Section 40(7) provides that in any proceedings for infringement, other than criminal proceedings, where the subject matter of the patent is a process for obtaining a product, the burden of establishing that the product was not made by the process shall rest on the defendant if
(a) the product is new; or
(b) a substantial likelihood exists that the product was made using another process and the patentee has been unable, through reasonable efforts, to determine the process used.