Cas Medical Systems, Inc.

Edwards Lifesciences Corporation

Bo Chen

Paul B Benni

Andrew Kersey

A method and apparatus for non-invasively determining the blood oxygenation within a subject's tissue is provided that utilizes a near infrared spectrophotometric (NIRS) sensor capable of transmitting a light signal into the tissue of a subject and sensing the light signal once it has passed through the tissue via transmittance or reflectance.

Method for spectrophotometric blood oxygenation monitoring

A near-infrared spectrophotometric system (e.g., a cerebral oximeter) includes a sensor portion and a monitor portion. The monitor portion includes a processor that runs an algorithm which utilizes the amount of detected light to determine the value of the oxygen concentration (e.g., the absolute level of oxygen concentration). The monitor portion also includes a visual display that displays the determined oxygen concentration values in various formats. The monitor portion may also include an audible device (e.g., a speaker), that provides audible indications of the determined oxygen concentration values. Various visual indicators may include, for example, color-coded graphs of the determined oxygenation values to alert the system user, for example, whether one hemisphere of the brain, or one or more regions of the brain, is in danger of adverse and potentially permanent damage. Also, data may be pre-processed by selecting the most clinically concerning sensor value (e.g., the sensor with the lowest value), and displaying only that sensor value and its identification on the display screen. Alternatively, an average value of multiple sensor measurements may be displayed. This reduces screen clutter and increases the speed of interpretation by the system user. Also, all sensor values may be averaged, and the average value displayed. The determined oxygenation values may also be provided in an audible format.

Indicators for a spectrophotometric system

A method and apparatus for non-invasively determining the blood oxygen saturation level within a subject's tissue is provided that utilizes a near infrared spectrophotometric (NIRS) sensor capable of transmitting a light signal into the tissue of a subject and sensing the light signal once it has passed through the tissue via transmittance or reflectance. The method includes the steps of: (1) transmitting a light signal into the subject's tissue, wherein the transmitted light signal includes a first wavelength, a second wavelength, and a third wavelength; (2) sensing a first intensity and a second intensity of the light signal, along the first, second, and third wavelengths after the light signal travels through the subject at a first and second predetermined distance; (3) determining an attenuation of the light signal for each of the first, second, and third wavelengths using the sensed first intensity and sensed second intensity of the first, second, and third wavelengths; (4) determining a difference in attenuation of the light signal between the first wavelength and the second wavelength, and between the first wavelength and the third wavelength; and (5) determining the blood oxygen saturation level within the subject's tissue using the difference in attenuation between the first wavelength and the second wavelength, and the difference in attenuation between the first wavelength and the third wavelength.

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Derby, CT, United States of America

Bo Chen