What Subject Matters Can be Protected by Patents in the US?

by Manni Li

As a patent attorney, I frequently get asked the question: "I have this great idea (or invention), can I get a patent on it?"  Well, the answer is a little more complicated than it seems.  So here is what I can provide:

First of all,  there are three types of patents in the US that cover different subject matters, or types of invention.  The first and most commonly used one is "utility patent," which is the equivalent of an "invention patent" in other countries and covers most subject matters.  The second one is a design patent that is directed to the protection of ornamental designs - only the design, not any functional part of the invention.  And the third type of patent is a plant patent that covers asexually reproduced plants.

Let's focus on the utility patent in the US.  What are the subject matters that may be patented in a utility patent?  The US patent laws have a threshold requirement that the claims, which defines the scope of protection in a patent, must fall into one of the four categories: process, machine, manufacture, or composition of matter; and in addition, any new and useful improvement thereof.   This is a threshold requirement because any invention protected by a patent must fall into one of the categories in addition to the requirements that the invention must also be new and useful.

These four categories of patentable subject matters are self-explanatory.  However, being in one of the categories is not enough. Based on the decisions from the courts, there are three judicially created exceptions to the patentable subject matters.  The judicial exceptions are subject matters that the courts have found to be outside of, or exceptions to, the four statutory categories of invention, and are limited to abstract ideas, laws of nature, and natural phenomena.   Because abstract ideas, laws of nature, and natural phenomena are the basic tools of scientific and technological work, the courts have expressed concern that monopolizing these tools by granting patent rights may impede innovation rather than promote it.

The exception of abstract ideas include (1) mathematical concepts – mathematical relationships, mathematical formulas or equations, mathematical calculations; (2) certain methods of organizing human activity – fundamental economic principles or practices (including hedging, insurance, mitigating risk); commercial or legal interactions (including agreements in the form of contracts; legal obligations; advertising, marketing or sales activities or behaviors; business relations); managing personal behavior or relationships or interactions between people (including social activities, teaching, and following rules or instructions); and (3) mental processes – concepts performed in the human mind (including an observation, evaluation, judgment, opinion).

The exceptions of the laws of nature and natural phenomena include naturally occurring principles/relations and nature-based products that are naturally occurring or that do not have markedly different characteristics compared to what occurs in nature. The courts have often described these exceptions using other terms, including "physical phenomena," "scientific principles", "natural laws," and "products of nature."

As an applicant, what can you do when the claims you are seeking to protect your invention are found by the Patent Office to be directed to one of those exceptions?  While an abstract idea, law of nature, or mathematical formula can not be patented, the courts have said that "an application of a law of nature or mathematical formula to a known structure or process may well be deserving of patent protection."    Based on the court decisions, the Patent Office applies a two-step analysis to determine if the invention is directed to something more than the unpatentable exceptions so that they are entitled to patent protection.  The two-step analysis is rather complicated and involves multiple sub-steps.  We will discuss the two-step analysis and how to draft the claims to protect your invention in the way that they are directed to patentable subject matters in subsequent articles.