Issue link: https://iconnect007.uberflip.com/i/626587
14 The PCB Design Magazine • January 2016 about the FDA in the U.S., Health Canada in Canada, and the Medical Device Directive for Europe. They all have requirements and guid- ances for how a medical device must be devel- oped. They care deeply about the efficacy and safety of the device. If we don't comply, we're not allowed to sell the device. For instance, one big part of our develop- ment process is repeatedly analyzing risk of harm either to the patient or the user. Risks must be evaluated and mitigated as required. All of this process must be documented cor- rectly. This is something that doesn't often get much consideration for a consumer product. Many of the decisions we make in the design process take risk of harm into account: Are we creating a potential hazard and how can we best mitigate it? You have to consider the probabil- ity of failure modes that might change the level of risk and potentially mitigate those too. None of the other industries I've worked in require this risk-based approach to safety. None of the others care about the safety of a patient. The patient is important because they must trust that the doctor and product really have their best interest at heart. They don't neces- sarily understand what the device is doing and what the risks are. In some cases they are not even conscious. Shaughnessy: What trends are you seeing in medical pcBs? MacCallum: More and more devices want touchscreens and full-on embedded processors whether they are running An- droid or Linux, etc. Users ex- pect the same sort of interfaces they see with their phones and tablets. We're also seeing a lot of RF, Bluetooth and Wi-Fi. Network connectivity is big. That means suddenly you've got RF sub-circuits. Broadly speaking, phones, laptops, and tablets are all converging. Lots of clients would love if their primary interface to the device was an iPhone. That trend has interest- ing implications from a safety perspective. The FDA has guidances which relate to using smart- phones and tablets for that purpose. As we jam more things into our medical devices, the complexity, density and quantity of PCBs increase. Manufacturing requirements and tolerances will become more stringent, and it's going to be great. We're going to have elec- tronics all over the place. With phones, we've seen that the more sen- sors they put on, the more apps you can get and suddenly your phone is not only your pocket computer. Sometimes it even works as a phone. It's your notebook, weather predictor, naviga- tion system and all sorts of fun stuff. The more sensors become inexpensive and available, the more tricks we develop to obtain medical information from these sensors and the more we're going to jam them into a single device. There will continue to be special pur- pose devices mind you; I don't expect to see an MRI in a phone, not just for the basic geomet- ric reasons. As people invent new technologies, they seem to start as single-purpose devices. As those evolve they get smarter, cheaper, and lighter. Eventually they'll converge with some oth- er existing technology. I suspect that just as quickly as we can take older technology, mea- MEDICAL PCB DESIgN: NoT JuST ANoTHER HIgH-REL BoARD feature interview