Measurement apparatus

(12) United States Patent

Heinonen et al.

US006295506B1

(io) Patent No.: US 6,295,506 Bl (45) Date of Patent: Sep. 25,2001

(54) MEASUREMENT APPARATUS

FOREIGN PATENT DOCUMENTS

(75) Inventors: Pekka Heinonen; Harri Okkonen,

both of Espoo; Jukka Berg, Oulu, all of (FI)

(73) Assignee: Nokia Mobile Phones Limited, Espoo (FI)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/178,313

(22) Filed: Oct. 23, 1998

(30) Foreign Application Priority Data

Oct. 27, 1997 (FI) 974065

(51) Int. C I. A61B 5/00

(52) U.S. CI 702/104; 600/301

(58) Field of Search 702/104, 30, 31;

379/106.02; 340/501; 600/301, 316

(56) References Cited

U.S. PATENT DOCUMENTS

4,706,207 11/1987 Hennessy et al 364/555

5,174,963 12/1992 Fuller et al 422/82.05

5,307,263 * 4/1994 Brown 364/413.09

5,507,288 4/1996 Bocker et al 128/633

5,772,586 * 6/1998 Heinonen et al 600/300

5,802,465 9/1998 Hamalainen et al 455/403

5,809,115 9/1998 Inkinen 379/93.05

5,840,020 * 11/1998 Heinonen et al 600/309

5,872,713 * 2/1999 Douglas et al 364/413.09

5,878,376 * 3/1999 Schurr 702/102

5,899,855 * 5/1999 Brown 600/301

6,106,780 * 8/2000 Douglas et al 422/58

6,122,536 * 9/2000 Sun et al 600/341

6,168,563 * 1/2001 Brown 600/301

A system for measuring the blood glucose level in a sample of a patient's blood. Consumable test strips (5) are provided together with a code (7) which identifies the manufacturing batch of the strip (5). Ameasurement unit (2) is provided and is coupled to a mobile telephone (1). The measurement unit (2) is arranged to receive a test strip (5) and to determine a color change in a reagent (4) due to reaction of the reagent (4) with a blood sample. The identification code (7) is read at the same time by the measurement unit (3) and is transmitted by the mobile telephone (1) to a central database (9) provided by the test strip manufacturer. The database (9) contains identification codes (7) together with associated calibration data. Upon receipt of an identification code (7), the remote database (9) transmits the associated calibration data to the mobile telephone (1) which uses the calibration data to calculate a test result from the measured change in color. The result can be displayed to the patient on a display of the telephone (1).

11 Claims, 2 Drawing Sheets

MEASUREMENT APPARATUS

FIELD OF THE INVENTION

The present invention relates to measurement apparatus and in particular to measurement apparatus which makes use 5 of a consumable reagent in a measuring process.

BACKGROUND OF THE INVENTION

There are many examples of measurement apparatus which make use of a consumable reagent as part of a 10 measuring process. Consumable reagents are generally of a chemical, biochemical, or biological nature. One example of such an apparatus is a blood glucose meter designed to measure the level of glucose in a sample of a patient's blood. A small amount of a suitable reagent is printed or otherwise 15 deposited onto an elongate plastic strip which can be inserted into the blood glucose meter. The meter comprises a refiectometry based measuring system which detects a change in the color of the printed reagent due to a reaction between the active reagent and glucose present in the blood 20 sample.

It will be appreciated that in the case of a blood glucose meter, where a patient determines an insulin treatment regime on the basis of blood glucose measurements, the ^ accuracy of the meter is critical. This requires very precise calibration of the meter. Initial calibration of the meter is normally carried out during and immediately following manufacturing, with certain calibration data being stored in permanent memory of the meter. However, calibration of the meter at this stage cannot easily account for changes and variations in the properties of the consumable reagents themselves, variations which might arise due to slight changes in the manufacturing process of the reagent and the test strip, environmental factors such a temperature and humidity, and changes in the property of the reagent over time.

It is known to provide blood glucose test strips, or rather a pack of such test strips, with a machine readable memory in which calibration data is stored. When a new pack of test strips is opened, the machine readable memory is read by the meter and calibration data downloaded into the memory of the blood glucose meter. In this way it is possible to take account of reagent manufacturing variations in the calibration of the meter. However, it will be appreciated that providing a machine readable memory with each packet of test strips is relatively expensive both in terms of the hardware required and in terms of the additional time required to program the memory during the manufacturing process.

In addition, it remains difficult to account for changes in the properties of a reagent over time. At best, only a poor estimate can be made based upon some predetermined criteria and only then if the age of the reagent is known. As such, manufacturers of blood glucose test strips tend to supply test strips in very limited numbers and make tight specifications for storage and lifetime to ensure that the properties of the reagents remain within desired limits. These specifications tend to work against economies of scale in the manufacturing and distribution of test strips.

These problems are not limited to blood glucose test strips and apply equally to other fields in which consumable reagents are used.

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measurement apparatus for measuring a physical parameter using a consumable reagent, said reagent having an identification code associated therewith;

automatic telephone answering means;

a database coupled to the automatic telephone answering means and containing a set of consumable reagent identification codes and respective calibration data;

means for coupling the measurement apparatus to the automatic telephone answering means via a telephone link,

the automatic telephone answering means being arranged to receive an identification code transmitted from the measurement apparatus over said telephone link, to subsequently access said database to identify the calibration data associated with said transmitted identification code, and to either transmit the identified calibration data to the measurement apparatus, or to calculate a test result using the identified calibration data and transmit the test result to the measurement apparatus.

By storing the calibration data for specific consumable reagents at a central database, it is possible to update the calibration data to reflect changes which may occur to the consumable reagents over time. Furthermore, it is no longer necessary to supply the calibration data to the end user with the reagents. This simplifies the manufacturing process and also eliminates the need to supply complex memory means to the end user.

A further advantage of the present invention is that data generated by the measurement apparatus using the consumable reagent can be transmitted to the central database where information from many apparatus can be collected and analysed.

In one embodiment of the present invention, the automatic telephone answering means is arranged to transmit calibration data associated with the received identification code back to the measurement apparatus. The measurement apparatus comprises data processing means for processing said measured physical parameter, using the received calibration data, to provide a test result. Preferably, the measurement apparatus comprises a display for displaying the test result to a user.

In an alternative embodiment of the present invention, the measurement apparatus is arranged to transmit said measured physical parameter to the automatic telephone answering means together with said identification code. The system further comprises data processing means, coupled to the database and the automatic telephone answering means, for calculating a test result using the identified calibration data and the received physical parameter. The automatic telephone answering means is arranged to transmit the test result back to the measurement apparatus, e.g. for display on a display of the apparatus. An advantage of this embodiment is that it is possible to use relatively complex algorithms to compute the test result due to the relatively high processing capability which can be provided at a central facility. Furthermore, the algorithm can be easily updated or modified.

Preferably, the identification code is provided with the consumable reagent in a machine readable form. For example, the code may be contained in a bar-code or in a solid state memory. The measurement apparatus is provided with a machine reader which is capable of reading the identification code into a memory of the measurement apparatus. An identification code may be provided with each individual consumable reagent or may be provided with a batch of such units. Where the consumable reagents are