US 11,653,862 B2
Non-invasive optical physiological differential pathlength sensor
Cristiano Dalvi, Lake Forest, CA (US); Ferdyan Lesmana, Irvine, CA (US); Hung The Vo, Fountain Valley, CA (US); Jeroen Poeze, Rancho Santa Margarita, CA (US); Jesse Chen, Foothill Ranch, CA (US); Kevin Hughes Pauley, Lake Forest, CA (US); Mathew Paul, Irvine, CA (US); Sean Merritt, Lake Forest, CA (US); Thomas B. Blank, Laguna Beach, CA (US); and Massi Joe E. Kiani, Laguna Niguel, CA (US)
Assigned to Cercacor Laboratories, Inc., Irvine, CA (US)
Filed by Cercacor Laboratories, Inc., Irvine, CA (US)
Filed on May 20, 2016, as Appl. No. 15/160,907.
Claims priority of provisional application 62/233,126, filed on Sep. 25, 2015.
Claims priority of provisional application 62/165,618, filed on May 22, 2015.
Prior Publication US 2016/0367173 A1, Dec. 22, 2016
Int. Cl. A61B 5/1455 (2006.01); A61B 5/00 (2006.01)
CPC A61B 5/14552 (2013.01) [A61B 5/0075 (2013.01); A61B 5/6838 (2013.01); A61B 2562/0238 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of measuring a blood or interstitial fluid constituent of a patient by varying light emitted in a physiological optical sensor, the method comprising:
determining a temperature, a drive current, a forward voltage, and a duty cycle of a light emitter that emits light at a first wavelength;
varying at least one of the determined temperature, drive current, forward voltage, and duty cycle of the emitter to cause the emitter to sweep through a range of wavelengths of light;
directing a first portion of the light emitted by the emitter to tissue of the patient and detecting, with a first detector, first attenuated light comprising the first portion of the emitted light over the swept range of wavelengths after attenuation through the tissue of the patient, wherein the first detector is configured to output a first plurality of signals corresponding to the detected, first attenuated light;
directing a second portion of the light emitted by the emitter to a second detector without attenuation through the tissue of the patient and detecting, with the second detector, second attenuated light comprising the second portion of the emitted light over the swept range of wavelengths, wherein the second detector is configured to output a second plurality of signals corresponding to the detected, second attenuated light,
wherein the emitter and the first detector are movable relative to each other and the emitter and the second detector are moveable relative to each other, and
wherein a thickness of the tissue is controlled at least in part by a depth stop such that a first distance between the emitter and the first detector is fixed to define a first known path length and a second distance between the emitter and the second detector is fixed to define a second known path length;
receiving and processing the first and second plurality of signals with a data collection device;
determining a plurality of bulk absorbance values based on the received and processed first and second plurality of signals from the first and second detectors, each of the plurality of bulk absorbance values indicative of an amount of light absorbed by the tissue of the patient;
determining a plurality of tissue absorption segments based on the plurality of bulk absorbance values determined from the first and second plurality of signals outputted by the first and second detectors over the range of wavelengths swept by the emitter; and
combining the plurality of tissue absorption segments to form a plurality of tissue absorption bands and generate at least a portion of a tissue absorption profile.