Del Mar Engineering Laboratories v. Physio-Tronics, Inc.

Del Mar Engineering Laboratories (Del Mar) is the assignee of patent # 3,267,934. Claims one through eight of this patent relate to a device for measuring electrically the “ST segment” of the human heartbeat. Physio-Tronics, Inc., is the southwest distributor of Quinton Instruments, a Washington corporation. Del Mar brought this suit against Physio-Tronics alleging infringement of its patent by two devices produced by Quinton Instruments.

Physio-Tronics contends that the patent is invalid: first, because William Thornton, the original patentee, deceptively failed to disclose that he had made public use of a ratemeter, an unrelated device covered by claims 15 and 16 of the same patent; second, because the patent claims relating to the “ST segment” measuring device fail under the statutory defenses of anticipation and obviousness; finally, it contends that if the patent is valid, there was no infringement by the Quinton equipment. The trial judge concluded that the patent was valid and that it had been infringed. We affirm.

I. INVALIDITY OF THE PATENT FOR FAILURE TO DISCLOSE A PUBLIC USE

The statutory bar of 35 U.S.C. § 102 (b) prevents entitlement to a patent if there is a…