US 11,832,928 B2
Heart failure indicator
Catherine Anne Kingsford, Wavell Heights (AU)
Assigned to IMPEDIMED LIMITED, Pinkenba (AU)
Appl. No. 15/999,048
Filed by Impedimed Limited, Pinkenba (AU)
PCT Filed Feb. 15, 2017, PCT No. PCT/AU2017/050128
§ 371(c)(1), (2) Date Aug. 16, 2018,
PCT Pub. No. WO2017/139839, PCT Pub. Date Aug. 24, 2017.
Claims priority of provisional application 62/295,967, filed on Feb. 16, 2016.
Prior Publication US 2019/0357804 A1, Nov. 28, 2019
Int. Cl. A61B 5/0537 (2021.01); A61B 5/02 (2006.01); A61B 5/00 (2006.01)
CPC A61B 5/0537 (2013.01) [A61B 5/02028 (2013.01); A61B 5/4875 (2013.01); A61B 5/6823 (2013.01); A61B 5/6832 (2013.01); A61B 5/4881 (2013.01); A61B 5/7203 (2013.01); A61B 5/7225 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A system for determining a heart failure indicator indicative of a heart failure disease state in a biological subject, the system including:
a) at least one signal generator coupled to first electrodes provided in electrical contact with the subject in use, the at least one signal generator being adapted to generate a drive signal;
b) at least one sensor coupled to second electrodes provided in electrical contact with the subject in use, the at least one sensor being adapted to measure a response signal; and,
c) at least one processing device that:
i) at least in part controls the at least one signal generator and receives an indication of a measured response signal from the at least one sensor, allowing impedance measurements to be performed across at least one body segment of the subject, the at least one body segment including at least
a limb of the subject, and
a torso of the subject;
ii) determines a fluid level indicator using first impedance values obtained by performing impedance measurements across the at least one body segment of the subject at a first time, wherein the first fluid level indicator is a ratio of extracellular fluid levels to total body water in the at least one body segment;
iii) determines a second fluid level indicator using second impedance values obtained by performing impedance measurements across the at least one body segment of the subject at a second time, wherein the second fluid level indicator is a ratio of extracellular fluid levels to total body water in the at least one body segment; and,
iv) determines a heart failure indicator by:
(1) using the first and second fluid level indicators to determine a fluid level change using a difference between the first and second fluid level indicators; and
(2) using the fluid level change to determine the heart failure indicator, wherein the heart failure indicator is indicative of at least one of:
a presence, absence, degree or severity of heart failure;
a likelihood the subject has heart failure;
a prognosis associated with heart failure;
an indication of worsening heart failure; or
an indication of cardiac decompensation.