System and method for determining physiological parameters based on electrical impedance measurements

A method for monitoring breathing, the method comprising:

• positioning a plurality of transducers on a surface of a person, the plurality of transducers comprising at least two excitation transducers and at least two measuring transducers;
• generating excitations on at least a subset of the plurality of transducers, the excitations driven in different configurations from at least one of the two excitation transducers;
• obtaining measurement response signals at a response detector, as acquired from all or the subset of the plurality of transducers;
• spatially pre-conditioning the obtained measurement signals to convert the measurement response signals into spatial vectors;
• and then
• performing multiple-input-multiple-output (MIMO) analog to information conversion (AIC) of the measurement signals to correlate the measurement signals of a sub-space of desired physiological activities as breathing signals and measurement signals of a sub-space of undesired physiological activities as ambulatory motion signals;
• wherein inputs of the MIMO AIC are the spatial vectors, and the MIMO AIC identifies and then tracks the breathing signals and the ambulatory motion signals;
• and
• classifying the measurement signals of the sub-space of desired physiological activities as respiratory information and classifying the sub-space of undesired signals as ambulatory motion information.

An impedance measurement system comprising:

• a plurality of transducers configured for positioning at a surface of an object, the plurality of transducers comprising at least two excitation transducers and at least two measuring transducers, wherein the plurality of transducers correspond to a plurality of channels;
• an excitation driver coupled to at least a subset of the plurality of channels and configured to generate excitations on at least a subset of the plurality of transducers in different configurations from at least one of the two excitation transducers:
• a response detector configured to measure a response on at least a subset of the plurality of transducers to define measurement signals;
• and
• a processor having a physiological parameter extraction module that uses multiple-input-multiple-output (MIMO) analog to information conversion (AIC) of the measurement signals to correlate the measurement signals in order to separate the measurement signals of a sub-space of desired physiological activities, as distinguished from a sub-space of undesired signals;
• wherein the processor is configured to pre-condition the measurements signals prior to the MIMO AIC using a signal pre-conditioner that utilizes spatial differentiation;
• wherein the MIMO AIC identifies and then tracks the sub-space of the desired physiological activities;
• and
• wherein the processor is configured to classify the measurement signals of the sub-space of desired physiological activities as respiratory information and classify the sub-space of undesired signals as ambulatory motion information.