Method, System, and Computer Program Product For The Evaluation of Glycemic Control in Diabetes From Self-Monitoring Data

Abstract

A method, system, and computer program product related to the diagnosis of diabetes, and is directed to predicting the long-term risk of hyperglycemia, and the long-term and short-term risks of severe hypoglycemia in diabetics, based on blood glucose readings collected by a self-monitoring blood glucose device. The method, system, and computer program product pertain directly to the enhancement of existing home blood glucose monitoring devices, by introducing an intelligent data interpretation component capable of predicting both HbA 1c and periods of increased risk of hypoglycemia, and to the enhancement of emerging continuous monitoring devices by the same features. With these predictions the diabetic can take steps to prevent the adverse consequences associated with hyperglycemia and hypoglycemia.

1 . A computerized method for evaluating the long term probability for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said method comprising:
 computing weighted deviation toward low blood glucose (WL) and estimated rate of fall of blood glucose in the low BG range (DrDn) based on said collected BG data; and   estimating the number of future SH episodes using a predetermined mathematical formula based on said computed WL and DrDn.   
     
     
         2 . The method of  claim 1 , wherein:
 said computed WL is mathematically defined from a series of BG readings x 1 , x 2 , . . . x n  taken at time points t 1 , t 2 , . . . , t n  as:   
       
         
           
             
               WL 
               = 
               
                 
                   1 
                   n 
                 
                  
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                    
                   
                     wl 
                      
                     
                       ( 
                       
                         
                           x 
                           i 
                         
                         ; 
                         2 
                       
                       ) 
                     
                   
                 
               
             
           
         
         
           where:
 wl(BG;a)=10.f(BG) a  if f(BG)>0 and 0 otherwise, 
 a=2, representing a weighting parameter, and 
 
         
         said computed DR is mathematically defined as:
 DrDn=average of s k+1 -s k , provided that s k <s k+1 , 
 where: s k =10.S(k+t 1 ) 2  for k=0,1, . . . ,
     S ( t   j )= f ( x   j ), for  j= 1 , . . . , n.    
 
 
       
     
     
         3 . The method of  claim 1 , wherein said estimated number of future SH episodes (EstNSH) is mathematically defined as :
     EstNSH= 3.3613( WL )−4.3427( DrDn )−1.2716.
   
     
     
         4 . The method of  claim 1 , further comprising:
 defining predetermined EstNSH categories, each of said EstNSH categories representing a range of values for EstNSH; and   assigning said EstNSH to at least one of said EstNSH categories.   
     
     
         5 . The method of  claim 4 , wherein said EstNSH categories are defined as follows:
 category 1, wherein said EstNSH category is less than about 0.775;   category 2, wherein said EstNSH category is between about 0.775 and about 3.750;   category 3, wherein said EstNSH category is between about 3.750 and about 7.000; and   category 4, wherein said EstNSH category is above about 7.0.   
     
     
         6 . The method of  claim 5 , further comprising:
 defining a probability of incurring a select number of SH episodes respectively for each of said assigned EstNSH categories; wherein said probability and said respective select number of SH are defined as:   said classified category 1 corresponds with about a 90% probability of incurring about 0 SH episodes and about a 10% probability of incurring about 1 or   said classified category 2 corresponds with about a 50% probability of incurring about 0 SH episodes, 25% probability of incurring about 1 to about 2 SH episodes, and 25% probability of incurring more than 2 SH episodes over the predetermined duration;   said classified category 3 corresponds with about a 25% probability of incurring about 0 SH episodes, 25% probability of incurring about 1 to about 2 SH episodes, and 50% probability of incurring more than 2 SH episodes over the predetermined duration; and   said classified category 4 corresponds with about a 20% probability of incurring about 0 to about 2 SH episodes and about a 80% probability of incurring more than 2 SH episodes over the predetermined duration.   
     
     
         7 . The method of  claim 4 , further comprising:
 defining a probability of incurring a select number of SH episodes respectively for each of said assigned EstNSH categories; and   providing at least one probability of incurring a select number of SH episodes according to said EstNSH category to which said EstNSH is assigned.   
     
     
         8 . A computerized method for evaluating the long term probability for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said method comprising:
 computing weighted deviation toward low blood glucose (WL) and estimated rate of fall of blood glucose in the low BG range (DrDn) based on said collected BG data;   estimating the number of future SH episodes using a predetermined mathematical formula based on said computed WL and DrDn; and   defining a probability of incurring a select number of SH episodes respective to said estimated SH episodes.   
     
     
         9 . A system for evaluating the long term probability for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said system comprising:
 a database component operative to maintain a database identifying said BG data;   a processor programmed to:
 computing weighted deviation toward low blood glucose (WL) and estimated rate of fall of blood glucose in the low BG range (DrDn) based on said collected BG data; and 
 estimating the number of future SH episodes using a predetermined mathematical formula based on said computed WL and DrDn. 
   
     
     
         10 . The system of  claim 9 , wherein:
 said computed WL is mathematically defined from a series of BG readings x 1 , x 2 , . . . x n  taken at time points t 1 , t 2 , . . . , t n  as:   
       
         
           
             
               WL 
               = 
               
                 
                   1 
                   n 
                 
                  
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                    
                   
                     wl 
                      
                     
                       ( 
                       
                         
                           x 
                           i 
                         
                         ; 
                         2 
                       
                       ) 
                     
                   
                 
               
             
           
         
         
           where:
 wl(BG;a)=10.f(BG) a  if f(BG)>0 and 0 otherwise, 
 a=2, representing a weighting parameter, and 
 
         
         said computed DR is mathematically defined as:
 DrDn=average of s k+1 -s k , provided that s k <s k+1 , 
 where:
     s   k =10. S ( k+t   1 ) 2  for  k= 0,1 , . . . , t   n - t   1 , 
     S ( t   j )= f ( x   j ), for  j= 1 , . . . , n.    
 
 
       
     
     
         11 . The system of  claim 9 , wherein said estimated number of future SH episodes (EstNSH) is mathematically defined as :
     EstNSH= 3.3613( WL )−4.3427( DrDn )−1.2716.
   
     
     
         12 . The system of  claim 9 , wherein said processor being further programmed to:
 define predetermined EstNSH categories, each of said EstNSH categories representing a range of values for EstNSH; and   assign said EstNSH to at least one of said EstNSH categories.   
     
     
         13 . The system of  claim 12 , wherein said EstNSH categories are defined as follows:
 category 1, wherein said EstNSH category is less than about 0.775;   category 2, wherein said EstNSH category is between about 0.775 and about 3.750;   category 3, wherein said EstNSH category is between about 3.750 and about 7.000; and   category 4, wherein said EstNSH category is above about 7.0.   
     
     
         14 . The system of  claim 13 , wherein said processor being further programmed to:
 define a probability of incurring a select number of SH episodes respectively for each of said assigned EstNSH categories, wherein said probability and said respective select number of SH are defined as:
 said classified category 1 corresponds with about a 90% probability of incurring about 0 SH episodes and about a 10% probability of incurring about 1 or 
 said classified category 2 corresponds with about a 50% probability of incurring about 0 SH episodes, 25% probability of incurring about 1 to about 2 SH episodes, and 25% probability of incurring more than 2 SH episodes over the predetermined duration; 
 said classified category 3 corresponds with about a 25% probability of incurring about 0 SH episodes, 25% probability of incurring about 1 to about 2 SH episodes, and 50% probability of incurring more than 2 SH episodes over the predetermined duration; and 
 said classified category 4 corresponds with about a 20% probability of incurring about 0 to about 2 SH episodes and about a 80% probability of incurring more than 2 SH episodes over the predetermined duration. 
   
     
     
         15 . The system of  claim 12 , wherein said processor being further programmed to:
 define a probability of incurring a select number of SH episodes respectively for each of said assigned EstNSH categories; and   provide at least one probability of incurring a select number of SH episodes according to said EstNSH category to which said EstNSH is assigned.   
     
     
         16 . A glycemic control system for evaluating the long term probability for severe hypoglycemia (SH) of a patient, said system comprising:
 a BG acquisition mechanism, said acquisition mechanism configured to acquire BG data from the patient,   a database component operative to maintain a database identifying said BG data;   a processor programmed to:   computing weighted deviation toward low blood glucose (WL) and estimated rate of fall of blood glucose in the low BG range (DrDn) based on said collected BG data; and   estimating the number of future SH episodes using a predetermined mathematical formula based on said computed WL and DrDn.   
     
     
         17 . A computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to evaluate long term probability for severe hypoglycemia (SH) of a patient based on BG data, said computer program logic comprising:
 computing weighted deviation toward low blood glucose (WL) and estimated rate of fall of blood glucose in the low BG range (DrDn) based on said collected BG data; and   estimating the number of future SH episodes using a predetermined mathematical formula based on said computed WL and DrDn.   
     
     
         18 . The computer program product of  claim 17 , wherein said computer program logic further comprises:
 defining a probability of incurring a select number of SH episodes respective to said estimated SH episodes.   
     
     
         19 . A computerized method for evaluating the short term risk for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said method comprising:
 computing weighted deviation toward low blood glucose (WL);   determining Max(wl) by calculating maximum value of wl(BG;2); and   determining risk value by taking the geometric mean of WL and Max(wl) over said predetermined duration, said risk value is mathematically defined as:
 risk value=√{square root over (WL•Max(wl))}. 
   
     
     
         20 . The method of  claim 19 , wherein:
 said computed WL is mathematically defined from a series of BG readings x 1 , x 2 , . . . , x n  taken over the predetermined duration as:   
       
         
           
             
               WL 
               = 
               
                 
                   1 
                   n 
                 
                  
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                    
                   
                     wl 
                      
                     
                       ( 
                       
                         
                           x 
                           i 
                         
                         ; 
                         2 
                       
                       ) 
                     
                   
                 
               
             
           
         
         
           where:
 wl(BG;a)=10.f(BG) a  if f(BG)>0 and 0 otherwise, 
 a=2, representing a weighting parameter. 
 
         
       
     
     
         21 . The method of  claim 19 , further comprising:
 providing a predetermined threshold risk value; and   comparing said determined risk value to said threshold risk value.   
     
     
         22 . The method of  claim 21 , wherein:
 if said determined risk value is greater than said threshold value then short term risk of incurring a hypoglycemic episode is high; and   if said determined risk value is less than said threshold value then short term risk of incurring a hypoglycemic episode is low.   
     
     
         23 . The method of  claim 22 , wherein said short term is approximately a 24 hour period. 
     
     
         24 . The method of  claim 22 , wherein said short term ranges from about 12 to about 72 hour period. 
     
     
         25 . The method of  claim 22 , wherein said threshold value is approximately 17. 
     
     
         26 . The method of  claim 22 , wherein said threshold value is between about 12 to 25. 
     
     
         27 . A system for evaluating the short term risk for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said system comprising:
 a database component operative to maintain a database identifying said BG data;   a processor programmed to:
 compute weighted deviation toward low blood glucose (WL); 
 determine Max(wl) by calculating maximum value of wl(BG;2); and 
 determine risk value by taking the geometric mean of WL and Max(wl) over said predetermined duration, said risk value is mathematically defined as:
 risk value=√{square root over (WL•Max(wl))}. 
 
   
     
     
         28 . The system of  claim 27 , wherein:
 said computed WL is mathematically defined from a series of BG readings x 1 , x 2 , . . . x n  taken over the predetermined duration as:   
       
         
           
             
               WL 
               = 
               
                 
                   1 
                   n 
                 
                  
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                    
                   
                     wl 
                      
                     
                       ( 
                       
                         
                           x 
                           i 
                         
                         ; 
                         2 
                       
                       ) 
                     
                   
                 
               
             
           
         
         
           where:
 wl(BG;a)=10.f(BG) a  if f(BG)>0 and 0 otherwise, 
 a=2, representing a weighting parameter. 
 
         
       
     
     
         29 . The system of  claim 27 , wherein said processor being further programmed to:
 provide a predetermined threshold risk value; and   compare said determined risk value to said threshold risk value.   
     
     
         30 . The system of  claim 29 , wherein:
 if said determined risk value is greater than said threshold value then short term risk of incurring a hypoglycemic episode is high; and   if said determined risk value is less than said threshold value then short term risk of incurring a hypoglycemic episode is low.   
     
     
         31 . The system of  claim 30 , wherein said short term is approximately a 24 hour period. 
     
     
         32 . The system of  claim 30 , wherein said short term ranges from about 12 to about 72 hour period. 
     
     
         33 . The system of  claim 30 , wherein said threshold value is approximately 17. 
     
     
         34 . The system of  claim 30 , wherein said threshold value is between about 12 to 25. 
     
     
         35 . A glycemic control system for evaluating the short term risk for severe hypoglycemia (SH) of a patient, said system comprising:
 a BG acquisition mechanism, said acquisition mechanism configured to acquire BG data from the patient,   a database component operative to maintain a database identifying said BG data;   a processor programmed to:
 compute weighted deviation toward low blood glucose (WL); 
 determine Max(wl) by calculating maximum value of wl(BG;2); and 
 determine risk value by taking the geometric mean of WL and Max(wl) over said predetermined duration, said risk value is mathematically defined as:
 risk value=√{square root over (WL•Max(wl))}. 
 
   
     
     
         36 . A computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to evaluate the short term risk for severe hypoglycemia (SH) of a patient based on BG data collected over a predetermined duration, said computer program logic comprising:
 computing weighted deviation toward low blood glucose (WL);   determining Max(wl) by calculating maximum value of wl(BG;2); and   determining risk value by taking the geometric mean of WL and Max(wl) over said predetermined duration, said risk value is mathematically defined as:
 risk value=√{square root over (WL•Max(wl))}. 
   
     
     
         37 . The computer program product of  claim 36 , wherein said computer program logic further comprises:
 providing a predetermined threshold risk value; and   comparing said determined risk value to said threshold risk value.