This paper proposes a noninvasive method of physiological parameter measurement with the collected facial video images for continuous online monitoring. Blood pressure (BP) is one of the important physiological indexes for human health prognoses. Based on the photoplethysmograph (PPG) technology, the variation of the facial skin colour along with the heart beating can thus be captured via the camera. So the related BP information can be extracted from the blind source signal separation. The detailed procedure of the BP measurement from the facial video is explained, including video collection, face tracking, signal pre-processing and BP signal extraction. The systolic and diastolic BP model can be derived based on the radial resonance theory and the involved parameters are fitted via the sampling data. Experiments are performed in different scenarios to discuss the impact factors on the BP detection together with error compensation analysis. The experimental results demonstrate that the proposed BP online measurement can be used as an indicator to monitor the status of the human health continuously.

A microrobot with untethered control in 3D space is a good choice to be applied in the fields of biomedicine with in small and confined workspace. In this paper, an electromagnetic actuation system (EMA) which combined with Helmholtz coil and Maxwell coil for the microrobot 5 DOF locomotion in 3D space is built. The magnetic field analysis of the proposed 3D EMA system was analyzed by finite-element-method (FEM) with multi-physics COMSOL software. The proposed EMA system can produce magnetic field with different characteristics such as a controllable uniform gradient magnetic field, a rotating magnetic field and a oscillating magnetic field in a three-dimensional space by independently changing the current in each coil. In this paper the 3D motion dynamic equation model of microrobot was established. A novel control method for the gravity compensation for the wireless locomotive microrobot was proposed. The proposed method has the property that the direction of magnetic flux and the locomotion path of the microrobot are independent. Meanwhile, it can achieve the horizontal motions or nearly horizontal motions and overcome the gravity well at the same time. It has been verified by experiments in 3D liquid environment. With the proposed method, the microrobot shows good performance in horizontal motions as well as various motions in the 3D space.

Magnetic localization is an effective method for obtaining the pose of a wireless capsule endoscope (WCE) because it is able to provide the position and orientation of the magnet in places where visual methods are not available. In magnetic positioning, the magnetic dipole model is often used to calculate the magnetic field of a magnetic source. However, the magnetic field calculated by the magnetic dipole model introduces positioning errors when a permanent magnet is used as the magnetic source and the size of the permanent magnet cannot be ignored. In this paper, a WCE localization method was proposed based on the combination of the magnetic dipole model and the analytical model. A cylindrical magnet was mounted in the WCE. The magnetic field of the magnet was calculated using the magnetic dipole model and the rough position of the magnet was estimated using the Particle Swarm Optimization (PSO) algorithm; then the magnetic field of the magnet was described using the analytical model and the estimated result of the PSO algorithm was used as the initial value of the Levenberg-Marquardt (L-M) algorithm to calculate the pose of the WCE. Experiments on static and dynamic localization of magnet were carried out in the localization system. The experimental results verified the feasibility of the proposed method.

Trajectory planning is always a hot issue for harvesting manipulator in practice considering that the limitations of manipulator mechanical structure and other nonlinear factors lead to long harvest time, big jerk and high energy consumption. The cubic spline algorithm, fifth-order polynomial interpolation algorithm, a fusing cubic spline and fifth-order polynomial algorithm are used to shorten harvesting time, reduce jerk and enhance the robustness of the harvesting manipulator, respectively. Then the trajectory planning problem is converted into a multi-objective optimization solution problem. A non-dominated sorting genetic algorithm-the third version (NSGA-III) technology is used to address multi-objective optimization constrained problems with time, energy consumption and jerk optimization objectives. The Pareto optimal set containing the multiple constraints is obtained through the NSGA-III algorithm. Comparing with a non-dominated sorting genetic algorithm-the second version (NSGA-II) technique, optimal solution with a shorter time is chosen from the non-dominated Pareto optimal set and sent to the manipulator controller actuator. Under the robot operating system (ROS), the cubic spline algorithm, fifth-order polynomial interpolation algorithm, a fusing cubic spline and fifth-order polynomial algorithm with the structural coefficient obtained respectively through NSGA-III algorithm and NSGA-II algorithm are simulated. The simulation results show that the NSGA-III algorithm has a better result in addressing the trajectory planning problem. The experimental analysis of the harvesting manipulator verifies the proposed scheme that a cubic spline method based on the NSGA-III algorithm is effective and feasible to reduce time and improve harvesting efficiency for kiwifruit harvesting.

This paper focuses on improving tracking performance of totally uncoupled compliant micromanipulator based on robust control method of elliptical hysteresis model. The hysteresis model and hysteresis compensation model for proposed mechanism based on Piezoelectric transducer (PZT) are established by using elliptical model method. The values of elliptical hysteresis model parameters are identified by simulating method with different frequencies of control input. The uncertainty model is also established, the values of corresponding estimated parameters are conformed by experiment method. Based on the uncertainty model and elliptical hysteresis model, the robust tracking control method is presented and utilized to evaluate the tracking performance of proposed mechanism under inputting different tracking curves. The proposed method can accurately control the output displacement and improve tracking performance of this mechanism, which are validated and carried out by using experimental studies. Additionally, the coupling errors between two directions are kept within 0.14% and the tracking errors for different curves are within 2.5%.

Generally, giant magnetoresistive (GMR) sensors are only sensitive to the magnetic field in the plane of the substrate due to fabrication restraints. This paper designs and models slope magnetic flux guides that are deposited on the slope surface of a silicon substrate. Finite element method (FEM) simulations are used to optimize the flux guide designs. The flux guides can be deposited with good symmetry and are able to convert the out-of-plane magnetic flux to the GMR sensor plane. Meanwhile, a Wheatstone bridge is configured to deduce a differential voltage only relative to the z-component of the magnetic field. Additionally, the magnetic field in the active region of the GMR sensor would be intensified. With these flux guides, the magnetic field perpendicular to the chip surface can be detected with the GMR sensors in-plane. Also, the sensitivity of the sensor can be improved due to the amplification ability of the flux guides. An integrated 3-axis magnetic sensor with better angular position can be realized with the slope flux guides.