Acoustic sensor and ventilation monitoring system
Inventors
Joseph, Jeffrey I • HELMOND, Noud Van • TORJMAN, Marc C • DEVINE, Denise L • DICCIANI, Nance K • LOEUM, Channy
Assignees
Thomas Jefferson University • RTM Vital Signs LLC
Publication Number
US-11213225-B2
Publication Date
2022-01-04
Expiration Date
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Abstract
A method of monitoring respiration with an acoustic measurement device, the acoustic measurement device having a sound transducer, the sound transducer configured to measure sound associated with airflow through a mammalian trachea, the method includes correlating the measured sound into a measurement of tidal volume and generating at least one from the group consisting of an alert and an alarm if the measured tidal volume falls outside of a predetermined range.
Core Innovation
The invention relates to a method of monitoring respiration with an acoustic measurement device, the acoustic measurement device having a sound transducer configured to measure sound associated with airflow through a mammalian trachea. The method includes correlating the measured sound into a measurement of tidal volume and respiratory rate and generating at least one from the group consisting of an alert and an alarm if the measured tidal volume falls outside of a predetermined range. The disclosure further relates to a device and system for an acoustic ventilation monitoring system including a wearable Trachea Sound Device (TSD) that transmits data to a diagnostic software application on the patient's cell phone or clinician's cell phone, or hospital monitor.
The background identifies limitations of existing monitoring methods, noting that current respiratory monitors measure thoracic electrical impedance or use nasal cannula capnography and pulse oximetry, which are described as cumbersome, easily dislodged, prone to false alarms, or that pulse oximeters alarm only after moderate to severe hypoventilation. The patent states that quantitative measurement of ventilation has not been well established in clinical diagnostics and highlights the inability to continuously and accurately monitor/measure airflow into and out of the lungs during ambulation in the hospital or real-world environment. The disclosure therefore addresses the need for a non-invasive real-time monitoring system that continuously quantifies and analyzes respiratory rate, tidal volume, and related physiological conditions.
The system continuously measures, analyzes, records, and displays variables such as respiratory rate (RR), tidal volume (TV), minute ventilation (MV), airway patency, heart rate (HR), body temperature, body activity level, body coordination, body position, snoring, coughing, and apnea episodes in ambulatory and hospitalized patients. Real-time diagnostic algorithms correlate measured tracheal sound energy into measurements of the patient's tidal volume and respiratory rate, assign likelihood values, calculate rates of change and trends, and update a Risk-Index Score (RIS) to produce alerts and alarms when thresholds are exceeded. The disclosure describes a small wearable TSD with microphones, accelerometer, telemetry, and processing that wirelessly communicates measured data to a controller for real-time analysis and alerting.
Claims Coverage
This coverage addresses two independent claims and identifies six main inventive features claimed in the independent claims.
Acoustic measurement of tracheal airflow
An acoustic measurement device configured to measure sound vibrations associated with airflow through a mammalian trachea.
Correlating measured sound into tidal volume and respiratory rate
Correlating the measured sound vibrations into a measurement of tidal volume and respiratory rate.
Calculating tidal volume metrics at a time interval
Calculating at least one selected from the group consisting of absolute tidal volume, a direction of tidal volume, and a rate of change of tidal volume at a first time interval.
Correlating tidal volume metrics to a risk score
Correlating the at least one selected from the group consisting of absolute tidal volume, a direction of tidal volume, and a rate of change of tidal volume at the first time interval to a risk score defined on a predefined scale, the risk score being indicative of a likelihood of an adverse event.
Including duration of tidal volume deviation
Calculating at least one selected from the group consisting of absolute tidal volume, a direction of tidal volume, a rate of change of tidal volume, and a duration of time that the measured tidal volume deviates from a predetermined range and correlating those to a risk score on a predefined scale.
Generating an alert when risk score exceeds threshold
Generating an alert if the risk score correlated to the at least one selected from the group consisting of the absolute tidal volume, the direction of tidal volume, the rate of change of tidal volume, and the duration of time that the measured tidal volume deviates from a predetermined range deviates from a predetermined risk threshold.
The independent claims collectively claim an acoustic measurement device that measures tracheal airflow sound, correlates measured sound into tidal volume and respiratory rate, calculates tidal volume metrics including absolute value, direction, rate of change and duration of deviation at defined intervals, maps those metrics to a predefined risk score indicative of an adverse event, and generates alerts when the risk score deviates from a predetermined threshold.
Stated Advantages
Continuous non-invasive real-time monitoring and analysis of respiratory rate, tidal volume, minute ventilation, airway patency, heart rate, temperature, body activity, body coordination, and body position.
Early detection and prediction of hypoventilation, opioid induced respiratory depression, and other adverse events using a Risk-Index Score with reported high sensitivity and specificity for mild, moderate, and severe hypoventilation.
Automated alerts and alarms to patients, caregivers, clinicians, and emergency personnel, and capability to transmit data to central monitoring stations and electronic medical records.
Ability to interface with and automatically trigger therapeutic responses, including embodiments combining the AVMS with a wearable or implantable drug infusion pump or an auto-injector to deliver an opioid reversal medication.
Applications that can improve clinical outcomes and decreased costs, enhance patient safety, and improve patient compliance and monitoring after hospital discharge.
Fitness and performance monitoring for athletes and military personnel, including detection/prediction of overheating/exhaustion prior to adverse events.
Documented Applications
Prediction and detection of opioid induced respiratory depression and opioid overdose by measuring patterns in respiratory rate, tidal volume, snoring, activity level, body coordination, and body position.
Prediction of heat exhaustion and heat stroke by measuring heart rate, respiratory rate, tidal volume, and body temperature and assigning likelihood values compared to thresholds.
Fitness tracking and training by measuring respiratory rate, tidal volume, minute ventilation, heart rate, and body temperature during exercise and recovery to assess physical fitness and training progress.
Continuous monitoring of hospitalized patients in operative rooms, PACU, ICU, emergency rooms, and general floors to detect hypoventilation, airway patency issues, and clinical deterioration.
Home and post-discharge monitoring of patients taking opioids or other respiratory depressant medications, including transmission of data to a smartphone application and central monitoring station.
Monitoring and early detection of decompensation in chronic respiratory diseases such as COPD and asthma by comparing measured RR and TV against known or patient-specific baselines.
Integration with closed-loop therapeutic delivery, for example automatically triggering an auto-injector to deliver naloxone based on real-time AVMS data.
Use by first responders and in industrial or occupational settings to detect hyperventilation or hypoventilation conditions, and to detect low oxygen situations in environments such as oil fields, breweries, chemical facilities, mining operations, aviation, and space applications.
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