In reversing and remanding the district court ruling on summary judgment, the U. S. Court of Appeals for the Federal Circuit sorted through competing dictionary definitions to find the district court erred in its claim construction. Tehrani v. Hamilton Medical, Inc., Case Nos. 02-1177, -1178, -1227 (Fed. Cir. July 13, 2003).
The patent in suit (the `268 patent) relates to an apparatus and method for automatically controlling a respirator used for mechanical ventilation of a patient who needs assistance in breathing. The claimed apparatus controls the number of breaths delivered to the patient per minute (breath frequency) and the volume of gas delivered with each breath (tidal volume or ventilation) by calculating the proper breath frequency and tidal volume based on data representing at least five factors: air viscosity in the lungs, lung elastance, barometric pressure, oxygen level of the patient and carbon dioxide level of the patient.
