What is the primary purpose of digital pulse oximetry?

The primary purpose of digital pulse oximetry is to measure oxygen saturation in the blood. This non-invasive method uses light absorption properties of hemoglobin to evaluate how much oxygen is being carried in the bloodstream. The device typically attaches to a fingertip or earlobe and shines light through the skin to assess the percentage of hemoglobin that is saturated with oxygen. Accurate measurement of oxygen saturation is vital in various clinical scenarios, such as in patients with respiratory disorders or during anesthesia, to ensure adequate oxygen delivery to tissues.

The other functions highlighted in the options are essential health indicators, but they do not fall under the capabilities of a pulse oximeter. Blood pressure measurement requires different instrumentation, heart rate can be determined by pulse oximetry but isn't its primary function, and respiratory rate assessment generally involves observation or advanced monitoring technologies, not pulse oximetry. Thus, the focus of this tool is specifically on assessing oxygen saturation levels for diagnostic and monitoring purposes in healthcare settings.