making , ▁construct ing , ▁using , ▁and ▁s elling " ▁should ▁be ▁read ▁in ▁the ▁context ▁of ▁their ▁French ▁counter parts , ▁" fab ri quer , ▁constru ire , ▁explo iter ▁et ▁v endre ". ▁This ▁has ▁affected ▁the ▁interpretation ▁of ▁the ▁term ▁" use " ▁in ▁cases ▁involving ▁pat ent ▁in fr ing ement . ▁ ▁M aking , ▁construct ing , ▁and ▁s elling ▁Before ▁an ▁in fr ing ement ▁can ▁be ▁established , ▁it ▁is ▁necessary ▁ ▁to ▁construct ▁the ▁claims ▁to ▁determine ▁what ▁elements ▁of ▁the ▁in vention ▁are ▁essential ▁and ▁which ▁are ▁non - ess ential . ▁Once ▁the ▁essential ▁elements ▁are ▁established , ▁making , ▁construct ing ▁or ▁s elling ▁something ▁that ▁copies ▁the ▁essential ▁elements ▁will ▁be ▁considered ▁in fr ing ing . ▁ ▁Pur pos ive ▁construction ▁of ▁claims ▁Canadian ▁pat ents ▁should ▁be ▁given ▁a ▁pur pos ive ▁construction . ▁The ▁words ▁used ▁by ▁the ▁invent or ▁are ▁read ▁in ▁a ▁manner ▁consistent ▁with ▁what ▁it ▁is ▁pres umed ▁the ▁invent or ▁intended ; ▁the ▁interpretation ▁should ▁be ▁sympath etic ▁to ▁the ▁express ▁or ▁implicit ▁purpose ▁of ▁the ▁pat ent . ▁The ▁invent or ' s ▁intent ▁must ▁be ▁based ▁on ▁the ▁pat ent , ▁the ▁court ▁is ▁not ▁allowed ▁to ▁use ▁extr insic ▁evidence ▁of ▁the ▁invent or ' s ▁intent . ▁Cour ts ▁should ▁not ▁take ▁a ▁purely ▁literal ▁interpretation ▁of ▁the ▁pat ent , ▁courts ▁should ▁determine ▁whether ▁a ▁Person ▁Sk illed ▁in ▁the ▁Art ▁would ▁conclude ▁that ▁strict