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 .
Claim Rejections - 35 USC § 103
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.
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.
Claim(s) 1-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over “Pinter”, US Patent 8831898 in view of “Fink”, US Publication 20080275316.
Regarding claim 1, Pinter discloses a bio-impedance measurement circuit operable in at least two modes — a four-point mode and a two-point mode — and discloses obtaining measurement voltages in both modes and combining them to cancel electrode/contact resistance errors (col. 2, ll.1-2: “the circuit is operable in a two-point measurement mode and a four-point measurement mode” and col.2, ll.6-9: “combine the measurement voltages from the two-point and the four-point measurement modes”; see also col.5, ll.7 to col. 6, ll.9 describing the two-step procedure and FIG.5 showing switching unit 50 allowing the current source to be connected to different terminals). Pinter therefore discloses (a) a four-wire sensing arrangement with measurement electrodes and drive electrodes (col.1, ll.41-53 describing the four-point technique; FIG.2 showing drive and measurement electrodes), and (b) voltage measurement arrangement and switching for two- and four-point modes (col. 2, ll.10-36; FIG.5 showing switching unit). Pinter further discloses:
“first pin … configured to be coupled with a first end of a portion of a body… second pin… configured to be coupled with a second end of the portion of the body of the subject” [e.g., col. 1, ll.22-53; FIG.2; describing feeding current and measuring voltage; electrodes for the four-point arrangement where terminals 1–4 are coupled to the body).
“voltage measurement circuitry … determine a first voltage difference … with the first impedance coupled to the first pin and the second impedance decoupled … determine a second voltage difference … with first decoupled and second coupled … defining … compensation for errors due to electrode contact impedance in a four-wire sensing arrangement”[col.2, ll.6-49; “derive the impedance to be measured by combining the measurement voltages from the two-point and the four-point measurement modes”; formula in col.2, l.40 combining relationship; expressly teaches obtaining a two-point measurement and a four-point measurement and combining results to correct for electrode resistance).
However, Pinter does not explicitly disclose the claimed arrangement where “first impedance circuitry coupled to a first pin … selectively couple a first pre-determined amount of impedance to the first pin” and “second impedance circuitry coupled to a second pin … selectively couple a second pre-determined amount of impedance to the second pin” in the exact form of selectively coupling a (known) impedance between each sense pin and ground in the particular sequence recited (i.e., measure with first impedance coupled and second decoupled, then measure with first decoupled and second coupled). Pinter’s reconfiguration is accomplished via switching the current-source connection between electrode terminals (two-point vs four-point), rather than switching known impedance elements to ground at each sense electrode pin.
Fink supplies the missing “selectively coupled predetermined impedance” hardware architecture. Fink describes an impedance measurement/matching system that interfaces with a microprocessor and uses a reconfigurable switch network to select the impedance presented by a resistor ladder network to reduce errors due to unknown/changing skin/electrode impedance [Abstract; [0007, 0013]. Fink further teaches that the resistor ladder network includes resistors and microcontroller-activated switches to implement “any combination of resistors” in parallel to create a desired impedance [0015, 0017]. Fink also describes that, during the matching/sensing mode, switch states create a defined current/voltage path to ground [0016], and that the microprocessor sends control signals to the switch network to select the impedance state [0016- 0017].
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Pinter by implementing the per-sense-electrode selective predetermined impedance coupling using the switchable resistor/capacitor ladder taught by Fink. Fink and Pinter are combinable because both references address measurement inaccuracies caused by electrode/skin interface impedance and both rely on microprocessor-controlled reconfiguration/switching of circuit states to improve measurement accuracy [Pinter: col.1, ll.12-19; col.2, ll.25-36; col.7, ll.14-21; Fink: 0007, 0013]. An ordinary artisan would have been motivated to integrate Fink’s reconfigurable ladder/switch impedance network into Pinter’s four-electrode measurement circuit to obtain controlled, repeatable electrical loading conditions at the measurement electrode nodes (corresponding to Pinter’s electrodes 2 and 3), since Pinter teaches that remaining errors are attributable to electrode contact quality at those measurement electrodes and that electrode-contact-related error terms are variable [Pinter: col.3, ll.49-55; col.4, ll.32-44]. It would have been an obvious design choice to provide separate impedance circuitry for each measurement electrode node (first and second pins corresponding to Pinter’s electrodes 2 and 3), each selectively coupleable to ground via switch-controlled ladder states, and to take two voltage differences under complementary (“first-coupled/second-decoupled” and swapped) impedance-loading configurations, using the paired results for compensation -- i.e., a straightforward extension of Pinter’s teaching to use multiple measurement configurations and combine their results to cancel electrode-resistance/contact effects [Pinter: col.3, l.42 to col.4, l.20; col.5, l.61 to col.6, l.9] using the known reconfigurable impedance-network switching of Fink [0015–0017]. This combination could be implemented using well-known switching/control techniques and would yield predictable results because the circuit is configured to generate deterministically different electrical states whose contributions can be processed algebraically for compensation, as taught by Pinter’s multi-configuration error correction to cancel electrode-resistance/contact effects.
Regarding claim 2, Fink discloses resistor(s) coupled to ground and switches between those resistors and the electrode input and microprocessor control of those switches [0014–0017; FIG.1, FIG.2; “resistor ladder network 106 … microcontroller activated switches 202”]. Fink teaches “a resistor ladder network 106 … resistors 201 and microcontroller activated switches 202 to implement any combination of resistors in parallel” [0015–0016; FIG.2] which corresponds to “first pre-determined amount of impedance that is coupled to a ground of the circuitry; and a first switch coupled between the first pre-determined amount of impedance and the first pin, the first switch to selectively couple the first pre-determined amount of impedance to the first pin; and [analogously for] second pre-determined amount of impedance and second switch”.
Regarding claim 3, Pinter discloses current source/driving electrodes used to apply a known current to the body and measures the resultant voltages [col.1, ll.23-53; FIG.1–FIG.2: “A measurement instrument … current source 12 … used to feed a known current I into the unknown impedance Z”].
Regarding claim 4, Pinter discloses AC current sources and frequencies suitable for bio-impedance [col.7, l.57 to col.8, l.3; indicates ac current source and frequency range; “current source used for the specific bio-sensing example given above is an ac current source. A typical range for the measurement frequency is then 5 kHz to 1 MHz.”].
Regarding claim 5, Pinter discloses processor/microcontroller control over switching and sequencing of measurement modes [col.6, ll.42-45: “automated control of the two measurement steps, with the switching unit 50 controlled by a microcontroller”], and Fink likewise teaches microprocessor control of switching in the ladder network [0014–0017]. The recited processor-caused sequence — cause first pre-determined amount of impedance to be coupled, measure first voltage difference, couple second pre-determined amount of impedance, measure second voltage difference — is an obvious sequencing and control of switches and measurement instruments given Pinter’s and Fink’s teachings as discussed above.
Regarding claim 6, Pinter discloses performing measurements in multiple modes and compensating [col.5, l.15 to col.6, l.9], and Fink teach additional measurement sequences to determine intermediate voltages and calibrations. Fink teaches switching to “open” for returning to “regular operation” and leaving ladder programmed [0016–0017]. The claimed third voltage difference measured in a configuration with both pre-determined amount of impedances decoupled corresponds to taking a baseline measurement (no swap impedances connected), which is an obvious additional measurement one of ordinary skill in the art would take while performing multiple measurement and returning to “regular operation”.
Regarding claim 7, Pinter discloses reactive components and complex impedances [col.5, l.61 to col.6, l.9: “Ri can be a complex number, rather than a purely ohmic resistor”]. It is well known in the art that the impedance elements used as coupling elements may be resistors or capacitors depending on measurement frequency and design. It would have been obvious to substitute capacitors for resistors to implement frequency-dependent coupling in a bio-impedance measurement context.
Regarding claim 8, Pinter discloses electrodes coupled to the body to measure bio-impedance and the positions as sense and drive electrodes [col.1, ll.23-53].
Regarding claim 9, Pinter discloses the system of force [i.e., drive] electrodes + sense electrodes + circuitry that selectively determines voltages with switching between configurations as discussed above. The claimed additional recitation that the first impedance circuitry selectively couples first pre-determined amount of impedance between first sense electrode and ground is not explicitly disclosed in Pinter, but Fink teaches such switchable impedance-to-ground circuitry [0014–0017, FIG.1–FIG.2] as discussed above.
Regarding claim 10, Pinter discloses obtaining a measurement in two modes and combining them to cancel electrode resistance (col.2, ll.6-51]. Fink teaches the method of selectively coupling a pre-determined amount of impedance to electrode input to produce the measurement states used in the claim’s sequence [0014–0017]. The step of determining first voltage difference with first pre-determined amount of impedance coupled and second decoupled, and second with reversed coupling corresponds to Pinter’s teaching of obtaining two different measurements in different configurations and combining to compensate for contact impedance as discussed above.
Regarding claim 11, Pinter and Fink disclose measuring an additional measurement with both pre-determined amount of impedances (or both sense electrodes) uncoupled—a baseline measurement as discussed above in reference to claim 6.
Regarding claims 12-16, Pinter discloses instrumentation amplifiers, differential voltage measurement between sense electrodes, signal generator/current source injection and instrumentation amplifier measurement chain [e.g., col.1, ll.41-53] while Fink teaches resistor ladder and switches to ground and microprocessor control [0014–0017; FIG.1–FIG.2] as discussed above. Claim 16’s capacitors are an obvious design alternative (reactive elements) as discussed above for claim 7.
Regarding claim 17, Pinter and Fink combined disclose the process of applying a signal via drive electrode(s), measuring a first voltage difference in a first configuration, changing to a second configuration, measuring a second voltage difference, and combining both to compensate for electrode contact impedance [Pinter: col.1, l.63 to col.2, l.24; col.5, l.7 to col.6, l.9] with the other limitations as discussed above.
Regarding claim 18, Fink discloses switching resistors to ground and using switches to couple/decouple impedances under processor control [0014–0017]. Pinter discloses the measurement sequence [e.g., col.5, l.7 to col.6, l.9]; the specific sequence in claim 18 (decouple first impedance, couple second impedance) is within the routine control of the microcontroller and taught by Fink’s switchable network and Pinter’s measurement sequencing.
Regarding claim 19, Pinter discloses that voltage measurement circuitry compares voltages of the sense electrodes and outputs voltage differences [col.1, ll.41-53; describes using high input impedance voltage measurement between measurement electrodes and measuring voltage] and Fink also discloses the sensing chain, ADC and microprocessor handling of measured voltages [0014–0017; FIG.1 elements 103–105]. The recited functional steps [comparing voltages and outputting difference] are conventional and taught by the references.
Regarding claim 20, Pinter discloses that the signal applied to the body is provided by a generator/current source coupled to a drive electrode [col.1, ll.23-53; col.7, l.57 to col.8, l.3].
Response to Arguments
Applicant’s arguments have been considered but are moot and not persuasive in view of the new ground of rejection above and the following.
Applicant argues that “Fink is silent as to first/second impedance circuitry coupled to first/second pins…” Examiner submits Fink’s architecture supports at least the concept of discrete, preselected impedance values implemented via switchable elements and selecting which impedance to present to an electrode input [0015-17]. Even if Fink does not label “first pin” and “second pin” in those exact terms, the rejection has mapped the concept of the ladder/switch network to each sensing electrode input as discussed above.
Applicant argues that “Fink teaches away because it uses measured skin impedance, not pre-determined amounts Examiner submits that Fink’s use of measured skin impedance to choose which predetermined ladder configuration to switch in is not the same as discouraging predetermined impedances. In fact, Fink’s ladder necessarily consists of predetermined resistor values; switching among them is the mechanism that Pinter teaches to combine voltages from controlled configurations. Additionally, to “teach away,” the prior art should indicate that the claimed approach is undesirable or would not work – having a different goal is not the same as teaching away. Fink’s focus on matching/eliminating impedance sensitivity does not discourage using selectable impedance states during measurement and is consistent with calibration/control.
In closing, examiner submits that one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. As discussed above, it would have been obvious to an ordinary artisan to implement the claimed first/second impedance circuitry by using Fink’s reconfigurable resistor ladder/switch network as the “first” and “second” impedance circuitry, where the first pin and second pin are the two sense/measurement electrodes used by Pinter for the voltage difference. In a first measurement state, the ladder network can be configured so that the impedance shunt corresponding to a selected (“predetermined”) ladder setting is coupled to the first sense/measurement electrode node while the shunt is left open/decoupled for the second node, and in a second state the configuration is swapped. The processor in such a system would then determine the first and second voltage differences between the two sense electrodes for the respective switch states and use those values to compensate for electrode contact impedance errors, consistent with Pinter’s teaching that electrode/contact resistance errors are cancelled by combining measurement voltages obtained from controlled configurations.
Conclusion
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 Tse Chen whose telephone number is (571)272-3672. The examiner can normally be reached M-F 7-3 EST.
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/TSE W CHEN/Supervisory Patent Examiner, Art Unit 3791
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