Method for determining non-invasively a heart-lung interaction

Inventors

SOLA I CAROS, Josep • Brunner, Josef X.

Assignees

Sentec AG

Abstract

The present disclosure concerns a method for determining a heart-lung interaction factor of a subject, comprising: measuring a heart activity-related signal comprising heart activity-related information; from the heart activity-related signal, calculating a frequency of cardiac cycle and a frequency of respiratory cycle; from the heart activity-related signal, determining a cardiac cycle energy at the frequency of cardiac cycle, determining a respiratory cycle energy at the frequency of respiratory cycle, and determining a heart-lung interaction energy at an intermodulation frequency corresponding to the difference between the frequency of respiratory cycle and the frequency of cardiac cycle, or the sum of the frequency of respiratory cycle and the frequency of cardiac cycle; and determining a heart-lung interaction factor from the ratio of the heart-lung interaction energy and one of the cardiac cycle energy and the respiratory cycle energy. The heart-lung interaction factor can be determined non-invasively.

Core Innovation

The disclosed invention provides a non-invasive method for assessing intravascular fluid status of a subject by determining a functional hemodynamic parameter from a heart-lung interaction factor (HLI). The method measures a heart activity-related signal comprising heart activity-related information, and derives from this signal a cardiac cycle frequency (f_h) and a respiratory cycle frequency (f_r).

From the heart activity-related signal, the method determines a cardiac cycle energy (E_h) at f_h and a respiratory cycle energy (E_r) at f_r. It further determines a heart-lung interaction energy (E_hli) at an intermodulation frequency (f_hli) corresponding to the difference between f_r and f_h or the sum of f_r and f_h. The HLI is determined from a ratio involving E_hli and one of E_h and E_r.

The functional hemodynamic parameter is then determined from the heart-lung interaction factor. The heart activity-related signal comprises an electrical impedance tomography (EIT) signal obtained from a plurality of pixels of EIT images acquired using an EIT imaging measurement technique, linking cardiac and respiratory cycle energies with an intermodulation-derived energy for fluid-state assessment.

Claims Coverage

The input includes one independent claim directed to a non-invasive method that derives a functional hemodynamic parameter from an HLI factor. The inventive features cover EIT-based acquisition, frequency and energy determination for cardiac and respiratory cycles, intermodulation energy determination, and ratio-based HLI determination followed by conversion to a functional hemodynamic parameter.

The claim coverage centers on using an EIT-derived heart activity-related signal to compute cardiac and respiratory cycle frequencies and energies, computing a heart-lung interaction energy at an intermodulation frequency, determining HLI from a ratio involving E_hli and E_h and/or E_r, and deriving a functional hemodynamic parameter from the resulting HLI for assessing intravascular fluid status.

Stated Advantages

Documented Applications