As the person above provided examples, an easier way to observe the difference between significant risk medical devices and non significant risk devices is looking at the classification which is defined by the FDA. If a device is labeled as NSR, it would most likely be a Class I medical device, due to its non-invasive nature. Whereas a SR device would be labeled to either a Class II or Class III medical device, which is more invasive and may act as an implant or be life sustaining.