Bio-impedance analyzer
AssigneeUTI Limited Partnership
InventorsAbdulwadood Abdullah Al-Ali, Brent Maundy, Ahmed Elwakil
Life of this patent
Estimating the term…
Abstract
Systems and methods relating to bio-impedance analysis. The system eliminates the need for hardware phase measurements by using the K-K transform to extract the phase from the magnitude detected. The system has a magnitude detection sub-system that includes a signal generation block, a DC cancellation block, and an amplitude control block. An A/D converter converts the detected magnitude into a digital signal and signal processing is performed to extract the phase of the signal from the magnitude detected.
Claims17
A system for bio-impedance analysis, the system comprising:
- a signal generation block for generating an excitation signal;
- at least two signal processing blocks for processing said excitation signal, said at least two signal processing blocks being coupled between a first probe and said signal generation block;
- a magnitude sensing block for detecting a magnitude of an unknown impedance of a sample for use in said bio-impedance analysis, said magnitude sensing block being coupled to a second probe, an output of said magnitude sensing block being a magnitude of said unknown impedance;
- at least one data processing device for determining phase information of said unknown impedance based on said magnitude of said unknown impedance;
- wherein
- said sample for use in said bio-impedance analysis is to be coupled between said first probe and said second probe;
- said signal generation block is controlled by at least one processor.
Computer readable media having encoded thereon computer readable and computer executable instructions that, when executed, implements a method for calculating phase information for an impedance from a measured magnitude of said impedance, the method comprising:
- a) receiving measured magnitude of said impedance;
- b) performing a data fitting operation to fit
- ln(|Z(ω)|)to ln(|{circumflex over (Z)}(x)|)
- where |Z(ω)| is said measured magnitude for said impedance;
- c) dividing a result of step b) into a plurality of segments, each segment being taken over a predefined frequency range;
- d) calculating limits of a numerical integration for each segment, said limits for each segment including xmin, xmax, and a step size over N data points;
- e) performing a numerical integration for each point in each segment based on said limits calculated in step d), a result of said numerical integration being said phase of said impedance, said numerical integration being performed on
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A method for determining phase information for an impedance from a measured magnitude of said impedance, the method comprising:
- a) receiving at a processor a measured magnitude of said impedance;
- b) using said processor to perform a data fitting operation to fit
- ln(|Z(ω)|)to ln(|{circumflex over (Z)}(x)|)
- where |Z(ω)| is said measured magnitude for said impedance;
- c) using said processor to divide a result of step b) into a plurality of segments, each segment being taken over a predefined frequency range;
- d) determining, using said processor, limits of a numerical integration for each segment, said limits for each segment including xmin, xmax, and a step size over N data points;
- e) using said processor to perform a numerical integration for each point in each segment based on said limits calculated in step d), a result of said numerical integration being said phase of said impedance, said numerical integration being performed on
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Dependencies are inferred from the claim text.