Visual Servoed Robotic Mouse Oocyte Rotation.

Unlabelled: Both injection and biopsy of a mammalian cell require positioning and orientation of a biological cell in a three-dimensional space under a microscope. Manual cell manipulation and orientation is the most commonly used method that is based on a trial-and-error and direct cell poking approach.

Objective: Solve inherent problems of existing approaches, including low efficiency, poor success rate and inconsistent output.

Autofocusing and Polar Body Detection in Automated Cell Manipulation.

Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a bright-field microscope automatically, and a technique that can detect and track the presence and orientation of the polar body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes.

Automatic segmentation of zona pellucida and its application in cleavage-stage embryo biopsy position selection.

A very important step of Pre-implantation genetic diagnosis (PGD) is embryo biopsy, in which process the zona pellucida (ZP) is cut open partially and a part of cellular material is extracted from the embryo. Recognition of the ZP is necessary not only for embryo biopsy, but also for other applications such as zona pellucida thickness variation (ZPTV), embryo dissection, etc. The ZP opening position is closely related to the cell survival rate after the biopsy.

Visual Servoed Three-Dimensional Cell Rotation System.

Three-dimensional (3-D) positioning and orientation of embryos/oocytes is necessary to facilitate micromanipulation tasks such as cell injection and cellular structural biopsy commonly performed under a microscope. Conventional cell orientation is performed manually by using a vacuum equipped micropipette to aspirate and release the cell, which is a trial-and-error approach. The conventional method relies heavily on the skill of the operator; it also suffers from low precision, low success rate and low controllability.

A Hand-held Instrument for in vivo Probe-based Confocal Laser Endomicroscopy during Minimally Invasive Surgery.

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.

A Micro Motion Sensing System for Micromanipulation Tasks.

An optical-based motion sensing system has been developed for real-time sensing of instrument motion in micromanipulation. The main components of the system consist of a pair of position sensitive detectors (PSD), lenses, an infrared (IR) diode that illuminates the workspace of the system, a non-reflective intraocular shaft, and a white reflective ball attached at the end of the shaft. The system calculates 3D displacement of the ball inside the workspace using the centroid position of the IR rays that are reflected from the ball and strike the PSDs.

Drift-free position estimation of periodic or quasi-periodic motion using inertial sensors.

Position sensing with inertial sensors such as accelerometers and gyroscopes usually requires other aided sensors or prior knowledge of motion characteristics to remove position drift resulting from integration of acceleration or velocity so as to obtain accurate position estimation. A method based on analytical integration has previously been developed to obtain accurate position estimate of periodic or quasi-periodic motion from inertial sensors using prior knowledge of the motion but without using aided sensors. In this paper, a new method is proposed which employs linear filtering stage coupled with adaptive filtering stage to remove drift and attenuation.

A hand-held instrument to maintain steady tissue contact during probe-based confocal laser endomicroscopy.

Probe-based confocal laser endomicroscopy (pCLE) provides high-resolution in vivo imaging for intraoperative tissue characterization. Maintaining a desired contact force between target tissue and the pCLE probe is important for image consistency, allowing large area surveillance to be performed. A hand-held instrument that can provide a predetermined contact force to obtain consistent images has been developed.

Compact Sensing Design of a Handheld Active Tremor Compensation Instrument.

Active physiological tremor compensation instruments have been under research and development recently. The sensing unit of the instruments provides information on three degrees-of-freedom (DOF) motion of the instrument tip using accelerations provided by accelerometers placed inside the instruments. A complete vector of angular acceleration of the instrument needs to be known to obtain information on three DOF motions of the tip.

Tracking Control of Hysteretic Piezoelectric Actuator using Adaptive Rate-Dependent Controller.

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.

Micromanipulation accuracy in pointing and tracing investigated with a contact-free measurement system.

This study examines micromanipulation accuracy in pointing and in tracing a circle, using a novel contact-free measurement system. Three groups of subjects enable us to investigate the influence of age and micromanipulation expertise. The results show that, for all groups of subjects, a 10x magnification increases accuracy, but larger magnification does not improve it further.

Feedforward Controller of Ill-Conditioned Hysteresis Using Singularity-Free Prandtl-Ishlinskii Model.

Piezoelectric, magnetostrictive, and shape memory alloy actuators are gaining importance in high-frequency precision applications constrained by space. Their intrinsic hysteretic behavior makes control difficult. The Prandtl-Ishlinskii (PI) operator can model hysteresis well, albeit a major inadequacy: the inverse operator does not exist when the hysteretic curve gradient is not positive definite, i.

Estimating Displacement of Periodic Motion With Inertial Sensors.

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Accuracy of inertial sensors is greatly handicapped by the notorious integration drift, which arises due to numerical integration of the sensors zero bias error. A solution is proposed in this paper to provide drift free estimation of displacement from inertial sensors.