Tehrani v Hamilton Bonaduz AG & Ors [2021] EWHC 3457 (IPEC)

22 December 2021

Henry Ward successfully appeared for the defendants (“Hamilton”) in proceedings brought by Professor Tehrani for the infringement of her patent relating to the method and apparatus for controlling a ventilator.  Hamilton counterclaimed for revocation of the patent on the grounds of lack of novelty, lack of inventive step and insufficiency.

The patent related to the method and apparatus for automatically controlling the mechanical functions of a ventilator, thereby improving the oxygenation of patients during ventilatory therapy.  Specifically, the claims covered the processing of data to measure oxygen levels and produce output data to control positive end-expiratory pressure, the required concentration of oxygen in the patient’s next breath, breathing frequency and the inhalation-exhalation ratio.  Professor Tehrani alleged that Hamilton’s Intellivent-ASV System infringed the patent.

Hacon HHJ held that when Hamilton’s System was being used to increase the treatment level of the patient it fell within the normal construction of claim 1 of the patent.  However, the patent lacked novelty and inventive step in light of a paper published 8 years before the priority date.  The paper described a system using a closed-loop, computer controlled, algorithm that allows for automated changes.

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