• Proceedings of the KOSOMBE Conference
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• v.1990 no.05
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• pp.17-20
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• 1990

• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.41-50
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• 1993

This paper proposes an adaptive technique for the cardiac output regulation of a pendulum type electromechanical TAH. This techinque, which consists of two RLSE's and two PASTC' 5, performs Its controllability over the TAIB so that the m(RAP) and m(LAP) values re- main close to their desired values under she assumption that the variation of m(RAP) and m (LAP) are dominated by the variation of C.0. and the difference between the left and right ventricular output, respectively. To evaluate the performance of the proposed control system, a simulation is performed by using a human model which contains physiologic, drug and treatment, artificial heart and noise models. As a result, dual adaptive controller showed that abnormal m(LAP) and m(RAP) could be recovered to the normal range within 10minute and maintained desired value in steady state. The operation of this controller prored to be robust in spite of the rapid variation of human status.

• Proceedings of the KOSOMBE Conference
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• v.1990 no.05
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• pp.1-6
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• 1990

A new version of moving actuator electromechanical total artificial heart was designed to improve total efficiency, durability, and fitting inside thoracic cavity. As compared with our present type of the rolling cylinder actuator, this new model has a pendulum-type actuator with reciprocating motion around the fixed circular path, connected through the gear mechanisms to the motor. By using this mechanism, the efficiency and durability could be improved by replacing sliding mechanism with rolling contact elements. Also, the height of the pump could be decreased from 9cm to 7cm with static stroke volume 65cc. With these improvements, we have implanted this new pump in human size animal (less than 70Kg weight).

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.222-226
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• 1995

인공심장에서의 박출량제어는 전부하에 따른 심박출균형, 심실내 완전충만과 완전구출을 구현하는데 그 목적이 있다. 본 논문에서는 인공심장 내부의 심실간 공간 압력파형을 심박출량의 제어에 활용하였다. 이를 위해서는 심실간 공간의 압력파형을 심실 유입부와 유출부의 혈류량에 대한 정보, 이동작동기의 위치신호와 동기시켜 해석하는 것이 필요하다. 이러한 압력파형의 해석을 바탕으로, 심실간 공간의 음압 크기로 좌,우 심방압을 추정하고 작동기의 좌,우 수축기때 심실간 공간의 음압크기를 비슷하게 유지하도록 작동거리를 제어하면 좌우 심박출 균형을 이룰 수 있음을 확인하였다. 또한, 심실의 완전충만과 완전구출의 실현을 위한 심실 충만 정도를 추정할 수 있게 하는 인자를 제시하였다.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.199-202
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• 1996

Artificial hearts are intended for use in patients with severe forms of heart disease for which no surgical repair is possible. The moving-actuator pump was developed to decrease the overall volume size of the electromechanical total artificial heart (TAH) by eliminating the occupied space of the fixed-actuator in the conventional pusher-plate type pump. In our pump, the actuator moves back and forth for alternative ejections of left and right ventricles. The problem of fitting the TAH to atrial remnants and arterial vessels could also be improved by circular or penduluous mot ion of the actuator instead of linear mot ion of the pusher-plate in the conventional pumps. We have evaluated two types of moving- actuator pump; one is a rolling cylinder type, and the other a pendulum type pump. In the rolling cylinder pump, frictional energy loss exists between the pump housing's guide bars and the actuator's end caps, while the bottom rack under the cylindrical actuator increases the height of the pump, the pump is therefor not implantable inside the small chest of human-sized animals with a body weight of less than 70kg. The new human type pump has a penduluous mot ion actuator to correct the above problems while maintaining the advantage of the moving- actuator's small total volume. The totally implantable TAH is composed of a blood pump, a control system and pheriperal equipments. The blood pump, which is constructed by a moving actuator, a right and left blood sac, and four artificial valves, is implanted in the thoracic. In 1988, the first implantation of the rolling cylinder TAH was performed into a female calf weighing 100kg, and the cal f recovered to the degree of voluntary standing and eat ing and survived to 100 hrs. We then survived two female sheep weighing about 63kg with the new human type TAH for three days.