Circuit for automatically deriving and measuring relative voltages associated with impedance components of a biological object

Claim 1

In a circuit for automatically deriving and measuring relative voltages associated with impedance components of a biological object, a source of amplitude-modulated high-frequency current, first and second equal resistances connected in series with the source, means for coupling the biological object to be investigated in series with the first and second resistances, a first comparator having a first input connected to a first connecting point of the source and the first resistance and a second input connected to a reference voltage, a step-by-step voltage generator having a triggering input connected to the output of the first comparator, second and third comparators individually having first inputs connected to a second connecting point of the first and second resistances and to a third connecting point of the second resistance and the coupling means, respectively, first and second means for recording the values of voltages at the second and third connecting points, first and second gate means having outputs individually connected to the inputs of the first and second recording means, respectively the first and second gate means further having first inputs individually connected to the outputs of the second and third comparators, respectively and second inputs connected to the output of the step-by-step voltage generator, and feed-back means for individually coupling the outputs of the first and second recording means to second inputs of the second and third comparators, respectively.