CHOPPER-STABILIZED INSTRUMENTATION AMPLIFIER FOR IMPEDANCE MEASUREMENT
First Claim
1. An electrical impedance sensing device comprising:
- a current source configured to generate a modulated current at a modulation frequency for application to a load to produce an input signal;
an amplifier configured to amplify the input signal to produce an amplified signal;
a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load.
1 Assignment
0 Petitions
Accused Products
Abstract
In general, this disclosure is directed to a mixer amplifier that can be utilized within a chopper stabilized instrumentation amplifier. The chopper stabilized instrumentation amplifier may be used for physiological signal sensing, impedance sensing, telemetry or other test and measurement applications. In some examples, the mixer amplifier may include a current source configured to generate a modulated current at a modulation frequency for application to a load to produce an input signal, an amplifier configured to amplify the input signal to produce an amplified signal, and a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load.
-
Citations
50 Claims
-
1. An electrical impedance sensing device comprising:
-
a current source configured to generate a modulated current at a modulation frequency for application to a load to produce an input signal; an amplifier configured to amplify the input signal to produce an amplified signal; a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A biological impedance sensing device comprising:
-
means for applying a current modulated at a modulation frequency across a load to produce an input signal; means for amplifying the input signal to produce an amplified signal; means for demodulating the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load. - View Dependent Claims (15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
-
17. The sensing device of 14, wherein the load includes a biological load, the device further comprising first implantable electrodes coupled to apply the modulated current across a biological load, and second implantable electrodes coupled to sense the input signal produced across the biological load.
-
27. An implantable medical device comprising:
-
a therapy delivery module configured to deliver a therapy to a patient; an impedance sensor comprising; a current source configured to generate a modulated current at a modulation frequency for application across a biological load to produce an input signal, an amplifier configured to amplify the input signal to produce an amplified signal, and a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the biological load; and a processor configured to control the therapy delivery module and process a representation of the output signal produced by the sensor. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
-
-
38. A method for sensing impedance of a load, the method comprising:
-
applying a current modulated at a modulation frequency across a load to produce an input signal; amplifying the input signal with an amplifier to produce an amplified signal; and demodulating an amplitude of the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50)
-
Specification