US 12,029,555 B2
Sensor and apparatus for determining at least one parameter of blood circulating in an extracorporeal blood circuit
Paolo Rovatti, Finale Emilia (IT); Enrico Ravagli, Bagnacavallo (IT); and Stefano Severi, Rimini (IT)
Assigned to GAMBRO LUNDIA AB, Lund (SE)
Appl. No. 16/982,317
Filed by GAMBRO LUNDIA AB, Lund (SE)
PCT Filed Mar. 20, 2019, PCT No. PCT/EP2019/056938
§ 371(c)(1), (2) Date Sep. 18, 2020,
PCT Pub. No. WO2019/180068, PCT Pub. Date Sep. 26, 2019.
Claims priority of application No. 18162977 (EP), filed on Mar. 20, 2018.
Prior Publication US 2021/0015990 A1, Jan. 21, 2021
Int. Cl. A61B 5/145 (2006.01); A61B 5/00 (2006.01); A61B 5/02 (2006.01); A61B 5/026 (2006.01); A61B 5/1455 (2006.01); A61B 8/00 (2006.01); A61M 1/16 (2006.01); A61M 1/36 (2006.01)
CPC A61B 5/14535 (2013.01) [A61B 5/0071 (2013.01); A61B 5/0075 (2013.01); A61B 5/0261 (2013.01); A61B 5/1455 (2013.01); A61B 5/6866 (2013.01); A61B 8/00 (2013.01); A61M 1/1603 (2014.02); A61M 1/1619 (2014.02); A61M 1/3601 (2014.02); A61M 1/3609 (2014.02); A61M 1/3612 (2014.02); A61M 1/3669 (2013.01); A61B 2562/00 (2013.01); A61B 2562/04 (2013.01); A61B 2562/146 (2013.01); A61B 2562/16 (2013.01); A61B 2562/164 (2013.01); A61B 2562/166 (2013.01); A61B 2562/228 (2013.01); A61M 1/1605 (2014.02); A61M 1/1613 (2014.02); A61M 2205/3306 (2013.01); A61M 2205/3334 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A non-invasive blood volume sensor for determining at least one property of blood flowing in an extracorporeal segment of an extracorporeal blood treatment apparatus comprising:
at least one source for directing a signal towards the blood along an emission axis;
a plurality of detectors configured to receive the signal emitted by the at least one source after the signal at least partially passes through the blood flowing in the extracorporeal segment, and to emit respective output signals related to the received signal; and
a controller configured to receive the respective output signals from the plurality of detectors and to determine a value of the at least one property of the blood based on the output signals, wherein the property of the blood is one of a blood volume variation, a hemoglobin concentration change, or a parameter related to the blood volume variation or the hemoglobin concentration;
wherein the controller is further configured to use a state-space mathematical model for determining the value of the at least one property of the blood and/or an auxiliary blood parameter, wherein the state-space mathematical model includes the following equations:

OG Complex Work Unit Math
wherein
ΔRBV(t) is a differential relative blood volume,
Na p1 (t) is a differential plasma sodium concentration in the extracorporeal segment at instant t,
Napl(t) is a plasma sodium concentration in the extracorporeal segment at instant t,
NaIn(t) is an inlet dialysate sodium concentration at instant t at an inlet of a filtration unit, and
τDiff is a diffusion time; wherein the diffusion time is approximate to a constant time, included between 1000 and 1200 seconds.