[6] On December 15, 2000, in the case of Free World Trust v. Électro Santé Inc., a decision was rendered by the Supreme Court of Canada on the infringement of patents 156 and 361.

[7] The case was even noted in Canada for setting out "the test for patent infringement" and "the principles of purposive claim construction".

[8][9] The court transcripts explain that Électro Santé Inc., a competitor, developed similar technology that used a microcontroller rather than the circuits.

Free World Trust sued Électro Santé for patent infringement on the ground that although the means may be different the result of the inventions were the same.

In this case, the essential elements of the two patents held by Free World included controls that regulated the electro-magnetic waves "by circuit means".

He states that one of the purposes of the Patent Act is to achieve fairness and predictability in order to promote research and development.

Binnie was hesitant for courts to attempt to find the "spirit of the invention" which would create more uncertainty and unpredictability.

His proposed "purposive construction" approach would avoid literal interpretation while limiting the scope of substantive claims in attempt to balance fairness between the patentee and the public.

In applying these principles to the facts of the case, Binnie found that Electro Sante's invention did not infringe upon Free World's patent.