Examination of peripheral blood smears by light microscopy helps to provide valuable information for disease diagnosis, but remains one of the major labor-intensive procedures in hematology laboratory. As a key part of white blood cell morphology examination, leukocyte detection at 10× magnification objective lens is considered as small object detection problem in this paper. After establishing leukocyte dataset at 10× magnification objective lens, we design a classification-based two-stage approach to this challenging problem. Stage one generates proposals by pixellevel ANN pipeline based on the color and size of leukocyte. Stage two is responsible for proposal classification task by CNN architecture. Extensive experiments are carried out to prove its effectiveness for peripheral blood samples. Experimental results demonstrate that the proposed classification-based approach, obtains a desired precision of 94.69%, recall of 95.73%, accuracy of 90.85% and Fβ of 0.96. The data is available at https://doi.org/10.6084/m9.figshare.9037370.v1.

The pectoral fin is a major source of thrust generation for fish utilizing median or paired fins (MPF) mode. Along with the pectoral fin, spanwise flexibility plays a major role in the generation of thrust. This paper investigates the effect of spanwise flexibility on propulsion performance using theoretical and experimental studies. For this study, the kinematic model of oscillating pectoral fin is first established based on the mechanism of active/passive flexible deformation. The dynamic model of the oscillating pectoral fin is developed based on the blade element theory. The influence of spanwise flexibility on propulsion performance is analyzed theoretically. Experiments have also been carried out to study the propulsion performance of the bionic pectoral fin by changing spanwise flexibility. Both calculated results and experiment results show that the propulsion performance of the bionic pectoral fin can be enhanced with the certain degree of spanwise flexibility.

Swimming stability is essential to a bionic robotic fish which is aiming to be applied to practical application. The stability can be controlled through two kinds of methods, the passive control method and the active control method. The latter one performs more flexibility. Forces of disturbance caused by movements of the bionic pectoral foils and the horizontal tail of a bionic fish imitating cownose ray propelled by oscillating paired pectoral foils are analyzed. Simulation model based on both PID method and fuzzy control method for the stability performance of the bionic fish in condition of compensating work by horizontal tail or not are built. Results show that the stability of the bionic fish can be obviously improved by actively control of the horizontal tail.

In this paper, the configuration of a five-limbed modular robot is introduced. A specialised locomotion gait is designed to allow for omni-directional mobility. Due to the large diversity resulting from various gait sequences, a criteria for selecting the best gaits based on their stability characteristics is proposed. A series of simulations is then performed to evaluate the various gaits in different walking directions. A gait arrangement scheme toward omni-directional locomotion is finally derived. Lastly, Experiments are also carried out on our pentapedal robot prototype in order to validate the results of simulation. The experiments confirm the gait analysis and selection is highly accurate in the evaluation of gait stability.

Pectoral foil structure and motion discipline of cow-nosed ray as nature prototype is analyzed. A bionic pectoral fin is designed according to the analysis results. Propulsion performance of the bionic fin at sinusoidal motion law is studied experimentally on a towing platform, at the oscillating frequency from 0.2 Hz to 2 Hz and amplitude from 2.5° to 30°. Well driving ability is obtained, and maximal average thrust of 2.75N is achieved by a single bionic fin expressed at towing speed of 10 cm/s. A biomimetic fish utilizing the kind of bionic fin is developed, and swimming speed of 0.9BL (body length) in maximum can be reached.

A novel robot mechanism-tetrahedral rolling robot is introduced in the paper. The robot comprises of six extension struts and four node flats. When the COG of tetrahedron exceeds the stability region, the robot will roll. The structure of the tetrahedral rolling robot is described. Designing method of the robot is given, and it is proved correct and feasible through experiment. Kinematic model in different motion phase is analyzed in the paper, and the rolling critical condition is formulated. The effectiveness of the method is testified through simulation. The study of the paper will provide important reference for the dynamic analysis, optimization design and control of the tetrahedral rolling robot.

This paper proposed a new method of designing a flexible biomimetic fish propelled by oscillating flexible pectoral fins. The molding soft body is adopted in the robotic fish. Pneumatic artificial muscles are utilized as driving sources and two ribs with distributed flexibility as main parts of the propulsive mechanism. The leading edge locomotion profile of the flexible pectoral fin in air is studied experimentally, and the flapping locomotion in water is observed too. Finally, the effectiveness of the proposed method is illustrated by the experiment. It shows that the robotic fish can realize self-driven, and it can swim at a speed of 0.18 m/s~0.20 m/s after optimization.

A flexure-based compliant parallel manipulator (FCPM) is a kind of compliant mechanism characterized by a complicate topological structure and multiple degrees of freedom (DOFs). Compared with its rigid-counterpart, a FCPM becomes more complicate in its mobility analysis. In this paper, the screw theory is applied to the mobility analysis of our FCPM as an instance of general FCPM. Firstly, the compliance matrices of both compliant elements and the whole mechanism are calculated by using adjoint transformation of compliance matrix between different coordinate frames. Secondly, the mobility characteristics of the FCPM is investigated by proposing a concept of "primary mobility of a FCPM" and a method of quantifying the primary mobility of the FCPM providing that the compliance matrix of the manipulator should be calculated primarily. The theoretical result reveals that mobility characteristics of the FCPM with current design parameters can satisfy the designer's original desire

An automatic micro manipulation system, which aims at various kinds of operations in the field of bio-engineering has been developed. Visual servo control is usually employed to improve the performance of the system. However, the great amount of computation that is required in image processing hinders the formation of a closed-loop control system with visual servo. In this paper, efforts are made to improve the performance of the vision system in two aspects: algorithm design and hardware implementation. Methods of correlation based pattern matching and morphological operation based image processing technique are used to implement the fast visual information abstraction, thus forming a real-time visual servo control system. The system performance and the result of an experiment on gene injection are given.