Prosecution Insights
Last updated: April 19, 2026
Application No. 18/953,925

HYDRODYNAMIC FOCUSING APPARATUS AND METHODS

Non-Final OA §103
Filed
Nov 20, 2024
Examiner
CHAUDRY, ATIF H
Art Unit
3753
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Cytonome/St LLC
OA Round
1 (Non-Final)
70%
Grant Probability
Favorable
1-2
OA Rounds
2y 10m
To Grant
87%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
745 granted / 1061 resolved
At TC average
Strong +17% interview lift
Without
With
+17.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
39 currently pending
Career history
1100
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
55.0%
+15.0% vs TC avg
§102
24.8%
-15.2% vs TC avg
§112
16.1%
-23.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1061 resolved cases

Office Action

§103
Notice of Pre-AIA or AIA Status The present application is being examined under the pre-AIA first to invent provisions. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1-5, 7, 9, 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ho et al (20090201504) in view of Haussecker (20040043506), further in view of Turner et al (20040095574). Regarding claim(s) 1,2,12 in making and/or using the device of Ho, for producing a focused sample in a microfluidic flow channel, one would perform the steps of receiving a sample stream 71 at an inlet 61 of the microfluidic flow channel 65,66 formed in a substantially planar substrate 90,91,92 having upper and lower surfaces; flowing the sample stream through a lateral fluid focusing component 72,72 of a fluid focusing region (region of intersection of 71,72 in Fig 9a) of a core stream forming geometry (laterally narrowing in downstream direction) to focus the stream laterally, the sample stream and a focusing fluid 72,72 entering the fluid focusing region in a same plane relative to the microfluidic flow channel which lies in a first plane; flowing the sample stream through a first vertical fluid focusing component (intersection of 78,78, Fig 11b) downstream (Para 69, last sentence says vertical focusing 78 can be downstream of lateral focusing) of the lateral fluid focusing feature to provide a first vertical influence to focus the sample stream; and flowing the focused sample stream through the microfluidic flow channel downstream of the vertical fluid focusing component 78,78. Ho discloses a single focusing portion with a lateral focusing point followed by a vertical focusing point but fails to disclose multiple serial focusing portions. Haussecker, Fig 3, teaches a microfluidic assembly for use with a particle processing instrument (abstract states: the apparatus and method can be useful to detect molecules of interest in a microfluidic process), the microfluidic assembly comprising: a substrate (Para 38); and a flow channel formed in the substrate, the flow channel having: an inlet (inlet of 30) configured to receive a sample stream (Para 24); a fluid focusing region 36-60 configured to focus the sample stream, the fluid focusing region having multiple serial focusing portions 36, 44, 60. It would have been obvious to a person having ordinary skill in the art at the time of the invention to have provided the device disclosed by Ho with multiple serial focusing portions as taught by Haussecker in order to improve focusing towards the center of flow path. Ho as such modified would have a second focusing region with second lateral and vertical focusing component downstream of the first focusing region (with a vertical fluid focusing component) to provide a second vertical influence to focus the sample stream. Ho as modified fails to disclose an inspection region downstream of the fluid focusing region with channel downstream of the focusing mechanism shifting upwards to a second plane above the first plane. Turner, Fig 1-3, teaches a microfluidic focusing device with an inspection region 4c downstream of the fluid focusing space 4,4b such that the plane of the flow channel (at 4c) shifts vertically upward downstream of the focusing feature to bring the samples closer to inspection device 22,24 on top. It would have been obvious to a person having ordinary skill in the art at the time of the invention to have provided the device disclosed by Ho as modified with an inspection region with channel plane shifted upwards at location downstream of the fluid focusing mechanism as taught by Turner in order to enable sample analysis and to bring the samples closer to inspection device on top. As to claim 3, Ho, fig 11b, shows the focusing fluid flows 72,72 into the lateral fluid focusing component (intersection) through a first side wall opening and a second side wall opening that is opposed to the first side wall opening. As to claim 4, the lateral focusing component 72,72, the first vertical fluid focusing component 78,78 (Para 69, vertical focusing 78 downstream of lateral focusing), and the second vertical fluid focusing component (at second downstream focusing mechanism in view of Haussecker) are provided at different longitudinal locations along the microfluidic flow channel. As to claim 5, Ho, fig 11b, shows the lateral fluid focusing component 72,72 is configured to introduce focusing fluid into the microfluidic flow channel symmetrically with respect to a centerline of the sample stream. As to claim 7, Ho as modified would have serially arranged sets of vertical fluid focusing component 78,78 in fluid communication with a first set of fluid focusing channels (pathways of upstream portions of 78); including a second vertical fluid focusing component 78,78 in fluid communication with a second set of fluid focusing channels (pathways of upstream portions of 78); and wherein each of the sets of fluid focusing channels (pathways of upstream portions of 78)are symmetrically arranged with respect to a centerline (in 71) of the flow channel. As to claim 9, Ho as modified would have the fluid focusing region has a varying width (at the first lateral focusing intersection where width includes 71 and tapering sections of 72) sections of the width or upstream of the first and second vertical focusing fluid components; and wherein the flow channel has a constant width (width of 71 up to start next serially arranged focusing mechanism in view of Haussecker) between the first and second vertical focusing fluid components and an inspection region. Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ho et al (20090201504) in view of Haussecker (20040043506) and Turner et al (20040095574), further in view of Bohm et al (20050092658). Ho as modified fails to disclose a bubble valve diverter downstream of focusing region. Bohm teaches a bubble valve diverter 100a,100b downstream of focusing region 12,14 for sorting. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have provided the system disclosed by Ho as modified with a bubble valve diverter downstream of focusing region as taught by Bohm in order to enabling discriminate sorting. Claim(s) 8, 10,11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ho et al (20090201504) in view of Haussecker (20040043506) and Turner et al (20040095574), further in view of Gilbert et al (AU 2011205167 A1). As to claim 8, Ho as modified discloses fluid focusing region has an upstream end region (at lateral focusing region of first of serial lateral+vertical focusing mechanisms) and a downstream end region (portion of channel at vertical focusing region of first of serial lateral+vertical focusing mechanisms and including downstream lateral+vertical serial focusing mechanisms), wherein the lateral fluid focusing region is located in the upstream end region, and wherein the first vertical focusing component and the second vertical focusing component are located in the downstream end region. Ho as modified fails to disclose lateral+vertical focusing mechanism having widthwise taper between lateral and vertical focusing regions. Gilbert, (fig 7A,7B,8B) teaches lateral+vertical focusing mechanism having widthwise taper 17 between lateral focusing region (at intersection of 16,12,a,12b) and vertical focusing region (at intersection of 17,19). It would have been obvious to a person having ordinary skill in the art at the time of the invention to have provided the device disclosed by Ho as modified with each lateral+vertical focusing mechanism having widthwise taper between lateral and vertical focusing regions as taught by Gilbert in order to improve lateral focusing. As to claims 10, 11, Ho as modified fails to disclose focusing fluid inlet ports for introducing focusing fluid in the upper surface of the planar substrate and an outlet port formed in the upper surface of the planar substrate. Gilbert, (fig 7A,7B,8B) teaches fluid inlet ports 11a-11d for introducing focusing fluid in the upper surface of the planar substrate and an outlet port 812 formed in the upper surface of the planar substrate. It would have been obvious to a person having ordinary skill in the art at the time of the invention to have provided the device disclosed by Ho as modified with focusing fluid inlet ports and outlet port in the upper surface of the planar substrate as taught by Gilbert in order to provide a convenient fluid ports’ location. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Atif Chaudry at phone number 571-270-3768. The examiner can normally be reached on Monday-Friday (9:30AM-6:00PM EST). If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisors can be reached by phone. Kenneth Rinehart can be reached at 571-272-4881, or Craig Schneider can be reached at 571-272-3607. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ATIF H CHAUDRY/Primary Examiner, Art Unit 3753
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Prosecution Timeline

Nov 20, 2024
Application Filed
Jan 10, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
70%
Grant Probability
87%
With Interview (+17.1%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 1061 resolved cases by this examiner. Grant probability derived from career allow rate.

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