The Apple Watch is here to ensure that your important medical data is measured and recorded. The future of health is on your wrist. Measure your blood oxygen level with a revolutionary new sensor and app.s. It can help you understand how well your body is absorbing oxygen, and the amount of oxygen delivered to your body. The remarkable new sensor and app in Apple Watch Series 6 allow you to take on-demand readings of your blood oxygen as well as background readings, day and night.