US 12,220,211 B2
Processing impedance signals for breath detection
Frederick J Geheb, Lenexa, KS (US); Gary A Freeman, Waltham, MA (US); and Ulrich Herken, Medford, MA (US)
Assigned to ZOLL Medical Corporation, Chelmsford, MA (US)
Filed by ZOLL Medical Corporation, Chelmsford, MA (US)
Filed on Jan. 24, 2023, as Appl. No. 18/158,593.
Application 18/158,593 is a continuation of application No. 16/717,153, filed on Dec. 17, 2019, granted, now 11,589,756.
Application 16/717,153 is a continuation of application No. 15/910,038, filed on Mar. 2, 2018, granted, now 10,548,486, issued on Feb. 4, 2020.
Application 15/910,038 is a continuation of application No. 14/200,571, filed on Mar. 7, 2014, granted, now 9,968,267, issued on May 15, 2018.
Claims priority of provisional application 61/791,150, filed on Mar. 15, 2013.
Prior Publication US 2023/0263405 A1, Aug. 24, 2023
Int. Cl. A61B 5/0205 (2006.01); A61B 5/00 (2006.01); A61B 5/08 (2006.01); A61B 5/11 (2006.01)
CPC A61B 5/0205 (2013.01) [A61B 5/0809 (2013.01); A61B 5/11 (2013.01); A61B 5/6823 (2013.01); A61B 5/725 (2013.01); A61B 5/74 (2013.01); A61B 5/7405 (2013.01); A61B 5/742 (2013.01); A61B 2562/0219 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a medical device comprising a cardiopulmonary resuscitation (CPR) treatment feedback device, a memory, and at least one processor; and
at least one sensor configured to provide at least an electrical impedance signal to the at least one processor, wherein the electrical impedance signal corresponds to an electrical impedance measured at a chest of a patient; and
wherein the at least one processor is configured to:
receive the electrical impedance signal from the at least one sensor,
process the electrical impedance signal to determine information representative of chest compression activity performed by a rescuer on the patient during a CPR treatment of the patient;
filter the chest compression activity from the electrical impedance signal;
analyze the filtered electrical impedance signal to identify one or more threshold values for identifying individual ventilation cycles, wherein the one or more threshold values comprise a positive threshold value and a negative threshold value determined based on the filtered electrical impedance signal;
generate a positive threshold function based on the positive threshold value and the filtered electrical impedance signal and a negative threshold function based on the negative threshold value and the filtered electrical impedance signal;
determine airflow activity information of the patient based on the positive threshold function and the negative threshold function and the filtered electrical impedance signal;
based on the airflow activity information, determine when the patient is being overventilated due to the CPR treatment; and
provide CPR treatment feedback comprising an instruction that ventilations should be adjusted when the patient is being overventilated.