System for the extrapolation of glucose concentration

• US 6,925,393 B1
• Filed: 11/13/2000
• Issued: 08/02/2005
• Est. Priority Date: 11/18/1999
• Status: Expired due to Term

• Current Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Original Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Inventors: Kalatz, Brit, Hoss, Udo
• Primary Examiner(s): Marschel, Ardin H.
• Assistant Examiner(s): LY, CHEYNE D
• Application Number:
  US09/711,855
• Time in Patent Office: 1,723 Days
• Field of Search: 702/27, 702/19, 702/22, 422/68.1, 703/11, 703/12
• US Class Current: 702/27
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G16H 15/00 ICT specially adapted for medical reports, e.g. generation or transmission thereof
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A system for the extrapolation of a glucose concentration has a data input device for entering administered insulin doses and their times of administration, a data input device for entering the carbohydrates consumed or to be consumed, a unit for determining an actual glucose concentration at a point in time (t_a) in a patient'"'"'s bodily fluid, a memory unit, and an evaluation unit for evaluation of the data stored in the memory unit, and for the extrapolation of a glucose concentration at a point in time t_p, whereby t_p is after t_a The extrapolation includes determining the portion (I_wirk) of insulin doses that become effective between t_a and t_p; determining the portion of consumed carbohydrate units KH_wirk, that become effective between t_a and t_p; and determining an extrapolated glucose concentration G_p at the point in time t_p with consideration for I_wirk and KH_wirk.

Claims

1. System for the determination of a glucose concentration, comprising:

a data input device for entering insulin doses administered (I_i) and their times of administration (t_i),

the same or a second data input device for entering carbohydrates (KH_j) consumed or to be consumed, and their times of consumption (t_j),

a unit for measuring the actual glucose concentration (G_a) in a patient'"'"'s bodily fluid at a specific point in time (t_a),

a memory unit for storing administered insulin doses and their times of administration, and carbohydrates consumed and their times of consumption,

an evaluation device for evaluating the data stored in the memory unit and extrapolating a glucose concentration at a point in time (t_p), whereby t_p is after t_a, and the extrapolation comprises the following steps;

determination of the portion (I_wirk) of insulin doses that take effect within the interval between t_a and t_p,

determination of the portion (KH_wirk) of carbohydrates consumed that take effect in the interval between t_a and t_p, and

determination of a glucose concentration G_p at the point in time t_p using I_wirk and KH_wirk, wherein

the portion of insulin doses (I_wirk) that take effect in the period between t_a and t_p is calculated using the following formula $I_{\mathrm{WIRK}}=\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\int <br><br>}_{t_a}^{t_p}<br><br>C_1<br><br>\left(t\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>d<br><br>t<br><br>\left(I_i\right);<br><br><br><br>\text{\hspace{1em}<br><br>}$$n=\mathrm{number}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{insulin}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{doses}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{to}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{be}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{considered}$

whereby C_l represents the quantity of insulin that is bioavailable at the point in time t and therefore represents the insulin effectiveness profile;

with ${\int <br><br>}_0^{\mathrm{\infty <br><br>}}<br><br>C_1<br><br>\left(t\right)<br><br>\text{\hspace{1em}<br><br>}<br><br>d<br><br>t=1.$

2. System according to claim 1, in which the unit used to measure the actual glucose concentration G_a is a microdialysis device.

3. System according to claim 1 that also includes a display unit for displaying the glucose concentration G_p.

4. System according to claim 1 that also includes a warning unit that emits a warning signal when the glucose concentration G_p is outside a selected normal range.

5. System according to claim 1 in which a user enters the carbohydrate units consumed (KH_j).

6. System according to claim 1 in which the system contains a control unit for an insulin infusion device or is connected to such a device, and in which the insulin doses administered (I_i) and their times of administration (t_i) are transmitted from the control unit to the date input device for entering insulin doses.

7. System according to claim 1, in which the point in time t_p is from 0.5 to 5 hours after t_a.

8. System according to claim 1, in which the point in time t_p is at least 2 hours after t_a and up to 4 hours after t_a.