Patent ID: 7260481
Filing Date: 2007-08-21
Classification: A61B

Abstract:
1. A vector detecting device comprising: a first reference-potential generating unit that generates a first reference-potential; an input amplifier that receives an AC signal with a known frequency, amplifies or buffers, and outputs the AC signal; a phase-sensitivity detector that detects a phase sensitivity of the amplified or buffered AC signal using the first reference-potential as a reference; a second reference-potential generating unit that generates a second reference-potential lower than the first reference-potential; a charge/discharge change-over switch that switches the connection between the first reference-potential and the second reference-potential and the AC signal of which the phase sensitivity has been detected by the phase-sensitivity detector; an integrator that integrates the AC signal of which the phase sensitivity has been detected, from the charge/discharge change-over switch, and outputs an integrated potential; a third reference-potential generating unit that generates a third reference-potential higher than the first reference-potential; a comparator that outputs signals at levels varying depending on whether the potential output and integrated by the integrator is higher than the third reference-potential or lower than the third reference-potential; an integrating-time timer unit that counts an outputting time of the potential integrated by the integrator; a sync-signal control unit that outputs to the phase-sensitivity detector two types of phase signals synchronous with the AC signal with a constant phase thereof; a charge/discharge control unit that outputs to the charge/discharge change-over switch a control signal for switching the connection between the first reference-potential and the second reference-potential and the AC signal of which the phase sensitivity has been detected to charge the integrator until a time counted by the integrating-time timer unit reaches a predetermined time from a charging start time and, thereafter, a control signal for switching the connection between the first reference-potential and the second reference-potential and the AC signal of which the phase sensitivity has been detected, to discharge the integrator until the levels of the signals output by the comparator change; and a vector-detecting-information calculating unit that calculates the vector detecting information of the AC signal received by the input amplifier on the basis of a time which reaches the predetermined time from the charging start time counted by the integrating-time timer unit when the charge/discharge control unit outputs to the charge/discharge change-over switch the control signal for switching the connection to charge the integrator, the time counted by the integrating-time timer unit when the charge/discharge control unit outputs to the charge/discharge change-over switch the control signal for switching the connection to discharge the integrator when the levels of the signals output by the comparator change, and the two types of phase signals output by the sync-signal control unit.