電動液壓人工心臟驅動葉片之設計與測試

The Design and Test for the Impeller Used in Electro-Hydraulic Artificial Heart

電動液壓式人工心臟是目前世界各人工心臟研究中心包括我們在內的主要發展方向。此型式利用由直流馬達帶動之泵浦葉片產生高壓之液壓油，代替使用在氣動式之壓縮空氣推動人工心臟。為獲得高效能之葉片，我們應用電腦數值模擬的技術，進行設計和分析。模擬結果顯示流場很均勻，只有葉尖邊緣發生渦流，此為主要之能量損耗來源。我們立即將它製作成品。為利於測試，我們也設計、裝置一個測試迴路，量測、比較三種導流道的各項性能包括：流量、壓力揚程、效率、轉速等。量測結果發現導流道較平順的測試件，有較佳的效率。可達到之最高揚程及流量分別為：24.4 mmHg、6.51/min。此結果雖可滿足右心之實際工作之要求，但左心之設計尚需要進一步的修正和改善。

The electro-hydraulic artificial heart is recently the main guidance for all of artificial heart research centers in the world, including us. Replacing the compression air as pushing power for the pneumatic type total artificial heart, the electro-hydraulic type artificial heart use hydraulic-impellers which are driven by DC motor to generate high pressure hydraulic oil to make the artificial heart works. In order to obtain a high performance impeller, we applied the numerical simulation technique to achieve the design and investigate it, and simultaneously an axial type impeller was developed. The simulation results presented a uniform flow for the overall field. Only the part near the up of impeller provides high possibility for vortex generation. So, the design was produced for testing. On the test study, we designed a test loop to measure and compare the characteristics of the impeller including flow rate, head, efficiency, and rotation rate in three different types of guiding flow channels. The results showed the most efficient design has been the one with smooth channel. The maximum head and flow rate are 24.4 mmHg and 6.51/min, respectively. Both the flow rate and head cannot satisfy the demand for the left artificial heart to work normally. This requires more modification and improvements for the design.