MÖLNLYCKE HEALTH CARE AB v BRIGHTWAKE LIMITED

Experimental evidence in patent proceedings includes technical imaging where its production requires sample preparation and the exercise of judgment. A party must give the prescribed notice, identifying both the experiment and the facts it seeks to establish. The notice regime protects against surprise, enables inspection or repetition, and permits the opposing party to answer the evidence. Non-compliance does not invariably require exclusion. The court may admit the evidence in special circumstances, including where exclusion would prevent the issues being fairly determined. Failure to give notice, and failure to repeat an experiment, may instead affect the weight given to it. The regime must nevertheless be applied strictly and should not be weakened by routine admission of late evidence.

The claimant, MÖLNLYCKE HEALTH CARE AB, brought patent infringement proceedings against BRIGHTWAKE LIMITED. Shortly before trial, the claimant served approximately 40 to 50 electron micrographs and sought to rely on them in support of its case concerning the structure and permeability of the defendant’s products.

The defendant applied to exclude the micrographs. The issue was whether they were photographs, for which notice had been given, or experiments, for which the required notice had not been served. The claimant argued that the techniques were standard and that the evidence should be admitted. The defendant relied on the absence of notice, the absence of witnessed repetition, and the resulting forensic prejudice.

The central issue was whether the micrographs constituted experiments requiring notice and, if so, whether the court should nevertheless admit them.

1. The application to exclude was dismissed. The electron micrographs were admitted, without an order for repetition. Their lack of repetition was left to affect the weight of the evidence and could ultimately result in the evidence being given no weight.
2. Practice Direction 63, part 7.1 used mandatory language. The applicable direction was likewise mandatory. Experimental proof includes an exercise requiring judgment by the operator. The fact that the resulting material takes the form of images does not create a meaningful distinction between a photograph and an experiment. The preparation of samples and their examination by scanning electron microscopy therefore constituted experiments: Consafe v Emtunga [1999] RPC 154.
3. The notice regime serves more than the possibility of repetition. It requires a proper explanation of what was done and identifies the facts which the experiment is intended to establish. This enables the opposing party to understand the case, investigate the evidence, obtain responsive evidence, and decide whether repetition or inspection is required.
4. The approach in Monsanto v Cargill [2008] FSR 7 recognised both that straightforward experiments may not always require repetition and that the regime for managing experimental evidence must not be weakened. The court accepted that the claimant should have served notice, but considered that repetition might not have been necessary and that the defendant had itself failed adequately to address the infringement issue concerning the old product.
5. Admission was therefore the fair case-management outcome. The evidence was admitted reluctantly, with the warning that late and unrepeated experimental evidence might receive little or no weight. A proposed preliminary inquiry concerning the old product was refused because the trial was already taking place and there might be no inquiry if the patent were invalid or the new product were held not to infringe.