Conventionally, as a device for easily analyzing characteristics of bodily fluid of a man or an animal, for example, a device for electrochemically measuring blood sugar has already been put to practical use.
A biosensor is a device of this type, and hereinafter, a biosensor and a measuring device to be combined with the biosensor will be described.
FIG. 21 shows a long and narrow strip-shaped sensor 31 for collecting blood, which is set in a sensor insertion slot 31a of a measuring device 32. The sensor 31 is provided with a cavity (not shown) for collecting blood, in its semi-circular front end that protrudes from the measuring device 32 in a state where the sensor 31 is housed in the measuring device 32. Further, the sensor 31 is provided with, in the cavity, a reagent layer containing an enzyme, an electron carrier, and the like, and electrodes.
The measuring device 32 contains an electric circuit for measuring a current value according to concentration of glucose in blood, which current is generated by a reaction between the glucose in blood and the reagent layer, by applying a voltage to the electrode, and measured blood sugar is displayed on a display 33 which is placed on an upper surface of the measuring device 32.
For every measurement, a new sensor 31 is inserted into the sensor insertion slot on a side surface of the measuring device 32, and blood of a patient is applied onto the sensor 31 to perform measurement. The sensor 31 after measurement is discarded for hygienic reasons.
Usually, skin of a body part, such as a fingertip, is lanced with a lancet device 34 as shown in FIG. 22(a) to extract a very small quantity of blood, and the blood is collected in the cavity of the sensor 31.
In the lancet device 34 whose internal structure is shown in FIG. 22(b), a force is elastically applied to a lancet 35 by a spring coil 36. When an operation button 37 is pushed, an engagement member 37a which is united with the operation button 37 is disengaged from a ring-shaped groove 35a of the lancet 35, whereby a force applied to the lancet 35 by the spring 36 is released, and a tip of a needle 35b of the lancet 35 forcibly projects from a front end of an approximately cylindrical-shaped case 38. The lancet 35 comprises the needle 35b which is made of metal, and a holder 35c for holding the needle 35b, which is made of plastic. Usually, the lancet 35 is replaced with a new one at every measurement, for hygienic reasons.
Further, a biosensor to be used for analyzing bodily fluid extracted from a man or an animal is usually preserved in a state where it is wrapped with an aluminum wrapper or the like, or in a state where it is contained in a plastic case. When the biosensor is used, it is taken out of the aluminum wrapper or the plastic case.
FIG. 23(a) is a diagram illustrating a state where a biosensor 110 having a reagent layer (not shown) for analyzing bodily fluid, and an electrode (not shown) for removing an electric signal according to result of analysis, is hermetically wrapped with an aluminum wrapper 120. To be specific, a biosensor 110 which comprises an approximately rectangular-shaped plate member having a shorter side of an approximately semi-circular shape is wrapped with an aluminum wrapper 120 having a rectangular shape that is a little larger than the biosensor 110. FIG. 23(b) shows a state where a plurality of biosensors 110, which are arranged with their approximately-semi-circular-shaped ends facing upward and their surfaces being in contact with each other, are hermetically contained in a cylindrical plastic case 130 with a lid.
When performing measurement, the biosensor 110 which is preserved as shown in FIG. 23(a) or 23(b) is removed, and another shorter side of the biosensor 110, which is not the approximately-semi-circular-shaped side, is inserted into a biosensor insertion slot 114a of a measuring device 114 to prepare for measurement as shown in FIG. 24.
Since the conventional biosensor and measuring device thereof are constructed as described above, when preparing for measurement, a patient sets a new lancet 35 in the lancet device 34 as described above. Then, the patient sets a new sensor 31 in the measuring device 32, whereby preparation for measurement is completed. Thereafter, the patient operates the lancet device 34 to take blood from his/her fingertip or the like, and applies it onto a front end of the sensor 31 that is set in the measuring device 32 to perform measurement. In this way, the patient must perform replacement of the lancet and replacement of the sensor separately for every measurement, resulting in complicated operation.
Further, since it is necessary to monitor blood sugar a few times a day, sizes of these devices are reduced in consideration of portability. In a conventional system, however, the patient must carry the sensor 31, the measuring device 32, the lancet 35, and the lancet device 34 together, resulting in a voluminous system as a whole. Further, since the patient must manage the sensor 31 and the lancet 35 separately, operation and measurement are troublesome, resulting in poor usability.
The present invention is made to solve the above-mentioned problems and has for its object to provide a lancet-integrated sensor in which a sensor and a lancet are integrated to facilitate operation and management, and improve portability, as well as a measuring device to be combined with the lancet-integrated sensor.
Further, with respect to the conventional biosensors, as described above, each biosensor is wrapped with an aluminum wrapper, or plural biosensors are stored in a plastic case with a lid, whereby the biosensors are prevented from contamination due to moisture.
However, when preparing for measurement, a patient must break the aluminum wrapper 120 to take the biosensor 110, or open the lid 130a of the plastic case 130 to take the biosensors 110 one by one. Further, the patient must insert this taken biosensor 110 toward the sensor insertion slot 114a of the measuring device 114. Therefore, preparation for measurement is troublesome, and usability is poor.
The present invention is made to solve the above-mentioned problems and has for its object to provide a biosensor cartridge by which a biosensor stored in a case is easily inserted into a measuring device without troublesome operation.