System for performing pulse oximetry
First Claim
1. A method for performing a pulse oximetry, the method comprising:
- emitting, by at least one light source of a wearable device, a red signal and an infrared signal at a human tissue, the human tissue including a pulsatile tissue and a non-pulsatile tissue;
detecting, by at least one optical sensor of the wearable device, a first signal, the first signal representing an intensity of a modulated red signal, the modulated red signal being generated by an interaction of the red signal with the human tissue;
detecting, by the at least one optical sensor of the wearable device, a second signal, the second signal representing an intensity of a modulated infrared signal, the modulated infrared signal being generated by an interaction of the infrared signal with the human tissue;
shifting, by at least one processor communicatively connected to the at least one optical sensor, the first signal by a first parameter Lred to account for a contribution to the first signal due to a reflection of the red signal from the non-pulsatile tissue;
shifting, by the at least one processor, the second signal by a second parameter Lir to account for a contribution to the second signal due to a reflection of the infrared signal from the non-pulsatile tissue;
determining, by the at least one processor and based on the shifted first signal and the shifted second signal, a ratio for obtaining an oxygen saturation;
determining, by the at least one processor and based on the ratio, a value of the oxygen saturation;
wherein Lred and Lir are positive arbitrary scalars pre-determined in a calibration process, the calibration process including determination of Lred and Lir based on a relationship log((IHred−
Lred)/(ILred−
Lred))/log((IHir−
Lir)/ILir−
Lir))=Rtrue, wherein Rtrue is a true ratio for obtaining the oxygen saturation, IHred is a maximum of the first signal, ILred is a minimum of the first signal, ILir is a maximum of the second signal, and IHir is a minimum of the second signal; and
wherein the value of the oxygen saturation is used to provide reports on a symptom or a progression of one or more chronic diseases of a user.
2 Assignments
0 Petitions
Accused Products
Abstract
Provided are a method and systems for performing pulse oximetry. A light signal is emitted for a period of time and a modulated light signal is detected. The modulated light signal includes a red signal and an infrared signal. The modulated light signal is originated by an interaction of the light signal with a pulsatile tissue and a non-pulsatile tissue. The modulated light signal is processed to estimate an oxygen saturation in the pulsatile tissue during the period of time. The processing includes removing a non-pulsatile component resulting from the interaction of the light signal and the non-pulsatile tissue. The non-pulsatile component can be removed by removing a first parameter from an intensity of the infrared signal and a second parameter from an intensity of the red signal. The parameters are pre-determined using a calibration process to reproduce a true value for a ratio used to determine the oxygen saturation.
80 Citations
18 Claims
-
1. A method for performing a pulse oximetry, the method comprising:
-
emitting, by at least one light source of a wearable device, a red signal and an infrared signal at a human tissue, the human tissue including a pulsatile tissue and a non-pulsatile tissue; detecting, by at least one optical sensor of the wearable device, a first signal, the first signal representing an intensity of a modulated red signal, the modulated red signal being generated by an interaction of the red signal with the human tissue; detecting, by the at least one optical sensor of the wearable device, a second signal, the second signal representing an intensity of a modulated infrared signal, the modulated infrared signal being generated by an interaction of the infrared signal with the human tissue; shifting, by at least one processor communicatively connected to the at least one optical sensor, the first signal by a first parameter Lred to account for a contribution to the first signal due to a reflection of the red signal from the non-pulsatile tissue; shifting, by the at least one processor, the second signal by a second parameter Lir to account for a contribution to the second signal due to a reflection of the infrared signal from the non-pulsatile tissue; determining, by the at least one processor and based on the shifted first signal and the shifted second signal, a ratio for obtaining an oxygen saturation; determining, by the at least one processor and based on the ratio, a value of the oxygen saturation;
wherein Lred and Lir are positive arbitrary scalars pre-determined in a calibration process, the calibration process including determination of Lred and Lir based on a relationship log((IHred−
Lred)/(ILred−
Lred))/log((IHir−
Lir)/ILir−
Lir))=Rtrue, wherein Rtrue is a true ratio for obtaining the oxygen saturation, IHred is a maximum of the first signal, ILred is a minimum of the first signal, ILir is a maximum of the second signal, and IHir is a minimum of the second signal; and
wherein the value of the oxygen saturation is used to provide reports on a symptom or a progression of one or more chronic diseases of a user. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A system for performing a pulse oximetry, the system comprising:
a wearable device including; at least one light source configured to emit a red signal and an infrared signal at a human tissue of a user, the human tissue including a pulsatile tissue and a non-pulsatile tissue; and at least one optical sensor configured to; detect a first signal, the first signal representing an intensity of a modulated red signal, the modulated red signal being a result of an interaction of the red signal with the human tissue; and detect a second signal, the second signal representing an intensity of a modulated infrared signal, the modulated infrared signal being a result of an interaction of the infrared signal with the human tissue; and at least one processor communicatively connected to the at least one optical sensor and configured to; shift the first signal by a first parameter Lred to account for contribution due to reflection of the red signal from the non-pulsatile tissue; shift the second signal by a second parameter Lir to account for contribution due to reflection of the infrared signal from the non-pulsatile tissue; determine, based on the shifted first signal and the shifted second signal, a ratio to be used to obtain an oxygen saturation; and determine, based on the ratio, a value of the oxygen saturation;
wherein Lred and Lir are positive arbitrary scalars pre-determined in a calibration process, the calibration process including determination of Lred and Lir based on a relationship log((IHred−
Lred)/(ILred−
Lred))/log((IHir−
Lir)/ILir−
Lir))=Rtrue, wherein Rtrue is a true ratio for obtaining the oxygen saturation, IHred is a maximum of the first signal, ILred is a minimum of the first signal, IHir is a maximum of the second signal, and ILir is a minimum of the second signal; and
a cloud-based computing resource configured to provide, based on the value of the oxygen saturation, reports on a symptom or a progression of one or more chronic diseases of the user.- View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
18. A non-transitory computer-readable storage medium having embodied thereon instructions, which when executed by a processor, causes a system to perform steps of a method, the method comprising:
-
emitting at a human tissue, by at least one light source of a wearable device, a red signal and an infrared signal, the human tissue including a pulsatile tissue and a non-pulsatile tissue; detecting, by at least one optical sensor of the wearable device, a first signal, the first signal representing an intensity of a modulated red signal, the modulated red signal being a result of interaction of the red signal with the human tissue; detecting, by the at least one optical sensor of the wearable device, a second signal, the second signal representing an intensity of a modulated infrared signal, the modulated infrared signal being a result of interaction of the infrared signal with the human tissue; shifting the first signal by a first parameter Lred to account for a contribution due to reflection of the red signal from the non-pulsatile tissue; shifting the second signal by a second parameter Lir to account for contribution due to reflection of the infrared signal from the non-pulsatile tissue; determining, based on the shifted first signal and the shifted second signal, a ratio to be used to obtain an oxygen saturation; determining, based on the ratio, a value of the oxygen saturation;
wherein Lred and Lir are positive arbitrary scalars pre-determined in a calibration process, the calibration process including determination of Lred and Lir based on a relationship log((IHred−
Lred)/(ILred−
Lred))/log((IHir−
Lir)/ILir−
Lir))=Rtrue, wherein Rtrue is a true ratio for obtaining the oxygen saturation, IHred is a maximum of the first signal, ILred is a minimum of the first signal, IHir is a maximum of the second signal, and ILir is a minimum of the second signal; and
providing reports on a symptom or a progression of one or more chronic diseases of a user based on the value of the oxygen saturation.
-
Specification