Abstract: A device may identify a peak timestamp and a trough timestamp based on a first principal component of photoplethysmography (PPG) data associated with a plurality of wavelength channels. The device may generate a peak absorption spectrum based on the peak timestamp and the PPG data, and may generate a trough absorption spectrum based on the trough timestamp and the PPG data. The device may determine a measured arterial blood spectrum based on the peak absorption spectrum and the trough absorption spectrum. The device may fit the arterial blood spectrum model to the measured arterial blood spectrum to determine a set of values, each value in the set of values corresponding to a variable in a set of variables. The device may calculate an arterial oxygen saturation value based on one or more values of the set of values.

Abstract: A device may identify a peak timestamp and a trough timestamp based on a first principal component of photoplethysmography (PPG) data associated with a plurality of wavelength channels. The device may generate a peak absorption spectrum based on the peak timestamp and the PPG data, and may generate a trough absorption spectrum based on the trough timestamp and the PPG data. The device may determine a measured arterial blood spectrum based on the peak absorption spectrum and the trough absorption spectrum. The device may fit the arterial blood spectrum model to the measured arterial blood spectrum to determine a set of values, each value in the set of values corresponding to a variable in a set of variables. The device may calculate an arterial oxygen saturation value based on one or more values of the set of values.

Abstract: A device may identify a peak timestamp and a trough timestamp based on a first principal component of photoplethysmography (PPG) data associated with a plurality of wavelength channels. The device may generate a peak absorption spectrum based on the peak timestamp and the PPG data, and may generate a trough absorption spectrum based on the trough timestamp and the PPG data. The device may determine a measured arterial blood spectrum based on the peak absorption spectrum and the trough absorption spectrum. The device may fit the arterial blood spectrum model to the measured arterial blood spectrum to determine a set of values, each value in the set of values corresponding to a variable in a set of variables. The device may calculate an arterial oxygen saturation value based on one or more values of the set of values.

Abstract: A patient interface for a reusable optical sensor, the patient interface including a compliant element defining a pocket having a lower wall defining an opening therethrough, the pocket being configured to removably receive the reusable optical sensor. The compliant element includes a first wing and a second wing configured for conformal placement on a patient's body. A condition of a patient may be monitored by inserting an optical sensor into a patient interface, applying the patient interface to the patient, obtaining a measurement with the optical sensor related to the condition of the patient, removing the patient interface from the patient, and removing the sensor from the patient interface.

Abstract: A patient interface for a reusable optical sensor, the patient interface including a compliant element defining a pocket having a lower wall defining an opening therethrough, the pocket being configured to removably receive the reusable optical sensor. The compliant element includes a first wing and a second wing configured for conformal placement on a patient's body. A condition of a patient may be monitored by inserting an optical sensor into a patient interface, applying the patient interface to the patient, obtaining a measurement with the optical sensor related to the condition of the patient, removing the patient interface from the patient, and removing the sensor from the patient interface.

Abstract: Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

Abstract: The invention relates to systems and methods for measuring properties of samples with standardized spectroscopic systems. The methods can include (i) measuring, with a first spectroscopic system, spectra of at least three different reference targets; (ii) calibrating the first spectroscopic system; (iii) measuring, with the first spectroscopic system, a spectrum of a known reference specimen having a known value of the property; (iv) generating a model for the measured property using the spectrum of the known reference specimen; (v) measuring, with a second spectroscopic system, the spectra of at least three different reference targets; (vi) calibrating the second spectroscopic system; (vii) applying the model to the second spectroscopic system; (viii) measuring a spectrum of the sample using the second spectroscopic system; and (ix) determining a value of the property using the model.

Abstract: We disclose measurement systems and methods for measuring analytes in target regions of samples that also include features overlying the target regions. The systems include: (a) a light source; (b) a detection system; (c) a set of at least first, second, and third light ports which transmit light from the light source to a sample and receive and direct light reflected from the sample to the detection system, generating a first set of data including information corresponding to both an internal target within the sample and features overlying the internal target, and a second set of data including information corresponding to features overlying the internal target; and (d) a processor configured to remove information characteristic of the overlying features from the first set of data using the first and second sets of data to produce corrected information representing the internal target.

Abstract: A spectrometer system includes a thermal light source for illuminating a sample, where the thermal light source includes a filament that emits light when heated. The system additionally includes a spectrograph for measuring a light spectrum from the sample and an electrical circuit for supplying electrical current to the filament to heat the filament and for controlling a resistance of the filament. The electrical circuit includes a power supply that supplies current to the filament, first electrical components that sense a current through the filament, second electrical components that sense a voltage drop across the filament, third electrical components that compare a ratio of the sensed voltage drop and the sensed current with a predetermined value, and fourth electrical components that control the current through the filament or the voltage drop across the filament to cause the ratio to equal substantially the predetermined value.