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 .
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-12, and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrakumar(WO 2016054274 A1) in view of Zhang(US 20220266027 A1) (cited previously).
Regarding claim 1, Chandrakumar teaches a stimulator device, comprising: a plurality of electrode nodes; sense amplifier circuitry comprising a first input and a second input, wherein the sense amplifier circuitry is configurable to receive one of the plurality of electrode nodes at the first input, wherein the sense amplifier circuitry is configured to sense a tissue signal; a detector configured to produce data indicative of the DC offset voltage between the first input and the second input; and control circuitry configured to use the data to control the stimulation circuitry to issue a compensating current at the first input, the second input, or both of the first and second inputs, to reduce or eliminate the DC offset voltage(Turning now to the drawings, a high dynamic range sensing front-end for bio- signal recording systems in accordance with embodiments of the invention are disclosed. In one embodiment, a bio-signal amplifier includes an input signal comprising an input voltage and an input current, where the input signal is modulated to a predetermined chopping frequency; a first amplifier stage that includes a first input configured to receive the modulated input signal and generate a first output, where the first output comprises an offset current and a portion of the modulated input current; a parallel-RC circuit connected to the first amplifier stage and configured to receive the first output and generate a parallel-RC circuit output by selectively blocking the offset current utilizing at least one RC resistor and at least one RC capacitor; a second amplifier stage connected to the parallel-RC circuit that includes a second input configured to receive the parallel-RC circuit output and generate a second output, where the second output is an amplified version of the input signal with ripple-rejection[0006]. The output ripple can be minimized by employing various feedback techniques. For example, a ripple-rejection feedback loop can be used where the output ripple is down-converted and utilized as an input to an integrator. The output of the integrator is then summed with the output current of g.sub.mi , thus creating a negative feedback loop which nulls the output ripple. In another example, a foreground calibration can be performed to generate a compensating current using a DAC to cancel the offset, where the compensating current is then fed to the output of g.sub.mi - Typically, the input devices of g.sub.mi can be implemented using multiple small devices that can be redistributed between the positive and negative signal paths to reduce the offset[0059]. The electrode- tissue interface can generate DC offset voltages on the order of 50 mV, which can generate DC currents if the recording front-end input-impedance is relatively small. Further, these DC currents, if allowed to flow for long periods of time, can corrode the electrode and cause tissue damage at the electrode-tissue interface[0043]). Chandrakumar fails to disclose wherein each of the electrode nodes is associated with a different electrode configured to contact a patient’s tissue; stimulation circuitry configurable to provide stimulation to one or more of the plurality of electrode nodes to provide stimulation to the patient’s tissue.
However, Zhang teaches “disclosed herein is a medical device comprising: a plurality of electrode nodes, each electrode node configured to be coupled to an electrode configured to contact a patient's tissue; and control circuitry configured to: use one or more of the plurality of electrodes as stimulating electrodes to provide stimulation to the patient's neural tissue, use one or more of the plurality of electrodes as sensing electrodes to sense neural responses evoked by the stimulation[0026]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to both stimulate and sense target tissue in the patient’s system.
Regarding claim 2, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, but Chandrakumar fails to disclose further comprising a DC-blocking capacitor between each of the electrode nodes and its associated electrode.
However, Zhang teaches “Also shown in FIG. 3 are DC-blocking capacitors Ci 38 placed in series in the electrode current paths between each of the electrode nodes ei 39 and the electrodes Ei 16 (including the case electrode Ec 12)[0013]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to both stimulate and sense target tissue in the patient’s system.
Regarding claim 3, Chandrakumar in view of Zhang teaches the stimulator device of claim 2, wherein the compensating current reduces or eliminates the DC offset voltage by charging or discharging the DC-blocking capacitor associated with the first input(Chandrakumar - For example, a ripple-rejection feedback loop can be used where the output ripple is down-converted and utilized as an input to an integrator. The output of the integrator is then summed with the output current of g.sub.mi , thus creating a negative feedback loop which nulls the output ripple. In another example, a foreground calibration can be performed to generate a compensating current using a DAC to cancel the offset, where the compensating current is then fed to the output of g.sub.mi - Typically, the input devices of g.sub.mi can be implemented using multiple small devices that can be redistributed between the positive and negative signal paths to reduce the offset[0059]. Further, the bio-signal amplifier can also include an auxiliary path configured for boosting input impedance by pre-charging at least one input capacitor. In addition, the bio-signal amplifier can also include a DC-servo feedback loop that includes an integrator that utilizes a duty-cycled resistor[Abstract]).
Regarding claim 4, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, but Chandrakumar fails to disclose wherein the one electrode node received at the first input is different from the one or more electrode nodes that provide the stimulation to the patient’s tissue.
However, Zhang teaches “Aspects of the disclosed methods and systems can differentiate between changes in the sensed neural responses that are caused by the environment at stimulating electrodes and changes in the neural responses that are caused by the environment at sensing electrodes[abstract]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to both stimulate and sense target tissue in the patient’s system.
Regarding claim 5, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, wherein the sense amplifier circuitry is configured to sense a neural response to the stimulation as the tissue signal(Chandrakumar - Another desired feature of a front-end includes simultaneous stimulation and recording, where the recording system should be able to record neural signals in the presence of large artifacts[0040]).
Regarding claim 6, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, wherein the sense amplifier circuitry is configurable to receive another one of the plurality of electrode nodes at the second input(Chandrakumar - In various embodiments, the supply can be set at 1 .2V and the total bias-currents in the first 802 and second stages 804 at 1 μΑ and 0.2μΑ respectively[0069]. In many embodiments of the invention, an auxiliary path can be utilized to pre-charge input capacitors to the correct potential before connecting input electrodes. An auxiliary path for pre-charging input capacitors in accordance with an embodiment of the invention is shown in FIG. 4. In various embodiments, the input capacitor boost technique includes a system 400 that utilizes an auxiliary path 402 for pre-charging input capacitors 404, 406 to a predetermined potential before connecting the input electrodes[0046]. Figure 8 shows the first and second input circuits in parallel with connection to their own repective electrodes).
Regarding claim 7, in view of Zhang teaches the stimulator device of claim 6, wherein the control circuitry is configured to issue the compensating current at the first and second inputs to reduce or eliminate the DC offset voltage(Chandrakumar - In another example, a foreground calibration can be performed to generate a compensating current using a DAC to cancel the offset, where the compensating current is then fed to the output of g.sub.mi[0059]).
Regarding claim 8, Chandrakumar in view of Zhang teaches the stimulator device of claim 7, but Chandrakumar fails to disclose wherein the compensating currents at the first and second inputs are of opposite polarities.
However, Zhang teaches “To recover all charge by the end of the second pulse phase 30b of each pulse (Vc4=Vc5=0V), the first and second phases 30a and 30b are preferably charged balanced at each electrode, with the phases comprising an equal amount of charge but of the opposite polarity[0015]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to both stimulate and sense target tissue in the patient’s system.
Regarding claim 9, Chandrakumar in view of Zhang teaches the stimulator device of claim 6, but Chandrakumar fails to specify wherein the electrode nodes received at the first and second inputs are different from the one or more electrode nodes that provide the stimulation to the patient’s tissue.
However Zhang teaches “As noted above, it is preferred to sense an ESG signal differentially, and in this regard, the sense amp circuitry 110 comprises a differential amplifier receiving the sensed signal S+(e.g., E8) at its non-inverting input and the sensing reference S− (e.g., E9) at its inverting input. As one skilled in the art understands, the differential amplifier will subtract S− from S+ at its output, and so will cancel out any common mode voltage from both inputs. This can be useful for example when sensing ECAPs, as it may be useful to subtract the relatively large scale stimulation artifact 134 from the measurement (as much as possible) in this instance. That being said, note that differential sensing will not completely remove the stimulation artifact, because the voltages at the sensing electrodes S+ and S− will not be exactly the same. For one, each will be located at slightly different distances from the stimulation and hence will be at different locations in the electric field 130. Thus, the stimulation artifact 134 can still be sensed even when differential sensing is used[0066]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to both stimulate and sense target tissue in the patient’s system and the system having different nodes for each.
Regarding claim 10, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, but Chandrakumar fails to disclose wherein the compensating current comprises one or more charge imbalanced pulses.
However, Zhang teaches “passive recovery switches 41.sub.i may be attached to each of the electrode nodes 39, and are used to passively recover any charge remaining on the DC-blocking capacitors Ci 38 after issuance of the second pulse phase 30b—i.e., to recover charge without actively driving a current using the DAC circuitry. Passive charge recovery can be prudent, because non-idealities in the stimulation circuitry 28 may lead to pulse phases 30a and 30b that are not perfectly charge balanced[0016]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify the electrode nodes being configured with electrode to deliver current with various charge pulses.
Regarding claim 11, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, but Chandrakumar fails to disclose wherein the control circuitry comprises an algorithm to control the stimulation circuitry to issue the compensating current.
However, Zhang teaches “The control algorithm 1202 may be used to control one or more stimulation parameters 1204, such as current amplitude, frequency, pulse width, stimulation fractionalization, and the like[0123]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify an algorithm in the system to analyze and adjust the current as stimulation occurs.
Regarding claim 12, Chandrakumar in view of Zhang teaches the stimulator device of claim 11, but Chandrakumar fails to disclose wherein the algorithm is configured to iterate by periodically producing the data indicative of the DC offset voltage, and periodically using the data to control the stimulation circuitry to issue the compensating current.
However, Zhang teaches “Thus, the control algorithm can determine a control decision to accurately adjust stimulation based on the new observed neural response. With each iteration of the control algorithm the base prediction model can be updated based on the algorithm at each timestep[0135]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would specify an algorithm in the system to analyze and adjust the current as stimulation occurs.
Regarding claim 16, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, wherein the detector comprises an Analog-to-Digital Converter (ADC), wherein the ADC provides a digitized value indicative of the DC offset voltage as the data(Chandrakumar - To reduce area, the input can be DC coupled and a DC servo loop can be used to cancel the large DC offsets. As illustrated, the servo loop 170 includes adding a DC offset 172 to the signal of interest 174. The DC coupled signal is then amplified by an amplifier 176 where the analog output is digitized by an analog-to-digital converter (ADC) 178[0036]).
Regarding claim 17, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, further comprising an ADC configured to produce a digitized waveform of the sensed tissue signal, wherein the digitized waveform comprises a plurality of samples(Chandrakumar - The system 200 is configured to amplify a signal using an amplifier 202 where the analog output is converted to digital form using an ADC 204. Once saturation is detected using a saturation detector 206, a reset signal 208 is asserted to discharge the high time-constant nodes in the front-end, allowing the circuit to recover quickly from saturation[0039].
Chandrakumar fails to show a digitized waveform of the sensed tissue signal, however Zhang teaches “The waveform appearing at sensing electrode E8 (S+) is shown in FIG. 5, which includes a stimulation artifact 134 as well as an ECAP. The stimulation artifact 134 comprises a voltage that is formed in the tissue as a result of the stimulation, i.e., as a result of the electric field 130 that the stimulation creates in the tissue[0058]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the sensed stimulation therapy of Zhang. Doing so would demonstrate a graphical example of a digitized waveform representing the tissue signal for the display.
Regarding claim 18, Chandrakumar in view of Zhang teaches the stimulator device of claim 17, wherein the detector is configured to determine whether the digitized waveform is saturated(Chandrakumar - A topology that utilizes a saturation detector in accordance with the prior art is shown in FIG. 2A. The system 200 is configured to amplify a signal using an amplifier 202 where the analog output is converted to digital form using an ADC 204. Once saturation is detected using a saturation detector 206, a reset signal 208 is asserted to discharge the high time-constant nodes in the front-end, allowing the circuit to recover quickly from saturation[0039]).
Regarding claim 19, Chandrakumar in view of Zhang teaches the stimulator device of claim 18, wherein the data indicative of the DC offset voltage comprises an indication of high saturation or low saturation( Chandrakumar -Another desired feature of a front-end includes simultaneous stimulation and recording, where the recording system should be able to record neural signals in the presence of large artifacts. An independent-component analysis (ICA) based process to detect the presence of motion artifacts in the recorded data in accordance with the prior art is shown in FIG. 2B. As illustrated in 250, upon detection of motion artifacts by an ICA 252, a combination of a level-detect circuit 254 and DC-level shifters 256 can be used to regulate the DC level at the output of the first stage to move the circuit away from saturation. This design demonstrates a saturation-tolerant input range of 4.4 mV for interferers like motion artifacts, which are slowly varying compared to the signal of interest[0040]).
Regarding claim 20, Chandrakumar in view of Zhang teaches the stimulator device of claim 1, wherein the data comprises one or more digital signals indicative of saturation(Chandrakumar - A topology that utilizes a saturation detector in accordance with the prior art is shown in FIG. 2A. The system 200 is configured to amplify a signal using an amplifier 202 where the analog output is converted to digital form using an ADC 204. Once saturation is detected using a saturation detector 206, a reset signal 208 is asserted to discharge the high time-constant nodes in the front-end, allowing the circuit to recover quickly from saturation[0039]).
Claim(s) 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrakumar(WO 2016054274 A1) in view of Zhang(US 20220266027 A1) and further in view of Irazoqui(WO 2017214638 A1) (cited previously).
Regarding claim 13, Chandrakumar in view of Zhang teaches the stimulator device of claim 12, but fail to disclose wherein a charge of the compensating current is adjusted as the algorithm iterates.
However, Irazoqui teaches “In some exemplary embodiments, method 1200 may include operation 1210 of automatically adjusting stimulus parameters by the system (e.g. automatically generating a command at the implanted module or external base station that adjusts the stimulus parameters) based at least in part on a measured patient response. For example, the system may be configured with a closed-loop control algorithm such that stimulus parameters are adjusted until a desired subject response is attained[00216]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the system of wireless implantable devices of Irazoqui. Doing so would specify an algorithm in the system to analyze and adjust the current as stimulation occurs.
Regarding claim 14, Chandrakumar in view of Zhang teaches the stimulator device of claim 11, but fails to disclose wherein the algorithm is configured to calculate a charge using the data that eliminates the DC offset voltage, and to control the stimulation circuitry to issue the compensating current with the calculated charge.
However, Irazoqui teaches “A two-stage miller- compensated OTA was designed for very low power, noise, and offset. Both of the OTAs were matched together to further reduce the effect of an offset between two current branches. A 100-mV reference voltage VREF is chosen as a tradeoff between minimum power consumption and maximum dynamic range across the pressure range. A full scale dynamic range of 70 nA is achieved in the AID[00388]. Three negative feedback loops are introduced in the R - 1.sub.2 converter. A pseudo-differential reference voltage VREF of 100 mV is generated by the BGR as explained earlier (VREF = VR7 -VR.sub.6 = VR.sub.6 -VR5). The first and second feedback loop (depicted as 1 and 2 in the Figure 47) set the reference voltages of VR7 = 700 mV and VR5 = 500 mV at the nodes "X" and "Y", respectively, and are designed with a high loop gain (>95 dB). The third feedback loop sets the common-mode reference voltage of VR6 = 600mV at node "N". As a result, each resistor in the sensor sees a voltage drop of 100 mV across it. The difference current AJD flows through the transistors M3 and M4, which is copied via current mirrors M4 - M5. Since the third feedback loop sees both first and second loops as a load, it has a lower loop gain (>70 dB) compared to the other two feedbacks. The first and second feedback loops are designed with lower settling time than the third feedback loop, to ensure accurate startup and stability. All of the OTAs are matched with each other in a single block to reduce the effect of offset voltages[00390]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the system of wireless implantable devices of Irazoqui. Doing so would specify an algorithm in the system to analyze and adjust the current as stimulation occurs.
Regarding claim 15, Chandrakumar in view of Zhang teaches the stimulator device of claim 11, but fail to disclose further comprising DC offset compensating circuitry configured to issue a DC current, wherein the algorithm is further configured to enable the DC offset compensation circuitry to issue the DC current at the first input or the second input to reduce or eliminate the DC offset voltage.
However, Irazoqui teaches “To further increase the accuracy of the DAC 341 output, calibration registers may also be defined by the user which are used by the microcontroller to automatically compensate for static DC offset voltages that may be present on the output of the DAC 341. There can be a range of these DC offset voltages, and calibration values to compensate for these offsets can be obtained experimentally during the fabrication of each Bionode[00173]. Additionally, the circuitry 340 illustrates a single pull double throw (SPDT) switch 343 is placed between the DAC 341 output and the current source 342[00172]”.
It would be obvious to one of ordinary skill in the art before the effective filing date to configure the neural recording systems of Chandrakumar with the system of wireless implantable devices of Irazoqui. Doing so would specify an algorithm in the system to analyze and adjust the current as stimulation occurs.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Applicant argues previous art fails to disclose “to control the stimulation circuitry to issue a compensating current at the first input, the second input, or both of the first and second inputs, to reduce or eliminate the DC offset voltage”. However, new art Chandrakumar does contain multiple inputs, both stimulating and sensing neural tissue, and a compensating current to alter the DC offset voltage[abstract],[0059],[0043], and [0052]. Chandrakumar can be naturally combined with Zhang and Irazoqui to teach all claimed material , therefore the 103 rejections for all claims stand.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARIA CATHERINE ANTHONY whose telephone number is (703)756-4514. The examiner can normally be reached 7:30 am - 4:30 pm, EST, M-F.
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/MARIA CATHERINE ANTHONY/Examiner, Art Unit 3796
/CARL H LAYNO/Supervisory Patent Examiner, Art Unit 3796