Validating the Accuracy of a Continuous Respiratory Rate Measurement Device

While respiratory rate is considered a critical vital sign, it often goes unmeasured or is ignored primarily due to shortcomings of the currently used measurement methods. Respiratory rate provides important information on a person's health condition and physiological stability, and an abnormal respiratory rate is a strong indicator that a health crisis is imminent. In fact, a sudden change in respiratory rate is one of the strongest predictors of mortality. Current techniques of monitoring respiratory rate have drawbacks that limit the frequency and convenience of the respiratory monitoring. Recognizing that closer respiration monitoring can save lives and improve quality of life, reduce hospital stays, and lower medical costs, the health care industry is seeking improved respiration monitoring products. The allocation of high-risk patients to intensive care for more careful monitoring or after surgery is often arbitrary, and such care might not be available routinely. For those patients who are cared for in 'general' wards where staffing levels are limited, a practical continuous monitor of respiratory rate would be of great value. This study will act as a pilot to determine the feasibility of using respiratory sensor device to monitor respiratory rate in hospitalized patients.

Deriving a measurement of respiratory rate from a respiratory rate monitoring (RRM) device is a technological approach that may overcome these limitations. The device principle is based on a piezoelectric sensor where chest expansions and contractions generate very small amounts of current by the piezoelectric sensor. The expansion and contractions are measured very accurately by over-sampling, filtering and digital signal processing to remove noise and any bias generated by the piezoelectric sensor itself or the sampling circuitry.

The study will be conducted from March 2021 to September 2021. During the first phase a convenience sample of 30 patients undergoing general anesthesia with muscle paralysis and mechanical ventilation will be recruited. This phase will help to validate the RRM against capnography in mechanically ventilated patients with a set respiratory rate. Following the first phase, 120 patients undergoing a procedure using sedation or spinal anesthesia will be recruited. Patients will be breathing spontaneously, and the respiratory rate will be monitored by capnography connected to the face mask or nasal prongs. Respiratory rate detected by capnography is recorded in the electronic medical records on a minute to minute interval.