There are many devices that exists where they do not have ISO standards but still maybe in use. I believe that ISO are mandatory because any device that can endanger a person’s life must not be used. Tgey are just a matter of safety. As of many people may invent or innovate a use of medical device and if there are drawbacks to it, people may ignore them to reduce any further complications or failure. This harms the patient at the end if anything goes wrong. To ensure this safety ISO are made. The devices that are actually made by aiming a good deed it would be made safe even without ISO standards.