本研究以原水母瓣的設計概念為基礎，提出一款外形較符合流體力學原理的修正型水母瓣(Modified Jellyfish Valve)。原水母瓣中央血流速度快，因此我們減少該區堿的輪輻數目，並將原水母瓣的梯型輪幅外形修改為較流線型的橢圓型，以降低瓣膜後方分離泡及紊流小渦產生的機會。為避免薄膜因輪幅減少而發生脫垂(Prolapse)，則在辦膜出口處增加一竇腔(Sinus)設計以增加薄膜支撐面積並協助薄膜提早關閉。在定常流場(Steady Flow)實驗中發現修正型水母瓣的有效孔徑面積(EOA)大於原水母瓣；分別為2.564 及1.612 (流量24l/min)。為了觀察心瓣在真實人體使用時的性能參數；故設計一脈動複製器(Pulse Duplicator)來產生與人體真實流場相仿的脈動流場，並比較機械瓣(Metronic Hall Valve)、修正型水母瓣與原水母瓣在脈動流場下之性能。我們發現在低流量(< 5L/min)下，機械瓣的EOA與迴流量均比兩款水母瓣大，而修正型水母瓣的有效孔徑面積較原水母瓣略大，約增加10%~80%，但迴流量則為原水母瓣的1.5~4倍。

A modified Jellyfish valve was designed based on the original Jellyfish valve and fluid dynamic consideration. The new design reduced the number of spokes positional in the central flow region and adopted elliptic cross sections to make the spokes more streamline shaped. In order not to make the valve membrane prolapse during the diastole phase, a sinus was added at the outlet of the Jellyfish valve. This idea not only increases the supporting area of the membrane, but helps the membrane to close earlier so that the regurgitation is minimized. Experiments were conducted to evaluate the homodynamic performances of the two Jellyfish valves. In the steady-state flow test, the Effective Orifice Area (EOA) has been shown almost doubled with the modified design for flowrate up to 24 L/min. Unsteady experiment using pulse duplicator were also performed for Medtronic Hall, Jellyfish and modified Jellyfish valves. It was found that , for flowrate less than 5 L/min , Medtronic Hall Valve has larger EOA and regurgitation flow as compared to the two Jellyfish valves . Moreover, in this low flowrate range, the modified Jellyfish valve enjoys larger EOA but comparable regurgitation flow as compared to those of the original design. As a result, it is justified in the present research that the strategies proposed to modify the Jellyfish valve are feasible and effective.

[1]Vongpatanasin, W., Hills, L. D., and Lange, R. A., “Prosthetic Heart Valves,” The New England Journal of Medicine, Vol. 335, No. 6, 1996, pp. 407-416.

[2]Long, S. Y., Bi, Y., et. al., “New Polyurethane Valves in New Soft Artificial Hearts,” ASAIO Transactions , Vol. 35, 1989, pp. 301-304.

[3]Imachi, K., Mabuchi, K., et. al., “ In Vitro and In Vivo Evaluation of a Jellyfish Valve for Practical Use,” ASAIO Transactions, Vol. 35, 1989, pp. 298-301.

[4]Imachi, K., Mabuchi, K., et. al., “Blood Compatibility of the Jellyfish Valve Without Anticoagulant,” ASAIO Transactions, Vol. 37, 1991, pp. M220 -M222.

[5]Iwasaki, K., Umezu, M., et. al.,“Design Improvement of the Jellyfish Valve for Long-term Use in Artificial Hearts, ” The International Journal of Artificial Organs, Vol. 24, No. 7, 2001, pp. 463-469.

[6]Imachi, K., Umezu, M., et. al., ”The Improve Jellyfish Valve：Durability Enhancement With Sufficient Blood Compatibility,” ASAIO Journal, Vol. 48, 2002, pp. 532-537.

[7]Imachi, K., Mabuchi, K., et. al. , ” Fabrication of a Jellyfish Valve for Use in an Artificial Heart,” ASAIO Journal, Vol. 38, 1992, pp. M237-M242.

[8] Marlothaya, C., “A Manual Pulse Duplicator：A Simple Device Used in Testing Hand Made Cardiac Valves,” J. Med. Ass. Thailand, Vol.62, September, 1979, pp. 523-526.

[9] Yoganathan, A. P., and Corcoran, W. H., “Pressure Drops Across Prosthetic Aortic Heart Valves Under Steady and Pulsatile Flow - In Vitro Measurements,” Journal of Biomechanics, Vol. 12, 1979, pp. 153-164.

[10]Westerhof, N., Elzinga, G. and Sipkema P. “An Artificial Arterial System for Pumping Hearts,” Journal of Applied Physiology, Vol. 31, Nov. 1971, pp. 776 -781.

[11]Bowles, C. T.,Shah S. S., et. al., ”Development of Mock Circulation Models for the Assessment of Counterpulsation Systems,” Cardiovascular Research, Vol. 25, 1991, pp. 901-908.

[12]Papaioannou, T. G., Mathioulakis D. S., et. al., “Arterial Compliance Is a Main Variable Determining the Effectiveness of Intra Aortic Balloon Counterpulsation：Quantitative Data From an In Vitro Study,” Medical Engineering and Physics, Vol. 24, 2002, pp. 279-284.

[13]Sakhaeimanesh, A. A., and Morsi, Y. S., “Analysis of Regurgitation, Mean Systolic Pressure Drop and Energy Losses for Two Artificial Aortic Valves,” Journal of Medical and Technology, Vol. 23, No. 2, 1999, pp. 63-68.

[14]Christian, O., “Pulsatile Flow Studies of Prosthetic Aortic Valves,” Scand J Thor Cardiovasc Sugr, Vol. 5, 1971, pp. 1-12.

[15]Cornhill J. F., Phil, D., et. al., “An Aortic Left Ventricular Pulse Duplicator Used In Testing Prosthetic Aortic Heart Valves,” The Journal of Thoracic and Cardiovascular Surgery, Vol. 73, No. 4, 1977, pp.550-558.

[16]Abdallah, S. A., Su, C. S., and Hwang, N. H. C., “Dynamic Performance of Heart Valve Prostheses and the Testing Loop Characteristics,” Trans Am Soc Artif Intern Organs, Vol. 29, 1983, pp. 296-300.

[17]Kitamura, T., Affeld, K., and Mohnhaupt, A., “ Design of a New Pulse Duplicator System for Prosthetic Heart Valves”, Journal of Biomechanical Engineering, Vol. 109, 1987, pp. 43-47.

[18]Arabia, A. A., Talbot, T., et. al., “A Computerized Physiologic Pulse Duplicator for In-Vitro Hydrodynamic and Ultrasonic Studies of Prosthetic Heart Valves”, Original Research, 1989, pp. 205-215.

[19]Schichl, K., and Affeld, K., “A Computer Controlled Versatile Pulse Duplicator for Precision Testing of Artificial Heart Valves”, The International Journal of Artificial Organs, Vol. 16, Nov. 10., 1993, pp. 722-726.

[20]Suga, H., Sagawa, K., and Shoukas, A. A., ”Load Independence of the Instantaneous Pressure – Volume Ratio of the Canine Left Ventricle and Effects of Epinephrine and Heart Rate on the Ratio,” Circulation Research, Vol. 32, 1973, pp. 314-322.

[21]Yu, Y. C., Boston, J. R., et. al., “Pressure – Volume Relationship of a Pulsatile Blood Pump for Ventricular Assist Device Development,” ASISO Journal, 2001, pp. 293-301.

[22]洪瑞鴻等, “鳳凰七號人工心臟控制器使用說明書”, 1999年三月。

[23]阮婷婷, ”二維翼型人工心瓣之最佳化設計”, 成功大學航空太空工程研究所論文, 2002年七月。

[24]邱旻瑩, ”人工主動脈心瓣之流場特性”, 成功大學航空太空工程研究
所論文, 2002年七月。

[25]顏大欽, ”三葉片人工心之流體動力特性研究”, 淡江大學水資源及環
境工程研究所論文，1999年六月。