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US 2024/0188903 A1Published application
System and method of measuring venous oxygen saturation using intelligent pulse averaging with integrated ekg and ppg sensors
AssigneeHemocept Inc.
InventorsEric Raman, Kevin Peterson, Iain Hueton
Life of this patent
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Abstract
A system using combined electrocardiography (EKG) and photoplethysmography (PPG) sensing, to determine venous oxygen saturation is described. The system uses averaging of similar pulses based on Prior (or n−1) R-to-R pulse wave duration, and current (or n) R-to-R pulse wave duration for evaluation of the metabolic reserve and/or stress of the patient.
Claims14
A computer logic system for determining venous oxygen saturation, the computer logic system configured to:
- obtain (a) a PPG signal from a device that includes at least one PPG sensor mounted thereon for measuring the person's PPG signal at multiple wavelengths of light, and (b) an EKG signal from a plurality of electrodes coupled to a person;
- identify cardiac cycles in the EKG signal;
- segment the PPG signal into a series of PPG signal segments based upon features in the identified cardiac cycles,
- sort the PPG signal segments into a plurality of bins based upon a similarity in durations of prior R-to-R cardiac cycles and a similarity in durations of current R-to-R cardiac cycles,
- generate a composite signal for each of the plurality of bins,
- generate a composite Signal Prime Over Signal (SPOS) for each of the composite signals by calculating a derivative of the composite signal and normalizing the derivative of the composite signal by the composite signal itself, and
- measure venous oxygen saturation of the person by:
- (a) calculating arterial oxygen saturation by comparing the composite SPOS signals measured at different wavelengths of light,
- (b) sub-sampling composite signals at two consecutive signal maxima measured at different wavelengths of light, and
- (c) comparing the sub-sampled composite SPOS signals measured at different wavelengths of light to the calculated arterial oxygen saturation to determine venous oxygen saturation.
7 more elements
A method for determining venous oxygen saturation comprising:
- obtaining, via a computer logic system, (a) a PPG signal from a device that includes at least one PPG sensor mounted thereon for measuring the person's PPG signal at multiple wavelengths of light, and (b) an EKG signal from a plurality of electrodes coupled to a person;
- identifying, via the computer logic system, cardiac cycles in the EKG signal;
- segmenting, via the computer logic system, the PPG signal into a series of PPG signal segments based upon features in the identified cardiac cycles,
- sorting, via the computer logic system, the PPG signal segments into a plurality of bins based upon a similarity in durations of prior R-to-R cardiac cycles and a similarity in durations of current R-to-R cardiac cycles,
- generating, via the computer logic system, a composite signal for each of the plurality of bins,
- generating, via the computer logic system, a composite Signal Prime Over Signal (SPOS) for each of the composite signals by calculating a derivative of the composite signal and normalizing the derivative of the composite signal by the composite signal itself, and
- measuring, via the computer logic system, venous oxygen saturation of the person by:
- (a) calculating arterial oxygen saturation by comparing the composite SPOS signals measured at different wavelengths of light,
- (b) sub-sampling composite signals at two consecutive signal maxima measured at different wavelengths of light, and
- (c) comparing the sub-sampled composite SPOS signals measured at different wavelengths of light to the calculated arterial oxygen saturation to determine venous oxygen saturation.
7 more elements
Dependencies are inferred from the claim text.