Systems and processes for detecting oxygen saturation and compensating for skin tone variation

A system for deriving an estimated oxygen saturation percentage (SpO2%) for a patient comprising:

• at least one processor communicably coupled to a patch for affixing to a patient and configured to:
• receive reflectance red data and IR data derived from a photoplethysmography (PPG) sensor coupled to the patch and associated with a time period, wherein:
• the patch comprises a bottom surface located above the PPG sensor;
• and
• upon attaching the bottom surface to the patient, the PPG sensor is pressed into the skin of the patient thereby increasing amplitude of the red data and IR data;
• and
• the red data has a mean AC amplitude value of about 100 and the IR data has a mean AC amplitude value of about 300;
• receive a series of heartbeats associated with the time period and derived from a heartbeat detector, the heartbeat detector comprising an electrocardiogram (ECG) sensor, an accelerometer, bioimpedance sensor, and/or a beat detector coupled to the patch;
• compute a series of peaks of the red data and IR data for the time period;
• compute a subset of the red data and IR data by excluding any peaks of the series of peaks that do not fall within a predetermined time window of a heartbeat of the series of heartbeats;
• estimate an oxygen saturation percentage (SpO2%) for the patient by computing an optical ratio of the red data and IR data included in the subset, thereby verifying peaks for the red data and IR data and eliminating potential noise and false peaks;
• and
• display on a computer screen the estimated SpO2% for the patient.

A system for deriving an estimated oxygen saturation percentage (SpO2%) for a patient comprising:

• at least one processor communicably coupled to a patch for affixing to a patient and configured to:
• receive reflectance red data and IR data derived from a photoplethysmography (PPG) sensor coupled to the patch, wherein:
• the patch comprises a bottom surface located above the PPG sensor, and
• upon attaching the bottom surface to the patient, the PPG sensor is pressed into the skin of the patient thereby increasing amplitude of the red data and IR data, and
• the red data has a mean AC amplitude value of about 100 and the IR data has a mean AC amplitude value of about 300;
• receive a series of heartbeats derived from a heartbeat detector;
• compute a series of peaks of the red data and IR data for a time period;
• compute a subset of the red data and IR data by excluding any peaks of the series of peaks that do not fall within a predetermined time window of a heartbeat of the series of heartbeats, wherein the series of heartbeats are associated with the time period;
• estimate an oxygen saturation percentage (SpO2%) for the patient by computing an optical ratio of the red data and IR data included in the subset, thereby verifying peaks for the red data and IR data and eliminating potential noise and false peaks;
• and
• display on a computer screen the estimated SpO2% for the patient.