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Blood feeding flow rate-controlling device and extracorporeal circulation device コモンズ

外国特許コード F160008895
整理番号 2011-10US
掲載日 2016年11月2日
出願国 アメリカ合衆国
出願番号 201314383876
公報番号 20150045712
公報番号 9381287
出願日 平成25年1月29日(2013.1.29)
公報発行日 平成27年2月12日(2015.2.12)
公報発行日 平成28年7月5日(2016.7.5)
国際出願番号 JP2013051906
国際公開番号 WO2013132923
国際出願日 平成25年1月29日(2013.1.29)
国際公開日 平成25年9月12日(2013.9.12)
優先権データ
  • 特願2012-053829 (2012.3.9) JP
  • 2013JP051906 (2013.1.29) WO
発明の名称 (英語) Blood feeding flow rate-controlling device and extracorporeal circulation device コモンズ
発明の概要(英語) A blood supply flow rate controlling device (2), which is a device for controlling the blood supply flow rate in an extracorporeal circulation device connected to a living body (10), includes rotational frequency detecting means that detects the rotational frequency of the centrifugal pump (40) of the extracorporeal circulation device, inlet pressure detecting means and outlet pressure detecting means that detect the inlet pressure and the outlet pressure of the centrifugal pump (40), respectively, flow rate regulating means that regulates a flow rate of blood supplied to the living body by adjusting a flow path cross section area of the blood circulation circuit (20), and controlling means that controls the flow rate regulating means.
従来技術、競合技術の概要(英語) BACKGROUND ART
Most blood pumps used in open heart surgery or for auxiliary circulation have been constant flow rate pumps exemplified by a roller pump.
The roller pump structurally delivers blood in such a way that rotating rollers compress a tube through which blood flows, which thus causes safety problems such as a great loss of blood cells and a risk of foreign material entrainment due to tubing wear.
Given this background, in recent years, a centrifugal pump replacing the roller pump has been increasingly used.
The centrifugal pump offers a variety of advantages compared to the roller pump, such as no occurrence of dangerous high pressure, a high level of safety against air entrainment, and no generation of excessive negative pressure.
However, even when the centrifugal pump operates at a constant rotational frequency, the centrifugal pump can cause a blood supply flow rate to be changed upon variation of pressure loading due to narrowing of the patient's blood vessels.
An additional flowmeter for sequentially monitoring the blood supply flow rate is thus required to be provided.
Also, attempts have been made to keep the blood supply flow rate constant by controlling an arterial line occluder (see, for example, Patent Literature 1) or by controlling the rotational frequency of the centrifugal pump (see, for example, Patent Literatures 2 and 3) under constant monitoring of the flowmeter.
As such a flowmeter, an ultrasonic flowmeter or an electromagnetic flowmeter can be used.

CITATION LIST

Patent Literature
Patent Literature 1: Unexamined Japanese Patent Application Kokai Publication No. 2006-325750.
Patent Literature 2: Unexamined Japanese Patent Application Kokai Publication No. H08-238310.
Patent Literature 3: Unexamined Japanese Patent Application Kokai Publication No. H09-122228.

特許請求の範囲(英語) [claim1]
1. A blood supply flow rate controlling device for use in an extracorporeal circulation device connected to a living body, the extracorporeal circulation device comprising a centrifugal pump for circulating blood through a blood circulation circuit, the blood supply flow rate controlling device comprising: rotational frequency detecting means that detects a rotational frequency of the centrifugal pump;
inlet pressure detecting means and outlet pressure detecting means that detect an inlet pressure and an outlet pressure of the centrifugal pump, respectively;
flow rate regulating means that regulates a flow rate of blood supplied to the living body by adjusting a flow path cross section area of the blood circulation circuit; and
controlling means that controls the flow rate regulating means, wherein
the flow rate regulating means is located downstream of the centrifugal pump,
the controlling means comprises an inputter, a storage, a processor, and an outputter,
the inputter is configured to receive inputs of a desired target blood supply flow rate entered by an operator, an inlet pressure detection value and an outlet pressure detection value respectively detected by the inlet pressure detecting means and the outlet pressure detecting means, a detected rotational frequency of the centrifugal pump detected by the rotational frequency detecting means, and an estimated blood flow rate equation for calculating an estimated blood flow rate of blood passing through the blood circulation circuit from the inlet pressure detection value, the outlet pressure detection value, and the detected rotational frequency,
the storage is configured to store the target blood supply flow rate, the inlet pressure detection value, the outlet pressure detection value, the detected rotational frequency, and the estimated blood flow rate equation,
the processor is programmed to calculate a differential pressure by subtracting the inlet pressure detection value from the outlet pressure detection value, the estimated blood flow rate from the differential pressure and the detected rotational frequency by the estimated blood flow rate equation, and a flow rate differential by subtracting the estimated blood flow rate from the target blood supply flow rate, and
the outputter is configured to output to the flow rate regulating means a control signal that reduces the flow path cross section area when the flow rate differential has a negative value, a control signal that increases the flow path cross section area when the flow rate differential has a positive value, and a control signal that reduces the flow path cross section area to zero when the estimated blood flow rate has a negative value.
[claim2]
2. The blood supply flow rate controlling device according to claim 1, wherein the estimated blood flow rate equation is expressed by the following equation 1:
Qe(f)=alpha (f).DELTA beta +beta (f) (equation 1)
where Qe is the estimated blood flow rate, f is the detected rotational frequency of the centrifugal pump, DELTA P is the differential pressure by subtracting the inlet pressure detection value from the outlet pressure detection value, and alpha and beta are respectively a slope and an intercept of a linear function of the flow rate of the centrifugal pump as a function of the differential pressure DELTA P at the rotational frequency of the centrifugal pump.
[claim3]
3. The blood supply flow rate controlling device according to claim 2, wherein the outputter is configured to output to the flow rate regulating means a control signal that reduces the flow path cross section area to zero when the estimated blood flow rate is above a predetermined threshold flow rate.
[claim4]
4. The blood supply flow rate controlling device according to claim 1, comprising: a display configured to display the target blood flow rate and the estimated blood flow rate,
the blood supply flow rate controlling device comprising a power supply independent of a power supply to the centrifugal pump.
[claim5]
5. An extracorporeal circulation device comprising the blood supply flow rate controlling device according to claim 1.
  • 発明者/出願人(英語)
  • NINOMIYA SHINJI
  • SUEDA TAIJIRO
  • KUROSAKI TATSUYA
  • KUDO MASAAKI
  • OKAMURA NAOYA
  • JOSHO GAKUEN EDUCATIONAL FOUNDATION
  • HIROSHIMA UNIVERSITY
国際特許分類(IPC)
米国特許分類/主・副
  • 2016/01/01

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