When people talk about U.S. Food and Drug Administration (FDA) design controls, they often place a lot of emphasis on inputs and outputs, verification, transfer, and the design history file. All good things, of course; without them, you won’t meet FDA requirements for your design controls. The problem, however, is that too often people forget to ask themselves “Why?”

Let me put it another way: Why are you creating this device in the first place? I’m assuming you want to meet a medical need of some kind. If that’s true, don’t start with what it does. Start with who it’s for.

The user’s needs are often given lip service in the medical device world, but there isn’t much emphasis on finding what those needs are. According to the FDA, all design controls should start with user needs and cascade down into the other stages of the process.

There are two things to think about when defining user needs. First, “intended use” is the general purpose—what the device does. Second, the “indications for use” describe the medical conditions your device will help diagnose, treat, prevent, cure, or mitigate.

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