Narigmed’s blood oxygen accessories with built-in blood oxygen module are suitable for measurement in various environments, such as high altitude areas, outdoors, hospitals, homes, sports, winter, etc. It can be adapted to a variety of equipment such as ventilators, monitors, oxygen concentrators, etc. Without changing the design of the equipment itself, the blood oxygen monitoring function can be accessed through software changes, which facilitates compatible design and has low cost of modification and upgrade.