Protecting Form in Functional Systems: Design Patents in Medical Robotics

Medical robotics sit at the uneasy intersection of functionality and appearance. Robotic surgical systems, rehabilitation devices, and assistive medical tools must meet stringent clinical, ergonomic, and regulatory requirements, often leaving limited freedom in how their physical form is constructed. 

Yet, visual design remains critical in medical robotics. It shapes clinician trust, influences adoption, and drives product differentiation in increasingly competitive markets. Against this backdrop, design patents have taken on increased strategic importance. 

Design patent filings at the U.S. Patent and Trademark Office (USPTO) have remained historically strong, even as utility patent filings in some hardware sectors have flattened. Although the USPTO doesn’t publish industry-specific design patent statistics, available classification data and portfolio analyses suggest that medical devices account for approximately 5% to 8% of U.S. design patent filings each year. Filings in medical robotics constitute a much smaller subset, likely well under 1% of annual design applications, reflecting both the sector’s functional constraints and its more selective use of design protection.

In this context, recent court decisions, most notably Range of Motion Products, LLC v. Armaid Co., 166 F.4th 981 (Fed. Cir. 2026), underscore the necessity for renewed attention to how design patents are drafted, enforced, and evaluated.

Design Patents in Medical Robotics

Design patents protect the ornamental appearance of an article of manufacture, rather than its functional operation. In medical robotics, design patent subject matter includes robotic arms and carts, end effectors, handheld therapeutic devices, clinician consoles, and graphical user interfaces (GUIs) used to control or visualize robotic operation. Even where functional constraints are significant, design protection remains available as long as the claimed features reflect ornamental choice, rather than functional necessity.

From a commercial standpoint, design patents offer distinct advantages. They typically issue more quickly and at lower cost than utility patents; avoid subject-matter eligibility challenges; and can provide meaningful leverage against visually similar competitors. 

The Ordinary Observer Test and the ‘Plainly Dissimilar’ Threshold

Design patent infringement is governed by the “ordinary observer” test, which asks whether an ordinary observer familiar with the prior art would find the accused design to be substantially the same as the patented design. In Egyptian Goddess Inc. v. Swisa Inc., the Federal Circuit confirmed this holistic approach and rejected the earlier “point of novelty” test.

At the same time, the Egyptian Goddess decision included a statement, later elevated into doctrine, that said designs that are “plainly” or “sufficiently” dissimilar may be resolved as a matter of law. In practice, this language has evolved into a screening mechanism. Courts often begin by placing the claimed design drawings alongside the accused product and asking whether the overall visual impressions are so different that no reasonable jury could find infringement. If so, summary judgment may be granted without further analysis.

It was this approach that proved dispositive in the Range of Motion case.

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Range of Motion and Its Dissent

The Federal Circuit’s decision in Range of Motion illustrates the growing importance of this threshold inquiry. There, the court affirmed summary judgment of noninfringement, concluding the accused device was plainly dissimilar from the claimed design based on differences in proportions, contours, and surface features. The court did not proceed to a full ordinary observer comparison informed by prior art.

Chief Judge Moore dissented, offering a pointed critique with relevance to industries like medical robotics. Her dissent argues that the “plainly dissimilar” framing risks inverting the U.S. Supreme Court’s instruction in Gorham Manufacturing v. White, which asks whether designs are “substantially the same,” not whether they are different. By encouraging courts to focus first on differences, the dissent suggests, courts may prematurely foreclose cases in which a reasonable jury could find substantial similarity.

The dissent also highlights a cognitive concern. Once points of distinction are identified, they tend to dominate perception, even if the overall impression remains similar. In fields where designs are constrained by function, as in medical robotics, such differences are often inevitable and may not meaningfully alter how end users perceive competing products.

Underlying these critiques is an institutional concern as well. Design patent infringement is a fact-intensive, visual inquiry, traditionally reserved for juries. The dissent warns that the growing use of the “plainly dissimilar” threshold shifts too much decision-making from juries to judges, particularly in close cases.

Functionality and Claim Construction

Range of Motion also implicates a second, longstanding tension in design patent law: the role of functionality. Courts may, during claim construction, identify features that are “primarily functional” and effectively exclude them from the claimed design.

In medical robotics, functionality arguments are pervasive. Device contours may be dictated by biomechanics, sterilization requirements, or interface compatibility. Handles, joints, and housings often exist within narrow design parameters, leaving limited room for variation. 

The Range of Motion dissent characterized functionality in design patents as a fundamental factual inquiry rooted in visual perception and design alternatives. When courts excise large portions of a design before infringement analysis, particularly in function-heavy products, the remaining claim scope may be too thin to capture copying that would be evident to ordinary users.

Implications for Medical Robotics Companies

For medical robotics companies, Range of Motion underscores both the value and the fragility of design patent protection. Design patents remain powerful tools for protecting system aesthetics and user-facing components, but potential enforcement faces heightened challenges where courts perceive visual differences or functional constraints.

This environment places increased pressure on careful drafting and portfolio strategy. Effective approaches include:

• Precise drafting that clearly distinguishes ornamental features from functional necessity 
• Filing multiple related designs to capture incremental variations; and 
• Aligning design protection with utility patents and other intellectual property protections.

Strategic Takeaways

Design patents can play a meaningful role in medical robotics, where appearance influences adoption and competitive positioning. At the same time, Range of Motion signals a broader doctrinal shift toward early resolution of infringement disputes, especially through the “plainly dissimilar” threshold. 

For innovators operating in medical robotics and other function-driven design spaces, this shift may narrow the practical scope of protection. Going forward, therefore, design protection should focus on anticipating not only how competitors may emulate their products, but also how courts will judge similarity at first glance.

Peter C. Lando’s practice spans all areas of intellectual property and related transactions. He leads IP due diligence, negotiates licensing deals, prepares patentability and freedom-to-operate opinions, prosecutes enforceable patents, provides trademark registration and enforcement strategies, and advises clients on trade secret policies and protecting proprietary information.

David M. Roccio focuses on patent portfolio development and strategic IP counseling across diverse technologies, including 3D printing, robotics, manufacturing, networking, semiconductors, and digital imaging. He prosecutes U.S. and international patent applications and advises on licensing, transactions, opinion letters, due diligence, and reexamination proceedings.