Injection and extraction of materials (e.g. protein, sperms, DNA, and blastomeres) into and from cells are essential operation for In Vitro Fertilisation (IVF), intracytoplasmic sperm injection (ICSI) and preimplantation genetic diagnosis (PGD). In order to perform the injection and extraction without damage to the cell, the cell needs to be at an optimal orientation. In this paper, a fully automated microrobotic system for cell orientation is presented. The proposed system overcomes several inherent problems in manual cell manipulation, including low efficiency, inconsistent output and poor success rate. The system can rotate a single fish embryo to a desired orientation by employing motion control, fluidic flow control, and computer vision. It is evaluated by using 60 Zebrafish embryos. Experimental results show that the system is capable of performing fast embryo orientation at a speed of 13 s/cell with a high success rate of 97.5% and a high in-plane rotation precision of 0.5°.

This paper presents a new hand-held device capable of amplifying delicate micromanipulation forces during minimal invasive surgical tasks. It relays force sensing to the user through a simple sliding feature that is coupled to the surgical tool, which translates relative to the casing of the device held by the operator. This forgoes the need of grounding frames or anchoring mechanisms to the body, allowing the device to be used in general surgical environments without affecting the workflow. The device uses a three-phase linear motor that is compact and capable of generating high forces that allow amplification factors of up to ×15. It features a closed-loop force control scheme to perform the required force amplification in which the force exerted on to the user is measured, forming the feedback in the control loop. The device permits interchangeability of instrumentation through a simple docking feature, and thus can be generalized to a range of surgical instruments for micromanipulation tasks. Detailed bench tests and user trials have been performed to validate the accuracy and practical performance of the device. The results have shown a five times reduction of the minimum force threshold perceived by the subjects and ergonomically sound manipulation advantages.

Probe-based confocal laser endomicroscopy (pCLE) provides high resolution imaging of tissue in vivo. Maintaining a steady contact between target tissue and pCLE probe tip is important for image consistency. In this paper, a new prototype hand-held instrument for in vivo pCLE during Minimally Invasive Surgery (MIS) is presented. The proposed instrument incorporates adaptive force sensing and actuation, allowing improved image consistency and force control, thus minimizing tissue deformation and induced micro-structural variations. The performance and accuracy of the contact force control are evaluated in detailed laboratory settings and in vivo validation of the device during transanal microsurgery in a live porcine model further demonstrates the potential clinical value of the device.

Inertial measurement units (IMU) consist of accelerometers. Estimation accuracy of acceleration in a particular direction depends on how accurately accelerometers are placed at desired or ideal orientations. The estimation inaccuracy which results from inaccurate orientation of an accelerometer can be eliminated if the orientation error or the angle between the actual and the ideal orientations is known. This paper presents a method of identification of the accelerometer orientation errors without requiring any rotational motion of the IMU in which accelerometers are placed. It also presents a method of compensation for the inaccuracy of acceleration estimation due to the accelerometer orientation errors using angular motion information.

This paper presents a 3-DOF low-cost hand-held micromanipulator driven by 3 piezoelectric actuators and built using rapid prototyping. Traditional pin and ball joints have been commonly replaced by flexure-based methods in the field of micromanipulation. Utilization of flexure-based joints have several advantages like the non-existence of backlash and assembly errors. However, most of the present flexure-based mechanisms are bulky and not suitable for hand-held applications. It is difficult and expensive to make such compact mechanism using traditional machining methods. In additional, traditional machining methods are limited to simple design. To reduce the cost of fabrication and also to allow more complex designs, Objet (a rapid prototyping machine) is proposed to be used to build the mechanism. With regards to hand-held applications, the size of the mechanism is a constraint. Hence, a parallel manipulator design is the preferred choice as compared to a serial mechanism because of its rigidity, compactness, and simplicity in design. For the illustration of an application, the mechanism is designed with an intraocular needle attached to it. Possible applications of this design include enhancement of performance in microsurgery and cell micromanipulation. Experiments are also conducted to evaluate the manipulator's tracking performance of the needle tip at a frequency of 10 Hz.

With the increasing popularity of actuators involving smart materials like piezoelectric, control of such materials becomes important. The existence of the inherent hysteretic behavior hinders the tracking accuracy of the actuators. To make matters worse, the hysteretic behavior changes with rate. One of the suggested ways is to have a feedforward controller to linearize the relationship between the input and output. Thus, the hysteretic behavior of the actuator must be first modeled by sensing the relationship between the input voltage and output displacement. Unfortunately, the hysteretic behavior is dependent on individual actuator and also environmental conditions like temperature. In this fast moving world, time is money and it is very costly to model the hysteresis regularly. In addition, the hysteretic behavior of the actuators also changes with age. Base on the studies done on the phenomena hysteretic behavior with rate, this paper proposes an adaptive rate-dependent feedforward controller with Prandtl-Ishlinskii (PI) hysteresis operators for piezoelectric actuators. This adaptive controller is achieved by adapting the coefficients to manipulate the weights of the play operators. Actual experiments are conducted to demonstrate the effectiveness of the adaptive controller.

Currently there is a lack of objective clinical diagnosis and classification of tremor is difficult when it is subtle. Thus in previous work, a sensing system has been developed to quantify pathological tremor in human upper limb. In this paper, a Kalman filter algorithm to fuse information from accelerometers and surface electromyography is proposed. As the ground truth, an optical motion tracking system will be utilized. Then two sensor fusion algorithms based on Kalman filter are formulated to estimate the joint angle of the limb from the reading of accelerometers and surface EMG. Initial results using tremor data from two Parkinson's disease patients show promising future in this sensor fusion. The sensing system and the algorithms proposed are useful for actively compensating the tremor and helping the clinicians in tremor diagnostics.

An optical sensing system has been developed using a pair of orthogonally placed position sensitive detectors (PSD) to track 3D displacement of a microsurgical instrument tip in real-time. An infrared (IR) diode is used to illuminate the workspace. A ball is attached to the tip of an intraocular shaft to reflect IR rays onto the PSDs. Instrument tip position is then calculated from the centroid positions of reflected IR light on the respective PSDs. The system can be used to assess the accuracy of hand-held microsurgical instruments and operator performance in micromanipulation tasks, such as microsurgeries. In order to eliminate inherent nonlinearity of the PSDs and lenses, calibration is performed using a feedforward neural network. After calibration, percentage RMS error is reduced from about 5.46 % to about 0.16%. The system RMS noise is about 0.7 mum. The sampling rate of the system is 250 Hz.