Portfolio Strategy
A medical device patent portfolio usually begins as a response to a single product: a founding invention, a provisional application, perhaps an international filing. As the company grows into a product line, adds manufacturing partners, and begins to attract investors or acquirers, that early collection of filings has to become something more deliberate. The question shifts from whether the company has patents to whether its patents protect the parts of the business that generate revenue, and whether they will hold up when someone examines them closely.
The most useful organizing principle for a device portfolio is the company's own roadmap. Each current and planned product, and each revenue line within it, should be traceable to specific patents and pending applications. Where a commercially important feature has no corresponding claims, that is a gap. Where the company is paying to maintain patents that cover abandoned designs or features no competitor would plausibly adopt, that is a cost without a corresponding benefit.
The mapping is worth repeating at each material change: a design freeze, a regulatory submission, a new indication, or a new market.
Device companies rarely depend on a single patent. A mature portfolio typically layers several kinds of protection, both within the patent estate and beyond it: design patents, trade secrets, trademarks and trade dress, copyright, and contract and data rights each protect something a utility claim may not. Core patents claim the fundamental architecture or mechanism of the device. Improvement patents cover later refinements, including changes made in response to clinical feedback, manufacturing experience, or regulatory requirements. Method-of-use claims can cover procedures and techniques, which may matter where the device itself becomes easier to design around, although 35 U.S.C. §287(c) bars infringement remedies against physicians and related health care entities for many medical procedures, so such claims are typically enforced against the manufacturer as induced or contributory infringement. Accessories, disposables, and consumables deserve particular attention, because for many device businesses the recurring revenue comes from single-use components rather than the capital equipment.
Layering means the expiration or invalidation of one patent does not leave the product line exposed. Each layer should be judged on what it covers, how easily it can be designed around, and whether infringement would be detectable.
U.S. continuation practice is one of the more valuable tools available to a device company. Under 35 U.S.C. §120, a later application can claim the benefit of an earlier application's filing date, provided the later application is filed before the earlier one is patented, abandoned, or otherwise terminated, and contains a specific reference to it. Keeping a family member pending allows the company to pursue new claims supported by the original disclosure, which can be drafted with the benefit of knowing what competitors have actually brought to market.
Two limits should be kept in view. First, a continuation does not extend patent term. Under 35 U.S.C. §154(a)(2), the term generally ends 20 years from the filing date of the earliest application referenced under section 120, 121, 365(c), or 386(c). Second, new claims must be supported by the original disclosure, so the initial specification should describe the alternative embodiments and foreseeable variations the inventors genuinely contemplate, while implementation details the company has deliberately chosen to keep as trade secrets stay out unless they are needed to support the claims.
Cost has also changed. Under the USPTO fee rule effective January 19, 2025, a continuing application filed six or more years after its earliest benefit date carries an additional fee of $2,700 ($1,080 for small entities), rising to $4,000 ($1,600 for small entities) at nine or more years. Current amounts should be confirmed against the USPTO fee schedule, but the structure makes long continuation chains a budgeting decision.
A U.S. utility patent requires maintenance fees at 3.5, 7.5, and 11.5 years after grant. Each fee may be paid without surcharge during the six months before its due date, and with a surcharge during a six-month grace period afterward. If a fee is not paid by the end of the grace period, the patent expires, subject to a petition to accept delayed payment where the delay was unintentional.
An annual portfolio review, with each maintenance deadline as the latest point for decision, keeps the budget concentrated on the rights that matter most. Foreign annuities, which in many jurisdictions are due annually, add up quickly across a family. A disciplined review asks whether the patent still reads on a current or planned product, whether it reads on a competitor's product, whether it supports a license or a financing, and whether it has value to a potential acquirer. Allowing a patent to lapse can be sound portfolio management, but it should be a recorded decision rather than an oversight.
Patents are territorial. In the United States, 35 U.S.C. §271(a) makes it infringement to make, use, offer to sell, or sell a patented invention within the United States, or to import it into the United States. Coverage decisions should therefore consider not only where the company sells, but where competitors manufacture and where devices are likely to be imported.
The main timing tools are well established. A U.S. application claiming foreign priority must generally be filed within 12 months of the earliest foreign application under 35 U.S.C. §119(a), and a nonprovisional must be filed within 12 months of a provisional to claim its benefit under 35 U.S.C. §119(e). An international application under the Patent Cooperation Treaty defers national and regional entry, typically to 30 months from the priority date under PCT Article 22, with some offices, including the European Patent Office, allowing 31 months. That deferral gives a growing company time to learn which markets will justify the translation and prosecution costs.
For foreign companies entering the U.S. market, a related question is whether U.S. filings drafted primarily for home-country practice would benefit from continuation claims written with U.S. competitors in mind.
Diligence reviewers generally want to see a clear schedule of patents and applications, their status and deadlines, the products each covers, and a clean record of ownership. They will also look for encumbrances, including licenses, security interests, and government or university rights. A portfolio that already maps patents to products and records the reasoning behind maintenance and coverage decisions tends to move through diligence with fewer surprises.
Ownership problems are among the most avoidable portfolio defects. In Board of Trustees of Leland Stanford Junior University v. Roche Molecular Systems, 563 U.S. 776 (2011), a university researcher had signed one agreement stating that he "agree[d] to assign" his rights and a later one stating that he "do[es] hereby assign" them. The Federal Circuit treated the first as a promise to assign in the future and the second as a present assignment; the Supreme Court affirmed the judgment, holding that the Bayh-Dole Act does not displace the basic rule that an invention belongs to its inventor unless rights are effectively assigned. Employment, consulting, and development agreements should be reviewed with that distinction in mind, particularly for founders, outside engineers, clinicians who contribute to design, and contract manufacturers.
Recording matters as well. Under 35 U.S.C. §261, an assignment is void against a later purchaser or mortgagee for value without notice unless it is recorded at the USPTO within three months of its date or before the later purchase or mortgage. Every inventor on every application should have a signed assignment, and every transfer from inventor to company, and between affiliated entities, should be recorded.
Many device companies, and especially those headquartered outside the United States, manage portfolios through local counsel in several countries. That arrangement works best when one advisor holds the overall view: a single docket of deadlines across jurisdictions, consistent claim strategy across a family, a shared record of prior art and positions taken during prosecution, and a common understanding of which products and markets the portfolio is meant to protect. Without it, local decisions that are reasonable in isolation can leave strong claims in one market and gaps in another.
Portfolio management is an ongoing discipline rather than a one-time project. Companies reviewing how their patents align with their products, markets, and plans for financing or exit may find it useful to discuss their situation with patent counsel. This article provides general information and is not legal advice for any specific situation.