Written By: Andrew Campbell Lee, Ph.D.
Practitioners must consider both the prior art  and the language  used in claims when preparing a patent application. Patentable subject matter includes “any new and useful process, machine, manufacture, composition of matter, or any new and useful improvement thereof.”  While this language appears to have clear meaning in the engineering field for mechanical and electrical inventions, algorithmic inventions must be claimed with the Alice Corp. Pty. Ltd. v. CLS Bank Intern. decision in mind. 
Several court decisions impact the determination of what is patentable. In Alice, the Supreme Court opined that abstract ideas, which are not themselves patent eligible, would not become patent eligible by “recit[ing] . . . generic computer components configured to implement the same idea.”  While several test constructs have been used to determine patent subject matter eligibility,  the two-part framework from Mayo was applied in Alice.  The Mayo test includes (1) determining whether the claims are directed to ineligible subject matter (e.g., laws of nature, natural phenomena, and abstract ideas), and (2) if so, a subsequent determination must be made as to “what else is there in the claims before us.” 
For example, an inventor’s disclosure for a technique to keep law school students awake during lecture may include a method comprising: identifying a facial expression indicative of weariness; determining a metric based at least in part on the identified facial expression; and determining a change in lighting if the metric exceeds a predetermined threshold.  This process, as written, could be a thought exercise (e.g., looking at a crowd of people). This claim would likely run into Alice issues, falling under either prong of the Mayo test.
The United States Patent and Trademark Office (“USPTO”) has provided some guidance in drafting claims with respect to subject matter eligibility.  With the USPTO’s guidelines in mind, a claim may be crafted such as, for example: A method for automatically adjusting lights based on audience, the method comprising: generating image data, using imaging equipment, indicative of an image; determining, using control circuitry, a facial expression metric associated with the image and based on a plurality of reference templates; and generating, using the control circuitry, a control signal based on the facial expression metric for causing an actuator to articulate a lighting fixture. This claim avoids categorization as an abstract idea, the first prong of the Mayo test, because there is tangible input and output requiring more than a generic computer. Further, if that same inventor describes training a neural network model to more accurately identify the weary students based on a dataset, the USPTO provides useful claim examples, including discussions, to help address these issues. 
 See 35 U.S.C.A. §§ 102-103 (West 2015) (regarding novelty and obviousness rejections based on prior art).
 See 35 U.S.C.A. § 112(b) (the claims must “particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention”).
 35 U.S.C.A. § 101 (West 1952) (“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”).
 Alice Corp. Pty. Ltd. v. CLS Bank Intern., 573 U.S. 208, 226-27 (2014).
 Id. (reasoning that “the system claims are no different from the method claims in substance”).
 See State Street Bank & Trust Co. v. Signature Financial Group, Inc., 149 F.3d 1368 (1998) (the machine or transformation test); see Bilski v. Kappos, 561 U.S. 593, 605 (2010) (which deemed the machine or transformation test of State Street a tool but not the “sole criterion”); see generally Daniel J. Burns, Patent Practice After Alice, 2016 WL 1595103, at 2 (March 2016) (providing an overview of patent practice following Alice).
 Alice, 573 U.S. at 217-18; see Mayo Collaborative Services v. Prometheus Laboratories, Inc., 566 U.S. 66, 77-80 (2012).
 Mayo, 566 U.S. at 77-78; see also Alice, 573 U.S. at 217-18.
 This claim is merely illustrative and has not undergone the 35 U.S.C. §§ 102-103 patentability analysis.
 See 2019 Revised Patent Subject Matter Eligibility Guidance, 84 Fed. Reg. 50 (Jan. 7, 2019) (hereinafter “2019 PEG”); see also October 2019 Update: Subject Matter Eligibility (October 17, 2019), https://www.uspto.gov/sites/ default/files/documents/peg_oct_2019_update.pdf (addressing comments submitted regarding the 2019 PEG).
 Subject Matter Eligibility Examples: Abstract Ideas (January 7, 2019), https://www.uspto.gov/sites/default/files/documents/101_examples_37to42_20190107.pdf [https://perma.cc/T9TF-LXXJ] (see particularly Example 39 for training a neural network).