Executive Summary: Key Legal and Evidentiary Issues

• Central issue concerned whether Simplot’s use of pulsed electric field (PEF) technology infringed McCain’s patent.

• Claims construction focused on terms like “high electric field” and “resistance to cutting.”

• Expert testimony was pivotal, especially on how the person of ordinary skill in the art (POSITA) would interpret the patent.

• Simplot raised alternative invalidity defences, including overbreadth and lack of utility.

• The Court excluded part of an expert’s evidence for failing to apply proper legal principles.

• No infringement was found, and McCain’s claims were dismissed in their entirety.

Facts and outcome of the case

McCain Foods Limited brought a patent infringement action against J.R. Simplot Company and Simplot Canada (II) Limited, alleging that Simplot’s method of processing potatoes using pulsed electric field (PEF) technology infringed Canadian Patent No. 2,412,841 (the ’841 Patent). Both companies manufacture and sell frozen French fries. McCain claimed that Simplot’s process, which involves treating potatoes with PEF before cutting, fell within the scope of its patent, which described applying a high electric field to vegetables or fruit to reduce resistance to cutting, under conditions that avoid any significant temperature increase.

The dispute hinged largely on how key terms in the patent should be interpreted. McCain argued for a broad interpretation that would include PEF technology, while Simplot contended that the patent was limited to lower electric field strengths and did not cover the PEF method it used. The Federal Court carefully analyzed the expert testimony, focusing on how a hypothetical skilled person in the field of food process engineering would understand the patent at the time of its publication.

Justice McHaffie concluded that a skilled person would not interpret the term “high electric field” to include the intense, short-duration pulses characteristic of PEF technology. Instead, they would understand the patent to refer to electric fields in the range of approximately 2 to 200 V/cm—well below the levels used by Simplot. Consequently, Simplot’s process did not infringe the patent. The Court also found that if McCain’s broader interpretation were accepted, the patent would be invalid due to overbreadth and lack of demonstrated utility.

In terms of procedural issues, the Court admitted most of the expert evidence but excluded portions of one expert’s report that failed to adhere to the principles of patent construction. Although Simplot had filed a counterclaim, it withdrew it at trial, so it was dismissed along with McCain’s main action.

The Court awarded a lump sum of C$1,700,000 in costs to Simplot, as agreed upon by the parties. No damages were awarded to either side. McCain’s action was dismissed in full.