Sensorless measurement of pulsatile flow rate using a disturbance force observer in a magnetically levitated centrifugal blood pump during ventricular assistance

Pai, Chi Nan; Shinshi, Tadahiko; Shimokohbe, Akira

doi:10.1016/j.flowmeasinst.2009.11.003

Cited by 11 publications

(5 citation statements)

References 16 publications

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“…First, the blood flow pulsatility caused by a beating heart was not considered in the evaluation of the proposed estimation method unlike previous studies. [5][6][7][8][9]13 In this study, a steady flow could be estimated accurately using the averaged radial impeller displacement. The averaging should be performed at least for 0.15 s to remove the data noise in this experiment.…”

Section: Clinical Applications Of the Proposed Estimation Methodsmentioning

confidence: 99%

“…impeller position). [10][11][12][13] Several research groups have investigated the dynamics of a magnetically levitated (maglev) impeller for application to the flow rate estimation of a blood pump with a magnetic bearing; 11,12 this has been used as a non-contact bearing in VADs such as HeartMate III (St Jude Medical, LLC) 14 and CentriMag (Thoratec Corporation) 15 to prevent blood complications in VAD applications.…”

Section: Introductionmentioning

confidence: 99%

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Flow rate estimation of a centrifugal blood pump using the passively stabilized eccentric position of a magnetically levitated impeller

2019

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Flow rate estimation for ventricular assist devices without additional flow sensors can improve the quality of life of patients. In this article, a novel flow estimation method using the passively stabilized displacement of a magnetically levitated impeller is developed to achieve sufficient accuracy and precision of flow estimation for ventricular assist devices in a simple manner. The magnetically levitated impeller used is axially suspended by a magnetic bearing in a centrifugal blood pump that has been developed by our group. The radial displacement of the impeller, which is restricted by passive stability, can be correlated with the flow rate because the radial hydraulic force on the impeller varies according to the flow rate. To obtain the correlation with various blood viscosities, the relationships between the radial displacements of the magnetically levitated impeller and the pressure head-flow rate characteristics of the pump were determined simultaneously using aqueous solutions of glycerol with a potential blood viscosity range. The measurement results showed that accurate steady flow rates could be estimated with a coefficient of determination of approximately 0.97 and mean absolute error of approximately 0.22 L/min without fluid viscosity measurements by using the relationships between the impeller displacement and the flow rate. Moreover, a precision of approximately 0.01 (L/min)/µm was obtained owing to a strong estimation indicator signal provided by the large displacement of the passively stabilized impeller; thus, the proposed estimation method can help ensure sufficient accuracy and precision for ventricular assist devices in a simple manner, even if the blood viscosity is unknown.

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Section: Clinical Applications Of the Proposed Estimation Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Flow rate estimation of a centrifugal blood pump using the passively stabilized eccentric position of a magnetically levitated impeller

2019

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“…The MagLev RBP was connected to a mock circulatory loop consisting of a pulsatile pump, an aorta simulator, a left atrium simulator, and a fluid resistance. The details of the mock circulatory loop are described in reference . The same ultrasonic flow meter and pressure transducers described above were used for the measurements.…”

Section: Methodsmentioning

confidence: 99%

Sensorless Viscosity Measurement in a Magnetically‐Levitated Rotary Blood Pump

et al. 2015

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Controlling the flow rate in an implantable rotary blood pump based on the physiological demand made by the body is important. Even though various methods to estimate the flow rate without using a flow meter have been proposed, no adequate method for measuring the blood viscosity, which is necessary for an accurate estimate of the flow rate, without using additional sensors or mechanisms in a noninvasive way, has yet been realized. We have developed a sensorless method for measuring viscosity in magnetically levitated rotary blood pumps, which requires no additional sensors or mechanisms. By applying vibrational excitation to the impeller using a magnetic bearing, we measured the viscosity of the working fluid by measuring the phase difference between the current in the magnetic bearing and the displacement of the impeller. The measured viscosity showed a high correlation (R(2) > 0.992) with respect to a reference viscosity. The mean absolute deviation of the measured viscosity was 0.12 mPa·s for several working fluids with viscosities ranging from 1.18 to 5.12 mPa·s. The proposed sensorless measurement method has the possibility of being utilized for estimating flow rate.

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“…External devices such as VAD have also a great potential to be used as model-based sensors, enabling for example, the measurement of the blood flow rate, based on electric current in the magnetic bearing that supports the rotor of the VAD [173].…”

Section: Recommendationsmentioning

confidence: 99%

Model-based management of cardiovascular failure: Where medicine and control systems converge

Desaive

Horikawa

Ortiz

et al. 2019

Annual Reviews in Control

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Cardiovascular disease is growing epidemically worldwide, multiplying the impact of increasingly aging populations on intensive care unit (ICU) demand. It is the leading cause of ICU admission, length of stay, mortality and, as a result, cost. Hence, there is a significant need to bring the gains in productivity enabled by automation and control systems technologies, which have arisen in so many sectors, to medicine and this field in particular. This review presents the background to the problem and the main issues arising in care from a control systems technology perspective. It then presents a vision of a more automated future with specific goals in the areas of dynamic systems modeling, system identification and control. These areas are reviewed, followed by specific recommendations for the field, where control systems expertise can be leveraged to best advantage.

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Sensorless measurement of pulsatile flow rate using a disturbance force observer in a magnetically levitated centrifugal blood pump during ventricular assistance

Cited by 11 publications

References 16 publications

Flow rate estimation of a centrifugal blood pump using the passively stabilized eccentric position of a magnetically levitated impeller

Flow rate estimation of a centrifugal blood pump using the passively stabilized eccentric position of a magnetically levitated impeller

Sensorless Viscosity Measurement in a Magnetically‐Levitated Rotary Blood Pump

Model-based management of cardiovascular failure: Where medicine and control systems converge

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