Bio electric impedance monitors, electrode arrays and method of use
Inventors
Hamski, Philip • Rinehart, Robert • Aba, Dios • Griofa, Marc O.
Assignees
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Publication Number
US-12502092-B2
Publication Date
2025-12-23
Expiration Date
Abstract
A portable bioelectric impedance monitor and methods using the monitor can measure and monitor extracellular fluid levels and/or cardiac signals. The monitor may include a tetrapolar electrode array lead with four electrodes arranged sequentially and axially along the lead, and circuitry coupled with the at least four electrodes configured to measure bioelectric impedance extracellular fluid and/or cardiac signals in a human subject at various frequencies. The electrodes are adhered to a human subject/patient on the patient's torso or one of the patient's limbs. One embodiment includes a Tetrapolar Analog Front End Patient Interface circuit configured to convert two electrode operation of a commercial Impedance Converter, Network Analyzer into a tetrapolar operation for excitation and impedance measurement of the human subject.
Core Innovation
The invention provides a method for long-term monitoring of a subject by generating, in a fluid monitor device, two excitation signals having a first excitation signal frequency of less than 15 kHz and a second excitation signal frequency of more than 15 kHz, with the two excitation signals having a total current of less than 1 mA. The method includes adhering first and second electrode lead arrays to opposite sides of a thorax, where each array includes current source electrodes and measurement electrodes vertically spaced apart at fixed distances for measuring bioimpedance signals generated in response to the two excitation signals.
From the received bioimpedance signals, the method generates both a hydration signal and a heart rate signal of the subject. The method determines one or more cardio cycles of the subject using the heart rate signal, and performs long-term monitoring of both a hydration state based on the hydration signal and the one or more cardio cycles. Hydration monitoring distinguishes hydration from excitation signals at different frequency ranges, including lower-frequency excitation less than 15 kHz for extracellular hydration and higher-frequency excitation greater than 15 kHz for extracellular and intracellular hydration.
The invention also provides a monitoring device with two electrode lead arrays adhered to opposite sides of a thorax, a multifrequency current source that generates the two excitation signals with the frequency and current constraints, and a processor that generates a hydration signal and a heart rate signal from bioimpedance subject signals. The processor determines one or more cardio cycles using the heart rate signal and performs long-term monitoring of both the hydration state based on the hydration signal and the one or more cardio cycles.
Claims Coverage
The partial content contains two independent claims: one method claim and one monitoring device claim. Across these independent claims, the inventive features are concentrated on multifrequency low/high excitation for hydration and hydration-state monitoring, thorax-worn two lead arrays with fixed electrode spacing and paired current-source/measurement electrode functions, and deriving hydration and heart-rate-based cardio-cycle information for long-term monitoring.
Two excitation signals with sub-15 kHz and above-15 kHz frequencies under a total current limit
Generating, by a current source in a fluid monitor device, two excitation signals with a first excitation signal having a frequency of less than 15 kHz and a second excitation signal having a frequency of more than 15 kHz and the two excitation signals having a total current of less than 1 mA.
Thorax-worn dual electrode lead arrays with fixed vertical spacing and paired electrode functions
Adhering a first electrode lead array vertically along a length of a first side of a thorax and adhering a second electrode lead array vertically along a length of an opposite side of the thorax, where each electrode lead array includes current source electrodes and measurement electrodes vertically spaced apart at a fixed distance and connected to upper and lower regions, and where corresponding electrode lead arrays are separated by a second fixed distance greater than the fixed distance.
Derive hydration and heart-rate signals from two bioimpedance signals generated by the two excitation signals
Delivering, by each current source electrode, the two excitation signals to the subject; receiving two bioimpedance signals through the measurement electrodes, where the two bioimpedance signals are generated based on the two excitation signals; generating, from the two bioimpedance signals, both a hydration signal of the subject and a heart rate signal of the subject.
Long-term monitoring using hydration state and one or more cardio cycles determined from the heart rate signal
Determining, using the heart rate signal generated from the two bioimpedance signals, one or more cardio cycles of the subject; and long-term monitoring, by the fluid monitor device, of both a hydration state based on the hydration signal and the one or more cardio cycles.
Monitoring device with thorax-worn dual electrode arrays and multifrequency current source delivering sub-15 kHz and above-15 kHz excitation
A monitoring device comprising a first and second electrode lead arrays configured to be adhered to a subject along two opposite sides of a thorax, and a monitor device connected to the first and second electrode lead arrays by first and second connectors and having a processor and a multifrequency current source that generates two excitation signals with a first excitation signal having a frequency of less than 15 kHz and a second excitation signal having a frequency of more than 15 kHz and the two excitation signals having a total current of less than 1 mA, wherein each current source electrode delivers the two excitation signals to the subject and the measurement electrodes receive the bioimpedance signals from the subject in response to the two excitation signals.
Processor generates hydration signal and heart rate signal, determines cardio cycles, and performs long-term monitoring
The processor having a plurality of lines of instructions that configure the processor to generate, from the bioimpedance subject signals, both a hydration signal and a heart rate signal of the subject; determine, using the heart rate signal, one or more cardio cycles of the subject; and perform long-term monitoring of both a hydration state based on the hydration signal and the one or more cardio cycles.
Across the independent claims, the core claim coverage centers on long-term thorax bioimpedance monitoring using two excitation frequencies on opposite-side electrode lead arrays with fixed electrode spacing, generating hydration and heart-rate signals from bioimpedance, deriving one or more cardio cycles from the heart rate signal, and using both outputs to monitor hydration state and cardiac-cycle information over the long term.
Stated Advantages
Documented Applications
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