EXHIBIT 10.15 SECOND AMENDMENT TO EMPLOYMENT AGREEMENT This Second Amendment ("Amendment") to the Employment Agreement ("Agreement"), dated as of January 1, 1996, between Image Guided Technologies, Inc., a Colorado corporation and f/k/a Pixsys, Inc. (the "Company"), and Paul L. Ray ("Ray"), as amended by that certain Amendment to Employment Agreement dated as of June 1, 1996, is entered into as of September 6, 1996. 1. Section 2 of the Agreement is hereby amended by changing the first sentence thereof to read in full as follows: Subject to earlier termination as provided in Section 5, the employment hereunder shall be for a period of three years, commencing on January 1, 1996 (the "Commencement Date") and ending on December 31, 1998. 2. All other terms and conditions of the Agreement shall remain in full force and effect. IMAGE GUIDED TECHNOLOGIES, INC. By: /s/ Robert E. Silligman -------------------------------------- Robert E. Silligman /s/ Paul L. Ray -------------------------------------- Paul L. Ray