Patent ID: 8227255
Filing Date: 2012-07-24
Classification: G01N,Y10S

Abstract:
1. A method of assaying an object using a sensor comprising a magnetic sensor, which has a plurality of magnetic field detection elements arranged two dimensionally in X rows and Y columns, where X and Y are natural numbers, the plurality of the magnetic field detection elements each generating an output value according to an intensity of a detected magnetic field, the sensor measuring an amount of magnetic particles on the magnetic sensor based on the output values, the magnet particles being specifically bound to the object that is bound to the magnetic sensor, the magnet particles being bound to the magnetic sensor through the object, the method comprising: applying a first magnetic field in which the magnet particles are between initial permeability and maximum permeability and a second magnetic field which is stronger than the first magnetic field and in which magnetization of a part or whole of the magnetic particles are saturated to the magnetic sensor bound to the magnetic particles through the object; determining the amount of the magnetic particles of each of the plurality of the magnetic field detection elements, the amount of the magnetic particles being proportional to a difference between a first dispersion index of a first output value distribution of the first magnetic field and a second dispersion index of a second output value distribution of the second magnetic field obtained from an identical magnetic field detection element of the plurality of the magnetic field detection elements, the dispersion index being at least one of standard deviation, average deviation, and variance; and determining an amount of the object based on the amount of the magnetic particles determined.