체외형 양심실 보조장치에서 전자기력을 이용한 새로운 작동기의 적용에 관한 연구 : A Study on Novel Application of Electromagnetic Actuator Mechanism in Development of Extracorporeal Electro-pneumatic Biventricular Assist Device
- 발행기관 고려대학교
- 발행년도 2006
- 학위수여년월 2006. 2
- 학위명 석사
- 학과 대학원 의학과 의용생체공학전공
- 식별자(기타) DL:000016999853
- 서지제어번호 000045272775
초록/요약
Backgrounds; A ventricular assist device (VAD) is one of the useful mechanical systems in treatment of acute or chronic heart failure. Considering the pathophysiology of heart failure, a versatile bi-ventricular assist device (BiVAD) in a single piece unit is considered to be ideal for treating heart failure. Among the various pumping mechanisms, an electro-pneumatic pump is a hybrid one integrating the advantages of pneumatic and electric pumps. The driving force of this hybrid system consists of two parts; one is electromechanical force compressing the air bellows and another is pneumatic force transmitting the energy to compress the blood sacs. As for the electric force, electromechanical mechanism has been a standard. However, it requires a movement converting system including a ball screw, a helical cam, or a solenoid-beam spring, which makes the device complex and may lessen reliability. Thus, it has been hypothesized that an electromagnetic actuator mechanism could eliminate the movement converting system and that thereby enhance the mechanical reliability and operative simplicity of an electro-pneumatic BiVAD. The purpose of this study is to develop a prototype pump with electromagnetic actuator mechanism and to provide in vitro data for performance evaluation. Materials and Methods; The electromagnetic actuator consists of stators with a single winding excitation coil and movers with a high energy density neodymium-iron-boron permanent magnet. A 0.5 mm diameter wire was used for the excitation coil, and 1000 turns were wound onto the stators core with parallel. Electronic control unit included a control module, a voltage regulator and a motor driver. A TMS320LF2406A digital signal processor (DSP) with timers, pulse width modulators (PWM), and 10 bit analog-to-digital (A/D) converter were used for the control module. A prototype of extracorporeal electro-pneumatic BiVAD was constructed, and the pump performance tests were performed using a mock system to evaluate the efficiency of the electromagnetic actuator mechanism. Results; When forward and backward electric currents were supplied to the excitation coil, the mover moved back and forth. The nominal stroke length of the actuator was 10 mm. The actuator dimension was 120 mm in diameter and 65 mm in height with a weight of 1.4 kg. The prototype pump unit was 150mm in diameter, 150mm in thickness and 4.5kg in weight. The maximum force output was 70N at input current of 4.5A and the maximum pump rate was 150 beats per minute. The maximum output was 2.0 L/minute at a rate of 80 bpm when the afterload was 100mmHg. Conclusion; A novel electromagnetic actuator system has been designed for a pulsatile blood pump. The system has been successfully actualized to construct the prototype of an extracorporeal electro-pneumatic biventricular assist device. The in vitro pump performance test shows the positive potential for extended reliability and mechanical simplicity.
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List of Table
List of Figure
Abstract
Ⅰ. 서 론
1. 이론적 배경
2. 개발 동기
3. 연구의 필요성
Ⅱ. 재료 및 방법
1. 작동기 구성
2. 작동기 원리
3. 펌프 구성
4. 제어기 설계
5. 작동기 및 펌프의 성능평가
Ⅲ. 연구 결과
Ⅳ. 고 찰
Ⅴ. 결 론
Ⅵ. 참고 문헌
감사의 글
List of Table
Table 1. Classifications of blood pump
Table 2. Properties of the Actuator
List of Figure
Figure 1. Maxwell Force
Figure 2. Lorentz Force
Figure 3. Configuration of the KH-VAD
Figure 4. Cross sectional view of KH-VAD showing ball screw type actuator
Figure 5. Composition of the actuator (a) Disassembled view of the actuator (b) Assembled view of the actuator (c) Sectional view of the stator
Figure 6. Operation of the actuator (a) Initial state which operates only permanent magnets (b) Direction of actuator when N-S pole is formed at both ends of the core (c) Direction of actuator when S-N pole is formed at both ends of the core
Figure 7. Exterior view of the prototype pump unit using the electromagnetic actuator (a) Schematic diagram of the pump unit (b) Photograph of the pump unit
Figure 8. Flow chart of the controller
Figure 9. Electronic control unit
Figure 10. Diagram of Mock circulation system
Figure 11. A photograph of the prototype pump connecting controller
Figure 12. Relationship between input voltage and input current
Figure 13. The change in force output with change in input current
Figure 14. The changes of pressure waveform with the changes of pump rate (a) 30 beats per minute (bpm) (b) 60 beats per minute (bpm) (c) 90 beats per minute (bpm) (d) 90 beats per minute (bpm)
Figure 15. The effect of the pump rate on the pump output of the in vitro experiment (afterload 100 mmHg)
