US 11,654,223 B2
Extracorporeal circulation management device with blood level detection in a reservoir without a sensor
Ryohei Katsuki, Kanagawa (JP); Tsuyoshi Hasegawa, Kanagawa (JP); Yuuki Hara, Kanagawa (JP); and Tomoaki Hashimoto, Kanagawa (JP)
Assigned to TERUMO KABUSHIKI KAISHA, Tokyo (JP)
Filed by TERUMO KABUSHIKI KAISHA, Tokyo (JP)
Filed on Aug. 27, 2018, as Appl. No. 16/113,405.
Application 16/113,405 is a continuation of application No. PCT/JP2017/006779, filed on Feb. 23, 2017.
Claims priority of application No. JP2016-059304 (JP), filed on Mar. 23, 2016.
Prior Publication US 2019/0001045 A1, Jan. 3, 2019
Int. Cl. A61M 1/36 (2006.01); G01F 23/14 (2006.01); G01F 23/18 (2006.01)
CPC A61M 1/3624 (2013.01) [A61M 1/3639 (2013.01); A61M 1/3666 (2013.01); G01F 23/14 (2013.01); G01F 23/18 (2013.01); A61M 2205/3334 (2013.01); A61M 2205/3389 (2013.01); A61M 2205/52 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An extracorporeal blood circulation system for monitoring blood level in a reservoir temporarily storing the blood, comprising:
a memory storage unit for storing blood pressure measurements from a pressure sensor monitoring a blood pressure within a tube unit conveying blood from the reservoir relative to atmosphere;
an input device configured for operator entry of an initial height data of the blood stored in the reservoir; and
a processing unit that detects a height of a top surface of the blood stored in the reservoir as a change in height from the initial height data based on changes in the blood pressure measurements and a conservation of mechanical energy of a blood flow inside the tube unit;
wherein the memory storage unit further stores blood density information, gravitational acceleration information, and flow velocity information from a flow rate measurement unit which is located in the tube unit;
wherein the processing unit 1) determines a calculated liquid level energy at the top surface of the blood stored in the reservoir based on the blood density information, the gravitational acceleration information, and the flow velocity information, 2) determines a measured energy at the tube unit based on the flow velocity information, the pressure measurements, the blood density information, and the gravitational acceleration information, and 3) determines the height based on the calculated liquid level energy and the measured energy;
wherein the height is further based on a pressure loss coefficient characterizing a pressure loss from the top surface of the blood stored in the reservoir to the tube unit;
wherein the processing unit generates corrected pressure loss coefficient information based on an average of a plurality of pressure loss coefficients determined in time series; and
wherein the height is based on the corrected pressure loss coefficient information.