Reframing Patent Eligibility: U.S. § 101 Case Law Through the Lens of Japanese Technicality Doctrine

I. Introduction

The recent Federal Circuit cases on patent eligibility do not simply show that U.S. law has become hostile to particular technologies. They show something more specific and more institutional: the United States often asks threshold eligibility doctrine to perform work that other patent systems assign to inventive step, enablement, support, or claim clarity. The point is not that those other systems are necessarily more generous. They may be demanding in different ways. The point is that the doctrinal location of the inquiry matters.

Japan offers a useful comparison because its patent statute starts from a different vocabulary. Article 2(1) of the Japanese Patent Act defines an "invention" as "a highly advanced creation of technical ideas utilizing the laws of nature." Tokkyo-ho [Patent Act], Law No. 121 of 1959, art. 2(1) (Japan). Article 29(1) then requires that the invention be industrially applicable, and Article 29(2) supplies the familiar inventive-step screen. Id. art. 29(1)-(2). The JPO Examination Guidelines and Handbook elaborate those provisions by identifying subject matter that is not a statutory invention, by addressing medical-activity exclusions under industrial applicability, by setting out support, clarity, and enablement requirements, and by giving a more specific framework for computer-software-related inventions. Japan Patent Office, Examination Guidelines for Patent and Utility Model in Japan pt. III, ch. 1, §§ 1, 2.1-2.2, 3.1.1-3.2.1; id. pt. II, ch. 1, § 1; id. pt. II, ch. 2, §§ 2-3; Japan Patent Office, Examination Handbook for Patent and Utility Model in Japan Annex B, ch. 1, §§ 2.1, 2.1.1.1-2.1.1.2, 2.2.3; id. Annex D, pts. 2-3.

That framework should not be overstated. Japanese law does not give a pass to every claim that recites a computer, a processor, a camera, or a measurable material property. A claim whose only contribution is a commercial rule, a mental process, a desired result, or a thin functional objective may still encounter difficulty. In Japan, however, those difficulties usually take a more focused form. A software claim may fail because the claimed information processing is not concretely realized by hardware resources, or because the alleged technical effect is unsupported or obvious. A medical claim may fail because it is drafted as a method of diagnosis practiced on the human body. A parameter-defined product may fail because the parameter is unclear, unsupported, or inadequately enabled across the claimed range. Those are not the same moves as calling a digital camera, a diamond compact, or an authentication protocol an "abstract idea."

This article uses six Federal Circuit decisions as pressure points: Recentive Analytics, Inc. v. Fox Corp., 134 F.4th 1205 (Fed. Cir. 2025); PowerBlock Holdings, Inc. v. iFit, Inc., 146 F.4th 1366 (Fed. Cir. 2025); CardioNet, LLC v. InfoBionic, Inc., 955 F.3d 1358 (Fed. Cir. 2020); U.S. Synthetic Corp. v. International Trade Commission, 128 F.4th 1272 (Fed. Cir. 2025); Yu v. Apple Inc., 1 F.4th 1040 (Fed. Cir. 2021); and CosmoKey Solutions GmbH & Co. KG v. Duo Security LLC, 15 F.4th 1091 (Fed. Cir. 2021). The exercise is necessarily predictive. It does not claim to reproduce an actual JPO office action, and it assumes that the U.S. claims would be translated into Japanese claim form without materially changing their technical substance. With that caveat, the cases suggest a recurrent pattern: where the claim is anchored in a concrete technical implementation, Japanese practice is more likely to locate the central dispute downstream from eligibility, while U.S. law sometimes resolves the same anxiety through § 101.

II. Japanese Eligibility Doctrine: A Narrower Threshold, Not a Free Pass

The Japanese eligibility inquiry begins with the statutory definition of invention. The requirement that the claimed subject matter be a "creation of technical ideas utilizing the laws of nature" excludes, among other things, laws of nature as such, mere discoveries, arrangements that do not use laws of nature, mental activities, aesthetic creations, and the mere presentation of information. JPO Examination Guidelines pt. III, ch. 1, § 2.1. The Guidelines also make clear that the phrase "highly advanced" does not smuggle inventive step into Article 2(1); inventive step is addressed separately under Article 29(2). That separation is central to the comparison with U.S. § 101.

For ordinary machines, electrical circuits, signal-processing devices, chemical products, and industrial tools, the Article 2(1) inquiry is usually not the battleground. The claimed subject matter uses physical laws and is framed as a technical product or process. The battleground shifts to novelty, inventive step, enablement, support, and clarity. This does not make Japanese examination lenient. It simply means that the examiner is less likely to ask whether the claim is "directed to" an abstract concept before reaching those other requirements.

Software and AI require more care. The JPO Handbook instructs examiners first to look to Part III, Chapter 1 and, if that does not resolve the issue, to decide from a software standpoint whether information processing by software is concretely realized using hardware resources. Examination Handbook Annex B, ch. 1, §§ 2.1.1, 2.1.1.1-2.1.1.2. The question is not answered by the word "computer" alone. A method for doing business, playing a game, or calculating a mathematical formula may still fail when the claim, considered as a whole, does not present technical information processing. Conversely, a software-related invention may satisfy Article 2(1) when the claim constructs a specific information processor or operation method through cooperation between software and hardware resources. Id. § 2.1.1.2. The Handbook examples make the distinction concrete: a bare computer for predicting sales may fail, while a computer that recites specific calculation or processing--for example, TF-IDF-based document summarization--may satisfy the statutory-invention requirement. Id.

Japanese case law points in the same direction, but not all in one direction. In Point Management Method, the IP High Court affirmed a non-eligibility conclusion where the claim disclosed a flow of point-management information using a network and point-account database but did not describe, in concrete terms, how the point-management processing and hardware resources cooperated. Intell. Prop. High Ct., Sept. 26, 2006, 2005 (Gyo-Ke) No. 10698 (Point Management Method). In Hashing, the court treated the asserted apparatus as no more than a mathematical algorithm where the claims did not recite how the algorithm operated in an arithmetic circuit. Intell. Prop. High Ct., Feb. 29, 2008, 2007 (Gyo-Ke) No. 10239 (Hashing). By contrast, in Interactive Dental Treatment Network, the IP High Court cancelled a JPO rejection because the claimed computer-based dental-treatment system supplied technical means--including a network server, database, communications network, computer, image display, and image processing--to support dental treatment, even though human judgment remained involved. Intell. Prop. High Ct., June 24, 2008, 2007 (Gyo-Ke) No. 10369 (Interactive Dental Treatment Network).

Medical technology presents a different limitation. The JPO treats methods of surgery, therapy, or diagnosis of humans as lacking industrial applicability, but it does not treat medical devices, pharmaceuticals, or device-control and data-processing inventions as excluded merely because they are used in medical care. JPO Examination Guidelines pt. III, ch. 1, §§ 3.1.1, 3.2.1. This is a bright practical distinction for drafters. The same technical insight can have a very different Japanese eligibility posture depending on whether it is claimed as a diagnostic act performed on a human subject or as a device, program, or signal-processing method.

Recent Japanese authority also reinforces the product/device side of the medical line. In the 2025 Tokai Ika Grand Panel decision, the IP High Court held that a product invention using an ingredient collected from a human and intended to be returned into that human was not, for that reason alone, an industrially inapplicable medical-practice invention. Intell. Prop. High Ct., Special Div., Mar. 19, 2025, 2023 (Ne) No. 10040. That holding is consistent with the JPO’s product/device distinction, but it should not be read as eliminating the exclusion for claims directed to surgery, therapy, or diagnosis of humans as methods.

Finally, Japanese law is relatively comfortable with claims that use parameters or functional language, but only within the constraints of Article 36 and Article 29. Claims must be supported by the specification, clear enough to define the invention, and enabled in view of the common general knowledge. Patent Act art. 36(4)(i), 36(6)(i)-(ii); JPO Examination Guidelines pt. II, ch. 1, § 1; id. pt. II, ch. 2, sec. 2, §§ 2.1-2.2; id. pt. II, ch. 2, sec. 3, §§ 2.1-2.3, 4.1.1. Thus, a parameter-defined product is not suspect because it has a parameter. It becomes suspect if the parameter lacks technical meaning, if the measurement method is indeterminate, if the specification does not support the full claimed range, or if the parameter merely redescribes an obvious product.

The IP High Court’s Grand Panel decision in the Parameterized Patent, or Polarizing Film, case supplies the leading judicial counterweight. There, the claimed film was defined by numerical relationships among two technical parameters. The court analyzed the defect under the support requirement, asking whether the specification disclosed, or enabled a skilled person to recognize from common general knowledge, that the claimed parameter range solved the stated problem. Intell. Prop. High Ct. Grand Panel, Nov. 11, 2005, 2005 (Gyo-Ke) No. 10042 (Parameterized Patent/Polarizing Film). That case is a useful reminder that Japanese law may be hospitable to parameter claiming as a category while still demanding substantial evidentiary support for the chosen range.

Those qualifications matter because they keep the comparison from becoming caricature. The Japanese screen is narrower than the U.S. abstract-idea inquiry in many technical cases, but it is not empty. It asks a different first question and then routes many hard patentability questions to different statutory provisions.

III. Case Studies in Doctrinal Allocation

A. Software at the Boundary: Recentive and CosmoKey

1. Recentive as the difficult case

Recentive is the hardest case for the comparative thesis because the claimed objectives were commercial rather than technical. The patents claimed the use of machine-learning models to generate television broadcast schedules and network maps for live events. The claims recited receiving historical and real-time event information, training or using machine-learning models, and outputting schedules or maps designed to optimize objectives such as viewership, revenue, or profit. The patentee did not claim a new machine-learning architecture or training technique; the asserted novelty lay in applying known machine-learning tools to the scheduling and mapping environment. The Federal Circuit affirmed dismissal under Rule 12(b)(6), holding that the claims were directed to the abstract idea of using generic machine learning to optimize business scheduling and mapping and that the additional computer implementation did not supply an inventive concept. Recentive, 134 F.4th at 1213-19.

A cautious Japanese analysis would not begin by asking whether "using machine learning" is abstract. It would ask whether the claimed invention, as a whole, is a creation of a technical idea utilizing laws of nature, and, because the claims use software, whether the claimed information processing is concretely realized through hardware resources. That inquiry could come out differently depending on claim drafting. The Point Management Method case and the Handbook’s sales-prediction example prevent an easy pro-eligibility answer: labels such as network, database, model, or server do not themselves show concrete software-hardware cooperation. See Intell. Prop. High Ct., Sept. 26, 2006, 2005 (Gyo-Ke) No. 10698 (Point Management Method); Examination Handbook Annex B, ch. 1, § 2.1.1.2. A claim that merely states a business scheduling rule and appends generic computer execution may have a real Article 2(1) problem. A claim that recites a concrete information-processing system with specific data structures, model-training operations, allocation constraints, and machine outputs would have a stronger statutory-invention posture.

Even on the stronger formulation, Recentive would remain vulnerable in Japan. The vulnerability would likely sound in inventive step and support rather than in a free-standing conclusion that the idea is abstract. The JPO would be expected to ask whether applying a known machine-learning model to known scheduling objectives yields a technical feature beyond ordinary automation of a business problem. It would also ask whether the specification supports the alleged effect across the claim scope. If the only improvement is a better business schedule, the Japanese case is weak even if the claim survives the Article 2 threshold.

This is an important qualification. Recentive should not be used to say that Japan would routinely allow business-oriented AI claims. The more defensible point is narrower: Japanese examination would likely force the applicant to identify a technical contribution in the architecture, data processing, training method, or interaction with technical constraints. U.S. law performed a similar sorting function through § 101; Japanese practice would more likely perform it through the software-related invention framework plus Article 29(2) and Article 36.

2. CosmoKey and the stronger software case

CosmoKey sits in a different part of the software spectrum. The claimed authentication method used a terminal, transaction partner, authentication device, mobile device, and two communication channels. The authentication function on the user device was normally inactive; the user activated it only for a transaction; the system checked whether activation occurred within a predetermined timing relation; and the function was automatically deactivated afterward. The district court treated the claims as directed to the abstract idea of authentication, but the Federal Circuit reversed. The panel assumed, without finally deciding, that authentication could be described abstractly, and held at Alice step two that the ordered combination recited a specific improvement to a particular computer-implemented authentication technique. CosmoKey, 15 F.4th at 1096-99.

The Japanese statutory-invention analysis would have more to work with here than in Recentive. The claim is not just a commercial objective implemented on a computer. It specifies device states, communications over multiple channels, a timing relation, activation for a transaction-specific interval, and automatic deactivation. Those limitations describe a concrete pattern of information exchange and device-state control in a networked system. Under the JPO software framework, that kind of claim would be a strong candidate for treatment as information processing concretely realized by software and hardware cooperation. See Examination Handbook Annex B, ch. 1, § 2.1.1.2.

This conclusion is not simply a product of calling the invention a "system." Interactive Dental Treatment Network is useful precisely because it did not treat system language as dispositive. The court looked to whether the claimed network, database, computer, image display, and image-processing arrangements supplied technical means supporting the task. That reasoning would cut the other way where a claim merely redescribes a human, commercial, or security practice in system language.

The counterargument would focus not on abstraction but on conventionality. Multi-factor authentication, out-of-band confirmation, timed challenges, and temporary activation were familiar security concepts. A Japanese examiner could therefore reject the claim as obvious if the prior art supplied a motivation to combine those features. But that is exactly the point of comparison: the Federal Circuit had to ask, under § 101 step two, whether the ordered combination was well-understood, routine, and conventional; a Japanese examiner would ordinarily ask the analogous question under Article 29(2), with support and clarity concerns under Article 36 if the claim language were too functional.

Taken together, Recentive and CosmoKey show why the software comparison cannot be reduced to "Japan allows what the United States rejects." Business-facing AI remains vulnerable in Japan unless the technical implementation does real work. Security protocols and network-control techniques are more readily characterized as technical, but they still must earn patentability over the prior art.

B. Machines, Hardware, and Result-Oriented Claiming: PowerBlock and Yu

1. PowerBlock as a control case for over-abstraction

PowerBlock involved selectorized dumbbells with a motor-driven selector. The claims recited nested weight plates, a handle, a movable selector with multiple adjustment positions, and an electric motor coupled to the selector. When the user selected a desired weight, the motor physically moved the selector to engage the appropriate plates. The district court characterized the claims as the abstract idea of automating weight selection with generic components. The Federal Circuit reversed, emphasizing that the claims were directed to a specific manner of performing automated weight stacking in a tangible mechanical system. PowerBlock, 146 F.4th at 1371-73.

For Japanese purposes, this is the closest thing in the set to an easy Article 2(1) case. The invention is a mechanical and electrical article that uses physical components to produce physical movement. It is also industrially applicable in the ordinary sense. That does not mean the claim is necessarily patentable. Motorizing a known selector mechanism might be obvious, and the breadth of the selector and control limitations might matter. But the Japanese examiner would have little reason to treat the claim as outside the statutory category of invention.

The value of PowerBlock is therefore methodological. It exposes the risk of defining the "idea" of a claim at a level of abstraction so high that ordinary machines become suspicious. Japanese doctrine would not need a special correction for that move because the Article 2(1) inquiry would remain tied to the claimed technical article. The harder work would occur where patent law usually expects it: prior art, claim scope, and disclosure.

2. Yu as the apparatus case with a real drafting problem

Yu complicates the picture. The representative claim recited an "improved digital camera" with two image sensors, two lenses, analog-to-digital converting circuitry, image memory, and a digital image processor configured to produce a first digital image "enhanced" with a second digital image. The Federal Circuit held the claim ineligible, characterizing it as directed to the abstract idea of taking two pictures and using one to enhance the other. The majority emphasized that the claim recited conventional camera components at a high level of generality and failed to claim a specific technical means for achieving the enhancement. Yu, 1 F.4th at 1042-45. Judge Newman dissented, reasoning that the claim recited a concrete camera, not an abstract idea. Id. at 1045-48 (Newman, J., dissenting).

Japan would likely analyze the claim differently, but not necessarily more favorably in ultimate result. A camera with sensors, lenses, conversion circuitry, memory, and a processor is a technical apparatus using optics and electronics. That makes Article 2(1) a much less natural ground of rejection than it was for the U.S. majority under § 101. Yet the claim has a serious Japanese vulnerability: "enhanced with" may describe an outcome without tying that outcome to the disclosed four-sensor arrangement, exposure strategy, signal-processing algorithm, or other concrete means.

A JPO examiner could therefore press the same basic concern through Article 36 and Article 29(2). If the specification discloses a particular multi-sensor architecture or black-and-white sensor arrangement but the claim covers nearly any dual-sensor camera that combines two images, the claim may outrun the support of the description. If dual-lens cameras and image-fusion techniques were known, the claim may also be obvious absent a specific technical feature that produces the alleged improvement. The Japanese result might therefore still be rejection, but the rejection would likely be about claim breadth, support, clarity, and inventive step rather than about whether a claimed camera is an abstract idea.

That difference is not merely semantic. A § 101 dismissal can dispose of the case at the pleading stage before a developed claim-construction or prior-art record. An Article 36 or Article 29 rejection, by contrast, identifies a defect that the applicant can often address through narrower claims, additional technical explanation, or evidence of technical effect. Yu thus becomes a drafting lesson: concrete hardware helps, but it does not rescue a claim whose alleged advance remains at the level of a desired result.

C. CardioNet and the Medical-Method Line

CardioNet concerned cardiac monitoring technology for detecting and distinguishing atrial fibrillation and atrial flutter. The representative claim recited a cardiac monitoring apparatus with electrodes, beat-detection components, and a relevance determiner applying specified logic to beat-to-beat timing information. The district court treated the claim as directed to an abstract diagnostic idea. The Federal Circuit reversed, holding that the claims were directed to a specific technological improvement in cardiac monitoring, not to a mental process or an abstract diagnostic correlation. CardioNet, 955 F.3d at 1368-71.

Japan adds a doctrinal complication that U.S. § 101 analysis does not track in the same way: industrial applicability for medical activity. If a CardioNet-type claim is drafted as a cardiac monitoring device, a control method for the device, a program, or a signal-processing method that outputs information, it has a strong Japanese eligibility posture. The claim is directed to technical processing of electrical physiological signals by a device. But if the same insight is claimed as "a method of diagnosing atrial fibrillation in a human subject" comprising measuring the patient and determining that the patient has atrial fibrillation, the JPO may treat it as a method of diagnosis of humans and reject it as lacking industrial applicability. JPO Examination Guidelines pt. III, ch. 1, §§ 3.1.1, 3.2.1.

The important point is that Japanese law is not merely more tolerant of medical diagnostics. It is tolerant of medical devices and technical data processing, while drawing a relatively firm line around diagnostic acts practiced on the human body. That line makes claim form unusually important. A U.S. practitioner reading CardioNet may focus on whether the claim improves a technological device enough to avoid abstraction. A Japan-focused drafter must also ask whether the claim format itself invites a medical-activity objection.

Japanese decisions reinforce both sides of that line. The Tokai Ika Grand Panel decision helps product and composition claims, because it rejected the argument that a product becomes an industrially inapplicable medical-practice invention merely because its manufacture and use involve a medical sequence. The Muscle Training Method case points in the same general direction from the opposite angle: possible medical use did not by itself defeat industrial applicability where the invention was framed and disclosed as training technology. Intell. Prop. High Ct., Aug. 28, 2013, 2012 (Gyo-Ke) No. 10400 (Muscle Training Method). Neither case, however, would save a claim whose operative steps are diagnosis or treatment of a human being as such.

This makes CardioNet both supportive and limiting for the article's thesis. It supports the thesis because device-form monitoring claims would likely be treated as technical inventions in Japan, with the real disputes directed to prior art and disclosure. It limits the thesis because the same underlying medical insight, drafted as a diagnostic method, could fail at the Japanese threshold even though a U.S. court might view the claim through a different Mayo/Alice lens.

D. Parameter-Defined Compositions After U.S. Synthetic

U.S. Synthetic is striking because the claims were composition-of-matter claims. The patent claimed polycrystalline diamond compacts used as cutting elements in drill bits. The claimed PDCs included a diamond table bonded to a carbide substrate and were defined by constituents, dimensions, grain characteristics, and measured material properties such as coercivity, specific magnetic saturation, and specific permeability. The Commission treated the magnetic-property limitations as result-oriented or abstract. The Federal Circuit reversed, holding that the claims were directed to a specific, non-abstract composition of matter defined by structural features and material properties that correlated with microstructure. U.S. Synthetic, 128 F.4th at 1281-84.

The Japanese analysis would likely start from the premise that a manufactured diamond compact is a technical product. The more careful statement is that Article 2(1) would not ordinarily be the meaningful obstacle. The obstacle would be the adequacy of the parameter limitations. Do the claimed magnetic properties have technical meaning? Is the measurement method sufficiently definite? Does the specification disclose why those properties correlate with microstructure and performance? Are the claimed ranges supported across their full breadth? Do the parameters distinguish a non-obvious product from prior-art PDCs, or do they merely re-label an obvious material?

Japanese practice is generally familiar with product claims defined in part by physical or chemical properties. That familiarity does not make parameter claiming risk-free. A parameter can clarify an invention when it captures a structural or functional feature that conventional claim language cannot easily express. It can also obscure the invention when the applicant uses a desired property as a substitute for teaching how to make and use the product. Article 36 and Article 29 are the natural tools for policing that distinction.

The Grand Panel’s Parameterized Patent decision makes the same point in litigation terms. The court did not treat parameters as a subject-matter defect. It asked whether the disclosure justified the range and its technical effect. For U.S. Synthetic, that means a Japanese tribunal would likely focus on the evidentiary link between coercivity, magnetic saturation, permeability, microstructure, and performance--not on whether the use of those measured properties turns the claimed compact into a non-technical idea.

In this respect, U.S. Synthetic shows a convergence rather than a divergence. The Federal Circuit's reversal moved U.S. law closer to the Japanese allocation of issues. The court treated the PDC as the concrete product that it was, while leaving enablement and other patentability questions to the provisions designed for them. The comparative lesson is not that every parameter-defined product is patentable. It is that physical products should not become abstract merely because some claim limitations are expressed through measurable properties.

IV. What the Comparison Shows - and What It Does Not Show

The six cases support a restrained conclusion. Japanese law would not necessarily produce more patents. It would more often ask different questions at different points in the analysis. For PowerBlock and U.S. Synthetic, the Japanese threshold inquiry would likely be brief because the claimed subject matter is a tangible machine or manufactured composition. For Yu, the presence of hardware would likely keep the claim within the statutory category, but the claim could still fail because the technical means are underclaimed. For CardioNet, device and signal-processing claims are much safer than diagnostic-method claims. For Recentive and CosmoKey, the distinction between business automation and technical information processing becomes decisive.

The comparison also reveals why U.S. § 101 can feel unstable. The Alice/Mayo inquiry often blends several questions: What is the claim really about? Is the asserted advance technological? Are the components conventional? Has the patentee claimed a result rather than a means? Would allowing the claim preempt too much future work? Those are legitimate patent-system concerns, but they do not all fit comfortably inside a threshold subject-matter category. When they are pressed into § 101, the same claim can look concrete or abstract depending on the level of generality selected by the decisionmaker.

Japanese doctrine has its own sources of uncertainty. The JPO Guidelines are administrative guidance, not a complete code of outcomes. English translations are provisional. Actual prosecution may depend on examiner practice, claim translation, amendments, and the prior-art record. In software cases especially, the line between a technical information-processing invention and a business method implemented on ordinary hardware can be contestable. A comparative article should therefore avoid saying that Japan "would" allow a claim when the more honest prediction is that Japan would likely classify the problem differently.

The better lesson is institutional. Japanese law tends to preserve eligibility as a technicality and industrial-applicability screen. It then relies on inventive step, support, clarity, and enablement to do much of the work that U.S. courts sometimes do through "abstract idea" analysis. That allocation does not eliminate hard cases. It makes the hard issue more visible: Is there a non-obvious technical contribution, and is that contribution actually claimed and disclosed?

V. Drafting Implications

The practical drafting consequence is not to prepare one specification for the United States and a wholly different specification for Japan. It is to write one technical narrative that can answer both systems, while keeping enough claim architecture to respond to their different doctrinal pressure points.

For software and AI inventions, the specification should not rest on the statement that a model produces a better business outcome. It should identify the technical problem, the technical data or system constraints, the structure of the information processing, the role of hardware resources, and the reason the claimed configuration produces a technical effect. Claims should avoid making the business objective the only apparent advance. For a Recentive-type invention, that means claiming more than the use of machine learning for scheduling; it means disclosing and claiming the technical features of the model, training process, data handling, or resource allocation that make the implementation more than ordinary automation. For a CosmoKey-type invention, it means claiming the state transitions, timing relations, channel interactions, and security effects that make the protocol a technical implementation rather than authentication in the abstract.

For hardware inventions, the claim should not rely solely on a desired result. PowerBlock shows the value of reciting physical components and their operational relationship. Yu shows the risk of claiming familiar hardware at a high level while leaving the alleged improvement in functional language. The safer approach in both jurisdictions is to claim the structure or processing that produces the result, not merely the result itself.

For medical-monitoring and diagnostic technologies, Japan requires special attention to claim category. Device claims, program claims, control-method claims, and signal-processing claims should be drafted to avoid characterizing the invention as a diagnostic method practiced on the human body. In the United States, the same claims should be framed as specific improvements to monitoring technology or signal processing, rather than as claims to a natural correlation or diagnostic conclusion. The overlap is substantial but not complete.

For composition and parameter-defined inventions, the specification should make the parameter do real technical work. It should define the measurement method, explain the relationship between the parameter and structure or performance, provide representative examples across the claimed range, and preserve fallback ranges and structural limitations. U.S. Synthetic illustrates the value of tying measured properties to microstructure; the same linkage helps in Japan under Article 36 and Article 29 even when eligibility is not the main issue.

Across all categories, the drafter should preserve multiple levels of claim specificity. Broad claims may be worth pursuing, but they should be accompanied by dependent claims and specification detail that isolate the technical contribution. That strategy is useful in U.S. litigation because it reduces the chance that a court will identify only an abstract result. It is equally useful in Japan because it gives the applicant room to answer inventive-step, support, clarity, and medical-activity objections without abandoning the commercial core of the invention.

VI. Conclusion

The comparison between recent Federal Circuit eligibility cases and Japanese patent eligibility doctrine is most persuasive when it is not overstated. Japan is not a jurisdiction in which every computer-implemented method, diagnostic insight, or parameter-defined product sails through examination. The JPO can be demanding, especially where the claim is business-facing, result-oriented, unsupported, or drafted in a prohibited medical-method form.

What Japan does offer is a different allocation of patentability questions. A concrete machine, device, composition, or technical information-processing system is less likely to be rejected at the threshold on a generalized non-technicality rationale. The examiner is more likely to ask whether the technical contribution is new, non-obvious, clearly claimed, sufficiently disclosed, and industrially applicable in the required sense. That allocation makes the analysis less frictionless than a simple pro-patent narrative, but more disciplined than an abstract-idea inquiry untethered from a stable level of generality.

For U.S. law, the Japanese comparison supports a modest critique of eligibility creep. The problem is not that courts ask whether claims are technological. Patent law must ask that question. The problem is that § 101 sometimes becomes the place where courts resolve obviousness, enablement, overbreadth, and functional claiming concerns without naming them as such. For practitioners, the lesson is immediate: front-load the technical narrative, claim the specific means as well as the useful result, and draft so that the same invention can be understood both as a concrete technological implementation under Alice/Mayo and as a technical idea utilizing laws of nature under Article 2(1).