System and method for screening and prediction of severity of infection

Abstract

A photoplethysmography (PPG) circuit obtains PPG signals at a plurality of wavelengths of light reflected from tissue of a user. A processing device generates parameters using the PPG signals to screen the user for an infection, such as sepsis, influenza and/or COVID-19. The processing device may also determine a severity level of the infection and a confidence level in the determination. The parameters may include a measurement of nitric oxide (NO) level, respiration rate, heart rate and/or oxygen saturation.

1 . A device, comprising:
 at least one memory device that stores at least a first photoplethysmography (PPG) signal at a first wavelength and a second PPG signal at a second wavelength, wherein the first PPG signal and the second PPG signal are obtained from light reflected from or transmitted through tissue of a user;   at least one processing circuit configured to:
 determine a first ratio R value using the first PPG signal and the second PPG signal, wherein the first ratio R value is obtained using an alternating current (AC) signal component in the first spectral response and an AC signal component in the second spectral response; and 
 determine a risk of sepsis in the user using the first ratio R value. 
   
     
     
         2 . The device of  claim 1 , wherein the at least one processing circuit is configured to determine a risk of sepsis in the user by:
 determining a classification of either sepsis or no sepsis.   
     
     
         3 . The device of  claim 2 , wherein the classification of either sepsis or no sepsis includes a confidence level. 
     
     
         4 . The device of  claim 1 , wherein the at least one processing circuit is configured to determine a risk of sepsis in the user by:
 determining a confidence level of no septic condition in the user and a confidence level of a septic condition in the user.   
     
     
         5 . The device of  claim 1 , wherein the at least one processing circuit is further configured to:
 determine a heart rate and oxygen saturation of the user using the first PPG signal or the second PPG signal or a third PPG signal at a third wavelength obtained from the user; and   determine the risk for sepsis in the user using the first ratio R value, the heart rate, and the oxygen saturation.   
     
     
         6 . The device of  claim 1 , wherein the at least one processing circuit is further configured to:
 obtain a temperature of the user; and   determine the risk for sepsis in the user using the first ratio R value and the temperature of the user.   
     
     
         7 . The device of  claim 1 , wherein the at least one processing circuit is configured to determine a first ratio R value using the first PPG signal and the second PPG signal by:
 determining a first L value using the first PPG signal by isolating an alternating current (AC) component of the first PPG signal;   determining a second L value using the second PPG signal by isolating an AC component of the second PPG signal; and   determining the first ratio R value using the first L value and the second L value.   
     
     
         8 . The device of  claim 1 , wherein the first wavelength is in a range of 380 nm to 410 nm and wherein the second wavelength equals or is above 660 nm. 
     
     
         9 . The device of  claim 1 , wherein the at least one processing circuit includes a processing circuit that includes artificial intelligence (AI) or neural network processing models. 
     
     
         10 . The device of  claim 1 , wherein the at least one processing circuit is configured to:
 obtain one or more PPG parameters from the first PPG signal and the second PPG signal, wherein the one or more PPG parameters include at least one of: a phase delay between the first PPG signal and the second PPG signal, a correlation of phase shape between the first PPG signal and the second PPG signal, a periodicity of first PPG signal or a periodicity of the second PPG signal; and   determine the risk for sepsis in the user using the first ratio R value and the one or more PPG parameters.   
     
     
         11 . A method, comprising:
 obtaining from a biosensor at least a first PPG signal from light reflected from skin tissue of a patient, wherein the light includes a first wavelength in an ultraviolet (UV) range and at least a second PPG signal from light reflected from skin tissue of the patient, wherein the light includes a second wavelength in an infrared (IR) range;   determining by at least one processing device a first ratio R value using the first PPG signal and the second PPG signal, wherein the first ratio R value is obtained using alternating current (AC) signal components in the first spectral response and the second spectral response; and   determining by the at least one processing device a risk of sepsis in the user using the first ratio R value.   
     
     
         12 . The method of  claim 11 , wherein determining a risk of sepsis in the user comprises:
 determining by the at least one processing device a classification of either sepsis or no sepsis.   
     
     
         13 . The method of  claim 12 , wherein determining a classification of either sepsis or no sepsis includes:
 determining by the at least one processing device a confidence level of no septic condition in the user and a confidence level of a septic condition in the user.   
     
     
         14 . The method of  claim 11 , further comprising:
 obtaining by the at least one processing device a heart rate and an oxygen saturation of the user; and   determining by the at least one processing device the risk for sepsis in the user using the first ratio R value, the heart rate, and the oxygen saturation.   
     
     
         15 . The method of  claim 11 , further comprising:
 obtaining by the at least one processing device one or more PPG parameters from the first PPG signal and the second PPG signal, wherein the one or more PPG parameters include at least one of: a phase delay between the first PPG signal and the second PPG signal, a correlation of phase shape between the first PPG signal and the second PPG signal, a periodicity of first PPG signal or a periodicity of the second PPG signal; and   determining by the at least one processing device the risk for sepsis in the user using the first ratio R value and the one or more PPG parameters.   
     
     
         16 . The method of  claim 11 , wherein the first wavelength is in a range of 380 nm to 410 nm and wherein the second wavelength equals or is above 660 nm. 
     
     
         17 . A device, comprising:
 at least one memory device that stores at least a first photoplethysmography (PPG) signal at a first wavelength and a second PPG signal at a second wavelength, wherein the first PPG signal and the second PPG signal are obtained from light reflected from or transmitted through tissue of a user;   at least one processing circuit configured to:
 determine a ratio R value using the first PPG signal and the second PPG signal, wherein the ratio R value is obtained using an alternating current (AC) signal component in the first spectral response and an AC signal component in the second spectral response; and 
 determine a hybrid quick Sequential Organ Failure Assessment (qSOFA) score using at least the ratio R value. 
   
     
     
         18 . The device of  claim 17 , wherein the hybrid quick Sequential Organ Failure Assessment (qSOFA) score indicates a risk of sepsis in the user. 
     
     
         19 . The device of  claim 18 , wherein the at least one processing circuit is further configured to:
 determine a heart rate and an oxygen saturation from the first PPG signal or the second PPG signal; and   determine the hybrid quick Sequential Organ Failure Assessment (qSOFA) score using at least the oxygen saturation, the heart rate, and the ratio R value.   
     
     
         20 . The device of  claim 19 , wherein the at least one processing circuit is further configured to:
 determine an estimated blood pressure from the first PPG signal or the second PPG signal; and   determine the hybrid quick Sequential Organ Failure Assessment (qSOFA) score using at least the estimated blood pressure, the oxygen saturation, the heart rate, and the ratio R value.