Respiratory Rate

Respiratory rate is the number of breaths a person takes per minute. It is a vital sign that reflects pulmonary function and overall metabolic status. Normal adult respiratory rate at rest is typically 12 to 20 breaths per minute. Rates outside this range can indicate respiratory distress, metabolic imbalance, pain, anxiety, or other clinical conditions.

Respiratory rate is often called the most neglected vital sign in clinical practice because it is frequently estimated rather than accurately counted. Studies have shown that changes in respiratory rate can be an early indicator of clinical deterioration, making accurate and consistent measurement particularly valuable for patient monitoring in both inpatient and remote care settings.

Contactless respiratory rate measurement using rPPG technology extracts breathing-related signals from facial video. These signals may be derived from subtle head movements caused by breathing, respiratory-induced variations in the PPG signal, or periodic changes in facial color associated with the respiratory cycle. This enables remote respiratory monitoring during telehealth visits without any additional devices.