Mathematical algorithm-based improvement to a known industrial or laboratory process may be patent eligible under 35 U.S.C. § 101

Pursuant to 35 U.S.C. § 101, "[w]hoever 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 therefore." The US Supreme Court has identified three types of subject matter that are not patent-eligible: Laws of nature, natural phenomena, and abstract idea. In Alice Corp. v. CLS Bank Int'l (2014), the United States Supreme Court applied a Two-Step test for patent eligibility.

In step one, the court must consider the claims "in their entirety to ascertain whether their character as a whole is directed to excluded subject matter." If not, the claim is potentially patentable. If the answer is affirmative, then the court must proceed to step two and determine whether the claim contains an "inventive concept" sufficient to transform the claimed abstract idea into a patent-eligible application. In XY, LLC v. Trans Ova Genetics (Fed. Cir July 2020), the Federal Circuit considered whether a software-implemented method of sorting particles using flow cytometry is patent eligible under 35 U.S.C. § 101.

Flow cytometry is a laboratory technique used to distinguish between different populations of cells within a sample by introducing the cells into a fluid stream, coupling the cells using a laser to a light-emitting element, such as a dye, and then detecting the resulting signals, such as fluorescence, at one or more signal detectors. The patent at issue, US Patent No. RE 46,559 (the '559 patent), claims n-dimensional data transformation methodologies for enhancing real-time discrimination and sorting of different types of particles, such as X and Y chromosomes in a sample, the signal data for which is generated and collected using flow cytometry.

Claim 1 recites a method of operating a flow cytometry apparatus with at least n detectors to analyze at least two populations of particles in the same sample. The method recites seven steps (a) through (g), where steps (a) "establishing a fluid stream…" and (b) "entraining particles from the sample in the fluid…" relate to enabling collection of signal data. Steps (c) through (g) are directed to executing software instructions to [c] "detect a first signal…," [d] "detect a second signal…," [e] convert the signals "into n-dimensional parameter data for the detected particles…", [f] "rotationally alter the n-dimensional parameter data so that spatial separation of the data…is increased," and [g] "to real-time classify each of the individual detected particles into one of a first population and a second population of the at least two populations based on at least the rotationally altered n-dimensional parameter data."

In December 2016, XY sued Trans Ova for infringement of seven patents relating to technology for sex selection of non-human mammals. Trans Ova filed a motion for judgment on the pleadings for the '559 patent, arguing that the asserted claims are patent ineligible under § 101. The district court applied the Alice Two-Step test, and determined the '559 patent claims are ineligible. At step one, the district court held that "claim 1 of the '559 patent was directed to the abstract idea of a mathematical equation that permits rotating multiple dimensional data." At step two, the district court "held that the asserted claims lacked an inventive step concept because XY admitted that each claim element was known in the art."

On appeal, XY argued that the district court erred in holding that under Alice step one, the claims are merely directed to an abstract idea of "a mathematical equation that permits rotating multi-dimensional data." The Federal Circuit agreed with XY stating, "[r]ather, the claims are directed to a purportedly improved method of operating a flow cytometry apparatus to classify and sort particles into at least two populations in real time, wherein first and second detectors detect signals from individual particles and a processor converts the signals to n-dimensional parameter data and rotationally alters that data to increase spatial separation among the data, thereby facilitating classification and sorting of each individual particle."

For its holding, the Federal Circuit relied on Diamond v. Diehr, 450 US 175 (1981) and Thales Visionix Inc. v. United States, 850 F.3d 143 (Fed. Cir. 2017). Like the claims in those cases, the Court stated that the '559 patent's claims "describe in detail a step-by-step method for accomplishing a physical process" and claim an improvement to that process "through the specific application of mathematical algorithms," such that individual particles are classified and separated from a sample "more accurately than in any other separation system." Likening the '559 patent's claims to those in Thales, the Court added that "both recite methods in which at least two detectors gather data about an object before mathematical operations are applied to the gathered data to generate more accurate information about the object than was previously possible in the art."

Further, the Federal Circuit stated that as in Diehr and Thales, the asserted patent claims "implement or apply mathematical formulas in a structure or process which, when considered as a whole, is performing a function which the patent laws were designed to protect." Accordingly, the Federal Circuit resolved that the '559 patent claims satisfy § 101 without needing to reach Alice step two.

In XY, LLC v. Trans Ova Genetics, the Federal Circuit has further clarified patent eligibility under 35 U.S.C. § 101 by demonstrating how a purported improvement to a known laboratory or industrial process may be patent eligible, even if a mathematical algorithm is intrinsic to the improvement.