A recent decision of the U.S. Court of Appeal for the Federal Circuit highlights the importance of the description in a patent specification and, in particular, that descriptions lacking technical detail to explain the invention will not stand up to scrutiny.

Patents can only be obtained for eligible subject matter such as a process, machine, manufacture, or composition of matter. Patents cannot be obtained for abstract ideas. The U.S. Supreme Court in Mayo and Alice set out a two-step test for subject matter eligibility.1 The first step asks whether claims of a patent are directed to a patent-ineligible concept. If the claims are directed to a patent-ineligible concept, then the analysis proceeds to the second step. The second step asks whether the claim elements contain an "inventive concept" sufficient to "transform" the nature of the claims into a patent-eligible application.

In Vehicle Intelligence and Safety LLC v. Mercedes-Benz USA, LLC (Fed. Cir. 2015), the Federal Circuit affirmed the judgment of the Northern District of Illinois, which applied the Mayo/Alice test and invalidated the claims for being drawn to ineligible subject matter.2 On appeal, the Federal Circuit unanimously held that the "claims cover only abstract ideas with routine data-gathering steps and conventional computer activity". The patent at issue claims methods and systems for screening equipment operators by an "expert system" for impairment, selectively testing those operators, and controlling the equipment if impairment is detected.

In applying the Mayo/Alice test, the Court considered the claims as well as the description. At the first step, the Court found that the claims are directed to the "abstract idea of testing operators of any kind of moving equipment for any kind of physical or mental impairment". The Court also examined the description but found no technical details as to how the "expert system" actually works or how the "expert system" provides faster, more accurate and reliable impairment testing. The description lists characteristics that may be measured and used, but fails to explain technical details such as how the characteristics are measured, how impairment is determined based on the measured characteristics, how a control response is selected based on the impairment, and how the selected control response is effected.

At the second step, the Court found that the claims do not "disclose an inventive concept sufficient to transform the abstract idea of testing operators of any kind of moving equipment for any kind of physical or mental impairment into a patent-eligible application of that idea." Here, the Court rejected the argument that the claimed methods are embedded in "specialized existing equipment modules". Again, finding that the description does not explain how the methods can be embedded into existing modules, or even what the hardware and software differences are, the Court held that the claims are not saved from abstraction.

Similar fate in Canada

The Vehicle Intelligence claims would have likely suffered a similar fate of invalidity in Canada. In Canada, subject matter eligibility is assessed based on a purposive construction of the claims to define the invention.3 Each claim element is determined to be essential or inessential and then only the essential elements are considered to define the invention. The Canadian Intellectual Property Office determines essentiality based on an identified problem and solution.4 The identification of the problem and solution is guided by the common general knowledge in the art and by the description.

Here, the Vehicle Intelligence claims may solve the problem related to screening equipment operators for impairment. Although the claims recite an "expert system", this element does not have a plain, common, and unambiguous meaning to a person of ordinary skill in the art. No details are provided in the claims or the description about how exactly the "expert system" is technically implemented. This lack of detail regarding technical implementation may be regarded as merely an idea to use an "expert system".5 Accordingly, the "expert system" itself may be found to lie outside the definition of the invention and the claims may be regarded as not defining a specific manner of operating the solution.

It's all in the detail

Vehicle Intelligence is a reminder to ensure that patent descriptions are written with technical details. First, technical details address the written description requirement, which requires the patent specification to describe the invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the invention.6 Second, technical details can help steer clear of indefiniteness objections for failing to particularly point out and distinctly claim the invention.

Finally, as seen in Vehicle Intelligence, technical details may save claims from being drawn to ineligible subject matter. In the first step of the Mayo/Alice test, technical details showing how the invention works may save claims from being drawn to abstract ideas. In the second step, technical details disclosing how the system can be implemented may transform an abstract idea to a patent-eligible application of an abstract idea; merely being tied to particular machines does not save claims from being directed to ineligible subject matter.

As much as patents are legal documents, patents are also technical documents. A valid patent cannot shy away from technical details. Inventors should be prepared to dive – and dive deep - into the subject matter with their patent agents to grasp the technical details of how an invention works. Then, ensure that those technical details are provided in the patent specification for valid and enforceable protection of the invention.


1. Mayo Collaborative Services v. Prometheus Laboratories, Inc., 132 S. Ct. 1289 (2012); Alice Corp. Party v. CLS Bank International, 134 S. Ct. 2347 (2014).

2. Vehicle Intelligence and Safety LLC v. Mercedes-Benz USA, LLC, Daimler AG (Fed. Cir. 2015), available at http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/15-1411.Opinion.12-22-2015.1.PDF.

3. Free World Trust v. Électro Santé Inc., 2000 SCC 66; Whirlpool Corp. v. Camco Inc., 2000 SCC 67.

4. Canadian Intellectual Property Office, Examination Practice Respecting Purposive Construction – PN2013-02 (March 8, 2013), available at https://www.ic.gc.ca/eic/site/cipointernet-internetopic.nsf/eng/wr03626.html.

5. Canadian Intellectual Property Office, Examination Practice Respecting Computer Implemented Inventions – PN2013-03 (March 8, 2013), available at https://www.ic.gc.ca/eic/site/cipointernet-internetopic.nsf/eng/wr03627.html.

6. Moba, B.V. v. Diamond Automation, Inc., 325 F.3d 1306, 1319, 66 USPQ2d 1429, 1438 (Fed. Cir. 2003).

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.