Research On Key Technology Of Biological Micromanipulation System Based On Visual Servoing

As micro field of electronics,biology,and medicine aspects were studied deeply,micro operation research was urgent requirement because of the miniaturization of operating object.Based on the biological operation such as cell fusion,chromosome transplant operation,transgenic research,micro surgery,DNA injection technology research were more and more wide,they all use micro operating system.This article mainly studied the adherent cell injection system.Microscope used to observe the micro organisms was usually operated by manual adjustment,which had low efficient.With the advancement of the research,the computer vision algorithm and intelligent control technology were gradually applied to micro injection system,performed automated and efficient operation.in front of the microscope visual operation,The operating efficiency of manual micromanipulation by professional is very low.Micromanipulation robot based on visual servo,liberating people from the operation state of fatigue and instability,the operation error can be avoid.this automatic system improved the operation efficiency,improved working conditions for professional,provides a good platform for the study of cell engineering,had great significance for the bioscience further development.Identification of micro injection needle and cells,microscopic image mosaicing,the visual tracking of visual servo control were three important links of the microinjection studied,the main content covered the above three links:(1)First,article introducted the whole system.According to the characteristics of the adherent cells and the operating tool and subject requirements,build a special operating system used for adherent cells microinjection.Article includes the introduction of the system hardware and software;According to function of each part of the injection system,divided the hardware system into function module,selected the key hardware of each module and made a brief introduction;The software platform of microinjection system and each part of the software function corresponding to the hardware module were introduced.(2)The identification and positioning of adherent cell and micro needle were proformed for cell injection system to realize accurate and efficient injection.First image preprocessing used gaussian filter to remove noise for cell images;Because adherent cells are transparent andhas random shape,the positioning using maximum entropy threshold segmentation method for segmentation,and the time-consuming shortcomings of this algorithm were improved through a fast maximum entropy threshold segmentation method.The experiment proves that the method not only present a clear segmentation effect,but also accelerated the segmentation time;For the plane positioning of needle,It proposed a method based on active contour model,because used threshold segmentation method was easy to appear the wrong,then determine the needle position by traversing contour points.Experiments prove that this method can obtain continuous smooth tip profile;In addition,detection positioning method of the Z direction of the needle were instructed detailedly.(3)According to the characteristics of microscopic vision was limited,and the adherent cell is still,control platform move to collect more adherent cell microscopic images and stitch them together,it formed a larger cell image contained abundant information,which was convenient for microinjection.The contrast experiments of extracting the image feature points,registration,joining together were performed through previous SIFT and SURF proposed in this paper,the results show that the selected SURF algorithm is faster and more applicable to microscopic image mosaic.Finally put forward the improved gradually into the fade out algorithm fusion technology,which suitable for microscopic image mosaicking,complete seamless splicing for microscopic image.Finaly complete a cellpanoramic image by image matching algorithm above.(4)For controling the needle based on image visual servo control method,the artical studied the needlepoint tracking technology.Due to the limitations of the traditional template matching method,article put forward a kind of needle point tracking algorithm based on B-Snake model,combining with kalman filter that forecast tracking position of needle,made simulations for the tracking effect of needle,outline of the needle obtained is not only smooth,but also has good dynamic segmentation effect.Compared tracking trajectory and error curve after using the kalman filter,it proved the real-time performance of using the kalman filter.Second,the optimized cell injection paths was designed,improving the efficiency of the injection.Finally control the robot movement using PID control method.