US 12,262,991 B2
System and method for non-invasive monitoring of hematocrit concentration
Rodolphe Katra, Blaine, MN (US)
Assigned to Medtronic Monitoring, Inc., San Jose, CA (US)
Filed by Medtronic Monitoring, Inc., San Jose, CA (US)
Filed on Oct. 25, 2021, as Appl. No. 17/452,190.
Application 17/452,190 is a continuation of application No. 15/866,118, filed on Jan. 9, 2018, granted, now 11,154,224.
Prior Publication US 2022/0039705 A1, Feb. 10, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. A61B 5/1455 (2006.01); A61B 5/00 (2006.01); A61B 5/145 (2006.01); A61B 5/02 (2006.01)
CPC A61B 5/14546 (2013.01) [A61B 5/0071 (2013.01); A61B 5/14535 (2013.01); A61B 5/1455 (2013.01); A61B 5/6826 (2013.01); A61B 5/0082 (2013.01); A61B 5/02028 (2013.01); A61B 2562/0233 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A system comprising:
a medical device comprising:
at least one light source configured to provide a first excitation signal to tissue of a patient, the first excitation signal configured to generate a continuous emission response spectrum from the tissue for at least two selected blood components; and
at least one light detector configured to receive the continuous emission response spectrum and detect a first emission response at a first emission wavelength and a second emission response at a second emission wavelength; and
one or more processors configured to:
calculate a ratiometric value based on a first emission response amplitude at the first emission wavelength and a second emission response amplitude at the second emission wavelength, wherein the first emission wavelength is selected to correspond with an isosbestic maximum associated with the at least two selected blood components of the continuous emission response spectrum and the second emission wavelength is selected to correspond with an isosbestic minimum associated with the at least two selected blood components of the continuous emission response spectrum, and the ratiometric value varies based on hematocrit level of the patient;
compare the calculated ratiometric value to a baseline ratiometric value;
determine a hematocrit level based on the comparison of the calculated ratiometric value to the baseline ratiometric value; and
generate an alert of a condition of the patient based on the comparison.