Abstract
A small auto micropipette system is developed to improve the reliability and accuracy of the automatic enzyme immunoassay analyzer’s microscale pipetting system. A sophisticated injection mechanism is designed by the means of dislocation parallel distribution of the screw and injector piston rod. It possesses the function of pipetting, taking and removing the pipette tips. In the control system, STM32 controller is used, controlling the single-axis S-type acceleration/deceleration algorithm and multi-threaded coordinated motion. The acceleration/deceleration curves are analyzed and optimized by using the method of segmentation; a minimum injection rate of 1 μL and a step rate of 0.05 μL are realized. The method of digital image processing is used to detect the amount of pipetting in micro-pipetting quantitatively. The liquid area is extracted by background contrast method, and the liquid volume in the tip is obtained by combining the geometric characteristics of the disposable tip, when the pipetting capacity is not qualified to carry out specific guidance on the pipetting system, and avoid the blocking needle, bubble and other abnormal pipetting phenomenon on the impact of pipetting accuracy. The experimental results show that the combination of the automatic sampling system and the image flow detection system can effectively improve the precision and reliability of the micropipetting system. Finally, the injection accuracy of the system at the test points with 10, 50 and 100 μL liquid volumes reaches 1.8%, 1.28% and 1.15% respectively.
Similar content being viewed by others
References
TAO L, LONG W, WANG Y Q. Design and implementation of the control system for an ARM9-based biochemical analyzer [J]. Advance Materials Research, 2011, 268/269/270: 454–457.
WU T Y. Research on high accuracy accumulation technology of high speed fully automatic biochemical analyzer [D]. Shenzhen: Shenzhen University, School of Health Science Center, 2016 (in Chinese).
ZHU L Q, ZHANG W C, DONG M L, et al. Method to improve the micropipette accuracy of full-automatic ELISA system [J]. Chinese Journal of Scientific Instrument, 2013, 34(5): 1008–1014 (in Chinese).
TAKEDA M, KATO Y, KATAGI H. Leakage detection method in automatic pipetting apparatus: EP 1999.
KAPLIT M. Differentiating between abnormal sample viscosities and pipette clogging during aspiration [J]. 2011.
WANG F B, LI Y Y, LIU J, et al. Realization of image process technology for computer vision based on OpenCV [J]. Machinery & Electronics, 2010, 6: 54–57 (in Chinese).
LIU Z W, SHANG Z W, HUANG Y B. Design of full automatic biochemical sampling system [J]. Journal of Engineering Design, 2016, 23(6): 612–619 (in Chinese).
HUANG Z B, HUANG Y L, YU S M. Several step stepper motor acceleration and deceleration method of comparative study and its application [J]. Mechanical and Electrical Engineering, 2011, 28(8): 951–974 (in Chinese).
SHIRONO K, SHIRO M, TANAKA H, et al. Evaluation of “method uncertainty” in the calibration of piston pipettes (micropipettes) using the gravimetric method in accordance with the procedure of ISO 8655-6 [J]. Accreditation & Quality Assurance, 2014, 19(5): 377–389.
LIU Z G, WAN L C. Error analysis of automatic sampling device [J]. Journal of Guangdong Polytechnic Normal University, 2014, 7(3): 38–42 (in Chinese).
Author information
Authors and Affiliations
Corresponding author
Additional information
Foundation item: the National Natural Science Foundation of China (No. U1733108), the Tianjin Science and Technology Support Program Key Project (No. 16YFZCSY00860)
Rights and permissions
About this article
Cite this article
Shang, Z., Zhou, X., Li, C. et al. Design of Micropipette System with High Precision for Small Enzyme Immunoassay Analyzer. J. Shanghai Jiaotong Univ. (Sci.) 24, 605–615 (2019). https://doi.org/10.1007/s12204-019-2104-4
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12204-019-2104-4