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 Arguments
Applicant’s arguments have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made.
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 20080274316.
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 impedance to the first pin” and “second impedance circuitry coupled to a second pin … selectively couple a second 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 teaches switching the current-source/drive connections between electrode terminals and using measurement electrodes in two-point vs four-point modes but does not explicitly show the specific per-sense-electrode switchable impedance-to-ground elements.
Fink discloses switching resistive elements to ground under microprocessor control for matching input impedance to skin/electrode interface. In particular, Fink teaches a reconfigurable switch network and resistor ladder network that can selectively present a chosen impedance at the input [0013–0017; FIG.1 and FIG.2 “reconfigurable switch network to select the input impedance of the electronic monitoring circuitry”; “resistor ladder network 106 … resistors 201 and microcontroller activated switches 202”]. Fink therefore explicitly provides the missing structure: switchable impedance(s) that can be coupled between an electrode input and ground under processor control. [0014: “the system includes … microprocessor 105 … reconfigurable switch network 106; FIG.1 is an exemplary schematic electrical circuit for a skin impedance matching system”; FIG.2 shows a resistor ladder 106 with switches 202]
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 impedance coupling using the switchable resistor/capacitor ladder taught by Fink. Pinter and Fink address the same technical problem: errors in bio-impedance measurement arising from electrode contact impedances and the need to obtain accurate impedance values. Pinter’s measurement method requires creating controlled known measurement states on sense terminals while Fink teaches a conventional and well-known way to present known impedances to electrode inputs (switchable resistor ladder under microprocessor control) [Fink: 0014–0017]. Combining these elements would be performed to “implement” Pinter’s two-step measurement/cancellation method using routine hardware (switchable impedances to ground), and hence to provide a concrete circuit implementation that provides the claimed compensation. The combination yields predictable results: switchable impedance elements are well-known passive network components and microprocessor-controlled switches are routine; implementing them in Pinter’s circuit to create the claimed first/second measurement states would produce the expected outcome of being able to measure the two voltages required for compensation, thereby cancelling electrode-contact impedance effects as taught by Pinter [i.e., cancellation equation], and as made practicable by Fink’s ladder and switching circuit [0014–0017, FIG.1–FIG.2]. In short, Pinter motivates reducing electrode contact error via comparative measurements while Fink motivates creating selectable input impedances to match or measure skin/electrode interface. One of ordinary skilled in the art wanting both accurate compensation and a practical way to create measurement states and match impedance in a deployed instrument would be motivated to combine both teachings.
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 impedance that is coupled to a ground of the circuitry; and a first switch coupled between the first impedance and the first pin, the first switch to selectively couple the first impedance to the first pin; and [analogously for] second 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 impedance to be coupled, measure first voltage difference, couple second 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 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 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 an 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 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 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].
Conclusion
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