). In one embodiment, there is a single, large, return electrode and a plurality of waveform electrodes 1 fashioned to form an array (pa. 0147 & Fig. 6) (this embodiment being analogous to the embodiment taught by Panescu). In a second embodiment, the waveform electrodes and return electrodes are both fashioned as electrode array assemblies (pa. 0149 & Fig. 8). In this embodiment, each electrode array is connected to a respective multiplexer circuit, wherein multiplexer circuit (52) is connected to the return electrode array (51) and multiplexer circuit (38) is connected to the waveform electrode array (18). The multiplexer circuit (38) may be an electronically controlled switch, a multiplexer, a gate array, or any suitable device that may be controlled by controller (16) to provide current waveforms or voltage waveforms from waveform generator (21) across selected, individual electrodes within the waveform electrode array assembly and one or more of the return electrodes in the return electrode array assembly (pa. 0151). The controller then calculates and stores information derived from the measured signal, e.g., impedance, resistance, reactance, admittance, conductance, and other electrical parameters based upon the plurality of different waveforms applied across the waveform electrodes and return electrodes (pa. 0154).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated the second embodiment of Cory, which includes an additional multiplexer circuit electrically connected to the plurality of return electrodes, into the system of Schwartz since it seems that either embodiment (single return electrode connected to a switch matrix vs a plurality of return electrodes connected to a switch matrix) would yield the same predictable results of allowing the system to determine/calculate impedance and other electrical parameters based on the waveforms applied across different combination of electrodes.
Regarding claim 3, Schwartz/Panescu/Cory combination discloses wherein the electrical controller is further configured to disconnect the catheter ablation device from the source of electrical energy or otherwise suspend said application of ablation energy during application of said AC current source (Schwartz, pa. 0217, 0233 & Figs. 2-3).
Regarding claim 7, Schwartz/Panescu combination discloses the invention substantially as claimed in claim 1 and discussed above.
However, they do not disclose including multiple analogue-to-digital converters (ADC) for simultaneous measurement of different current paths.
Cory, in the same field of endeavor, teaches how sampling of signals across the electrodes may be continuous, intermittent or periodic. If continuous, it may be detected as a digital signal, e.g., via an analog-to-digital (A/D) converter that converts the received analog signal (e.g., voltage or current) into a digital value (pa. 0155).
Although Cory is silent/not explicit about having multiple A/D converters, it would have been obvious to one having ordinary skill in the art at the time the invention was made to include more than one A/D converter for simultaneous measurement of different current paths into the system of Schwartz, since it has been held that mere duplication of the essential working parts of a device involves only routine skill in the art. St. Regis Paper Co. v. Bemis Co., 193 USPQ 8.
Furthermore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added multiple analogue-to-digital converters (ADC) for the purpose of converting raw analog signals into a usable digital form for simultaneous measurement of different current paths.
Regarding claim 8, Schwartz/Panescu/Cory combination discloses wherein the source of electrical energy is an RF generator (Schwartz, pa. 0169).
Regarding claim 22, Schwartz/Panescu/Cory combination discloses a logical unit (130) programmed to analyze the electrical impedance determined by the measurement circuitry to provide an estimate of a size of an ablation lesion in the tissue caused by the application of ablation energy by the catheter ablation device (Schwartz, pa. 0121, 0154 & Fig. 2).
Regarding claim 23, Schwartz/Panescu/Cory combination discloses wherein measuring the resulting voltages includes applying the AC current using one of the plurality of external electrodes (Schwartz, pa. 0107) and sequentially measuring voltage with the remaining external electrodes (Schwartz, pa. 0132-0138, 0140).
Regarding claim 24, Schwartz/Panescu/Cory combination discloses wherein the electrical controller is configured to, during an ablation process:
implement an initial setup phase (206, 208) including sequentially measuring an electrical impedance of each current path between the at least one catheter electrode and the plurality of external electrodes (Schwartz, pa. 0140, 0153) in order to select one or more current paths to use in monitoring tissue lesion development (Schwartz, pa. 0153 & Fig. 2). As described in paragraph 0140, multiple impedance measurements are acquired, such that the impedance Z(t) is a vector of measurements between the catheter electrode (c) and each pair of patch electrodes (p) (ci, (pi, . . . pm). At block 206, measurements of the field (by measurement circuitry 101B) comprise a characteristic signal at each frequency for each electrode selection, which is measured at block 208, to produce the set of impedance measurements Z(t) (pa. 0153). Hence, at least one, or all, current paths are monitored/selected for tissue lesion development;
implement an ablation phase (209), wherein in the ablation phase, RF energy is applied to the at least one catheter electrode to ablate the tissue to form a lesion (Schwartz, pa. 0157); and
implement a measurement phase (207, 209), wherein in the measurement phase the impedance of the selected one or more current paths is measured to monitor tissue lesion dimension (Schwartz, pa. 0159-0161, 0177).
Regarding claim 25, Schwartz/Panescu/Cory combination discloses wherein the system is configured to sequentially repeat the ablation phase and measurement phase until the lesion has reached a required size (Schwartz, pa. 0162, 0180-0181).
Regarding claim 26, Schwartz/Panescu/Cory combination discloses wherein the electrical controller is configured to select one or more current paths between the different combinations of pairs of connected electrodes to use in monitoring tissue lesion development based on the measure of impedance between the different combinations of the at least one catheter electrode and the plurality of external electrodes (Schwartz, pa. 0131-0138, 0140).
Regarding independent claim 27, Schwartz discloses a system (100) for monitoring tissue lesion development during a medical ablation process applied to a patient (pa. 0107 & Fig. 1B), the system comprising:
a catheter ablation device (111) having at least one catheter electrode (103) (pa. 0113, 0138);
the catheter ablation device connectable via an electrical feedline to a source of electrical energy (101A) and configured to apply ablation energy to ablate tissue in a target region (pa. 0107);
a plurality of external electrodes (105) for application to the body of the patient (pa. 0117, 0138);
an electrical controller (120) (pa. 0115);
measurement circuitry (120A, 120B, 101B) for determining an electrical impedance of a current path between the at least one catheter electrode and the external electrodes (pa. 0107, 0117, 0140-0141), the measurement circuitry configured to couple an AC current source (pa. 0004, 0115) to different combinations of the at least one catheter electrode and the plurality of external electrodes under control of the electrical controller (i.e., the controller 120 is capable of receiving dielectric property data, such as impedance data, from catheter electrodes 103 and/or skin patch electrodes 105, by controlling the input of AC current supplied by the field generator 101A; pa. 0107, 0115-0117), wherein each of the different combinations comprises a pair of connected electrodes including one catheter electrode from the at least one catheter electrode and one external electrode from the plurality of external electrodes (pa. 0132-0137, 0140);
wherein the electrical controller is configured to:
implement an initial setup phase (206, 208) in which the measurement circuitry is operated to sequentially couple the AC current source between the at least one catheter electrode and different ones of the plurality of external electrodes to measure the electrical impedance of each current path (pa. 0140, 0153), and, based on the measured impedances, select one or more current paths for subsequent monitoring (pa. 0153 & Fig. 2). As described in paragraph 0140, multiple impedance measurements are acquired, such that the impedance Z(t) is a vector of measurements between the catheter electrode (c) and each pair of patch electrodes (p) (ci, (pi, . . . pm). At block 206, measurements of the field (by measurement circuitry 101B) comprise a characteristic signal at each frequency for each electrode selection, which is measured at block 208, to produce the set of impedance measurements Z(t) (pa. 0153). Hence, at least one, or all, current paths are monitored/selected for tissue lesion development; and
thereafter, alternate between: (i) an ablation phase (209), in which ablation energy is delivered to the at least one catheter electrode to ablate tissue in the target region (pa. 0157), and (ii) a measurement phase (207, 209) (which is performed before during, and/or after the ablation of the target tissue, pa. 0228), in which the source of electrical energy is electrically disconnected from the catheter ablation device (at least in the step where the measurement step is performed before the ablation procedure) and the measurement circuitry is operated to measure impedance only along the selected one or more current paths to monitor tissue lesion development (pa. 0159-0161, 0177).
In further detail, Schwartz specifically discloses that in order to achieve accurate results of impedance measurements, they utilize numerous vector components (for example, measurements at multiple frequencies between different combinations of multiple catheter/skin patch electrode pairs using a vector formula (pa. 0137) which uses three elements: a set of frequencies, the set of catheter electrodes, and the set of skin electrodes (pa. 0132-0135) to extract strong correlations of lesion assessment.
At step 206 (pa. 0153 & Fig. 2), after applying fields of selected frequencies between the catheter electrodes and the skin electrodes, measurements of the field (for example by field measurer 101B, which is controlled by controller 120) comprise a characteristic signal at each frequency, and for each electrode selection, which is measured at block 208 to produce the set of impedance measurements Z(t). Later, these impedance measurements can be isolated in order to further understand the contributions of just the catheter electrodes or just the skin electrodes or both (pa. 0140-0142). Therefore, the device of Schwartz is able to supply current to the different sets of catheter/skin electrodes pairs and gather impedance information from either or both of the catheter/skin electrodes.
However, Schwartz does not disclose the measurement circuitry including a switch matrix comprising a plurality of switches, wherein the switch matrix is operated to sequentially couple the AC current source between the at least one catheter electrode and one external electrode.
Panescu, in the same field of endeavor, teaches a system for measuring impedance between a catheter electrode and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1). The system comprises a plurality of adjacent catheter electrodes (E1-E7) electrically coupled to their own signal wires (W1 to W7), and one external electrode (EI) is electrically coupled to its own signal wire (WI) (Col. 9, lines 27-33 & Fig 11). The system further includes an interface (56) element electronically configured to a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51). As seen in Fig. 12, when the setting switch SM in Position A, the interface configures the switching element for operation in the unipolar mode, and the interface electronically configures each individual electrode E1 to E7 to emit current by sequentially setting the associated switch SE1 to SE7. When the selected electrode E1 to E7 is so configured, it is electronically coupled to the supply of the current generator and emits current. The external electrode receives the current sequentially emitted by the selected catheter electrode E1 to E7 (Col. 10, lines 1-15).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the interface and the switching element with its plurality of switches to the measurement circuitry of Schwartz for the purpose of providing a more efficient process that is able to render impedance measurements with high accuracy and/or repeatability.
However, Panescu only teaches the different combinations of electrodes being between at least one catheter electrode and only one external electrode, not between at least one catheter electrode and the plurality of external electrodes.
Cory, in the same field of endeavor, teaches a system and method for applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue (pa. 0143). The system comprises waveform electrodes (1), return electrodes (7). In one embodiment, there is a single, large, return electrode and a plurality of waveform electrodes 1 fashioned to form an array (pa. 0147 & Fig. 6) (this embodiment being analogous to the embodiment taught by Panescu). In a second embodiment, the waveform electrodes and return electrodes are both fashioned in electrode array assemblies (pa. 0149 & Fig. 8). In this embodiment, each electrode array is connected to a respective multiplexer circuit, wherein multiplexer circuit (52) is connected to the return electrode array (51) and multiplexer circuit (38) is connected to the waveform electrode array (18). The multiplexer circuit (38) may be an electronically controlled switch, a multiplexer, a gate array, or any suitable device that may be controlled by controller (16) to provide current waveforms or voltage waveforms from waveform generator (21) across selected, individual electrodes within the waveform electrode array assembly and one or more of the return electrodes in the return electrode array assembly (pa. 0151). The controller then calculates and stores information derived from the measured signal, e.g., impedance, resistance, reactance, admittance, conductance, and other electrical parameters based upon the plurality of different waveforms applied across the waveform electrodes and return electrodes (pa. 0154).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated the second embodiment of Cory, which includes an additional multiplexer circuit electrically connected to the plurality of return electrodes, into the system of Schwartz since it seems either embodiment (single return electrode connected to the switch matrix vs a plurality of return electrodes connected to the switch matrix) would yield the same predictable results of allowing the system to determine/calculate impedance and other electrical parameters based on the waveforms applied across different combination of electrodes.
Regarding claim 28, Schwartz/Cory combination discloses wherein the electrical controller is further configured to, during the initial setup phase, to connect the at least one catheter electrode with each of the selected one or more external electrodes, one at a time, such that impedance is measured individually for each pair comprising the at least one catheter electrode and a selected external electrode (Schwartz, pa. 0140).
However, they do not disclose the switch matrix being operated to sequentially couple the AC current source between the at least one catheter electrode with each of the selected one or more external electrodes.
Panescu, in the same field of endeavor, teaches a system for measuring impedance between a catheter electrode and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1). The system comprises a plurality of adjacent catheter electrodes (E1-E7) electrically coupled to their own signal wires (W1 to W7), and one external electrode (EI) is electrically coupled to its own signal wire (WI) (Col. 9, lines 27-33 & Fig 11). The system further includes an interface (56) element electronically configured to a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51). As seen in Fig. 12, when the setting switch SM in Position A, the interface configures the switching element for operation in the unipolar mode, and the interface electronically configures each individual electrode E1 to E7 to emit current by sequentially setting the associated switch SE1 to SE7. When the selected electrode E1 to E7 is so configured, it is electronically coupled to the supply of the current generator and emits current. The external electrode receives the current sequentially emitted by the selected catheter electrode E1 to E7 (Col. 10, lines 1-15).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the interface and the switching element with its plurality of switches to the measurement circuitry of Schwartz for the purpose of providing a more efficient process that is able to render impedance measurements with high accuracy and/or repeatability.
Regarding claim 31, Schwartz/Panescu/Cory combination discloses wherein the controller is configured to sequentially repeat the ablation phase and measurement phase, using the selected one or more current paths, until the lesion has reached a required size (Schwartz, pa. 0185, 0198 & Fig. 3).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Schwartz, Panescu, and Cory, as applied to claim 1 above, and further in view of Panescu (U.S. Application No. 20150105765 A1), henceforth referred to as Panescu65.
Regarding claim 4, Schwartz/Panescu/Cory combination discloses the invention substantially as claimed in claims 1 and 3 and discussed above.
However, they do not disclose including a dummy resistive load for selective connection to the source of electrical energy during periods of operation of said measurement circuitry.
Panescu65, in the same field of endeavor, teaches including a dummy resistive load for selective connection to the source of electrical energy during periods of operation of said measurement circuitry (pa. 0085).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added a dummy resistive load for the purpose of dissipating or absorbing excess energy supplied to the system to prevent system failure.
Claims 6 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Schwartz, Panescu, and Cory as applied to claims 1 and 27 above, and further in view of Fay (U.S. Application No. 20160242667 A1).
Regarding claim 6, Schwartz discloses the catheter ablation device comprises at least two catheter electrodes (pa. 0138), and the measurement circuitry is further configured to conduct electrical impedance sensing by applying current between one pair of external electrode and catheter electrode and measuring voltage between the same pair of electrodes (pa. 0138, 0140-0141).
Panescu teaches measuring impedance between a plurality of catheter electrodes and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1) via a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51).
Cory teaches multiple multiplexer circuits, wherein multiplexer circuit (52) is connected to the return electrode array (51) and multiplexer circuit (38) is connected to the waveform electrode array (18) (pa. 0149).
However, Schwartz/Panescu/Cory do not disclose a four-terminal electrical impedance sensing configuration.
Fay, in the same field of endeavor, teaches a four-terminal electrical impedance sensing configuration, such that the four-terminal sensing configuration drives current through a pair of “current-carrying” electrodes and measures the voltage across a different pair of “sensing” electrodes (pa. 0115, 0118).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the four-terminal sensing because this useful configuration allows for simultaneous function of supplying current and sensing voltage, and eliminates lead/contact resistance errors by using separate pairs of wires for current injection and voltage sensing, ensuring precise measurement of low resistances.
Regarding claim 30, Schwartz discloses the measurement circuitry is configured to conduct impedance sensing, such that, for each impedance measurement, current is supplied between a pair of catheter electrode and external electrode, and voltage is sensed between the same pair of electrodes (pa. 0138, 0140-0141), with the controller selecting the electrode pairs for each measurement from among the selected one or more current paths (pa. 0121, 0140). Specifically, paragraph 0140 of Schwartz describes how multiple impedance measurements are acquired, such that the impedance Z(t) is a vector of measurements between any catheter electrode (c) and each pair of patch electrodes (p) (ci, (pi, . . . pm). At block 206, measurements of the field (by measurement circuitry 101B) comprise a characteristic signal at each frequency for each electrode selection, which is measured at block 208, to produce the set of impedance measurements Z(t) (pa. 0153). Hence, at least one, or all, current paths are monitored/selected by the controller for tissue lesion development.
Panescu teaches measuring impedance between a plurality of catheter electrodes and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1) via a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51).
Cory teaches multiple multiplexer circuits, wherein multiplexer circuit (52) is connected to the return electrode array (51) and multiplexer circuit (38) is connected to the waveform electrode array (18) (pa. 0149).
However, Schwartz/Panescu/Cory do not disclose a four-terminal impedance sensing configuration.
Fay, in the same field of endeavor, teaches a four-terminal electrical impedance sensing configuration, such that the four-terminal sensing configuration drives current through a pair of “current-carrying” electrodes and measures the voltage across a different pair of “sensing” electrodes (pa. 0115, 0118).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the four-terminal sensing because this useful configuration allows for simultaneous function of supplying current and sensing voltage, and eliminates lead/contact resistance errors by using separate pairs of wires for current injection and voltage sensing, ensuring precise measurement of low resistances.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Schwartz, Panescu, and Cory as applied to claim 1 above, and further in view of Hauck (A.U. Application No. 2006292698 A1).
Regarding claim 9, Schwartz/Panescu/Cory combination discloses the invention substantially as claimed in claim 1 and discussed above.
However, they do not disclose an external electrode dot harness for application across an external area of the patient's body.
Hauck, in the same field of endeavor, teaches wherein the plurality of external electrodes is provided as an electrode dot harness for application across an external area of the patient's body (pa. 0014 & Fig. 1).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the external electrodes of Schwartz with a conventional ECG electrode system for the purpose of producing electrocardiograms used in graphing voltage versus time of the electrical activity of the heart and analyze the changes in the normal ECG pattern occurring in numerous cardiac abnormalities.
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Schwartz (U.S. Application No. 20180125575 A1), in view of Panescu (U.S. Patent No. 5487391 A), in view of Cory (U.S. Application No. 20110082383 A1), and further in view of Fay (U.S. Application No. 20160242667 A1).
Regarding independent claim 32, Schwartz discloses a system (100) for monitoring tissue lesion development during a medical ablation process applied to a patient (pa. 0107 & Fig. 1B), the system comprising:
a catheter ablation device (111) having at least first and second catheter electrodes (103) (pa. 0113, 0138), the catheter ablation device connectable via an electrical feedline to a source of electrical energy (101A) and configured to apply ablation energy to ablate tissue in a target region (pa. 0107);
a plurality of external electrodes (105) for application to the body of the patient (pa. 0117, 0138);
measurement circuitry (120A, 120B, 101B) comprising a voltage sensing circuit (pa. 0107);
an electrical controller (120) (pa. 0115) configured to alternate between (i) an ablation phase (304), in which ablation energy is delivered to the at least one catheter electrodes to ablate tissue (pa. 0217, 0219), and (ii) a measurement phase (207, 209) (which is performed before, during, and/or after the ablation of the target tissue, pa. 0228), in which the source of electrical energy is electrically disconnected from the catheter ablation device (at least in the step where the measurement step is performed before the ablation procedure) and the impedance measurements are acquired (pa. 0159-0161, 0177);
wherein, during the measurement phase, the electrical controller is configured to perform impedance measurements by:
(i) supplying an AC current (pa. 0004, 0115) between an external electrode and a catheter electrode, wherein the selected first external electrode and the first catheter electrode define a current-injecting pair (pa. 0107, 0115-0117), and
(ii) sensing and recording a voltage between said electrode pair (pa. 0140).
Specifically, paragraph 0140 of Schwartz describes how multiple impedance measurements are acquired, such that the impedance Z(t) is a vector of measurements between any catheter electrode (c) and each pair of patch electrodes (p) (ci, (pi, . . . pm). At block 206, measurements of the field (by measurement circuitry 101B) comprise a characteristic signal at each frequency for each electrode selection, which is measured at block 208, to produce the set of impedance measurements Z(t) (pa. 0153).
In further detail, Schwartz specifically discloses that in order to achieve accurate results of impedance measurements, they utilize numerous vector components (for example, measurements at multiple frequencies between different combinations of multiple catheter/skin patch electrode pairs using a vector formula (pa. 0137) which use three elements: a set of frequencies, the set of catheter electrodes, and the set of skin electrodes (pa. 0132-0135) to extract strong correlations of lesion assessment.
At step 206 (pa. 0153 & Fig. 2), after applying fields of selected frequencies between the catheter electrodes and the skin electrodes, measurements of the field (for example by field measurer 101B, which is controlled by controller 120) comprise a characteristic signal at each frequency, and for each electrode selection, which is measured at block 208 to produce the set of impedance measurements Z(t). Later, these impedance measurements can be isolated in order to further understand the contributions of just the catheter electrodes or just the skin electrodes or both (pa. 0140-0142). Therefore, the device of Schwartz is able to supply current to the different sets of catheter/skin electrodes pairs and gather impedance information from either or both of the catheter/skin electrodes.
However, Schwartz does not disclose a switch matrix having a plurality of switches, wherein the switch matrix is operated by the controller to sequentially couple the AC current source between the at least one catheter electrode and an external electrode.
Panescu, in the same field of endeavor, teaches a system for measuring impedance between a catheter electrode and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1). The system comprises a plurality of adjacent catheter electrodes (E1-E7) electrically coupled to their own signal wires (W1 to W7), and one external electrode (EI) is electrically coupled to its own signal wire (WI) (Col. 9, lines 27-33 & Fig 11). The system further includes an interface (56) element electronically configured to a switching element (64) (i.e., a switch matrix) including an electronic switch (SM) and electronic switches (SE1 to SE7) that electrically couple a current generator (50) to the signal wires WI and W1 to W7 (Col. 9, lines 34-51). As seen in Fig. 12, when the setting switch SM in Position A, the interface configures the switching element for operation in the unipolar mode, and the interface electronically configures each individual electrode E1 to E7 to emit current by sequentially setting the associated switch SE1 to SE7. When the selected electrode E1 to E7 is so configured, it is electronically coupled to the supply of the current generator and emits current. The external electrode receives the current sequentially emitted by the selected catheter electrode E1 to E7 (Col. 10, lines 1-15).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the interface and the switching element with its plurality of switches to the measurement circuitry of Schwartz for the purpose of providing a more efficient process that is able to render impedance measurements with high accuracy and/or repeatability.
However, Panescu only teaches the different combinations of electrodes being between at least one catheter electrode and only one external electrode, not between at least one catheter electrode and the plurality of external electrodes.
Cory, in the same field of endeavor, teaches a system and method for applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue (pa. 0143). The system comprises waveform electrodes (1), return electrodes (7). In one embodiment, there is a single, large, return electrode and a plurality of waveform electrodes 1 fashioned to form an array (pa. 0147 & Fig. 6) (this embodiment being analogous to the embodiment taught by Panescu). In a second embodiment, the waveform electrodes and return electrodes are both fashioned in electrode array assemblies (pa. 0149 & Fig. 8). In this embodiment, each electrode array is connected to a respective multiplexer circuit, wherein multiplexer circuit (52) is connected to the return electrode array (51) and multiplexer circuit (38) is connected to the waveform electrode array (18). The multiplexer circuit (38) may be an electronically controlled switch, a multiplexer, a gate array, or any suitable device that may be controlled by controller (16) to provide current waveforms or voltage waveforms from waveform generator (21) across selected, individual electrodes within the waveform electrode array assembly and one or more of the return electrodes in the return electrode array assembly (pa. 0151). The controller then calculates and stores information derived from the measured signal, e.g., impedance, resistance, reactance, admittance, conductance, and other electrical parameters based upon the plurality of different waveforms applied across the waveform electrodes and return electrodes (pa. 0154).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated the second embodiment of Cory, which includes an additional multiplexer circuit electrically connected to the plurality of return electrodes, into the system of Schwartz since it seems either embodiment (single return electrode connected to a switch matrix vs a plurality of return electrodes connected to a switch matrix) would yield the same predictable results of allowing the system to determine/calculate impedance and other electrical parameters based on the waveforms applied across different combination of electrodes.
However, Schwartz/Panescu/Cory combination do not teach wherein, during the measurement phase, the electrical controller is configured to sequentially perform four-terminal electrical impedance measurements by supplying an AC current between a selected electrode pair, and (ii) simultaneously sensing and recording a voltage between a selected second, different electrode pair, wherein the current-injecting pair and the voltage-sensing pair are electrically distinct, and wherein four-terminal electrical impedance measurements are sequentially repeated for a plurality of different combinations of the selected first and second external electrodes and catheter electrodes so as to determine electrical impedance for different electrical paths through the body of the patient.
Fay, in the same field of endeavor, teaches a four-terminal electrical impedance sensing configuration, such that the four-terminal sensing configuration drives current through a pair of “current-carrying” electrodes and measures the voltage across a different pair of “sensing” electrodes, where different combinations of electrode pairs is contemplated and may be repeated (pa. 0115, 0118).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the four-terminal sensing configuration to the measurement circuitry of Schwartz because this useful technique allows for simultaneous function of supplying current and sensing voltage, and eliminates lead/contact resistance errors by using separate pairs of wires for current injection and voltage sensing, ensuring precise measurement of low resistances.
Allowable Subject Matter
Claims 33-34 are allowable.
The following is an examiner’s statement of reasons for allowance: regarding claims 33-34, the Schwartz (U.S. Application No. 20180125575 A1), Panescu (U.S. Patent No. 5487391 A), Cory (U.S. Application No. 20110082383 A1), Fay (U.S. Application No. 20160242667 A1) references fail to teach the invention of the independent claims as a whole.
The Schwartz reference teaches a system (100) for monitoring tissue lesion development during a medical ablation process (pa. 0107 & Fig. 1B), the system comprising a catheter ablation device (111) with at least one catheter electrode (103) (pa. 0113, 0138), a plurality of external electrodes (105) (pa. 0117, 0138), a measurement circuitry (120A, 120B, 101B) for determining impedance (pa. 0107, 0117, 0140-0141), an electrical controller (120) arranged to control the application of an AC current source (pa. 0004, 0115) between different combinations of electrodes and measure resulting voltages to provide a measure of impedance (pa. 0132-0138). The measurement circuitry is able to switch between different combinations of the at least one catheter electrode and the plurality of external electrodes (pa. 0116, 0131-1038). However, Schwartz does not teach the controller being configured to, during the initial setup phase, select a subset of electrode pairs for impedance monitoring based on a criterion comprising the largest impedance change or highest sensitivity to local lesion formation, and to use only the selected subset for subsequent monitoring during the ablation process.
The Panescu reference teaches a system for measuring impedance between a catheter electrode and one indifferent (e.g., external) electrode in a unipolar arrangement (Col. 4, lines 66-67 – Col. 5, lines 1-2; Col. 11, lines 19-22 & Fig. 1) using a switching element (64) (i.e., a switch matrix) including a plurality of switches (Col. 9, lines 34-51). However, Panescu does not teach the controller being configured to, during the initial setup phase, select a subset of electrode pairs for impedance monitoring based on a criterion comprising the largest impedance change or highest sensitivity to local lesion formation, and to use only the selected subset for subsequent monitoring during the ablation process.
The Cory reference teaches a system comprising waveform electrodes (1) and return electrodes (7). In one embodiment, the waveform electrodes and return electrodes are both fashioned in electrode array assemblies (pa. 0149 & Fig. 8). A multiplexer circuit (38) is controlled by a controller (16) to provide current waveforms or voltage waveforms from waveform generator (21) across selected, individual electrodes within the waveform electrode array assembly and one or more of the return electrodes in the return electrode array assembly (pa. 0151). However, Cory does not cure the deficiencies described above.
Fay teaches a four-terminal electrical impedance sensing configuration, such that the four-terminal sensing configuration drives current through a pair of “current-carrying” electrodes and measures the voltage across a different pair of “sensing” electrodes (pa. 0115, 0118). However, Fay is similarly deficient.
No other pertinent prior art references were found that would overcome the above deficiencies. Therefore, there is no motivation (either in these references or
elsewhere in the art) for making such specific and significant modifications thereto to
arrive at claims 33-34.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably
accompany the issue fee. Such submissions should be clearly labeled “Comments on
Statement of Reasons for Allowance.”
Response to Arguments
Applicant's arguments filed 08/06/2026 have been fully considered but are not persuasive.
With regards to independent claim 1, Applicant argues that the Examiner's conclusion of introducing a switching mechanism into Schwartz "for the purpose of providing a more efficient process that is able to render impedance measurements with high accuracy and/or repeatability" overlooks technical consequences such as additional series resistance, parasitic capacitance and leakage paths associated with the switch elements and their connections, and switching transients and settling behavior, as the circuit reconfigures between electrode combinations. Applicant further contends that these issues are expressly recognized in the present application, and this reflects a recognition by the inventors that impedance measurements are highly sensitive to frequency-dependent parasitic and circuit effects, and that such effects must be actively managed in order to preserve measurement fidelity. However, Examiner, respectfully, disagrees.
The Schwartz reference discloses a system that compares impedance measurements across different electrode combinations and across different excitation frequencies (pa. 0132-0138). Specifically, Schwartz uses numerous vector components (i.e., measurements at multiple frequencies between different combinations of multiple catheter/skin patch electrode pairs using a vector formula; pa. 0137) which use three elements: a set of frequencies, the set of catheter electrodes, and the set of skin electrodes (pa. 0132-0135) to extract strong correlations of lesion assessment. After applying fields of selected frequencies between the catheter electrodes and the skin electrodes, a set of impedance measurements Z(t) are produced (pa. 0140-0142). Hence, the device of Schwartz is already capable of controlling the application of an AC current source between different combinations of the at least one catheter electrode and the plurality of external electrodes to measure resulting voltages which measures electrical impedance, but the reference is silent on the exact hardware used to accomplish such switching mechanism. Specifically, Shwartz does not disclose using a switch matrix comprising a plurality of switches to achieve such functionality. Examiner highlights that while Shwartz is silent on the exact hardware, the functionality is still present in the invention, leading one of ordinary skill in the art to interpret the presence of some sort of switching mechanism similar/analogous to the switch matrix of Panescu in order to perform such complex combination tasks.
Therefore, the system of Shwartz might already contemplate all of the “technical consequences” Applicant is concerned with given that the system does utilize some version of the switch matrix that is explicitly recited in the Panescu reference. Again, the Panescu reference is brought in to clearly and expressively teach a system in the same field of endeavor which uses a switch matrix comprising a plurality of switches in order to perform the combination functionalities already disclosed in the Schwartz reference.
Lastly, with regards to Applicant’s concern that neither the Schwartz, or any other reference cited above, explicitly manage sensitiveness to frequency-dependent parasitic and circuit effects in order to preserve measurement fidelity, such limitations are not cited in the claim language, and therefore such arguments are considered moot.
With regards to independent claim 1, Applicant argues that Examiner cannot simply replace Schwartz's single return electrode with a plurality of return electrodes as disclosed in Cory, contending that this would yield the "same predictable results." Specifically, Applicant contends that introducing plural return electrodes into a system such as Schwartz alters what is measured, because changing the return electrode configuration changes the electrical volume being interrogated. However, Examiner disagrees.
As explained above, the Schwartz reference does disclose using a plurality of skin patch electrodes, such as 4, 5, or 6 electrodes (pa. 0138). Therefore, Schwartz’s system does contemplate using a plurality of active and return electrodes. The Cory reference is only utilized to teach that, after the combination of the Panescu reference only using a switch matrix between one return/external electrode and a plurality of catheter electrodes, that it would have been obvious to further modify the combination to illustrate how a similar type of switching circuit is able to couple current between either a single external electrode and a plurality of waveform electrodes (embodiment 1) or between multiple external and waveform electrodes (embodiment 2). Therefore, the resultant combination of all three references would yield the claim language of wherein the measurement circuitry includes a switch matrix comprising a plurality of switches and configured to couple the AC current source to different combinations of the at least one catheter electrode and the plurality of external electrodes under control of the electrical controller.
With regards to independent claim 27, Applicant argues that the Schwartz reference does not disclose an initial setup phase because block 206 of Schwartz applies AC fields to perform multiple impedance measurements across different electrode pairs and frequencies, and block 208 measures and records the resulting impedance data as part of a broad impedance vector Z(t). Applicant contends that Schwartz only discloses acquiring impedance data across all catheter-patch electrode pairs and analyzing that data collectively as a vector, and that they do not disclose or suggest selecting a subset of electrode pairs or current paths, based on measured impedance, for subsequent monitoring as required by the claim. However, Examiner disagrees.
The claim language of the independent claim 27 is broad and only requires that the initial setup phase measures the electrical impedance of each current path, and, based on the measured impedances, select one or more current paths for subsequent monitoring. Hence, the claim language does not require that the system for monitoring tissue lesion development only selects a subset of electrode pairs or current paths, based on measured impedance, for subsequent monitoring. The claim language allows for more than one, or in Shwartz’s case all of the electrodes to be used for measurement of the electrical impedance during the initial setup phase. Therefore, the rejection is maintained.
With regards to independent claim 32, Applicant argues that the specific four-terminal impedance measurement architecture and associated control scheme is not taught nor suggested by the cited prior art. Applicant argues that Fay's four-terminal sensing is a local sensing technique, whereas Schwartz's system operates by driving current between catheter electrodes and spatially distributed external electrodes to interrogate impedance along trans-body current paths. Applicant asses that Fay does not disclose or suggest the claimed control scheme in which such measurements are performed during a dedicated measurement phase following electrical disconnection of the ablation energy source, and that implementing Fay's four-terminal sensing into Schwartz would require substantial redesign of the measurement circuitry to coordinate measurements across both catheter and external electrodes. However, Examiner disagrees.
The Schwartz reference is used to disclose the catheter ablation device comprising at least two catheter electrodes (pa. 0138), and the measurement circuitry being configured to conduct electrical impedance sensing by applying current between one pair of external electrode and catheter electrode and measuring voltage between the same pair of electrodes (pa. 0138, 0140-0141). The Fay reference is utilized to teach a four-terminal electrical impedance sensing configuration, such that the four-terminal sensing configuration drives current through a pair of “current-carrying” electrodes and measures the voltage across a different pair of “sensing” electrodes (pa. 0115, 0118). In some instances, a current may be injected between an electrode 24 and one or more return electrodes (e.g. patch electrode) (pa. 0110). Therefore, Fay is not just concerned with local sensing techniques, and contemplates a similar system similar to Schwartz’s. Hence, by just incorporating the four-terminal sensing system of Fay into the measuring circuitry of the Schwartz reference, a simultaneous function of supplying current and sensing voltage using different electrode pairs can be achieved while ensuring precise measurements.
In response to applicant's argument that implementing such a configuration described in the claim language in the ablation monitoring context of Schwartz would require substantial redesign, 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). Therefore, based on the reasonings set-forth above, the rejection is maintained.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
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/A.V.G./Examiner, Art Unit 3794
/Ronald Hupczey, Jr./Primary Examiner, Art Unit 3794
