Invention Analysis and Claiming: Problem-Solution-Based Claims¹

Ronald Slusky mentored dozens of attorneys in “old school” invention analysis and claiming principles over a 31-year career at Bell Laboratories. He is now in private practice in New York City. This article is adapted from his book “Invention Analysis and Claiming: A Patent Lawyer’s Guide” published by the American Bar Association and available at ababooks.org. Ron can be reached at 212-246-4546 and rdslusky@verizon.net

Previous columns advanced problem-solution analysis as a powerful paradigm for surfacing the concept underlying an invention. Central to that analysis is the problem-solution statement—a one-sentence definition of the invention, stating as broadly as possible a) the problem the invention solves, and b) the inventor’s solution to that problem, but without the overall problem-solution statement reading on the prior art.

Here, for example, is a problem-solution statement for L’Esperance’s pioneering invention for laser-surgery eyesight correction²:

The problem of correcting sight is solved by operating solely upon the anterior surface of the cornea of the eye using selective ultraviolet irradiation and attendant ablative photodecomposition of the anterior surface of the cornea in a volumetric removal of corneal tissue and with depth penetration into the stroma and to a predetermined curvature profile.

In this column we look at a technique that transforms the problem-solution statement into a broad claim directed to the inventive concept.  That such a technique exists should come as no surprise. A claim is a definition, defining the metes and bounds of the parcel of intellectual property the inventor seeks to own. A definition is made up of words.  Thus the words that inform that definition ought to be pretty much the same, no matter what format we may use to define an invention, be it a problem-solution statement or a claim.

The Three Steps

Problem-solution claim drafting transforms the problem-solution statement into a claim in three steps that will readily produce claim(s) as broad as the problem-solution statement itself:

• Remove the problem-related language including the boilerplate "The problem of…is solved by,” but retain language defining the environment or context in which the problem arises.
• Stitch the remaining language into one or more claims, adding as few words as possible.
• Compare the resulting claim(s) to the problem-solution statement to verify the accuracy of the transformation.

The reader may be skeptical. It is not uncommon, after all, to spend an hour or more drafting and re-drafting a broad claim when writing it from scratch in the attempt to get everything “just right.” How can a handful of cookbook-like steps so easily bypass all of the critical thinking that typically goes into the drafting of a broad a claim?

Actually, none of that critical thinking is bypassed.  We have already brought our best thinking to bear in identifying the problem and the solution and refining them into a sharply focused problem-solution statement.  In patent work, as in life generally, there is no free lunch.  But by this point we've already paid for lunch.

Example of the Technique

A problem in microwave ovens is that standing waves at fixed locations within the oven cavity (main chamber) create “hot spots” where the food is heated more intensely. If nothing else were done, this would result in uneven heating. The solution is to engender relative motion between the food and the microwave energy source, such as by revolving the food on a turntable, so that as much of the food as possible gets its fair share of that more intense energy. Here is the problem-solution statement:

The problem of non-uniform heating of food in a microwave oven cavity is solved by engendering relative motion between the food and the microwave energy source during the heating process.

And here are the steps of the methodology, used in this particular case to produce both method and apparatus claims. Underscoring indicates words added in the stitching process.

Questions and Answers

Q: Why is the stitching step made so constraining?

A: We worked hard to formulate a problem-solution statement that defines the invention in words that are "just right."  This is not the time to get overly creative.  It is all too easy for the effort expended in bringing the problem-solution statement hard up against the prior art to become compromised if we stray too far from its original language.  There is plenty of opportunity for creativity when we use other approaches to draft further claims for the patent application.

Q: Are there no options?

A: A few limited options are available when carrying out the stitching step:

• Preamble: Some of the problem-solution statement language can be put into the preamble or it can all be left for the body of the claim.
• Rearrangement/repetition: Rearrangement is fine as long as the relationships among the elements of the problem-solution statement are preserved. Repeating a few words or phrases may also be necessary to make the claim hang together.
• Statutory claim type: The problem-solution statement can be transformed into one or more of the statutory claim types, such as the method and apparatus claims of the example above.
• Structural elements vs. means-plus-function:  Apparatus claims may recite one or more of its elements as structural components or as means-plus-function components.

Q: Why is the problem-related language removed?

A: A claim reading on prior art is unpatentable whether or not the prior art solves the problem the inventor was concerned about.³ Thus words in a claim that define the problem to be solved do not enhance its patentability and, accordingly, are surplus. The recited combination of elements or steps must distinguish the invention on its own merits without regard for the problem it solves.
Problem-defining language can actually be damaging.  Potential infringers may assert that they solve a different problem from what’s stated in the claim.  And they will then argue that if the inventor did not intend the invention to be limited to solving any particular problem, the claim would not have included it.
Meritorious or not, there is no point in opening the door to this kind of attack. 

Q: Why is language defining the environment or context retained?

A: Language in the problem-solution statement defining the context or the environment is necessary to define the invention.  We would otherwise have eliminated it when vetting the problem-solution statement.

In the microwave oven invention, as it turns out, distinguishing over the prior art requires defining the invention in the context of a microwave oven cavity. Indeed that context-defining term was not removed during step 1.

Q: Why is Step 3 necessary, given that the claim was produced so directly from the problem-solution statement?

• A: We want to assure ourselves that the transformation to claim form was carried out accurately and that nothing untoward has happened that would compromise the breadth of the invention as claimed, such as the addition of new elements, relationships among elements or new modifiers (adjectives or adverbs). 
• If the steps of the methodology have been followed carefully, none of these potentially narrowing changes should have occurred.

The Myth Of The “Too-Short” Claim

Problem-solution-based claims are typically short—a consequence of our efforts to minimize the number of limitations in the problem-solution statement.

A short claim is better than a long one.  However, we sometimes hear that examiners don't "like" claims that are too short.  They "like" to see lots of structure, and lots of claim elements.  In short, lots of limitations. As a result some practitioners do not claim the invention as broadly as they could, anticipating that unless the claim looks "long enough," the examiner will object to the claim based on its being, for example, “functional.”

This does a disservice to the client.  The fact that claim language may be functional, for example, is not a proper grounds of rejection.⁴ We have already assured ourselves that the problem-solution statement defines subject matter that is "statutory," "novel" and "non-obvious."⁵  Therefore, a claim based on that problem-solution statement should equally pass muster, no matter how few words or individual claim elements the claim contains. 

Next month: Drafting “infringeable” claims by focusing on the “Opposing Team.”

Endnotes