Any medical device must be both accurate and precise. Lets take a simple blood pressure cuff. If I put it on my arm and test it 10 times there should only be slight differences between each of the measurements. The device must also be accurate. This is important for the FDA because if they are approving a device to be used on or in the body then it is their job to make sure that the device will be consistent in its reporting (precise) and will show the actual value it is testing (accurate). If we are designing a machine that will test someone’s reflexes in terms of how fast they react the device must be precise in that when the same person is repeatedly tested in the same conditions their reaction time should all be measured as similar. and accurate in that the device must measure the reflex time correctly. If the device cannot do both of these consistently then what use is it? Accuracy and precision are important for the FDA because it is one of the ways they can determine if a device is going to be useful if it is approved for use.