Patent ID: 8060203
Filing Date: 2011-11-15
Classification: A61B,A61N

Abstract:
1. An apparatus for obtaining variation over time of a medical parameter of a human being, comprising: a sensor configured for in vivo implantation in a human being to sense a periodic physiological signal in the human being; a controller configured to operate said sensor to obtain said sensed signal for at least one predetermined level of activity of the human being and to obtain a sensed reference signal from the sensor for a predetermined reference level of said activity; a first quantity determining unit that determines a first quantity from each of said sensed signal said sensed reference signal; a second quantity determining unit that determines a second quantity from each of said sensed signal and said sensed reference signal; a loop generator that plots related values of said first and second quantities for said reference signal to generate a loop template from said reference signal and that plots related values of said first and second quantities for said sensed signal to generate a loop in each period of said signal in a coordinate system having an origin and a coordinate system axis; comparator circuitry that compares a loop characteristic of said loop in each period of said signal and in said loop template to determine a relation between said sensed signal and said sensed reference signal for each period, said loop characteristic being selected from the group consisting of an angle that a radius of the origin to a predetermined point on the loop contour, corresponding to a predetermined time in the period of said sensed signal, forms with respect to said coordinate system axis in each of said loop and said loop template, and a number of turn-arounds within each loop and said loop template during each period of said sensed signal; and a trend determining unit configured to determine a trend in a medical parameter of the human being by analyzing said relation obtained for said different periods.