In order for the United States Patent and Trademark Office (USPTO) to issue a patent, a patent examiner must find that the underlying invention is “useful” for purposes of 35 U.S.C. § 101. Specifically, that section states that a patent will only be granted for a “useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.” Utility is a requirement for utility patents, which are distinct from design patents, given that a “utility patent” protects the manner in which an article is used whereas a “design patent” protects an article’s shape, configuration or ornamentation.

Though utility is a condition precedent to the issuance of a utility patent, it is not difficult to show that an invention is useful in some way. In other words, for an invention to violate the utility requirement, it must be “totally incapable of achieving a useful result.” Thus, partial usefulness is all that is needed for an invention to satisfy the utility requirement, and the burden is on the USPTO to provide evidence showing that one of ordinary skill in the art would reasonably doubt the asserted utility. If the USPTO does this successfully, only then does the burden shift to the applicant to show that the claimed utility is in fact valid.

When a patent application does fail the utility requirement, it may be the result of the inventor’s failing to explicitly disclose the utility of the invention in the application, though this is not always necessary as utility can often be implicit. Inventions may also fail to meet the usefulness requirement where the stated use is not credible, e.g. a patent on a perpetual motion machine. Specifically, the logic underlying the invention itself must be sound, and the facts supporting the asserted utility are logically consistent with that utility. While these “impossibility” rejections are sometimes valid, it is not uncommon for a patent application deemed to fail the utility requirement is succeeded by an identical application that does meet the requirement. This is because evidence of the inventions utility may not have been readily available initially, but after time has passed evidence of its utility becomes available, allowing the applicant to adequately respond to an examiners rejection for lack of utility. Clinical products that require long testing and experimentation periods usually fall into this category, as it will be years before any credible evidence exists with which to combat the examiner’s rejection.

In practical terms, the best way to know if your invention is going to meet the utility requirement is to build a prototype and see if it works. It is for this reason that having built a prototype of the invention is all but necessary for a patent to issue on many types of inventions. To learn more about these initial phases of the patent application process, building a prototype, and to learn more about the utility requirement as a condition precedent to patentability, it is of course best to speak to an experienced patent attorney.