Diabetes management system and method for controlling blood glucose

Abstract

A diabetes management system for predicting a future blood glucose value of a patient and for recommending a corrective action to the patient when the future blood glucose value lies outside of a target range. The system includes a patient-operated apparatus for measuring blood glucose values and for storing data relating to insulin doses administered to the patient. The apparatus predicts the patient's future blood glucose value based upon the patient's current blood glucose value, the fraction of insulin action remaining from the insulin doses, and the patient's insulin sensitivity. The apparatus also determines the corrective action for the patient when the predicted blood glucose value lies outside of a target range. The system also includes a physician computer in communication with the apparatus for receiving the blood glucose values and insulin dose data and for calculating an adjusted insulin sensitivity for use in subsequent predictions.

Description

CONTINUATION APPLICATION INFORMATION

This application is a

After displaying supplemental insulin dose D, microprocessor 22 determines if the patient wishes to enter a dose value for the supplemental insulin dose by displaying the prompt “SUPPLEMENTAL INSULIN TAKEN? YES/NO?”, step 230. In response to a NO input from the patient, the program module ends. In response to a YES input, microprocessor 22 proceeds to step 232, entering and storing the dose value and insulin type of supplemental insulin dose D. Step 232 is analogous to step 104 previously described with reference to FIG. 7A. Following step 232, the program module ends.

In step 234, microprocessor 22 determines if glucose value G(t_j) is less than hypoglycemic value H. If future blood glucose value G(t_j) is not less than hypoglycemic value H, microprocessor 22 proceeds to step 240. If glucose value G(t_j) lies below hypoglycemic value H, microprocessor 22 audibly alerts the patient by causing speaker 54 to emit audible tones, step 236. This alerts the patient that he or she is likely to develop hypoglycemia unless a carbohydrate supplement is taken.

In step 238, microprocessor 22 calculates a number B of grams of carbohydrates to be consumed by the patient and displays a recommendation to consume number of grams B, step 238. Following step 238, the program module ends. Microprocessor 22 preferably calculates number of grams B in dependence upon carbohydrate value C and the difference between future blood glucose value G(t_j) and target blood glucose value T according to equation (4):
B=(T−G(t_j))/C  (4).
If future blood glucose value G(t_j) is not less than hypoglycemic value H, then glucose value G(t_j) lies in a range between hypoglycemic value H and minimum value R_min.

In this case, microprocessor 22 displays to the patient “POSSIBLE FUTURE HYPOGLYCEMIA: RECOMMEND SUBSEQUENT GLUCOSE MEASUREMENT IN 1.5 HOURS”, step 240. Following step 240, the program module ends. Because the patient's blood glucose concentration may rebound, it is presently preferred not to recommend a carbohydrate supplement unless future blood glucose value G(t_j) is below hypoglycemic value H.

FIG. 10 is a flow chart illustrating the steps included in the graph program module of step 220. In steps 302-310, microprocessor 22 generates a plurality of predicted future blood glucose values for various time points between time t_d and time t_j. The future blood glucose values are used to generate blood glucose value curve 50 of graph 48. In the preferred embodiment, the future blood glucose values are calculated for time points which increase from time t_d to time t_j in five minute increments. It is obvious that the time increments may be varied as desired in alternative embodiments.

In step 302, microprocessor 22 sets time t_j equal to time t_d plus five minutes. In step 304, microprocessor 22 determines insulin action values F_k(t_j) for each dose value I_k stored in memory 24. Step 304 is analogous to step 210 previously described with reference to FIG. 9A. In step 306, microprocessor 22 calculates future blood glucose value G(t_j). Step 306 is analogous to step 214 previously described with reference to FIG. 9A.

In step 308, microprocessor 22 determines if time t_j is greater than or equal to the ultimate time point at which the last insulin dose k injected by the patient will have no insulin action remaining. If time t_j is not greater than or equal to the ultimate time point, microprocessor 22 sets time t_j equal to time t_j plus five minutes, step 310. Microprocessor 22 then repeats steps 304-308 to calculate a subsequent future blood glucose value.

If time t_j is greater than or equal to the ultimate time point, microprocessor 22 generates blood glucose value curve 50 from the calculated future blood glucose values and displays graph 48 on display 14, step 312. Following step 312, the graph program module ends. As shown in FIG. 1, graph 48 includes line 52 indicating the patient's hypoglycemic threshold and line 53 indicating the patient's hyperglycemic threshold. Lines 52 and 53 enable the patient to determine the time point at which he or she is predicted to develop hypoglycemia and hyperglycemia, respectively.

The diabetes management system of the present invention provides a significant improvement over conventional diabetes management systems by alerting the patient to the possible development of hypoglycemia or hyperglycemia between meals, thereby allowing the patient to take early corrective action. Conventional management systems are unable to account for the insulin action remaining from previous insulin doses and therefore restrict insulin supplements to pre-meal times. Thus, in using these conventional systems, the patient must wait until the next meal time to correct hyperglycemia, and may develop hypoglycemia without warning.

The following is an illustrative example of how apparatus 10 assists a patient in preventing hyperglycemia between meals. The example assumes the patient has an insulin sensitivity value of 40 mg/dl per unit, a target blood glucose range of 100 mg/dl-150 mg/dl, a target blood glucose value of 120 mg/dl, a hypoglycemic value of 70 mg/dl, and a carbohydrate value of 4 mg/dl per gram.

In the example, the patient eats a late dinner at 8:40 PM. Before eating, the patient estimates that the meal requires 15 units of bolus insulin and injects 15 units of lispro at 8:30 PM. The patient records the dose value, dose type, and time of injection in apparatus 10. At bedtime, 11:00 PM, the patient uses apparatus 10 to measure his or her blood glucose value. Apparatus 10 produces and displays to the patient a current blood glucose value of 480 mg/dl. The patient then requests apparatus 10 to predict a future blood glucose value at the ultimate time point.

Microprocessor 22 retrieves from memory 24 the dose value and corresponding insulin type of the dose injected by the patient at 8:30 PM. Microprocessor 22 calculates time after injection value Z_k to be 150 minutes. Microprocessor 22 then retrieves from Table 2 the values X₀=150 minutes, Y₀=0.40, X₁=165 minutes, and Y₁=0.32. Microprocessor 22 calculates insulin action value F_k(t_d) from equation (2B) as:

$F_k\left(t_d\right)=0.40+\frac{\left(150-150\right)\left(0.32-0.40\right)}{\left(165-150\right)}=0.40.$

Microprocessor 22 thus determines that the lispro insulin dose injected at 8:30 PM has 40% of its insulin action remaining at 11:00 PM. Microprocessor 22 also sets insulin action value F_k(t_j) equal to 0.0 for each dose value stored in memory 24. For simplicity of understanding, the example assumes that only the dose injected at 8:30 PM has remaining insulin action. Microprocessor 22 then calculates the predicted blood glucose value at 3:00 AM according to equation (1) as:
G(t_j)=480−40(15×.40)=240 mg/dl.
This indicates that the patient can expect an ultimate blood glucose value of 240 mg/dl when the insulin dose has been completely absorbed. The predicted value of 240 mg/dl is greater than the patient's maximum value of 150 mg/dl, so microprocessor 22 calculates a supplemental insulin dose for the patient and displays the recommended supplement on display 14. The supplemental dose D is calculated from equation (3) as:
D=(240−120)/40=3 units of supplemental insulin.

The patient takes the supplemental insulin dose and records the dose value in apparatus 10. From taking the supplemental insulin dose, the patient obtains eight hours of normal blood glucose in place of hyperglycemia. An adjusted insulin sensitivity may also be determined from the dose values and measured blood glucose values recorded in apparatus 10 as follows. The next morning, the patient measures his or her pre-breakfast blood glucose value using apparatus 10. The patient then transmits the recorded dose values and blood glucose values measured at bedtime and before breakfast to healthcare provider computer 38.

An adjusted insulin sensitivity value is calculated in healthcare provider computer 38 by subtracting the pre-breakfast blood glucose value from the bedtime blood glucose value. The result is divided by the total number of units of insulin which had remaining insulin action at bedtime. The number of units of insulin having remaining insulin action at bedtime is equal to the total number of units of the supplemental insulin dose plus the fraction of any previously injected insulin doses having remaining action.

An illustrative example will now be given using the same values presented above, where the patient's bedtime blood glucose value equals 480 mg/dl, the supplemental insulin dose value equals 3 units, and the fraction of insulin action remaining from a previous 15 unit insulin dose is 0.40. The present example further assumes a pre-breakfast blood glucose value of 138 mg/dl measured the following morning. The adjusted sensitivity value is calculated as:
S=(480−138)/(3+(15×0.40))=38 mg/dl per unit.
The insulin sensitivity value S is preferably updated over time as a moving average of the individually calculated sensitivity values.

A second example illustrates how apparatus 10 assists a patient in preventing hypoglycemia. The second example assumes the same values presented in the first example except that the patient's blood glucose value at 11:00 PM is now assumed to be 280 mg/dl. Microprocessor 22 calculates the predicted glucose value at 3:00 AM from equation (1) as:
G(t_j)=280−40(15×0.40)=40 mg/dl.
The predicted value of 40 mg/dl is less than the patient's hypoglycemic value of 70 mg/dl. Accordingly, microprocessor 22 calculates a carbohydrate supplement and displays the number of grams of carbohydrates to be consumed by the patient. The number of grams of carbohydrates is calculated from equation (4) as:
B=(120 mg/dl−40 mg/dl)/4=20 grams.
The patient consumes the carbohydrate supplement and successfully avoids hypoglycemia.

SUMMARY, RAMIFICATIONS, AND SCOPE

Although the above description contains many specificities, these should not be construed as limitations on the scope of the invention but merely as illustrations of the presently preferred embodiment. Many other embodiments of the invention are possible. For example, the system of the invention may be implemented in many different hardware configurations. It is presently preferred to provide the patient with a small, portable apparatus to facilitate use of the apparatus throughout the day. However, in alternative embodiments, the apparatus may comprise a personal computer, a multi-media processor connected to a television, or any other electronic device capable of performing the functions described.

Additionally, the system is not limited to establishing a communication link between the apparatus and healthcare provider computer through a telephone line or data connection cord. Those skilled in the art will recognize that the apparatus may be placed in communication with the healthcare provider computer through a computer network, a wireless communication network, or a data storage card, such as a smart card, exchanged between the physician and patient. Specific techniques for establishing communication links between a physician and a remotely located patient are well known in the art.

The insulin sensitivity values and insulin action values for determining remaining insulin action may differ in alternative embodiments. The values shown in the preferred embodiment are exemplary of one possible embodiment of the invention and are not intended to limit its scope. Further, the insulin action values may be derived from standard data or derived from the blood glucose values and insulin dose values of an individual patient. The insulin action values may be further customized to the individual patient in dependence upon the patient's preferred mode of insulin administration, e.g. syringe injections into the thigh, gut, or arm, insulin pump administrations, or inhalation.

Further, the insulin action values need not be stored in tabular form. In an alternative embodiment, the apparatus stores first and second mathematical equations derived from the insulin action curves. The first equation expresses remaining insulin action as a function of time after injection of a dose of regular insulin. The second equation expresses remaining insulin action as a function of time after injection of a dose of lispro insulin. In this embodiment, the apparatus determines an insulin action value by determining the time after injection and calculating the insulin action value using the equation corresponding to the type of insulin injected.

The preferred embodiment includes a patient-operated apparatus and a healthcare provider computer in communication with the apparatus. This configuration of system components is presently preferred for ease of setting, storing, and adjusting the target blood glucose value and insulin sensitivity value of the patient under the supervision of a healthcare provider. However, those skilled in the art will recognize that the apparatus itself may also be programmed to adjust the patient's insulin sensitivity value based upon the stored blood glucose values and insulin dose values, eliminating the need for the healthcare provider computer if physician review is deemed unnecessary.

It is presently preferred to include a blood glucose meter in the apparatus for automated entry of blood glucose values. However, the apparatus need not include a blood glucose meter. In one alternative embodiment, the blood glucose meter is separate from the apparatus and the patient manually enters measured blood glucose values into the apparatus through the keypad. In another embodiment, the blood glucose meter is connectable to the apparatus through a serial input/output port for automated uploading of the blood glucose values. Similarly, in embodiments of the apparatus which include a modem, the modem need not be built into the apparatus. In alternative embodiments, the apparatus may be adapted to receive a separate modem card, as is well known in the art.

Moreover, the apparatus is not limited to storing patient data relating only to blood glucose and insulin dose values. In alternative embodiments, the apparatus also stores guidelines for diet, exercise, and other therapy parameters. Further, the apparatus may be programmed to prompt a patient for data relating to the therapy parameters and to display recommended guidelines to the patient.

Additionally, the invention may also be implemented as a simulation system for educating and training patients in blood glucose control. In the simulation embodiment, the insulin dose values are representative of simulated insulin doses and the blood glucose values are representative of simulated blood glucose concentrations. The patient enters various insulin dose values and blood glucose values in the simulation system to learn their effect on his or her future blood glucose concentration.

Therefore, the scope of the invention should be determined not by the examples given but by the appended claims and their legal equivalents.

Claims

1. An apparatus for assisting a patient having diabetes mellitus in controlling blood glucose, said apparatus comprising:

a) an input means for entering a blood glucose value g(t_d) representative of a blood glucose concentration of the patient at time t_d and for entering an insulin dose value I_k representative of an insulin dose administered to the patient prior to time t_d;

b) a memory means for storing an insulin sensitivity value representative of an insulin sensitivity of the patient and for storing information for determining an insulin action value f_k(2^d) representative of a fraction of insulin action remaining at time t_d from said insulin dose;

c) a processor connected to said input means and said memory means for determining said insulin action value f_k(t_d) and for determining a future blood glucose value g(t_j) representative of an expected blood glucose concentration of the patient at time t_j, wherein said processor determines said future blood glucose value g(t_j) in dependence upon said blood glucose value g(t_d), said insulin dose value I_k, said insulin sensitivity value, and said insulin action value f_k(t_d);

d) an interpolation formula to calculate the insulin action value f_k(t_d) programmed into the processor, the formula to calculate the insulin action value comprising

f_k(t_d)=Y₀+((Z_k−X₀)(Y₁−Y₀)/(X₁−X₀))

2. The apparatus of claim 1, wherein said memory means includes means for storing maximum and minimum values defining a target blood glucose range of the patient, said processor includes means for determining if said future blood glucose value g(t_j) lies outside of said target range and means for determining said corrective action for the patient when said future blood glucose value g(t_j) lies outside of said target range, and said display means includes means for recommending said corrective action to the patient.

3. The apparatus of claim 2, wherein said memory means further includes means for storing a target blood glucose value of the patient, said corrective action comprises an administration of a supplemental insulin dose, and said processor further comprises means for determining said supplemental insulin dose in dependence upon said insulin sensitivity value and a difference between said future blood glucose value g(t_j) and said target blood glucose value.

4. The apparatus of claim 2, wherein said memory means further includes means for storing a target blood glucose value of the patient, said corrective action comprises a consumption of a number of grams of carbohydrates, and said processor further comprises means for determining said number of grams in dependence upon a difference between said future blood glucose value g(t_j) and said target blood glucose value.

5. The apparatus of claim 1, wherein said memory means further includes means for storing a hypoglycemic value indicative of a hypoglycemic threshold of the patient, said processor includes means for determining if said future blood glucose value g(t_j) lies below said hypoglycemic value, and said apparatus further comprises audio means connected to aid processor for audibly alerting the patient when said future blood glucose value g(t_j) lies below said hypoglycemic value.

6. The apparatus of claim 1, wherein said input means comprises a blood glucose measuring means for measuring a blood sample of the patient and for producing said blood glucose value g(t_d) from a measurement of said blood sample.

7. The apparatus of claim 1, wherein said insulin dose has an insulin type, said input means includes means for entering said insulin type, and said processor includes means for determining said insulin action value f_k(t_d) in dependence upon said insulin type.

8. The apparatus of claim 7, wherein said insulin type is selected from the group consisting of regular insulin and lispro insulin.

9. The apparatus of claim 1, wherein said processor includes means for determining an insulin action value f_k(t_j) representative of a fraction of insulin action remaining at time t_j from said insulin dose and means for determining said future blood glucose g(t_j) in further dependence upon said insulin action value f_k(t_j).

10. The apparatus of claim 1, wherein said processor includes means for determining an ultimate time point at which said insulin dose will have no insulin action remaining and means for setting time t_j equal to said ultimate time point.

11. The apparatus of claim 1, wherein said processor includes means for determining a plurality of future blood glucose values representative of a corresponding plurality of expected blood glucose concentrations of the patient, and wherein said display means includes means for displaying said future blood glucose values in graphical form.

12. The apparatus of claim 1, further comprising a communication means connected to said processor for establishing a communication link between said apparatus and a healthcare provider computer and for transmitting and receiving data therebetween.

13. The apparatus of claim 12, wherein said communication means comprises a modem means for establishing said communication link through a communication network.

14. The apparatus of claim 12, wherein said communication means comprises an input/output port for establishing said communication link through a connection cord.

15. A system for assisting a patient having diabetes mellitus in controlling blood glucose, said system comprising:

a) an input means for entering a blood glucose value g(t_d) representative of a blood glucose concentration of the patient at time t_d and for entering an insulin dose value I_k representative of an insulin dose administered to the patient prior to time t_d;

b) a memory means for storing maximum and minimum values defining a target blood glucose range of the patient, an insulin sensitivity value representative of an insulin sensitivity of the patient, and information for determining an insulin action value f_k(t_d) representative of a fraction of insulin action remaining at time t_d from said insulin dose;

c) a processor connected to said input means and said memory means for determining said insulin action value f_k(t_d), for determining a future blood glucose value g(t_j) representative of an expected blood glucose concentration of the patient at time t_j, and for determining a corrective action for the patient when said future blood glucose value g(t_j) lies outside of said target range, wherein said processor determines said future blood glucose value g(t_j) in dependence upon said blood glucose value g(t_d), said insulin dose value, said insulin sensitivity value, and said insulin action value f_k(t_d); and

d) an interpolation formula to calculate the insulin action value f_k(t_d) programmed into the processor, the formula to calculate the insulin action value comprising:

f_k(t_d)=Y₀+((Z_k−X₀)(Y₁−Y₀)/(X₁−X₀))

16. The system of claim 15, wherein said memory means further includes means for storing a target blood glucose value of the patient, said corrective action comprises an administration of a supplemental insulin dose, and said processor further comprises means for determining said supplemental insulin dose in dependence upon said insulin sensitivity value and a difference between said future blood glucose value g(t_j) and said target blood glucose value.

17. The system of claim 15, wherein said memory means further includes means for storing a target blood glucose value of the patient, said corrective action comprises a consumption of a number of grams of carbohydrates, and said processor further comprises means for determining said number of grams in dependence upon a difference between said future blood glucose value g(t_j) and said target blood glucose value.

18. The system of claim 15, wherein said memory means further includes means for storing a hypoglycemic value indicative of a hypoglycemic threshold of the patient, said processor includes means for determining if said future blood glucose g(t_j) lies below said hypoglycemic value, and said system further comprises audio means connected to said processor for audibly alerting the patient when said future blood glucose value g(t_j) lies below said hypoglycemic value.

19. The system of claim 15, wherein said input means comprises a blood glucose measuring means for measuring a blood sample of the patient and for producing said blood glucose value g(t_d) from a measurement of said blood sample.

20. The system of claim 15, wherein said insulin dose has an insulin type, said input means includes means for entering said insulin type, and said processor includes means for determining said insulin action value f_k(t_d) in dependence upon said insulin type.

21. The system of claim 20, wherein said insulin type is selected from the group consisting of regular insulin and lispro insulin.

22. The system of claim 15, wherein said processor includes means for determining an insulin action value f_k(t_j) representative of a fraction of insulin action remaining at time t_j from said insulin dose and means for determining said future blood glucose value g(t_j) in further dependence upon said insulin action value f_k(t_j).

23. The system of claim 15, wherein said processor includes means for determining an ultimate time point at which said insulin dose will have no insulin action remaining and means for setting time t_j equal to said ultimate time point.

24. The system of claim 15, wherein said processor includes means for determining a plurality of future blood glucose values representative of a corresponding plurality of expected blood glucose concentrations of the patient, and wherein said display means includes means for displaying said future blood glucose values in graphical form.

25. The system of claim 15, wherein said input means includes means for entering a plurality of blood glucose values and a plurality of insulin dose values, and said system further comprises a computing means in communication with said processor for receiving said blood glucose values and said insulin dose values and for calculating from said blood glucose values and said insulin dose values an adjusted insulin sensitivity value.

26. The system of claim 25, wherein said input means, said memory means, said processor, and said display means are included in a patient-operated apparatus, said computing means comprises a healthcare provider computer, and said apparatus includes a communication means connected to said processor for establishing a communication link between said apparatus and said healthcare provider computer.

27. The system of claim 26, wherein said communication means comprises a modem means for establishing said communication link through a communication network.

28. The system of claim 26, wherein said communication means comprises an input/output port for establishing said communication link through a connection cord.

29. A method for assisting a patient having diabetes mellitus in controlling blood glucose, said method comprising the following steps:

a) providing the patient with an apparatus for determining a future blood glucose value g(t_j) representative of an expected blood glucose concentration of the patient at time t_j, wherein said apparatus comprises a memory, an input means for entering a blood glucose value g(t_d) representative of a blood glucose concentration of the patient at time t_d and for entering an insulin dose value representative of an insulin dose administered to the patient prior to time t_d, a display, and a processor connected to said memory, said input means, and said display;

b) storing in said memory an insulin sensitivity value representative of an insulin sensitivity of the patient;

c) storing in said memory information for determining an insulin action value f_k(t_d) representative of a fraction of insulin action remaining at time t_d from said insulin dose;

d) entering in said processor said insulin dose value and said blood glucose value g(t_d);

e) determining in said processor said insulin action value f_k(t_d) by programming the processor to execute an interpolation formula to calculate the insulin action value f_k(t_d) programmed into the processor, the formula to calculate the insulin action value comprising:

f_k(t_d)=Y₀+((Z_k−X₀)(Y₁−Y₀)/(X₁−X₀))

30. The method of claim 29, further comprising the step of determining in said processor an insulin action value f_k(t_j) representative of a fraction of insulin action remaining at time t_j, from said insulin dose, and wherein said future blood glucose value g(t_j) is determined in further dependence upon said insulin action value f_k(t_j).

31. The method of claim 29, wherein the step of determining said future blood glucose value g(t_j) is preceded by the steps of determining in said processor an ultimate time point at which said insulin dose will have no insulin action remaining and setting time t_j equal to said ultimate time point.

32. The method of claim 29, further comprising the steps of determining in said processor a plurality of future blood glucose values representative of a corresponding plurality of expected blood glucose concentrations of the patient and displaying said future blood glucose values in graphical form on said display.

33. The method of claim 29, further comprising the steps of storing in said memory maximum and minimum values defining a target blood glucose range of the patient, determining in said processor if said future blood glucose value g(t_j) lies outside of said target range, determining in said processor said corrective action for the patient when said future blood glucose value g(t_j) lies outside of said target range, and recommending said corrective action on said display.

34. The method of claim 33, wherein said corrective action comprises an administration of a supplemental insulin dose, and said method further comprises the steps of storing in said memory a target blood glucose value of the patient and determining in said processor said supplemental insulin dose in dependence upon said insulin sensitivity value and a difference between said future blood glucose value g(t_j) and said target blood glucose value.

35. The method of claim 33, wherein said corrective action comprises a consumption of a number of grams of carbohydrates, and said method further comprises the steps of storing in said memory a target blood glucose value of the patient and determining in said processor said number of grams in dependence upon a difference between said future blood glucose value g(t_j).

36. The method of claim 29, further comprising the steps of storing in said memory a hypoglycemic value indicative of a hypoglycemic threshold of the patient, determining in said processor if said future blood glucose value g(t_j) lies below said hypoglycemic value, and audibly alerting the patient when said future blood glucose value g(t_j) lies below said hypoglycemic value.

37. The method of claim 29, wherein said input means comprises a blood glucose meter and the step of entering said blood glucose value g(t_d) comprises the steps of measuring a blood sample of the patient with said glucose meter and producing said blood glucose value g(t_d) from a measurement of said blood sample.

38. The method of claim 29, wherein said insulin dose has an insulin type, said method further comprises the step of entering said insulin type in said processor, and said insulin action value f_k(t_d) is determined in dependence upon said insulin type.

39. The method of claim 38, wherein said insulin type is selected from the group consisting of regular insulin and lispro insulin.

40. A method for assisting a patient having diabetes mellitus in controlling blood glucose, said method comprising the following steps:

a) providing the patient with an apparatus for determining a future blood glucose value g(t_j) representative of an expected blood glucose concentration of the patient at time t_j, wherein said apparatus comprises a memory, an input means for entering a blood glucose value g(t_d) representative of a blood glucose concentration of the patient at time t_d and for entering an insulin dose value representative of an insulin dose administered to the patient prior to time t_d, a display, an a processor connected to said memory, said input means, and said display;

b) storing in said memory an insulin sensitivity value representative of an insulin sensitivity of the patient, information for determining an insulin action value f_k(t_d) representative of a fraction of insulin action remaining at time t_d from said insulin dose, and maximum and minimum values defining a target blood glucose range of the patient;

c) entering in said processor said insulin dose value and said blood glucose value g(t_d);

d) determining in said processor said insulin action value f_k(t_d) by programming the processor to execute an interpolation formula to calculate the insulin action value f_k(t_d) as stated in the formula to calculate the insulin action value comprising:

f_k(t_d)=Y₀₊((Z_k−X₀)(Y₁₋Y₀)/(X₁₋X₀))

41. The method of claim 40, further comprising the step of determining in said processor an insulin action value f_k(t_j) representative of a fraction of insulin action remaining at time t_j from said insulin dose, and wherein said future blood glucose value g(t_j) is determined in further dependence upon said insulin action value f_k (t_j).

42. The method of claim 40, wherein the step of determining said future blood glucose value g(t_j) is preceded by the steps of determining in said processor an ultimate time point at which said insulin dose will have no insulin action remaining and setting time t_j equal to said ultimate time point.

43. The method of claim 40, further comprising the steps of determining in said processor a plurality of future blood glucose values representative of a corresponding plurality of expected blood glucose concentrations of the patient and displaying said future blood glucose values in graphical form on said display.

44. The method of claim 40, wherein said corrective action comprises an administration of a supplemental insulin dose, and said method further comprises the steps of storing in said memory a target blood glucose value of the patient and determining in said processor said supplemental insulin dose in dependence upon said insulin sensitivity value and a difference between said future blood glucose value g(t_j) and said target blood glucose value.

45. The method of claim 40, wherein said corrective action comprises a consumption of a number of grams of carbohydrates, and said method further comprises the steps of storing in said memory a target blood glucose value of the patient and determining in said processor said number of grams in dependence upon a difference between said future blood glucose value g(t_j) and said target blood glucose value.

46. The method of claim 40, further comprising the steps of storing in said memory, a hypoglycemic value indicative of a hypoglycemic threshold of the patient, determining in said processor if said future blood glucose value g(t_j) lies below said hypoglycemic value, and audibly alerting the patient when said future blood glucose value g(t_j) lies below said hypoglycemic value.

47. The method of claim 40, wherein said input means comprises a blood glucose meter and the step of entering said blood glucose value g(t_d) comprises the steps of measuring a blood sample of the patient with said glucose meter and producing said blood glucose value g(t_d) from a measurement of said blood sample.

48. The method of claim 40, wherein said insulin dose has an insulin type, said method further comprises the steps of entering said insulin type in said processor, and wherein said insulin action value f_k(t_d) is determined in dependence upon said insulin type.

49. The method of claim 48, wherein said insulin type is selected from the group consisting of regular insulin and lispro insulin.

50. The method of claim 40, further comprising the steps of entering in said processor a plurality of blood glucose values and a plurality of insulin dose values, determining from said glucose values and said insulin dose values an adjusted insulin dose values an adjusted insulin sensitivity value, and storing said adjusted insulin sensitivity value in said memory.