Development of an Autoflow Cruise Control System for a Centrifugal Pump

Nishida, Hiroshi; Beppu, Toshiyuki; Nakajima, Masato; Nishinaka, Tomohiro; Nakatani, Hayao; Ihashi, K; Katsumata, Takahiro; Kitamura, Masaya; Aomi, Shigeyuki; Endo, Masahiro; Koyanagi, Hitoshi; Oshiyama, Hiroaki; Nogawa, Atsuhiko; Amano, Nobuhiko; Nojiri, Chisato; Akutsu, Tetsuzo

doi:10.1111/j.1525-1594.1995.tb02410.x

Cited by 8 publications

(6 citation statements)

References 3 publications

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“…Several studies have proposed systems that control arterial ow rate by tracking manually-regulated venous ow rate [14], [17], [18]. The control error of the most accurate system was 0.9% for a constant target ow rate and 6% for the ow rate modulated through CPB surgeries [18].…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, it is preferable to use a CPB system with a centrifugal pump. Several blood ow rate control systems have been developed for systems using centrifugal pumps [17], [18]; however, most systems were not designed to control the occluders but to maintain the target blood ow rate independent of the centrifugal pump speed. To solve this problem, a method was proposed to automatically control the occluder so that the arterial ow rate matches the manually-adjusted venous ow rate [14], [19].…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass

Takahashi

Kinoshita

Soh

et al. 2022

Preprint

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Performing a cardiopulmonary bypass (CPB) requires a well-trained perfusionist with skill and experience. In particular, operating the two occluders is difficult because it changes both the blood flow rate and reservoir level, and failure of the operation puts the patient’s life at risk. This study proposes an automatic control system with a two-degrees-of-freedom model matching controller nested in an I-PD feedback controller to simultaneously regulate the blood flow rate and the reservoir level. Experiments simulating CPB initiation and weaning were conducted using glycerin and bovine blood as perfusates. The results demonstrated that the arterial flow rate tracked the manually adjusted venous flow rate with a percentage error below 7.57%, and the reservoir level was maintained with an error below 4.89%. Then, experiments were conducted that simulated disturbances caused by venting/suction of blood from the surgical field and afterload fluctuation in the patient. The results showed that the control accuracies were not affected by afterload fluctuation; venting/suction disturbance worsened the accuracy of controlling the flow rate (3.26% error), while the reservoir level was maintained at 2.22% error. Thus, the robustness and control accuracies of the proposed system were demonstrated, and the system marks another step toward the automation of CPB.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass

Takahashi

Kinoshita

Soh

et al. 2022

Preprint

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“…This characteristic also makes the handling of flow control completely different between the conventional roller pump and the centrifugal pump. To narrow this gap, we have developed an easy and reliable autoflow control method in the centrifugal pump ( 1,2). However, the questions that follow have been raised from the clinical standpoint.…”

Section: Discussionmentioning

confidence: 99%

Afterload‐Dependent Flow Fluctuation of Centrifugal Pump: Should it be Actively Fixed?

Nishida¹,

Akazawa²,

Nishinaka³

et al. 1998

Artificial Organs

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To evaluate the clinical meaning and effects of afterload-dependent flow fluctuation in a centrifugal pump, concomitant measurement of flow rate and mixed venous oxygen saturation (SVO2) was performed in 5 cases of open heart surgery in which the patients underwent cardiopulmonary bypass (CPB) with the Terumo Capiox centrifugal pump. Continuous measurement of SVO2 using the 3M CDI System 100 was performed with a disposable cuvette incorporated into the drainage circuit. After the target flow rate of 2.4 L/min/m2 was obtained under a nonbeating condition, the pump rotational speed was fixed. During the cooling and low temperature period, SVO2 decreased as the flow rate spontaneously decreased but still stayed around 80% even with a 15-20% decrease in blood flow rate. This indicates that a luxury perfusion condition is ensured as long as the body temperature is kept low. In contrast, during the rewarming period, SVO2 decreased to around 70-75% despite a 15-25% spontaneous increase in flow rate. Although this level of SVO2 still indicates adequate systemic perfusion, there is a possibility of regional hypoperfusion in patients with such conditions as cerebrovascular disease. In conclusion, although diligent adjustment of the physiological fluctuating flow rate in the centrifugal pump seems unnecessary during conventional open heart surgery, manual control may be necessary especially during the rewarming period, normothermic surgery, or circulatory assist for shocked patients. From this study, we also conclude that the major benefit of the afterload-independent autoflow control system of the centrifugal pump is the improvement of safety in terms of the fixed reservoir level and the handling of cardiopulmonary bypass.

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“…Venous blood flow and oxygen partial pressure in the venous blood were the control variables in this simulation study without in vitro or in vivo test series. ANBE et al (1992a,b) andNISHIDA et al (1995) describe fuzzy and proportional control strategies of arterial blood flow. The results presented in their in vivo studies look promising.…”

Section: Introductionmentioning

confidence: 99%

Robust and self-tuning blood flow control during extracorporeal circulation in the presence of system parameter uncertainties

Misgeld

Werner

Hexamer

2005

Med. Biol. Eng. Comput.

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Three different discrete controllers were designed and tuned to be used in conjunction with a rotary blood pump during cardiopulmonary heart-lung support. The controllers were designed to operate in both steady and pulsatile modes. The system and methods were tested in a circulatory haemodynamic simulator. To guarantee stable control of the non-linear circulatory system in the presence of patient parameter uncertainties, a proportional plus integral (PI) and an H infinity controller were robustly tuned, using a non-linear time-varying model. (H infinity refers to the Hardy space, the set of bounded functions, analytic in the right half plane. The H infinity controller is the solution to the H infinity norm optimisation problem.) A self-tuning general predictive controller (GPC), together with an adaptive Kalman filter (KF) estimator, was compared with the two robustly tuned controllers. The closed-loop blood flow control circuit was set up in simulation routines first. The blood flow controllers were validated in a circulatory hydrodynamic simulator (MOCK) combined with a rotary blood pump. Parameters of the system simulator were changed continuously, and the controllers were tested over a wide range of different operating points. Disturbances in the form of discontinuous additive parameter uncertainties were applied. The closed-loop systems remained robustly stable. The robustly tuned H infinity controller showed the best control performance, in contrast to the GPC controller, which was near instability in regions of strongly varying non-linear system gain. Compared with the H infinity controller, the PI controller showed slightly worse behaviour, but the closed-loop response was acceptable, even in regions of strongly varying non-linear system gain and during pulsatile perfusion. The rotary blood pump could provide stationary and pulsatile perfusion under control conditions. Controlled variables were hereby mean blood flow, pulsatility index and heart rate. All three controllers were developed for an arterial mean flow of 0-6 l min(-1) and a heart rate of up to 70 beats per minute. Pulsatile closed-loop perfusion could provide up to 30 mmHg pressure variation in the simulated ascending aorta at a mean flow of 3 l min(-1).

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Development of an Autoflow Cruise Control System for a Centrifugal Pump

Cited by 8 publications

References 3 publications

Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass

Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass

Afterload‐Dependent Flow Fluctuation of Centrifugal Pump: Should it be Actively Fixed?

Robust and self-tuning blood flow control during extracorporeal circulation in the presence of system parameter uncertainties

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