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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 26 March 2026 has been entered.
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 1-4, 9-10 and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Thomson (US 20090101812 A1) in view of Schneider (WO 2009/143616 A1).
Regarding claim 1, Thomson teaches a method of analyzing ions in a differential mobility spectrometer (DMA, [0015]), comprising:
Controlling resolution achieved by the differential mobility spectrometer by introducing a drift gas (from source 66) through an inlet of a differential mobility spectrometer ([0027]; drift gas flow rate affects resolution, [0006]);
Performing differential mobility separation on ions within the drift gas using the differential mobility spectrometer as the drift gas transports the ions through ([0027]).
Thomson does not teach controlling resolution achieved by the differential mobility spectrometer while maintaining transmission efficiency of the differential mobility spectrometer essentially unchanged by using a flow rate greater than 10 mL/min.
Schneider teaches a differential mobility spectrometer comprising a curtain gas (208) that becomes the drift gas which has a flow rate of 25mL/min ([0018]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the claims to adjust the drift gas flow rate of Thomson to be greater than 10 mL/min, based on the teaching of Schneider that such a flow rate is known in the art and can be adjusted to control the resolution and the analysis duration of the spectrometer.
Thomson and Schneider do not state that they control the resolution while maintaining the transmission efficiency of the differential mobility spectrometer substantially unchanged. However as the combination of Thomson and Schneider meets all the other limitations of the claim, and there appears to be no particular structure or range of flow rates that enables the applicant’s system to achieve such a result wherein the prior art could not, it can be assumed that the effect discovered by the applicant would be present in the combined system (i.e. the system of Thomson where the drift gas flow rate is adjusted to above 10mL/min).
Regarding claim 2, Thomson teaches that controlling the resolution achieved by the differential mobility spectrometer comprises adjusting the resolution of the differential mobility separation for at least one species of ion of interest without substantially adjusting transmission of said at least one species of ion of interest ([0006]).
Regarding claim 3, Thomson teaches that the flow rate of the drift gas is substantially maintained during said adjusting step (continuous flow, [0006], [0018]).
Regarding claim 4, Thomson teaches that a throttle gas is not provided to an outlet of said differential mobility spectrometer during said adjusting step.
Regarding claim 9, Schneider teaches that the flow rate of the curtain gas is 25 L/min ([0034-0035]). It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to adjust the flow rate of the drift gas in the combined system to be 25 L/min or more, as a matter of adjusting a known result-effective variable (as the drift rate determines the resolution) for a known purpose (MPEP 2144.05 II A [R-01.2024]).
Regarding claim 10, Thomson in view of Schneider teaches the method of claim 1, wherein an outlet of the differential mobility spectrometer is sealed to an inlet of the vacuum chamber containing the at least one mass spectrometer, the method further comprising performing mass spectrometry on ions transported through the outlet of the differential mobility spectrometer into the inlet of the mass spectrometer (Thomson claim 10, fig. 1, [0015]).
Regarding claim 28, Thomson teaches a method of analyzing ions in a differential mobility spectrometer (DMA, [0015]), comprising:
Introducing a drift gas (from source 66) through an inlet of a differential mobility spectrometer ([0027]);
Performing differential mobility separation on ions within the drift gas using the differential mobility spectrometer as the drift gas transports the ions through ([0027]), and
Controllably adjusting ion separation resolution of the differential mobility spectrometer (drift gas flow rate affects resolution, [0006]).
Thomson does not teach controllably adjusting ion separation resolution achieved by the differential mobility spectrometer while maintaining transmission efficiency of the differential mobility spectrometer essentially unchanged by using a flow rate greater than 10 mL/min.
Schneider teaches a differential mobility spectrometer which can control the resolution of the differential mobility spectrometer (adjusting the flow rate adjusts the resolution, [0008]) using a curtain gas (208) that becomes the drift gas which has a flow rate of 25mL/min ([0018]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the claims to adjust the drift gas flow rate of Thomson to be greater than 10 mL/min, based on the teaching of Schneider that such a flow rate is known in the art and can be adjusted to control the resolution and the analysis duration of the spectrometer.
Thomson and Schneider do not state that they control the resolution while maintaining the transmission efficiency of the differential mobility spectrometer substantially unchanged. However as the combination of Thomson and Schneider meets all the other limitations of the claim, and there appears to be no particular structure or range of flow rates that enables the applicant’s system to achieve such a result wherein the prior art could not, it can be assumed that the effect discovered by the applicant would be present in the combined system (i.e. the system of Thomson where the drift gas flow rate is adjusted to above 10mL/min).
Claims 5, 6 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Thomson in view of Schneider and in further view of Covey (US 20160334369 A1).
Regarding claim 5, Thomson and Schneider teach all the limitations of claim 1 as described above. Thomson and Schneider do not teach adjusting a cross-sectional area of the inlet to adjust a residence time of ions within the differential mobility spectrometer.
Covey teaches a differential mobility spectrometer comprising an inlet for incoming ions, wherein the diameter of the inlet may be adjusted to control the resolution and sensitivity of the apparatus ([0074-0075]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the current claims to make the inlet of Thomson have an adjustable area as taught by Covey, in order to control the residence time of ions to control the resolution and sensitivity of the apparatus.
Regarding claim 6, Thomson and Schneider teach all the limitations of claim 1 as described above. Thomson and Schneider do not teach adjusting a cross-sectional area of an inlet to be in a range between 0.5-20mm.
Covey teaches a differential mobility spectrometer comprising an inlet (with a diameter of 0.5 mm) for incoming ions, wherein the diameter of the inlet may be adjusted to control the resolution and sensitivity of the apparatus ([0074-0075]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the current claims to make the inlet of Thomson have an adjustable area as taught by Covey, in order to control the residence time of ions to control the resolution and sensitivity of the apparatus, and to have the diameter be within the range taught by Covey as a known effective diameter used in the art.
Regarding claim 8, Thomson and Schneider teach all the limitations of claim 1 as described above. Thomson teaches that the differential mobility spectrometer comprises parallel plate electrodes (219) separated by an analytical gap. Thomson and Schneider do not teach that the inlet is adjustable relative to the cross-sectional area of the analytical gap.
Covey teaches a differential mobility spectrometer comprising an inlet for incoming ions, wherein the diameter of the inlet may be adjusted to control the resolution and sensitivity of the apparatus ([0074-0075]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the current claims to make the inlet of Thomson have an adjustable area as taught by Covey (i.e. be adjustable relative to the cross-sectional area of the analytical gap), in order to control the residence time of ions to control the resolution and sensitivity of the apparatus.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Thomson in view of Schneider and in further view of Schneider 2 (US 8,084,736 B2).
Regarding claim 11, Thomson and Schneider teach all the limitations of claim 10 as described above. Thomson and Schneider do not teach adjusting a resolution of the differential mobility separation for at least one species of ion of interest by adding or removing gas between the outlet of the differential mobility spectrometer and the inlet of the vacuum chamber containing the at least one mass spectrometer.
Schneider 2 teaches a differential mobility spectrometer upstream of another vacuum chamber, wherein a throttle gas is added between the outlet of the differential mobility spectrometer and the inlet of the vacuum chamber containing the at least one mass spectrometer (col. 2 lines 59-64) to control between sensitivity and selectivity (col. 5 lines 30-34).
It would have been obvious to one of ordinary skill in the art at the time of the effective filing of the claimed invention to incorporate an additional gas between the outlet of Thomson’s differential mobility spectrometer and the inlet of the vacuum chamber, because using such an additional gas is a known way to control sensitivity and selectivity as taught by Schneider 2.
Claims 12-13, 17-19, 22, 24-25 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Schneider in view of Thomson and in further view of Covey.
Regarding claim 12, Schneider teaches a system comprising:
A housing (206, 207) having an inlet (210) and an outlet (212);
A drift gas supply (220) for supplying a drift gas that flows through the inlet (gas coming into curtain chamber at up to 25 mL/min becomes drift gas, [0034] and [0018]);
Two parallel plate electrodes (206) disposed within said housing and separated from one another by a fixed distance, the volume between the two electrodes defining an analytical gap through which ions that enter the inlet are transported from the inlet to the outlet ([0014]) within the drift gas flowing through the analytical gap;
A voltage source for providing DC voltages to at least one of the parallel plate electrodes to generate an electric field, the electric field for passing through selected ion species based on mobility characteristics ([0034]) and
A resolution control mechanism to control resolution achieved by the system (controllable flow rate of curtain draft which becomes drift gas; drift gas flow controls resolution, Thomson [0008]).
Schneider does not teach an RF voltage provided to the plate electrodes.
Covey teaches a differential mobility spectrometer comprising an analytical gap for ion introduction, wherein an RF potential is added to a plate electrode at the analytical gap to focus the ions ([0018]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the current claims to incorporate an RF potential at Schneider’s plate electrodes, since such RF potential is known and used to focus ions in ion introduction to a spectrometer, as taught by Covey.
Schneider further fails to teach that the drift gas through the analytical gap has a flow rate of greater than 10mL/min.
However it would have been obvious to one of ordinary skill in the art at the effective filing of the claimed invention to adjust the flow rate of the analytical gap to be greater than 10L/min, as a matter of adjusting the curtain gas pressure and size of the gap no unexpected result.
Schneider and Covey do not state that they control the resolution while maintaining the transmission efficiency of the differential mobility spectrometer substantially unchanged by introducing the drift gas at the specified flow rate. However as the combination of Schneider and Covey meets all the other limitations of the claim, and there appears to be no particular structure or range of flow rates that enables the applicant’s system to achieve such a result wherein the prior art could not, it can be assumed that the effect discovered by the applicant would be present in the combined system (i.e. the system of Schneider where the drift gas flow rate is adjusted to above 10mL/min).
Regarding claim 13, Schneider teaches that the inlet comprises an aperture for allowing the traversal of drift gas into the housing. Schneider does not teach that a cross-sectional area of the aperture is adjustable.
Covey teaches a differential mobility spectrometer comprising an inlet for incoming ions, wherein the diameter of the inlet may be adjusted to control the resolution and sensitivity of the apparatus ([0074-0075]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the current claims to make the inlet of Schneider have an adjustable area as taught by Covey, in order to control the residence time of ions to control the resolution and sensitivity of the apparatus.
Regarding claim 17, Covey teaches that the diameter of the inlet is 0.5 mm ([0074-0075]).
Regarding claim 18, Schneider teaches that the aperture extends through at least one electrode plate, wherein the at least one electrode plate is electrically separated from the parallel plate electrodes (figs. 18-19).
Regarding claim 19, Schneider teaches that the system lacks a throttle gas supply.
Regarding claim 22, Schneider and Covey do not teach that the cross sectional area of the analytical gap is about 20mm2, or a length of the analytical gap along the direction of drift gas flow is greater than about 30mm. However, it would have been obvious to one of ordinary skill in the art at the time of the effective filing date of the claimed invention to incorporate such an area and/or gap length, as a matter of optimizing a known result-effective variable (the area and gap length control the flow rate which determines the resolution of the differential mobility spectrometer).
Regarding claim 24, Schneider teaches that an outlet is sealed to an inlet of the vacuum chamber containing at least one mass spectrometer (fig. 1).
Regarding claim 25, Schneider teaches a curtain chamber in which the housing is disposed (figs. 1-2) and a curtain gas supply for providing a flow of curtain gas into the curtain chamber ([0034-0035]), wherein a portion of the curtain gas outflows from an aperture in the curtain plate and the remainder forms the drift gas ([0034-0035]).
Regarding claim 27, Schneider teaches that the drift gas comprises at least one of a chemical modifier or a mixture of gases ([0014]).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Schneider in view of Covey and in further view of Schneider 2.
Regarding claim 20, Schneider and Covey teach all the limitations of claim 102as described above. Schneider and Covey do not teach a throttle gas supply for adding a throttle gas to the outlet of the housing, and wherein adjustments to the throttle gas are configured to modify residence time within a system.
Schneider 2 teaches a differential mobility spectrometer upstream of another vacuum chamber, wherein a throttle gas is added between the outlet of the differential mobility spectrometer and the inlet of the vacuum chamber containing the at least one vacuum chamber containing the at least one mass spectrometer to control between sensitivity and selectivity.
It would have been obvious to one of ordinary skill in the art at the time of the effective filing of the claimed invention to incorporate an additional gas between the outlet of Thomson’s differential mobility spectrometer and the inlet of the vacuum chamber, because using such an additional gas is a known way to control sensitivity and selectivity as taught by Schneider 2.
Response to Arguments
Applicant's arguments filed 26 March 2026 have been fully considered but they are not persuasive.
Regarding the argument that the gas flow of Thomson is introduced into the interface region and not the differential mobility analysis device, the gas of Thomson will flow naturally into the DMA from the drift gas.
While Thomson, Schneider and Covey do not discuss maintaining the DMA’s transmission efficiency effectively unchanged, In response to applicant's argument that Thomson, Schneider and Covey do not teach adjusting a resolution of the DMA device while maintaining the DMA devices transmission efficiency unchanged, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Schneider in particular teaches a high gas flow rate which increases the resolution of the DMA device. The unexpected benefit of maintaining the transmission efficiency appears to be an inherent feature of the high gas flow rate which would be part of the system even if it was not recognized in the prior art. There is no particular structure or method step cited in the current disclosure which allows the system to achieve this result which is not present in the prior art, nor do the prior art references appear to teach away from the use of a high drift gas flow rate.
Conclusion
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/DAVID E SMITH/Examiner, Art Unit 2881
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