Prosecution Insights
Last updated: April 19, 2026
Application No. 17/545,843

CELL-BASED BRAIN-MACHINE INTERFACE

Non-Final OA §101§112
Filed
Dec 08, 2021
Examiner
STUMPFOLL, DANA LYNN
Art Unit
3794
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Neuralink Corp.
OA Round
3 (Non-Final)
50%
Grant Probability
Moderate
3-4
OA Rounds
4y 1m
To Grant
99%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
23 granted / 46 resolved
-20.0% vs TC avg
Strong +49% interview lift
Without
With
+49.3%
Interview Lift
resolved cases with interview
Typical timeline
4y 1m
Avg Prosecution
45 currently pending
Career history
91
Total Applications
across all art units

Statute-Specific Performance

§101
3.5%
-36.5% vs TC avg
§103
50.1%
+10.1% vs TC avg
§102
18.8%
-21.2% vs TC avg
§112
24.0%
-16.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 46 resolved cases

Office Action

§101 §112
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/11/2026 has been entered. Response to Amendment The amendment filed 02/11/2026 has been entered. Claims 1-18 and 35 remain pending in the application. Claims 19-34 are cancelled. Applicant’s amendments to the claims have overcome some of the objections and rejections previously set forth in the Final Office Action mailed 08/29/2025. Response to Arguments Applicant's arguments filed 02/11/2026 have been fully considered but they are not persuasive. Regarding applicant’s arguments relating to the 35 U.S.C. 101 rejection the examiner respectfully disagrees. While the applicant has amended to incorporate wherein the exogenous neuronal cells are configured to engraft onto the brain, the claims are still directed to recording the naturally occurring response of cells which is a natural phenomenon. Further regarding the meaningful limitation, the claims do not link the computer of the brain-computer interface to the cortical graft layer. Rather, the claims simply recite a layer of cells and a signal detector to record a naturally occurring response of those cells. The applicant further recites wherein the brain-computer interface is the solution, however the claims are not directed to the brain-computer interface and rather they simply recite a layer of cells and recording a signal from that layer of cells. There is no connection to an actual brain-computer interface. No art rejection is provided herein; however upon further consideration the claims are rejected under 35 U.S.C. 101, and 35 U.S.C. 112(a) and 112(b). Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 1-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. The claims state a narrow use of brain-computer interface comprising a cortical graft layer. The written description, however, does not give details on the connection between the cortical graft layer and the computer interface. The specification puts forth different components that can be used in a system; but does not show a single embodiment where the cortical graft layer is the only part of the system provided and integrated into the brain as the interface to the computer. The inventor does not give much direction on steps or devices that allow for this capability and does not describe specific working examples. The specification describes in one example wherein the cells are tethered to electrodes which are further are tethered to an ECoG device, however there is no example described in the detailed description about simply providing cells on the brain to create a brain-computer interface. There is not enough detail provided to show how the layer of cells acts as an interface between the computer and the brain. It is unclear where the specification puts forth the needed structure and steps and specifics to allow for the cortical graft layer to provide an interface between an external recording device and the brain and what makes this device and process different to make it have this capability. The specification is only seen as describing a cortical graft layer and other devices including an array of electrodes for recording and stimulating the brain. There is no mention of how the cortical graft layer comprises the ability to provide bidirectional communication between the brain and an external device. There is also no mention of the specific makeup of the device that creates the brain-computer interface besides the mention of the cortical graft layer. Therefore, the specification and claimed invention lacks enablement as one of skill would not be able to ascertain that the applicant had possession of the claimed invention and gave enough detail for them to make and use the invention as claimed. Claims 1-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Regarding claim 1 and its subsequent dependents, the claim describes a brain-machine interface comprising a cortical graft layer. However, the specification does not give enough detail on the connection between the cortical graft layer and the connection to the external recording device. The specification describes an example wherein the cells are tethered to electrodes and to an ECoG array. The specification further describes that an ECoG array is placed over the cortex on top of the cell layer which establishes a direct link for transmitting information between the host brain cortex and the external ECoG array utilizing electrode (Paragraph [0102]); however, this connection is not described within the claims. Therefore, it is unclear how one of skill or ordinary skill would be able to understand that the inventor or joint inventor had possession of the invention as claimed. The specification is only seen as describing wherein the brain-computer interface utilizes an ECoG array comprising electrodes. There is no mention of the connection to the external device within the claim language. The specification lacks specifics on how the cortical graft layer is connected to the external device. This is seen as a lack of written description. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-18 and 35 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 recites “a brain-computer interface comprising: a cortical graft layer”. It is unclear as to how the cortical graft layer creates an interface as the interface described in claim 1 is simply a layer of cells configured to engraft on the brain. There is no connection between the cortical graft layer and an external device (computer). Therefore it is unclear as to how this layer of cells forms a brain-machine interface as there is no connection to an external device. For examination purposes the brain-computer interface is seen as being a layer of cells. All dependent claims inherit the deficiencies described above. Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claims 1-18 of the claimed invention are directed to a natural phenomenon (a product of nature) without significantly more. Claim 1 recites: A brain-computer interface (BCI) configured to be engrafted on a brain of a mammal, the BCI comprising: a cortical graft layer comprising a plurality of exogenous neuronal cells configured to be transplanted on the brain's cerebral cortex (natural phenomenon), the plurality of cells engraft being configured to engraft on the brain (natural phenomenon) and respond to an external stimulus with a detectable signal (detecting a natural phenomenon) and wherein the exogenous neuronal cells are configured to, at an outermost cortical layer, penetrate the brain by neurites growing from the exogenous neuronal cells (natural phenomenon). These limitations, as drafted, are all naturally occurring within the human body or are a part of the human body (i.e., the brain). The characteristics of these limitations are not markedly different from the product's naturally occurring counterpart in its natural state because they are directly harvested from their naturally occurring locations and then implemented as part of the plurality of neurons to perform the functions that they are designed to perform in the body. This judicial exception is not integrated into a practical application because merely placing the different types of neurons or other cells within cortical graft layer does not add a meaningful limitation as it is merely a nominal extra solution component for the claim, and is nothing more than an attempt to generally link the product of nature to a particular technological environment. Further, exciting the cells and recording a natural response of the cells is a natural phenomenon since the response is naturally occurring. The claims do not include additional elements that are sufficient to amount to significantly more than the judicial exception because the limitations are written such that they must include the naturally occurring phenomena to be implanted on cortical graft layer to act as they would within their natural habitat. Dependent claims 2-18 and 35 are rejected for the same reasons as stated in the rejection for independent claim 1 from which they depend. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Dana Stumpfoll whose telephone number is (703)756-4669. The examiner can normally be reached 9-5 pm (CT), M-F. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joanne Rodden can be reached on (303) 297-4276. 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. /D.S./Examiner, Art Unit 3794 /JOANNE M RODDEN/Supervisory Patent Examiner, Art Unit 3794
Read full office action

Prosecution Timeline

Dec 08, 2021
Application Filed
Apr 11, 2022
Response after Non-Final Action
Apr 03, 2025
Non-Final Rejection — §101, §112
Jul 10, 2025
Response Filed
Oct 23, 2025
Final Rejection — §101, §112
Nov 12, 2025
Interview Requested
Dec 15, 2025
Applicant Interview (Telephonic)
Dec 15, 2025
Examiner Interview Summary
Jan 12, 2026
Response after Non-Final Action
Feb 11, 2026
Request for Continued Examination
Mar 04, 2026
Response after Non-Final Action
Mar 16, 2026
Non-Final Rejection — §101, §112
Apr 09, 2026
Examiner Interview Summary
Apr 09, 2026
Applicant Interview (Telephonic)

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

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Prosecution Projections

3-4
Expected OA Rounds
50%
Grant Probability
99%
With Interview (+49.3%)
4y 1m
Median Time to Grant
High
PTA Risk
Based on 46 resolved cases by this examiner. Grant probability derived from career allow rate.

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