1. VARIAN Medical Systems Radiotherapy System Software Development Presented by Peter J Coronado 16 November 2004 at the Planning Meeting for the High Confidence Medical Device Software and Systems (HCMDSS) Workshop Arlington, Virginia

2. VARIAN Medical Systems Thesis and Guiding Principles Because patient and user safety depend upon it, software development tools need to be validated against intended use; however, this is nearly impossible to accomplish. Some guiding principles – Good documents ≠ Quality software From FDA on Design Controls “… a system of checks and balances” “… make systematic assessment of the design an integral part of development” “… deficiencies in design input requirements, and discrepancies between the proposed designs and requirements, are made evident and corrected earlier…” “… increase the likelihood that the design transferred to production will translate into a device that is appropriate for its intended use” From the MDD “If the device is intended for use in combination with other devices or equipment, the whole combination, including the connection system must be safe and must not impair the specified performances of the devices.”

3. VARIAN Medical Systems Radiotherapy Process Every step requires reliable software Diverse application technology Databases Image processing Physics algorithms Embedded systems Motion control Beam control Real-time Information must be reliably shared between workflow steps

4. VARIAN Medical Systems Medical device / software / system workflow Though shown like a waterfall, iterative development has become the primary model Multiple development teams build components in parallel Hardware / software integration in most devices (level 1) Nearest neighbors in radiotherapy workflow integrated next (level 2) Finally, end-to-end through the entire system (level 3) Risk Management

5. VARIAN Medical Systems Process Validation / Artifacts Tool chain MRD/SRD – Requisite Pro or MS Word SDD – MS Word / Visio / Rhapsody Compilers/Linkers – MSVC++, gcc Run-time libraries Operating systems – Windows, DOS, VxWorks Bug tracker – Rational Clearquest SCM – MS Sourcesafe DBMS – Sybase or MS SQL Server

6. VARIAN Medical Systems Contact Information Peter J Coronado E-mail – peter.coronado@varian.competer.coronado@varian.com Phone – 650.424.6320 Mail 3140 Hansen Way, MS F-055 Palo Alto, CA 94304

7. VARIAN Medical Systems BIO Peter Coronado has over 25 years of experience in software engineering having worked in numerous areas of technology, including control systems for medical linear accelerators and defense communications systems. He has developed, managed, and deployed complex systems built to the requirements of 21CFR820.30, DoD- STD-1703(NS), and DoD-STD-2167A. He has designed and deployed corporate development procedures in both defense and medical device companies. He is the designer and co-instructor of Varian Medical Systems’ design control procedures course. Most recently, he led the development team for the Trilogy linear accelerator that adapted Varian’s device for stereo tactic radio surgery applications. He is presently working on implementation of ISO14971 compliant processes throughout Varian. Peter holds a Masters Degree in Computer Science from Southern Methodist University and a Bachelors Degree in Engineering Mathematics from the Colorado School of Mines.