Development of a real-time and quantitative thrombus sensor for an extracorporeal centrifugal blood pump by near-infrared light

Sakota, Daisuke; Fujiwara, Tatsuki; Ohuchi, Katsuhiro; Kuwana, Katsuyuki; Yamazaki, Hiroyuki; Kosaka, Ryo; Nishida, Masahiro; Mizuno, Tomohiro; Arai, Hirokuni; Maruyama, Osamu

doi:10.1364/boe.9.000190

Cited by 10 publications

(13 citation statements)

References 26 publications

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“…Uriel et al used echocardiography for diagnosing thrombosis. Sakota et al developed a sensor using near‐infrared light to detect pump thrombosis quantitatively. Schalit et al developed a method for detecting pump thrombosis in a HVAD using an accelerometer directly attached to the pump housing.…”

Section: Discussionmentioning

confidence: 99%

“…Acoustic spectrum analysis to diagnose pump thrombosis has also been developed . Some of these methods have been evaluated in in vivo experiments and successful results have been obtained . Compared to these methods, the proposed method has the advantage of not requiring additional sensors.…”

Section: Discussionmentioning

confidence: 99%

“…As with the recent advent of artificial intelligent technologies in industrial products, we believe VADs should have intelligent functions to overcome the issue of pump thrombosis. With regard to this, several methods for detecting pump thrombosis using additional equipment, such as an infrared light source, an accelerometer, or an acoustic microphone, have been studied . As for implantable VADs, however, it is desirable to avoid the use of additional equipment inside the body due to the increased cost and complexity of the system.…”

Section: Introductionmentioning

confidence: 99%

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Detection of thrombosis in a magnetically levitated blood pump by vibrational excitation of the impeller

et al. 2020

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The use of contactless support technology for the impeller has led to an increase in the durability of ventricular assist devices (VADs), and these have been in clinical use worldwide. However, pump thrombosis and stroke are still issues to be solved.We have developed a method for detecting the thrombosis in a magnetically levitated blood pump without the need for additional sensors or other equipment. In the proposed method, a sinusoidal current is applied to the electromagnets used for the magnetic bearing, resulting in vibration of the impeller. The phase difference between the current and displacement of the impeller increases with pump thrombosis. First, we describe the principle by which the pump thrombosis is detected.Pump thrombosis reduces the narrowest fluid gap in the pump and this gives rise to a change in the phase difference. Second, we report on experiments in which we changed the narrowest fluid gap using oriented polypropylene tape and showed that decreasing the narrowest fluid gap resulted in an increase in phase difference. For these experiments, the measurements were repeated three times for each condition.Third, we examine the relationship between the pump thrombosis and the phase difference evaluated by observations of the underside of the impeller when operating the pump with porcine blood. Since light was unable to penetrate the blood layer, the erythrocytes were removed for this observation. Only one observation was made.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Detection of thrombosis in a magnetically levitated blood pump by vibrational excitation of the impeller

et al. 2020

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“…4 In such cases, the risk of thrombotic complications will rise, thus increasing the need for realtime thrombus detection. Thus far, various approaches to real-time thrombus monitoring in extracorporeal circuits have been proposed based on electrical, 5,6 sound, 7,8 or Real-time, non-invasive thrombus detection in an extracorporeal circuit using micro-optical thrombus sensors 1 Sensing System Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tosu, Saga, Japan 2 Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan optical [9][10][11][12] principles. However, invasiveness remains an issue with electrical monitoring techniques, as electrodes must be in contact with the blood.…”

Section: Introductionmentioning

confidence: 99%

Real-time, non-invasive thrombus detection in an extracorporeal circuit using micro-optical thrombus sensors

et al. 2020

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Introduction: Real-time, non-invasive monitoring of thrombus formation in extracorporeal circuits has yet to be achieved. To address the challenges of conventional optical thrombus detection methods requiring large devices that limit detection capacity, we developed a micro-optical thrombus sensor. Methods: The proposed micro-optical thrombus sensor can detect the intensity of light scattered by blood at wavelengths of 660 and 855 nm. Two thrombus sensors were installed on in vitro circuit: one at the rotary blood pump and one at a flow channel. To evaluate the variation in the ratio of incident light intensity at each wavelength of the two sensors, Rfluct (for 660 nm) and Ifluct (for 855 nm) were defined. Using fresh porcine blood as a working fluid, we performed in vitro tests of haematocrit (Hct) and oxygen saturation (SaO2) variation and thrombus detection. Thrombus tests were terminated after Rfluct or Ifluct showed a larger change than the maximum range of those in the Hct and SaO2 variation test. Results: In all three thrombus detection tests, Ifluct showed a larger change than the maximum range of those in the Hct and SaO2 variation test. After the tests, thrombus formation was confirmed in the pump, and there was no thrombus in the flow channel. The results indicate that Ifluct is an effective parameter for identifying the presence of a thrombus. Conclusion: Thrombus detection in an extracorporeal circuit using the developed micro-optical sensors was successfully demonstrated in an in vitro test.

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“…Feldmann et al employed on a non‐invasive acoustic method for detecting early pump thrombus in an HVAD, which was evaluated using an artificial thrombus made of silicone. A near‐infrared sensor has been developed by Sakota et al for a real‐time and quantitative thrombus detection in a monopivot centrifugal blood pump (HCF‐MP23; Senko Medical Instruments Mfg. Co., Ltd., Tokyo, Japan).…”

Section: Introductionmentioning

confidence: 99%

Mechanical antithrombogenic properties by vibrational excitation of the impeller in a magnetically levitated centrifugal blood pump

Murashige

Hijikata

2019

Artificial Organs

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Mechanical circulatory support devices have been used clinically for patients with heart failure for over 10 years. However, thrombus formation inside blood pumps remains a risk to patient life, causing pump failure and contributing to neurological damage through embolization. In this article, we propose a method for preventing thrombus formation by applying vibrational excitation to the impeller. We evaluate the ability of this method to enhance the antithrombogenic properties of a magnetically levitated centrifugal blood pump and ensure that the impeller vibration does not cause undue hemolysis. First, 3 vibrational conditions were compared using an isolated pump without a mock circulation loop; the vibrational excitation frequencies and amplitudes for the impeller were set to (a) 0 Hz‐0 μm, (b) 70 Hz‐10 μm, and (c) 300 Hz‐2.5 μm. The motor torque was measured to detect thrombus formation and obtain blood coagulation time by calculating the derivative of the torque. Upon thrombus detection, the pump was stopped and thrombi size were evaluated. The results showed an increase in the blood coagulation time and a decrease in the rate of thrombus formation in pumps with the impeller vibration. Second, an in vitro hemolysis test was performed for each vibrational condition to determine the effect of impeller vibration on hemolysis. The results revealed that there was no significant difference in hemolysis levels between each condition. Finally, the selected vibration based on the above test results and the non‐vibration as control were compared to investigate antithrombogenic properties under the continuous flow condition. The blood coagulation time and thrombi size were investigated. As a result, vibrational excitation of the impeller at a frequency of 300 Hz and amplitude of 2.5 μm was found to significantly lengthen clotting time, decreasing the rate of pump thrombus compared to the non‐vibration condition. We indicate the potential of impeller vibration as a novel mechanical antithrombogenic mechanism for rotary blood pumps.

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Development of a real-time and quantitative thrombus sensor for an extracorporeal centrifugal blood pump by near-infrared light

Cited by 10 publications

References 26 publications

Detection of thrombosis in a magnetically levitated blood pump by vibrational excitation of the impeller

Detection of thrombosis in a magnetically levitated blood pump by vibrational excitation of the impeller

Real-time, non-invasive thrombus detection in an extracorporeal circuit using micro-optical thrombus sensors

Mechanical antithrombogenic properties by vibrational excitation of the impeller in a magnetically levitated centrifugal blood pump

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