The Respiratory Monitoring System (RMS) consists of a miniature acoustic sensor and a soft flexible cradle that is adhered to the skin of the neck over the proximal trachea (within the sternal notch) with medical grade adhesive. The sensor body consists of a miniature bell stethoscope head, electronics, a microphone that faces the trachea and a microphone that faces the external environment, a Bluetooth low energy transmitter/receiver, an antenna, and a rechargeable battery. The sensor is secured by the cradle at the optimal location to measures the sounds of airflow in the proximal trachea during inhalation and exhalation.
Proprietary machine learning/AI algorithms convert the sounds of airflow into the measurements of respiratory rate (RR), tidal volume (TV), minute ventilation (MV), and duration of apnea. Sensor information is transmitted to a bedside PC that displays the vital sign data in real-time. The wearable, wireless RMS is being developed for hospital and outpatient use as a tool to detect and predict respiratory compromise/clinical deterioration in a more-timely and accurately manor (fewer false alerts/alarms) than current methods.
The breathing data from 14 to 20 participants will be recorded during one study session lasting approximately 90 minutes with the sensor/cradle adhered to the neck over the proximal trachea. Reference breathing data will be recorded simultaneously using a hospital ventilator's pneumotach and capnometer attached to a tight-fitting face mask.
Each subject will be instructed to breath the following protocol 3 or 4 times:
Record RMS data and pneumotach/capnometer data for \~400 seconds with the study subject breathing a normal RR and TV.
Record RMS data and pneumotach/capnometer data for \~70 seconds with the study subject breathing a normal RR and an increased TV.
Record RMS data and pneumotach/capnometer data for \~70 seconds with the study subject breathing a normal RR and decreased TV.
Record RMS data and pneumotach/capnometer data for \~120 seconds with the study subject breathing a normal RR and normal TV with a period of apnea in the middle (15 seconds).
Record RMS data and pneumotach/capnometer data for \~120 seconds with the study subject breathing a normal RR and decreased TV, with a period of apnea in the middle (15 seconds).
Record RMS data and pneumotach/capnometer data for \~120 seconds with the study subject breathing a decreased RR and decrease TV with a period of apnea in the middle (15 seconds).
RMS data will be compared to reference pneumotach/capnometer data (RR, TV, MV, and duration of apnea) to determine the accuracy of measurement. Data will be recorded in an environment with simulated hospital noise with adaptive filtering and active noise cancellation turned on and turned off.
This observational human study will compare the signal-to-noise ratio (SNR) and the measurement accuracy of the RMS in a noisy environment with the adaptive filtering and active noise cancellation turned on versus turned off.
Participants will be contacted by telephone 3 to 4 days later to confirm no adverse effects from the study methods or wearing the sensor.
