Biosensor, measuring instrument for biosensor, and method of quantifying substrate

Abstract

A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltage to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction, and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.

1 - 33 . (canceled) 
     
     
         34 . A biosensor system comprising:
 a biosensor for measuring a quantity of a substrate included in a sample liquid, said biosensor comprising:   an insulating board having a front side and a back side, and   a pair of electrodes on said front side of said insulating board, said electrodes being arranged to measure said liquid sample; and   a measuring device comprising:   a supporting section for detachably supporting said biosensor in a plurality of directions including a predetermined direction and an upside-down direction opposite to the predetermined direction,   a plurality of connecting terminals operable to be coupled to the electrodes of said biosensor, respectively, said plurality of connecting terminals including first and second connecting terminals, wherein said first and second connecting terminals are connected to one of the electrodes of the biosensor only when the biosensor is inserted into said supporting section in the predetermined direction out of the plurality of directions,   a driving power supply for applying a voltage to the electrodes of said biosensor via said connecting terminals, wherein said driving power supply applies a voltage to said first and second connecting terminals for detecting conductivity between said first and second connecting terminals,   a determining section for determining that the biosensor is not inserted in the predetermined direction when conductivity is not detected between said first and second connecting terminals, and   a conductivity detector to detect conductivity between connecting terminals coupled to one of the electrodes of the biosensor to determine whether the biosensor inserted into the measuring device is compatible with the measuring device and with measuring a blood sugar level.   
     
     
         35 . The biosensor system of  claim 34 ,
 wherein said biosensor further comprises a conductive layer formed on at least a part of said front side of said insulating board, and   wherein the pair of electrodes comprises a counter electrode and a measuring electrode which are formed by dividing said conductive layer by a slit.   
     
     
         36 . The biosensor system of  claim 34 , wherein said measuring device further comprises a display for providing a user with an alarm when said biosensor is inserted into a direction out of the plurality of directions other than the predetermined direction. 
     
     
         37 . The biosensor system of  claim 34 , wherein the measuring device further comprises a voltage detector to detect a voltage between connecting terminals coupled to electrodes of the biosensor to determine whether a used biosensor is inserted into the measuring device. 
     
     
         38 . The biosensor system of  claim 34 , wherein the measuring device comprises a voltage detector to detect a voltage between connecting terminals coupled to electrodes of the biosensor to determine whether the liquid sample has been applied to the biosensor as a drip error before the measuring device is ready for measurement. 
     
     
         39 . The biosensor system of  claim 34 , wherein the biosensor is not compatible with measuring lactic acid or cholesterol.