What is patent eligible subject matter in United States patent law?

A patent is a set of exclusive rights granted to an inventor. If an inventor is granted a patent, the inventor is given the exclusive right to make, sell and use their invention. When a person other than the inventor, makes, sells, or uses a patented invention, that is know as patent infringement. The inventor can sue to stop patent infringement and get money damages for patent infringement.

Getting a patent is not a simple task. There are many requirements that an inventor must meet to get a patent on an invention. The invention must meet the patent requirements, including novelty, non-obviousness, written description, and enablement. But the fundamental requirement is that the invention be eligible subject matter for a patent. If the subject matter of an invention is not eligible for a patent, the invention cannot be patented in the United States.

The question then becomes what is patent eligible subject matter in the United States?

To be eligible for a patent the invention (1) must be directed to one of the four categories in United States patent law, and (2) the invention must not be one exceptions created by case law.

The four categories are:

Process – a series of acts or steps.
Machine – a concrete thing, consisting of parts, or of certain devices and combination of devices.
Manufacture – an article produced from raw or prepared materials by giving to these materials new forms, qualities, properties, or combinations, whether by hand labor or by machinery.
Composition of matter – all compositions of two or more substances and all composite articles, whether they be the results of chemical union, or of mechanical mixture, or whether they be gases, fluids, powders or solids.

Some examples of things which do not fall into the four categories are:

a human;
a legal contract;
a company;
data;
electrical signals;
an arrangement of printed material;
a computer program.

If an invention in a patent application contains a combination of one of the four categories along with something which is not in one of the four categories than the invention cannot be patented. The United States Patent Office would reject the patent application on the grounds that the patent application does not comply with 35 U.S.C. 101.

Even if an invention falls into one of the four categories, the patent application can still be rejected if a judge made rule in case law deems the invention unpatentable. Examples of judge made exceptions to eligible subject matter include: laws of nature, natural phenomena, and abstract ideas. Various different cases have held that the following are also not eligible subject matter, including physical phenomena, scientific principles, systems that depend on human intelligence alone, disembodied concepts, mental processes and disembodied mathematical algorithms and formulas. The rationale behind these exceptions are that basic tools of scientific and technological work cannot be patented.

A patent application can still be granted if the invention uses one of the judge made exceptions but the patent application does not seek to claim the judge made exception. For instance titanium is a naturally occurring mineral and could not be claimed in a patent, but using titanium for airplane wings or surgical tools might be patentable.

It is best to consult with an experienced patent attorney to help you draft your patent application in a way that avoids rejection on the basis that the subject matter is not eligible for a patent.

If you have questions or comments for the authors of this blog please contact us at: admin@uspatentlaw.cn