A: Here are some guidelines regarding patentability:

U.S. patent law specifies that a patent can be obtained for any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvements thereof. Inventions must satisfy three criteria to be patentable: utility, novelty and non-obviousness.

Utility: An invention must work in some beneficial way. Mechanical inventions must be operable. A specific use must be identified for chemical compositions. Drugs should be demonstrably effective.

Novelty: An invention cannot be considered novel if it has been known or used by others in the U.S. or patented or published by others anywhere in the world before the date of invention. A new use of a known invention may be novel, however. The relationship between publication and timing of the patent application filing is of the utmost importance. When and how the invention is publicly disclosed will affect the novelty criterion. A premature "public utterance" of the invention can destroy the right to patent.

Non-obviousness: An invention must not be "obvious" to "one of ordinary skill in the art." Since these are subjective terms, there is frequent disagreement about the fulfillment of this requirement, particularly between the patent applicant (typically through a patent attorney) and the U.S. Patent and Trademark Office. This criterion must be assessed on a case-by-case basis and expert legal opinion is essential.