System and method for preventing hypoglycaemia in a human type 1 diabetic patient during physical activity

• US 9,204,826 B2
• Filed: 07/28/2006
• Issued: 12/08/2015
• Est. Priority Date: 07/29/2005
• Status: Expired due to Fees

• Current Assignee: Universita' Degli Studi Di Trieste (Repubblica Italiana), Universita' Degli Studi Di Udine (Repubblica Italiana)
• Original Assignee: Universita' Degli Studi Di Trieste (Repubblica Italiana), Universita' Degli Studi Di Udine (Repubblica Italiana)
• Inventors: Francescato, Maria P., Geat, Mario, Blokar, Marco, Silli, Elena, Accardo, Agostino, Carrato, Sergio
• Primary Examiner(s): Thomson, William
• Assistant Examiner(s): Archer, Marie
• Application Number:
  US11/996,984
• Publication Number:
  US 20080214905A1
• Time in Patent Office: 3,420 Days
• Field of Search: 600/316, 600/365, 600/508, 600300-301, 606/301
• US Class Current: 1/1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising

Abstract

A method for estimating the amount of carbohydrates needed by a DP-1 during a specific session of physical activity, comprises the following steps: defining of working constants and standard parameters; introducing of patient and therapy specific parameters, calculating of patient specific reference curves for a percentage carbohydrates consumption (% CHO); scheduling a training session; estimating the amount of carbohydrates (CHO) to be eaten before said physical activity; updating in real time the residual carbohydrates still available during said physical activity; and estimating the amount of carbohydrates to be restored after said physical activity.

Claims

1. A method for preventing hypoglycaemia in a DP-1 during physical activity, comprising the following steps:

providing a processing unit including memory that stores a program code that performs calculations and stores parameters of a process, the process comprising the steps of;

defining of working constants and standard parameters;

introducing of patient and therapy specific parameters;

calculating of patient specific reference curves for a percentage carbohydrates consumption (% CHO);

scheduling a training session;

estimating the amount of carbohydrates (CHO) to be eaten before said physical activity;

updating in real time the residual carbohydrates still available during said physical activity; and

calculating the amount of carbohydrates to be restored after said physical activity

wherein;

said step of introducing of patient and therapy specific parameters comprises the value of glucose oxidation rate approximated with a linear relationship characterized by a slope (BGm) and intercept (BGq), as a carbohydrates consumption (grams/minutes) in function of the heart rate (beats/minutes) and said step of updating in real time the residual carbohydrates still available during said physical activity comprises a calculation performed continuously of the current glucose oxidation rate calculated as the current heart rate using a linear relation and wherein a value of required carbohydrates for performing the physical activity is continuously calculated by multiplying the current glucose oxidation rate by the % CHO at the current time and wherein the amount of required carbohydrates for the physical activity is updated by accumulating the value of required carbohydrates calculated at a previous time

wherein said step of defining the working constants and standard parameters comprises the steps of;

defining the number of hours of contribution of dinner insulin;

defining the relationship between effective insulinemy and percentage carbohydrates defining the standard sensibility;

defining a reference glycemic curve;

defining the type-specific insulin curves; and

defining a type-specific standard insulin dose and wherein said relationship between effective insulinemy and percentage carbohydrates is a linear relationship having a slope mpg=4.398 and intercept qpg=10.76.

2. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein the number of hours to be defined in said step of defining the number of hours of contribution of dinner insulin is 7 hours.

3. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said standard sensibility is set as 4.836.

4. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said reference glycemic curve represents the standard value of glycaemia as a function of the time elapsed from the last meal.

5. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said type-specific insulin curves are curves representing the specific behaviour of each kind of insulin, presented as insulin blood concentration in function of time.

6. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said type-specific standard insulin dose is the standard amount of insulin yielding said type-specific insulin curves.

7. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of introducing of patient and therapy specific parameters further comprises the following values:

age;

weight;

sex;

extra cellular fluid (ECF).

8. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 7, wherein said value for the (ECF) when not available it can be approximated to (in Litres) 27% of the weight for men, and 22.5% of the weight for women.

9. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein for each insulin assumption of the patient the following information must be specified:

kind of insulin;

dose in units;

time of the injection.

10. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of determining the personal glucose oxidation rate relationship of a patient can be obtained by performing measures during controlled physical activity of said patient and then performing a linear regression on the obtained set of values.

11. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of calculating patient specific reference curves for a percentage carbohydrates consumption (% CHO) further comprises the following steps:

calculating a dose ratio for each assumed insulin, said dose ratio being obtained by dividing the assumed units of insulin by the weight of the subject, and then dividing by the standard dose for the assumed insulin;

calculating for each assumed insulin a specific curve thereof by multiplying a corresponding standard curve by the dose ratio calculated on the abovementioned step;

cumulating each specific curve to obtain an overall insulinemia of the patient expressed as a concentration of micro units of insulin in the blood;

calculating a value of insulin for a period as a ratio between the cumulated insulin of a predetermined period and the overall insulin of a day, and multiplied by the units of insulin actually assumed;

calculating the ratio between eaten carbohydrates and a sum of all the insulin for the period obtained at the previous step for each of the predetermined periods of the day, the obtained value being subsequently divided for a standard sensibility as obtained in the preceding steps to obtain a sensibility for the period in grams of carbohydrates per units of insulin, which indicates the ability of insulin to oxidize the carbohydrates;

summing the curves of all the insulin assumptions to obtain a curve representing a blood concentration of insulin as a function of time, and obtaining a curve of the total insulinemia for the whole day, said curve of the total insulinemia being further multiplied by said sensibility to obtain an effective insulinemia; and

normalizing the effective insulinemia into % CHO curves by a linear function having as slope (mpg) and as intercept (qpg).

12. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of scheduling the training session comprises the following data:

intensity of the activity, expressed as heart beats per minute (bpm);

starting time;

duration;

glycaemia half an hour before the starting time.

13. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of estimating of required carbohydrates to be eaten comprises the following steps:

calculating the grams of carbohydrates oxidized per minute, using a linear function of the bpm of the activity, having as slope (BGm) and as intercept (BGq);

multiplying the grams of carbohydrates oxidized per minute times a session duration obtaining, the total value of oxidized carbohydrates;

calculating the effective amount of carbohydrates to be assumed before an end of the specific session of physical activity by multiplying the estimated carbohydrates oxidation of the previous step by the %CHO consumption within the time range that goes from the beginning of the session to its end;

calculating the actual carbohydrates surplus as the carbohydrates already available in the patient body before the activity, by multiplying an ECF by the difference between the glycaemia half an hour before said activity and the standard reference glycaemia for that time defined by a reference glycemic curve; and

obtaining the estimated amount of carbohydrates to be assumed as the difference of the effective amount of carbohydrates to be consumed and the actual carbohydrates surplus.

14. The method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 1, wherein said step of updating in real time the residual carbohydrates still available during said physical activity further comprises the following calculations performed continuously:

the value of the corresponding required carbohydrates calculated by multiplying the current glucose oxidation rate by the % CHO at the current time; and

the amount of overall required carbohydrates being updated cumulating the value of carbohydrates calculated in the previous step.

15. Apparatus for carrying out a method for preventing hypoglycaemia in a DP-1 during physical activity, comprising:

a processor configured for executing program code that performs calculations and stores parameters of a process for preventing hypoglycaemia in a DP-1 patient, the process including the steps of;

defining of working constants and standard parameters including the steps of defining the number of hours of contribution of dinner insulin;

defining the relationship between effective insulinemy and percentage carbohydrates defining the standard sensibility;

defining a reference glycemic curve;

defining the type-specific insulin curves; and

defining a type-specific standard insulin dose and wherein said relationship between effective insulinemy and percentage carbohydrates is a linear relationship having a slope mpg=4.398 and intercept qpg=10.76;

introducing of patient and therapy specific parameters including the value of glucose oxidation rate approximated with a linear relationship characterized by a slope (BGm) and intercept (BGq), as a carbohydrates consumption (grams/minutes) in function of the heart rate (beats/minutes) and said step of updating in real time the residual carbohydrates still available during said physical activity comprises a calculation performed continuously of the current glucose oxidation rate calculated as the current heart rate using a linear relation and wherein a value of required carbohydrates for performing the physical activity is continuously calculated by multiplying the current glucose oxidation rate by the % CHO at the current time and wherein the amount of required carbohydrates for the physical activity is updated by accumulating the value of required carbohydrates calculated at a previous time;

calculating of patient specific reference curves for a percentage carbohydrates consumption (% CHO);

scheduling a training session;

estimating the amount of carbohydrates (CHO) to be eaten before said physical activity;

updating in real time the residual carbohydrates still available during said physical activity; and

calculating the amount of carbohydrates to be restored after said physical activity;

a chest strap detecting a heart rate of a patient and linked with the processor for introducing of patient and therapy specific parameters;

a control and input panel linked with the processor for inputting patient and therapy specific parameters;

data memory linked to the processor storing the patient and therapy specific parameters and a history of various sessions;

a power supply linked with the apparatus;

a display linked with the processor for displaying calculated values, patient and therapy parameters, current status and alarms in case of critical conditions;

a PC connection linked with the processor for communicating with an external device;

memory interfaces linked with the processor for communicating with an external device;

output peripherals including LEDs and a beeper linked with the processor providing an output response.

16. Apparatus for carrying out the method for preventing hypoglycaemia in a DP-1 during physical activity according to claim 15, wherein the apparatus overall sizes are chosen among the following group:

an integration in gym or electro-medical devices fixed apparatus;

a wrist watch-like apparatus/device;

belt supported apparatus;

necklace supported apparatus;

arm-wearable supported;

simple pocket apparatus.

17. A method for preventing hypoglycaemia in a DP-1 during physical activity, comprising the following steps:

providing a processing unit including memory that stores a program code that performs calculations and stores parameters of a process, the process comprising the steps of;

defining of working constants and standard parameters;

introducing of patient and therapy specific parameters;

calculating of patient specific reference curves for a percentage carbohydrates consumption (% CHO);

scheduling a training session;

estimating the amount of carbohydrates (CHO) to be eaten before said physical activity;

updating in real time the residual carbohydrates still available during said physical activity; and

calculating the amount of carbohydrates to be restored after said physical activity

wherein;

said step of introducing of patient and therapy specific parameters comprises the value of glucose oxidation rate approximated with a linear relationship characterized by a slope (BGm) and intercept (BGq), as a carbohydrates consumption (grams/minutes) in function of the heart rate (beats/minutes) and said step of updating in real time the residual carbohydrates still available during said physical activity comprises a calculation performed continuously of the current glucose oxidation rate calculated as the current heart rate using a linear relation and wherein a value of required carbohydrates for performing the physical activity is continuously calculated by multiplying the current glucose oxidation rate by the % CHO at the current time and wherein the amount of required carbohydrates for the physical activity is updated by accumulating the value of required carbohydrates calculated at a previous time and wherein said step of introducing of patient and therapy specific parameters further comprises the following values;

age;

weight;

sex; and

extra cellular fluid (ECF), wherein said value for the (ECF) when not available it can be approximated to (in Litres) 27% of the weight for men, and 22.5% of the weight for women.

18. A method for preventing hypoglycaemia in a DP-1 during physical activity, comprising the following steps:

providing a processing unit including memory that stores a program code that performs calculations and stores parameters of a process, the process comprising the steps of;

defining of working constants and standard parameters;

introducing of patient and therapy specific parameters;

calculating of patient specific reference curves for a percentage carbohydrates consumption (% CHO);

scheduling a training session;

estimating the amount of carbohydrates (CHO) to be eaten before said physical activity;

updating in real time the residual carbohydrates still available during said physical activity; and

calculating the amount of carbohydrates to be restored after said physical activity wherein;

said step of introducing of patient and therapy specific parameters comprises the value of glucose oxidation rate approximated with a linear relationship characterized by a slope (BGm) and intercept (BGq), as a carbohydrates consumption (grams/minutes) in function of the heart rate (beats/minutes) and said step of updating in real time the residual carbohydrates still available during said physical activity comprises a calculation performed continuously of the current glucose oxidation rate calculated as the current heart rate using a linear relation and wherein a value of required carbohydrates for performing the physical activity is continuously calculated by multiplying the current glucose oxidation rate by the % CHO at the current time and wherein the amount of required carbohydrates for the physical activity is updated by accumulating the value of required carbohydrates calculated at a previous time

wherein said step of defining the working constants and standard parameters comprises the steps of;

defining the number of hours of contribution of dinner insulin;

defining the relationship between effective insulinemy and percentage carbohydrates

defining the standard sensibility;

defining a reference glycemic curve;

defining the type-specific insulin curves; and

defining a type-specific standard insulin dose and wherein said standard sensibility is set as 4.836.