A literature review: robots in medicine

Robotic systems employed in the laboratory, in rehabilitation, and in surgery are reviewed. The advantages of using a robot system over manual procedures in the laboratory to prepare samples is discussed, and some of the obstacles are noted. A typical laboratory robot is described. Rehabilitative applications in the major research areas of tactile sensors, assistive devices for the blind, prosthetics, and orthotics are examined. Manipulators that can help a disabled individual with important everyday tasks and other assistive robotic systems in rehabilitation are described. A variety of robots that assist or perform surgery is surveyed. These applications include positioning in stereotactic neurosurgery, patient manipulation, an in vivo spinal kinematic instrument, and robotic radial keratotomy, among others.     

Output, Error, Equivocation, and Recalled Information in Auditory, Visual, and Audiovisual Information Processing with Constraint and Noise

Past controversies over the relative effectiveness of auditory, visual, and audiovisual channels are seen as the results of nondifferentiation of error and equivocation. Seventh grade students were used as Ss in an experiment consisting of noise and no noise conditions with constrained and nonconstrained communication in A, V, and AV treatments. Data were examined in terms of output, error, equivocation, and recalled (shared) information based upon information theory. The superiority of the AV treatment was substantiated in all respects of information processing, making less error and equivocation, but recalling more information correctly as compared with the A or V channel. Comparisons between A and V unequivocally established the fact that V made less error but more equivocation, whereas A processed more output information and also made more error; however, there was no significant difference between them in recalled information. The dependence of A upon constraint was found to be far greater than that of AV whose dependence in turn was greater than that of V. Noise was found to affect A most, V the next most, and AV the least. With between-channel redundancy AV seemed to be capable of reducing the effect of noise.     

Accumulation of butyltin compounds in cobia Rachycentron canadum raised in offshore aquaculture sites

Butyltin residues (monobutyltin, MBT; dibutyltin, DBT; tributyltin, TBT; tetrabutyltin, TeBT) in the sea water and in the cobia (Rachycentron canadum) from aquaculture sites located offshore of Penhu island, Taiwan, were collected and quantified. The average concentrations of MBT, DBT, TBT and TeBT in sea water were n.d.-28+/-3, 4.0+/-0.6-88+/-13, n.d.-43+/-4, and n.d.-7+/-1 ng l(-1), respectively. The total butyltin (sum of MBT, DBT, TBT, TeBT) residues in the skin, dorsal muscle, ventral muscle, dark muscle, and liver of the cobia were in the range of 72+/-12-2270+/-85, 79+/-11-688+/-33, 82+/-14-1715+/-104, 93+/-13-803+/-47, and n.d.-52,745+/-252 ng g(-1) (wet weight), respectively. Although in this study in most cases, the highest concentration of total butyltin residues was found in liver or skin, in some cases, the highest concentration was found in muscle tissue. The crude lipid content in the skin, dorsal muscle, ventral muscle, dark muscle, and liver of these cobia was in the range of 7.9+/-0.1-28+/-1%, 11.7+/-0.8-29+/-1%, 11.5+/-0.3-44+/-3%, 24.2+/-0.4-48.4+/-0.4%, and 55.7+/-0.1-87.7+/-0.4% (wet weight), respectively. The concentrations of crude lipid content, and the concentrations of total butyltin residues in these tissues were not correlated.     

Studies on the defect structures for two Rh centers in LiD

The defect structures for two Rh²⁺ centers {A} and {O} in LiD are theoretically studied by analyzing their experimental EPR parameters, based on the perturbation formulas of these parameters for a 4d⁷ ion with low spin (S = 1/2) in tetragonally compressed octahedra and orthorhombically elongated octahedra. Center {A} can be attributed to the substitutional Rh²⁺ at the Li⁺ site, associated with the next nearest neighbouring (nnn) Li⁺ vacancy V_Li along [0 0 1] (or C₄) axis as the compensator. In this center, the intervening ligand D⁻ in Rh²⁺ and the V_Li is found to shift towards Rh²⁺ by an amount ΔZ_A ≈ 0.01 Å due to the electrostatic repulsion of the V_Li. Center {O} is assigned to the elongation δ ≈ 0.072 Å of the ligand octahedron along [0 0 1] axis due to the Jahn–Teller effect, associated with one nnn V_Li along [1 0 0] (or X) axis. The intervening ligand may also suffer a displacement ΔX_O ≈ 0.11 Å towards Rh²⁺. In the calculations of the hyperfine structure constants, the reduction factors H (≈0.49 and 0.93) due to the Rh²⁺ 4d–5s orbital admixture are obtained for centers {A} and {O}.     

Robust neural force control scheme under uncertainties in robotdynamics and unknown environment

The original impedance function is known to lack robustness due to unknown robot dynamic model and the environment. In order to improve that result, a new impedance function is derived which specifies a desired force directly. This results in a new robust robot force tracking impedance control scheme, which employs a neural network as a compensator to cancel out all uncertainties. The proposed neural force control scheme is capable of making the robot track a specified desired force as well as of compensating for uncertainties in environment location and stiffness, and in robot dynamics. Separate training signals for free-space motion and contact-space motion control are developed to train the neural compensator online. The design of the training signals is justified. Simulation studies with a three-link rotary robot manipulator are carried out and the results show excellent force tracking performance     

Colloidal Particles that Rapidly Change Shape via Elastic Instabilities

The fabrication and properties of pH‐responsive colloidal particles are reported, which change shape rapidly (less than 200 ms), nearly independent of the diffusion of the pH altering species that trigger their actuation, and far more rapid than their Brownian motion. These particles are mechanically bistable, as revealed by their hysteretic shape response. Finite element analysis (FEA) shows that mechanical hysteresis and bistability derives from the colloids' spherical curvature. Mechanical characterization of the bilayered polymers comprising the colloidal particles shows that viscoelastic relaxation plays a non‐negligible role in limiting the shape switching rate; however, energy landscapes obtained from FEA simulations suggest that by tuning the elastic moduli and thicknesses of the constituent polymer layers, microparticles of the size shown here may be fabricated to actuate on timescales as fast as 1 μs.     

Reconfigurable Morphological Image Processing Accelerator for Video Object Segmentation

Video object segmentation is an important pre-processing task for many video analysis systems. To achieve the requirement of real-time video analysis, hardware acceleration is required. In this paper, after analyzing existing video object segmentation algorithms, it is found that most of the core operations can be implemented with simple morphology operations. Therefore, with the concepts of morphological image processing element array and stream processing, a reconfigurable morphological image processing accelerator is proposed, where by the proposed instruction set, the operation of each processing element can be controlled, and the interconnection between processing elements can also be reconfigured. Simulation results show that most of the core operations of video object segmentation can be supported by the accelerator by only changing the instructions. A prototype chip is designed to support real-time change-detection-and-background-registration based video object segmentation algorithm. This chip incorporates eight macro processing elements and can support a processing capacity of 6,200 9-bit morphological operations per second on a SIF image. Furthermore, with the proposed tiling and pipelined-parallel techniques, a real-time watershed transform can be achieved using 32 macro processing elements.     

Virtual surgeries in patients with congenital heart disease: a multi-scale modelling test case

The objective of this work is to perform a virtual planning of surgical repairs in patients with congenital heart diseases--to test the predictive capability of a closed-loop multi-scale model. As a first step, we reproduced the pre-operative state of a specific patient with a univentricular circulation and a bidirectional cavopulmonary anastomosis (BCPA), starting from the patient's clinical data. Namely, by adopting a closed-loop multi-scale approach, the boundary conditions at the inlet and outlet sections of the three-dimensional model were automatically calculated by a lumped parameter network. Successively, we simulated three alternative surgical designs of the total cavopulmonary connection (TCPC). In particular, a T-junction of the venae cavae to the pulmonary arteries (T-TCPC), a design with an offset between the venae cavae (O-TCPC) and a Y-graft design (Y-TCPC) were compared. A multi-scale closed-loop model consisting of a lumped parameter network representing the whole circulation and a patient-specific three-dimensional finite volume model of the BCPA with detailed pulmonary anatomy was built. The three TCPC alternatives were investigated in terms of energetics and haemodynamics. Effects of exercise were also investigated. Results showed that the pre-operative caval flows should not be used as boundary conditions in post-operative simulations owing to changes in the flow waveforms post-operatively. The multi-scale approach is a possible solution to overcome this incongruence. Power losses of the Y-TCPC were lower than all other TCPC models both at rest and under exercise conditions and it distributed the inferior vena cava flow evenly to both lungs. Further work is needed to correlate results from these simulations with clinical outcomes.     

A cost-effective three axis CMOS accelerometer combining micromachining and digital technology

In this paper, a three axis accelerometer is successfully developed by a mixing-mode chip design using CMOS surface-micromachining technology. The chip consists of mass-spring, the analog core and the digital circuit. The vibration sensor is implemented with micro-spring to change the capacitance between two metals. The analog core detects the capacitance differential to the frequency shifting using an oscillator. The digital control is to compute the amount of acceleration to the form of digital bit. The chip can detect the acceleration to 140 g for x axis and y axis with 10-bit resolution, and from 110 g for z axis with 9 bits. The detected speed is about 4 k bits per second, for three-axis output in parallel. The chip size is about 1,400 × 1,400 um², when TSMC 0.18 um 1P6 M process is employed. This 3D accelerometer can directly connect to the digital interface with three serial-port output for the information of X, Y and Z axis.     

Allyl Isothiocyanate (AITC) Induces Apoptotic Cell Death In Vitro and Exhibits Anti-Tumor Activity in a Human Glioblastoma GBM8401/luc2 Model

Some clinically used anti-cancer drugs are obtained from natural products. Allyl isothiocyanate (AITC), a plant-derived compound abundant in cruciferous vegetables, has been shown to possess an anti-cancer ability in human cancer cell lines in vitro, including human brain glioma cells. However, the anti-cancer effects of AITC in human glioblastoma (GBM) cells in vivo have not yet been examined. In the present study, we used GBM8401/luc2 human glioblastoma cells and a GBM8401/luc2-cell-bearing animal model to identify the treatment efficacy of AITC. Here, we confirm that AITC reduced total cell viability and induced cell apoptosis in GBM8401/luc2 cells in vitro. Furthermore, Western blotting also showed that AITC induced apoptotic cell death through decreased the anti-apoptotic protein BCL-2, MCL-1 expression, increased the pro-apoptotic protein BAX expression, and promoted the activities of caspase-3, -8, and -9. Therefore, we further investigated the anti-tumor effects of AITC on human GBM8401/luc2 cell xenograft mice. The human glioblastoma GBM8401/luc2 cancer cells were subcutaneously injected into the right flank of BALB/c nude mice to generate glioblastoma xenograft mice. The animals were randomly divided into three groups: group I was treated without AITC (control); group II with 0.1 mg/day of AITC; and group III with 0.2 mg/day of AITC every 3 days for 27 days. Bodyweight, and tumor volume (size) were recorded every 3 days. Tumors exhibiting Luc2 intensity were measured, and we quantified intensity using Living Image software on days 0, 12, and 24. After treatment, tumor weight from each mouse was recorded. Tumor tissues were examined for histopathological changes using H&E staining, and we analyzed the protein levels via immunohistochemical analysis. Our results indicate that AITC significantly inhibited tumor growth at both doses of AITC due to the reduction in tumor size and weight. H&E histopathology analysis of heart, liver, spleen, and kidney samples revealed that AITC did not significantly induce toxicity. Body weight did not show significant changes in any experiment group. AITC significantly downregulated the protein expression levels of MCL-1, XIAP, MMP-9, and VEGF; however, it increased apoptosis-associated proteins, such as cleaved caspase-3, -8, and -9, in the tumor tissues compared with the control group. Based on these observations, AITC exhibits potent anti-cancer activity in the human glioblastoma cell xenograft model via inhibiting tumor cell proliferation and the induction of cell apoptosis. AITC may be a potential anti-GBM cancer drug that could be used in the future.