Software Verification and Validation : The Role of IEC 60601-1

Abstract

When biomedical engineers begin to conceptualize a new medical device, verification and validation (V&V) is usually at the forefront of their thoughts. They want to start the effort well by making sure that they have the right tools and processes in place for “building the product right,” and they want to be able to conclude their efforts by demonstrating that they’ve “built the right product” for their customers. Standards have always played a role in V&V, but part of the third edition of IEC 60601-1—the standard on medical electrical equipment— deals with the V&V of increasingly complex medical devices in a whole new way. The complexity of medical devices has grown in almost unfathomable leaps and bounds from the likes of primitive tools used for trepanation, as shown in Figure 1a, a painting by Hieronymus Bosch circa 1488-1516, to the likes of modern computer-to-brain interfaces, such as BrainGate (Figure 1b), developed in 2008 by Cyberkinetics and Brown University. Arguably one of the most influential technologies in driving system complexity has been software. Software can introduce a level of product capability that begins to approach that of the human brain, and product complexity that begins to parallel that of human thought processes. If not designed with great care, software can also induce system failures, such as erratic operation or incorrect processing of data, which have uncanny parallels to conditions of the human brain, such as schizophrenia and bipolar disorder. While many debate the definition of software, the medical device community has agreed that a software product, which may by itself be considered a medical device, is a “set of computer programs, procedures, and possibly associated documentation and data.” Just as human physical and emotional health are intertwined and must be managed together, as system complexity grows, managing medical device complexity holistically becomes paramount to ensuring system health. Addressing both these systematic flaws and random faults (e.g., short-circuit caused by conductive pollution) becomes one of the primary means of ensuring that the medical device will do what it is intended to do and not do that which is not intended. As stated in its introduction, the third edition of IEC 60601-1 has changed in some very fundamental ways. First, the concept of “safety” has been broadened from the “basic safety” About the Author