Hess v. Advanced Cardiovascular Systems, Inc.
United States Court of Appeals for the Federal Circuit
106 F.3d 976 (1997)
Doctors Simpson and Roberts, developing a balloon angioplasty catheter, struggled to find a suitable balloon material and consulted Hess (plaintiff), an engineer with no prior angioplasty experience; Hess suggested a heat-shrinkable RayChem material, demonstrated a generally known heating process to form it into a balloon, and provided samples the doctors used in development. The doctors ultimately built the working balloon using a different process, called free-blowing, that Hess never suggested, and after patenting the catheter they assigned it to Advanced Cardiovascular Systems (ACS) (defendant); Hess sued to be added as a co-inventor on the patent, but the district court found his contributions didn't rise to the level of conception, and Hess appealed.
Whether suggesting an existing commercial material and demonstrating a generally known process for using it, without contributing to the process the inventors actually used in the final product, establishes patent co-inventorship.