Research Of Automated Ultrasonic Micro-dissection

Along with the rapid development of modern biology and the related techniques, micromanipulation technique has become a research focus, including micro-dissection which is frequently referred to as one of the important operations. At present, in biomedical field the specific organizations or single cell are mostly obtained by manual or machine assisted method, with unavoidable human errors due to long working at the microscope, heavy working intensity, easily fatiguing and so on and low accuracy, poor controllability. Therefore, micro-dissection technology is provided with not only theoretical necessity but practical significance.Based on the requirements of ultrasonic vibration micro-dissection, ultrasonic vibration is introduced into the microscopic cutting field in this paper. Ultrasonic vibration’s main characteristics and some actual applications are presented based on the analysis of the ultrasonic vibration micro-dissection theory. And theoretical basis is provided for further development of ultrasonic micro-dissection system.In view of different thickness of dissecting samples requirements different energy, select a suitable signal generator and piezoelectric ceramic that is suitable for adjustment of dissect tool’s vibration frequency and amplitude. Vibration test and the first-order modal analysis of selected piezoelectric ceramic are performed. Contraposing the particularity of micro-dissection environment and dissection tool, we not only designed the overall structure of the dissection tool but designed three connection ways of dissection needle to choose. Meanwhile we select the A601f camera of German’s basler company with high quality and image processing, high accuracy manipulator, the corresponding controller, precise air pump, etc.With VC6.0(programming software) for the development platform, using Microsoft’s MFC and computer vision library (OpenCV) with rich visual processing algorithm, the high speed image matching algorithm and control scheme are researched, procedure document with dynamic image collection and storage is developed, which can realize automatic searching micro tools, detecting the position of the cutting’s needle tip and tracking the needle visually in real time, thus successfully setting the needle in any position over the tissue. The control procedures of work stage and manipulator are developed to achieve precise positioning of dissection needle, accurately completing path planning and dissection operation.Finally, we use the depth-controlled and automated piezoelectric ultrasonic vibration micro-dissection system to dissect the4micron colon cancer tissues and Breast cancer tissues. Through analysis the theory and the experimental results, we got the best dissection parameters of the4um colon cancer tissues slice. In this circumstance, dissection for any shape can be accomplished ideally, also the post-dissection tissue can be taken away for further process. Experiments prove that depth-controlled automated piezoelectric ultrasonic vibration microscopic cutting system increases the automation degree of microscopic cutting, and obviously improves the accuracy and efficiency of dissection work.