Miniaturized noninvasive glucose sensor and continuous glucose monitoring system

Abstract

Systems and methods are described herein for utilizing a photoacoustic sensor for estimating analyte concentration levels. Also described here are training methods for training an analyte sensor to more accurately estimate an analyte concentration level on the basis of a received acoustic signal.

What is claimed is: 
     
         1 . An analyte monitor, the analyte monitor comprising:
 a light emitter configured to emit light toward a target,   a sensor configured to sense acoustic waves generated by analyte molecules in the target in response to the light emitted by the light emitter,   a resonance chamber sized to form a standing wave from generated acoustic waves, and   a signal processing module configured to estimate an analyte concentration level on the basis of acoustic waves sensed by the sensor.   
     
     
         2 . The analyte monitor of  claim 1 , wherein the light emitter is configured to emit light having a wavelength in the mid-infrared region. 
     
     
         3 . The analyte monitor of  claim 1 , wherein the sensor is positioned proximate to an anti-node of the standing wave to be formed in the resonance chamber. 
     
     
         4 . The analyte monitor of  claim 1 , wherein the signal processing module is configured to determine whether the estimated analyte concentration level falls within one of two or more pre-determined ranges. 
     
     
         5 . The analyte monitor of  claim 4 , further comprising a transmitter configured to transmit a signal when the estimated analyte concentration level falls within one of the two or more pre-determined ranges. 
     
     
         6 . The analyte monitor of  claim 1 , wherein the sensor comprises a microphone. 
     
     
         7 . The analyte monitor of  claim 1 , wherein the sensor comprises a transducer. 
     
     
         8 . The analyte monitor of  claim 1 , wherein the resonance chamber comprises a resonance branch for formation of the standing wave and a measurement branch connecting the resonance branch to the sensor, the measurement branch being positioned proximate to an anti-node of the standing wave to be formed in the resonance branch. 
     
     
         9 . A method for estimating analyte concentration levels of a specific target from acoustic signals generated by volumetric expansion of the target due to thermal vibration of analyte molecules in the target in response to irradiation of the target with light, the method comprising:
 obtaining acoustic signals with a sensor of a first analyte monitor and simultaneously obtaining analyte concentration levels using a reference analyte monitor to form a training set, the reference analyte monitor and the first analyte monitor being different monitors;   training an algorithm of a signal processing module of the first analyte monitor using features of the obtained acoustic signals and the obtained analyte concentration levels of the training set; and   after training of the algorithm, using the first analyte monitor to estimate analyte concentration levels from obtained acoustic signals.   
     
     
         10 . The method of  claim 9 , wherein the reference analyte monitor is a continuous glucose monitor having an invasive component and wherein the first analyte monitor is non-invasive. 
     
     
         11 . The method of  claim 9 , wherein the features of the obtained acoustic signals are selected from the group comprising: a timestamp of the recording acoustic signal; an amplitude of the acoustic signals, an in-phase component of the acoustic signals; and out-of-phase component of the acoustic signals; and a frequency of the acoustic signals. 
     
     
         12 . The method of  claim 9 , wherein the step of using the first analyte monitor to estimate analyte concentration levels from obtained acoustic signals comprises determining whether an estimated value of the analyte concentration level falls within two or more pre-determined ranges. 
     
     
         13 . The method of  claim 12 , further comprising determining a confidence level that the analyte concentration level falls within one of the two or more pre-determined ranges. 
     
     
         14 . The method of  claim 12 , wherein the method further comprises transmitting, using a transmitter, a signal in response to a determination that the estimated value of the analyte concentration level falls within one or more of the two or more pre-determined ranges. 
     
     
         15 . The method of  claim 14 , wherein the signal is a blood glucose concentration pre-determined range value or an alert signal. 
     
     
         16 . The method of  claim 9 , wherein the analyte molecules are glucose molecules. 
     
     
         17 . The method of  claim 9 , wherein the step of using the first analyte monitor to estimate concentration levels from obtained acoustic signals comprises amplifying and filtering of the obtained acoustic signal. 
     
     
         18 . The method of  claim 17 , wherein at least part of the amplifying and filtering of the obtained acoustic signal is performed using a resonance chamber. 
     
     
         19 . The method of  claim 9 , further comprising the steps of:
 converting the obtained acoustic signals into an analog electrical signal using a sensor; and   converting the analog electrical signal into a digital electrical signal using an analog-to-digital converter.   
     
     
         20 . A computer readable storage medium comprising instructions which, when executed by a processor, perform a method for estimating analyte concentration levels of a specific target from acoustic signals generated by thermal vibration of analyte molecules in the target in response to irradiation of the target with light, the method comprising:
 obtaining acoustic signals with a sensor of a first analyte monitor and simultaneously obtaining analyte concentration levels using a reference analyte monitor to form a training set, the reference analyte monitor and the first analyte monitor being different;   training an algorithm of a signal processing module of the first analyte monitor using features of the obtained acoustic signals and the obtained analyte concentration levels of the training set; and   after training of the algorithm, using the first analyte monitor to estimate analyte concentration levels from obtained acoustic signals.