Accuracy continuous glucose monitoring method, system, and device
A method, system, and device for improving the accuracy of a continuous glucose monitoring sensor by estimating a CGM signal at a time t+PH using a value of CGM at time t, using a real-time short-time glucose prediction horizon to estimate the real time denoised CGM value with a noise estimation algorithm.
1. A method for improving the accuracy of a continuous glucose monitoring system (CGM) comprising:
obtaining an output CGM signal at a time t from a CGM device;
removing random noise from said CGM signal by estimating a value of the CGM signal at a time t+PH using a noise state estimation, where PH is a preselected real-time short-time prediction horizon, the prediction horizon being a value that matches that of a diffusion constant of the blood glucose-to-interstitial glucose (BG-to-IG) kinetics for the CGM device, wherein the estimated value of the CGM signal at time t+PH is a closer approximation of blood glucose than the output CGM signal at time t;
substituting in real time the estimated value of the CGM signal at time t+PH for the output CGM signal at time t; and
using the estimated value of the CGM signal at time t+PH as the true value of the CGM signal at time t.
2. The method according to claim 1 , further comprising using a prediction horizon PH of less than 20 minutes.
3. The method according to claim 2 , further comprising compensating part of a delay introduced by low-pass characteristic of a blood glucose-to-interstitial (BG-to-IG) kinetic system.
4. The method according to claim 1 , further comprising compensating part of a delay introduced by a low-pass characteristic of a blood glucose-to-interstitial (BG-to-IG) kinetic system.
5. The method according to claim 1 , further comprising substituting a current CGM value given in output by a CGM sensor at time t, named CGM(t), with the glucose concentration predicted by a noise-estimation algorithm PH minutes ahead in time.
6. The method according to claim 5 , further comprising developing the algorithm in a stochastic context and implemented using a Kalman filter.
7. The method according to claim 1 , further comprising using CGM data only for real-time application.
8. A method for improving the accuracy of a continuous glucose monitoring (CGM) sensor comprising:
improving accuracy of CGM readings by reducing random noise and calibration errors in said readings using a real-time short-time prediction horizon, the prediction horizon being a value that matches that of a diffusion constant of the blood glucose-to-interstitial glucose (BG-to-IG) kinetics for the CGM sensor; and
denoising said CGM readings by using a Kalman filter (KF) coupled with a Bayesian smoothing criterion for the estimation of its unknown parameters such that the denoised CGM readings are a closer approximation of blood glucose than the un-denoised CGM readings.
9. A system for improving the accuracy of a continuous glucose monitoring sensor comprising:
a digital processor;
a continuous glucose monitoring (CGM) sensor in communication with the digital processor, the continuous glucose monitoring (CGM) sensor configured to generate a glucose signal; and
a denoising module, configured to receive the glucose signal from the continuous glucose monitoring (CGM) sensor, and generate an improved accuracy CGM signal by reducing random noise and calibration errors using a real-time short-time glucose prediction horizon (PH) to estimate the real time denoised value of the CGM signal, the PH being a value that matches that of a diffusion constant of the blood glucose-to-interstitial glucose (BG-to-IG) kinetics for the CGM sensor, the real time denoised value of the CGM signal being a closer approximation of blood glucose than the glucose signal.
10. The system according to claim 9 , wherein the denoising module is configured to use a prediction horizon PH of less than 20 minutes.
11. The system according to claim 9 , wherein the denoising module is configured to compensate part of a delay introduced by a low-pass characteristic of a blood glucose-to-interstitial (BG-to-IG) kinetic system.
12. The system according to claim 9 wherein the denoising module is configured to substitute a current CGM value given in output by a CGM sensor at time t, named CGM(t), with the glucose concentration predicted by a noise estimation algorithm PH minutes ahead in time.
13. The system according to claim 12 , wherein the algorithm is developed in a stochastic context and implemented using a Kalman filter.
14. The system according to claim 12 , wherein the denoising algorithm uses CGM data only for real-time application.
15. The system according to claim 9 , wherein the algorithm is developed in a stochastic context and implemented using a Kalman filter.
16. The system according to claim 9 , wherein the denoising algorithm uses CGM data only for real-time application.
17. A method of increasing accuracy of a continuous glucose monitoring (CGM) sensor signal measured at a time t, by using a short-time prediction horizon (PH) to estimate the value of the CGM signal at time t+PH by applying CGM data obtained at time t to a Kalman filter for time t+PH, and substituting the [the] estimated value of CGM signal at time t+PH for the real time CGM signal value obtained at time t, the PH being a value that matches that of a diffusion constant of the blood glucose-to-interstitial glucose (BG-to-IG) kinetics for the CGM sensor, wherein the estimated value of the CGM signal at time t+PH is a closer approximation of blood glucose than the CGM signal value obtained at time t.