| 主权项 |
1. An apparatus for measuring complex electrical admittance and/or complex electrical impedance in animal or human patients comprising:
two or more electrodes that are adapted to be disposed in the patient; and a housing adapted to be disposed in the patient, the housing having disposed in it a stimulator in electrical communication with two or more electrodes to stimulate with either current or voltage, a sensor in electrical communication with the same stimulating electrodes or with additional electrodes to sense a response based on the stimulation of the stimulating electrodes, and a signal processor in electrical communication with both the stimulator and the sensor to determine the complex electrical admittance or impedance of the patient with sinusoidal signals to determine the patient's blood component and muscle component, the stimulator and the sensor and the signal processor together using less than an average current of less than 23 mA in operation over time, wherein a real part, an imaginary part, a magnitude, and/or phase of admittance can be measured, a real part, an imaginary part, a magnitude, and/or phase of impedance can be measured, the stimulator produces an excitation wave that is any shape that can be defined by a repeated sequence of integer values, whose frequency components range from 0 to 1 MHz, the stimulator produces an excitation wave that is created by a resistor-summing network, called a SinDAC, such that a number of resistors, resistor values, digital output sequence, and rate of digital outputs are selected to define a shape and frequency of the excitation wave. |
