Novel Diagnostic and Monitoring Tool Helps Manage Asthma

A new diagnostic tool measures a patient's wheezing before and after tests with a bronchodilator, thereby demonstrating the effectiveness of asthma treatments.

The KarmelSonix Wheezometer quantifies wheezing activity by measuring the wheeze rate (Wz%), the portion of the respiratory cycle occupied by wheezing. The device records thirty seconds of breathing while applied to the neck area and analyzes and quantifies the wheezing in the audio recording, obtaining spot check measurements of present wheeze activity as often as needed without any patient effort; the device allows scrolling of the last ten measurements for review. The device uses a cascade of six proprietary technologies to isolate and compare the signals against false detection of ambient noises as wheeze. The device comes with an embedded processor and a self-contained cushioned built-in silicone coated sensor with broad-spectrum frequency response, with more than a 60-decibel dynamic range and superior ambient noise rejection.


The technology is based on acoustic signal acquisition and processing, and advanced signal processing techniques. Acoustic markers such as wheezes, rhonchi, and cough are recorded using propriety lung-sound sensors specifically-designed for lung-sound detection and thus are more oriented in detecting sounds characteristic to asthma than normal stethoscopes. The acquired data is analyzed by patented algorithms and signal-processing techniques that map out the data's spectral content on a graphic sonogram. Outside noises are cancelled out using patented ambient noise rejection techniques, to ensure the accuracy of physiological sound detection. The device was calibrated and validated by consensus of a panel of experts who evaluated and scored many recordings for presence of wheeze.

The WheezoMeter design is based on ergonomic human interfacing principles as dictated by functional and anatomical requirements, and facilitates the correct anatomical placement of the device in contact with the trachea at the correct contact force. Stable contact with the skin surface is provided for the duration of the test. The device isolates the measuring head and sensor from vibrations and hand tremor, and an optional infant sensor holder is available to provide better skin contact for babies and toddlers. The WheezoMeter is a product of KarmelSonix (Alta Loma, CA, USA), and has been approved by the U.S. Food and Drug Administration (FDA) in addition to the European Community (CE) Marking.

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