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Note: First published by ALM / in The Intellectual Property Strategist


Recent developments at the Federal Circuit and the USPTO can inform evolving patent strategy on medical technology. In one case, the Federal Circuit invalidated a patent relating to catheter insertion technology. In addition, the Patent Trial and Appeal Board (“PTAB”) considered subject matter eligibility of medical technology inventions in two decisions issued less than a year apart. In the first decision, the PTAB saved claims involving medical device location. In the second decision, the PTAB affirmed a final rejection of claims involving heart failure stratification.


In a decision that may have escaped due attention, the Federal Circuit provided another reason for medical technology companies not to delay patent application filings. One basis for early action has been legal consequences arising from preparations for marketing and sale of a medical device invention, including regulatory compliance. In this regard, medical technology companies should be familiar with patent validity issues that can arise for a medical device invention through, for example, an early 510(k) summary or even a referenced predicate device. Recently, the Federal Circuit has provided a reminder that sales and marketing activities in other contexts also can bar patent rights on medical technology.

In Junker v. Medical Components, Inc., 2021-1649 (Fed. Cir. 2022), the Federal Circuit decided the issue of whether commercial activities relating to a medical device prior to the critical date invoked the on sale bar of pre-AIA 35 U.S.C. § 102(b). The inventor created a new design for an peelable introducer sheath based on his experience with catheter insertion procedures. In particular, the inventor focused on the design for the handle of a peelable introducer sheath, which facilitated handling of the peelable introducer sheath during catheter-insertion procedures.

Prior to the critical date, a business partner of the inventor conveyed a letter to a potential buyer of the peelable introducer sheath. The letter provided a price chart for the peelable introducer sheath that specified various purchase options and associated order quantities. The letter characterized itself as a “quotation.” The letter concluded with an invitation to discuss the potential buyer’s specific requirements. Because the parties in the litigation agreed that the patented design of the peelable introducer sheath was ready for patenting at the time of the letter, the only remaining issue was whether the letter constituted a commercial offer for sale to trigger the on sale bar. Although it acknowledged specific terms provided in the letter, the district court found that use of the word “quotation” indicated that the letter reflected preliminary negotiations instead of a definite offer.

The Federal Circuit reversed, applying traditional contract law principles and thus finding that the letter was a commercial offer for sale. The Federal Circuit found that the letter was a response to a request for a quotation and constituted a specific offer, not merely an invitation to negotiate. Further, the Federal Circuit found that the letter contained necessary terms that are typically included in a commercial contract, such as shipment conditions relating to the peelable introducer sheath. The Federal Circuit also noted the letter’s inclusion of different purchase options and specified volume based discounts. Based in part on these considerations, the Federal Circuit ruled that the requirements of an on sale bar were satisfied, invalidating the patent on the peelable introducer sheath design.

While Junker v. Medical Components, Inc. is premised on pre-AIA section 102(b) in relation to a design patent, its rationale should apply equally to design patents and utility patents alike under AIA law. In view of this decision, medical technology companies are reminded that commercial activities can erase patent rights. Commercial communications with specific terms, even those that are carefully crafted as invitations to continue discussions toward a possible transaction, can invoke the on sale bar. Thus, for inventions warranting patent protection, medical technology companies should move swiftly to file patent applications, especially if contemporaneous marketing or commercial activities are planned.


Occasionally, the PTAB will reverse an examiner’s final rejection. Rarer still is reversal of a final rejection based on Alice Corp. v. CLS Bank Int’l, 573 U.S. 208, 216 (2014). In Ex parte Loose, Appeal 2022-001026 (PTAB June 6, 2022), the PTAB did both in the context of medical device technology. However, less than a year later, the PTAB in Ex parte An, Appeal 2022-004092 (PTAB March 29, 2023) affirmed under Alice a final rejection of claims directed to heart failure stratification. Ex parte Loose and Ex parte An are an informative contrast on disparate subject matter eligibility outcomes.

A. Ex parte Loose

The invention in Ex parte Loose involved assignment of a medical device from a data network to a physical location. Claim 1 recited an extensive method including nine steps that utilize a medical device, a data network interface, a data network device, a data network, and active network components (e.g., routers). In claim 1, various messages (e.g., data network messages, a group message, request messages, an acknowledgement message) are exchanged among the various network devices and various data sets are provided. Claim 1 culminated in assignment of the medical device to a patient data set that identifies a patient. The recitations of claim 1 alone spanned more than a page.

During prosecution, the examiner determined that the claims recited providing an assignment of a medical device to a physical location in an automated manner to transfer and display data associated with a patient. As such, the examiner rejected the claims under Alice as a mental process. The examiner further determined both the absence of integration into a practical application and the absence of “significantly more.”

The PTAB disagreed. First, the PTAB signaled its ultimate decision by citing the prohibition set forth in Alice against characterization of patent claims at an unduly high level and untethered from claim language. The PTAB then interpreted the claim as a “method [that] comprises providing a data network device, i.e., a hardware device, that sends and receives data network messages, e.g., data packets, from a plurality of active network hardware components, e.g., routers, and analyzes that information, in conjunction with stored data, to assign a medical device to a physical location and, thereby, to a patient data set, which identifies a particular patient.” With that interpretation, the PTAB found that the claims involved steps, such as “polling hardware components by sending and receiving data network messages,” that as a practical matter reasonably could not be performed in the human mind.

The PTAB also rejected the position of the examiner that the claimed invention merely automated assignment of medical devices to physical locations. The PTAB noted that conventional techniques involved direct manual entry of location data into a medical device itself. The PTAB contrasted these conventional techniques from the claimed invention by underscoring that the conventional techniques did not rely on message exchange or network device communications as did the particular process recited in the claims. 

B. Ex parte An

Less than a year after, the PTAB in Ex parte An affirmed a final rejection of another invention on medical related technology. In Ex parte An, the invention related to quantification of a risk of worsening heart failure (WHF) by using a physiological sensor circuit, such as a heart sound sensor circuit and a respiration sensor circuit. Claim 1 recited as follows:

  • A system comprising:
    • a heart sound sensor circuit configured to receive a heart sound signal of a subject;
    • a respiration sensor circuit configured to receive a respiration signal of the subject;
    • a control circuit including:
    • a signal processing circuit configured to:
    • produce a plurality of S3 heart sound measurements using the received heart sound signal;
    • determine a daily S3 heart sound value using the plurality of S3 heart sound measurements;
    • produce a plurality of respiration rate measurements using the received respiration signal; and
    • determine a representative respiration rate using the plurality of respiration rate measurements; and
    • a risk stratifier circuit configured to assign a risk category of worsening heart failure (WHF) for the subject using the representative respiration rate and the daily S3 heart sound value; and
    • a display configured to present an alert of the risk category to a user.

During prosecution, the examiner determined that the claims recite an abstract idea by providing “steps for determining daily, representative, or central tendency measurements of various parameters, and assigning a risk category of WHF for the subject using the daily, representative or central tendency measurements.” According to the examiner, the steps – apart from generically recited computer components and mathematical concepts – could be performed in the human mind. The examiner further determined that the additional elements in the claims were insufficient to constitute integration of the abstract idea into a practical application.

The PTAB affirmed. As to Prong One, the applicant inexplicably did not contest the examiner’s finding of an abstract idea. As a result, the PTAB found no error there. As to Prong Two, the PTAB indicated that the additional elements beyond the judicial exception included circuits configured to implement steps of the abstract idea and a display to present an alert. The PTAB characterized the circuits and display as “merely” generically recited computer components that

generally link use of a judicial exception to a certain technological environment or field of use. In explaining its decision, the PTAB stated that the specification of the application at issue described only generic computer components. For example, the PTAB pointed to a pertinent figure of the application that included a sensor circuit representative of a heart sound sensor circuit and a respiration sensor circuit that was depicted as a black box. In concluding its analysis of Prong Two, the PTAB rejected the applicant’s contention that the combination of daily S3 heart sound and respiration rate provided an improvement to the relevant technology or technical field of device based patient monitoring and WHF risk stratification. In addition to the PTAB’s position that the claimed circuits and display were generic computer components performing generic computer functions, the PTAB rejected the applicant’s contention because the combination of daily S3 heart sound and respiration rate were covered by the abstract idea, not the additional elements that should be the focus of the Prong Two inquiry.

After concluding that the claims were directed to an abstract idea, the PTAB next considered under Step 2B whether the additional elements of the claims amounted to an inventive concept. For this inquiry, the PTAB once again emphasized that the generically recited circuits and display performed basic computer functions that could be performed by a generic computer. As a result, the PTAB did not find anything that was “significantly more” than an instruction to apply the abstract idea to a generic computer.

C. Lessons

The examiner in Ex parte Loose embraced a broadest reasonable interpretation that characterized claimed functionality that was quintessentially non-human as somehow performable by the human mind. In response, the PTAB provided a helpful, albeit rare, check on that exuberance by recognizing significant technical detail recited in the claims. By comparison, Ex parte An involved functionally recited claims with little, if any, implementation detail. Nor could the specification support more detail, given its disclosure of a generic computer. As a result, the absence of technical specificity doomed the claims to subject matter ineligibility. 

These decisions suggest that, if Alice issues potentially arise, draft and amend claims with a certain level of technical specificity, a standard that is often achievable with medical technology. For example, the mechanisms that receive, analyze, manipulate, convey, and transform signals, biomarkers, or other types of medical or physiological expression, and their technical function, can be specified in the claims to avoid Alice. As another example, if there is an actual circuit or a hardware configuration to potentially claim, ask your inventors to proceed beyond a black box description. Once a certain level of detail is recited that reasonably excludes human performance, your claims will be more clearly eligible. At the same time, the rationale of Ex parte Loose can be leveraged to remind your examiner that the reach of Alice has recognized limits.


These Federal Circuit and PTAB decisions inform pre-filing and post-filing patent strategies for medical technology companies. Junker v. Medical Components, Inc. warrants caution in early marketing and sales activities. In this regard, pre-filing communications relating to an invention, potentially even those crafted to preserve patent rights, can implicate the on sale bar. Ex parte Loose and Ex parte An illustrate disparate outcomes under Alice based on claim scope. Your ability to resort to narrower claims to avoid Alice during prosecution may well depend on effective planning at the drafting stage.