Experimental Validation Phase Research Articles

Dynamics Modeling and Parameter Identification for a Coupled-Drive Dual-Arm Nursing Robot

A dual-arm nursing robot can gently lift patients and transfer them between a bed and a wheelchair. With its lightweight design, high load-bearing capacity, and smooth surface, the coupled-drive joint is particularly well suited for these robots. However, the coupled nature of the joint disrupts the direct linear relationship between the input and output torques, posing challenges for dynamic modeling and practical applications. This study investigated the transmission mechanism of this joint and employed the Lagrangian method to construct a dynamic model of its internal dynamics. Building on this foundation, the Newton-Euler method was used to develop a dynamic model for the entire robotic arm. A continuously differentiable friction model was incorporated to reduce the vibrations caused by speed transitions to zero. An experimental method was designed to compensate for gravity, inertia, and modeling errors to identify the parameters of the friction model. This method establishes a mapping relationship between the friction force and motor current. In addition, a Fourier series-based excitation trajectory was developed to facilitate the identification of the dynamic model parameters of the robotic arm. Trajectory tracking experiments were conducted during the experimental validation phase, demonstrating the high accuracy of the dynamic model and the parameter identification method for the robotic arm. This study presents a dynamic modeling and parameter identification method for coupled-drive joint robotic arms, thereby establishing a foundation for motion control in humanoid nursing robots.

Application of essential oils as natural antimicrobials in lactic acid bacteria contaminating fermentation for the production of organic cachaça

Sugarcane-based fermentation is an essential process for different sectors of economic importance, such as the food industry with fermented and distilled beverages. However, this process can suffer from high contamination by wild yeasts and bacteria, especially lactic acid bacteria (LAB). This makes it necessary to use decontamination strategies and search for new methods that have a low environmental impact and contribute to the production of organic products. Among the options, oregano and thyme essential oils stand out for their antibacterial compounds. The aim of this study was to use oregano and thyme essential oils as natural antimicrobials in the alcoholic fermentation of sugar cane juice. Initially, the minimum inhibitory concentration of the essential oils in the fermentation was assessed through turbidity in the sensitivity test, which allowed us to determine which concentrations of essential oils would inhibit the contaminants, 3 morphologically selected LAB strains, as well as assessing the viability of CA-11. For LAB, 3 concentrations of each essential oil were tested, ranging from 0.1 to 0.4 μl/mL, while for CA-11 it was 0.06, to 0.1 μl/mL. The results indicated a maximum total value of essential oils per ml of 0.06 μl. Based on this result, a 24-1 fractional factorial was established, with 8 conditions +3 central points, with 4 variables, oregano essential oil (0, 0.03 and 0.06 μl/ml), thyme (0, 0.03 and 0.06 μl/ml), initial soluble solids (14, 16 and 18°Brix) and initial yeast concentration (2.5, 3 and 3.5 g/l), with the temperature set at 32 °C for a period of 12 h. The results showed that the center point condition with 0.03 μl/ml of oregano EO, 0.03 μl/ml of thyme controlled the proliferation of contaminating bacteria compared to the control condition. In the experimental validation, the treatment with essential oils had a lower final population of LAB (5.95 log) than the final population of the control treatment (6.53 log), and it was also observed that the treatment with EOs had an alcohol production around 3 % higher than the treatment without antimicrobials. The experimental validation phase confirmed the synergistic action of oregano and thyme essential oils in controlling the proliferation of contaminating bacteria. In conclusion, it was possible to determine the synergistic antimicrobial action of essential oils against LAB during alcoholic fermentation based on organic sugar cane.

Exploring the mechanism of action of Sparganii Rhizoma-Curcumae Rhizoma for in treating castration-resistant prostate cancer: a network-based pharmacology and experimental validation study

Sparganii Rhizoma-Curcumae Rhizoma (SR-CR) is a classic drug pair for the treatment of castration-resistant prostate cancer (CRPC), but its mechanism has not been clarified. The study aims to elucidate the potential mechanism of SR-CR in the management of CRPC. The present study employed the TCMSP as well as the SwissTargetPrediction platform to retrieve the chemical composition and targets of SR-CR. The therapeutic targets of CRPC were identified through screening the GeneCards, Disgenet, and OMIM databases. Subsequently, the Venny online platform was utilized to identify the shared targets between the SR-CR and CRPC. The shared targets were enrichment analysis using the Bioconductor and Kyoto encyclopedia of genes and genomes (KEGG) databases. The active ingredients and core targets were verified through molecular docking and were validated using PC3 cells in the experimental validation phase. A total of 7 active ingredients and 1126 disease targets were screened from SR-CR, leading to a total of 59 shared targets. Gene Ontology (GO) analysis resulted in 1309 GO entries. KEGG pathways analysis yielded 121 pathways, primarily involving cancer-related signaling pathways. The results from molecular docking revealed stable binding interactions between the core ingredients and the core targets. In vitro cellular assays further demonstrated that SR-CR effectively suppressed the activation of the Prostate cancer signaling pathway in PC3 cells, leading to the inhibition of cell proliferation and promotion of apoptosis. The SR-CR exert therapeutic effects on CRPC by inhibiting cell proliferation and promoting apoptosis through the Prostate cancer signaling pathway.

Research on Rejoining Bone Stick Fragment Images: A Method Based on Multi-Scale Feature Fusion Siamese Network Guided by Edge Contour

The rejoining of bone sticks holds significant importance in studying the historical and cultural aspects of the Han Dynasty. Currently, the rejoining work of bone inscriptions heavily relies on manual efforts by experts, demanding a considerable amount of time and energy. This paper introduces a multi-scale feature fusion Siamese network guided by edge contour (MFS-GC) model. Constructing a Siamese network framework, it first uses a residual network to extract features of bone sticks, which is followed by computing the L2 distance for similarity measurement. During the extraction of feature vectors using the residual network, the BN layer tends to lose contour detail information, resulting in less conspicuous feature extraction, especially along fractured edges. To address this issue, the Spatially Adaptive DEnormalization (SPADE) model is employed to guide the normalization of contour images of bone sticks. This ensures that the network can learn multi-scale boundary contour features at each layer. Finally, the extracted multi-scale fused features undergo similarity measurement for local matching of bone stick fragment images. Additionally, a Conjugable Bone Stick Dataset (CBSD) is constructed. In the experimental validation phase, the MFS-GC algorithm is compared with classical similarity calculation methods in terms of precision, recall, and miss detection rate. The experiments demonstrate that the MFS-GC algorithm achieves an average accuracy of 95.5% in the Top-15 on the CBSD. The findings of this research can contribute to solving the rejoining issues of bone sticks.

Intelligent Real-Time Deep System for Robust Objects Tracking in Low-Light Driving Scenario

The detection of moving objects, animals, or pedestrians, as well as static objects such as road signs, is one of the fundamental tasks for assisted or self-driving vehicles. This accomplishment becomes even more difficult in low light conditions such as driving at night or inside road tunnels. Since the objects found in the driving scene represent a significant collision risk, the aim of this scientific contribution is to propose an innovative pipeline that allows real time low-light driving salient objects tracking. Using a combination of the time-transient non-linear cellular networks and deep architectures with self-attention, the proposed solution will be able to perform a real-time enhancement of the low-light driving scenario frames. The downstream deep network will learn from the frames thus improved in terms of brightness in order to identify and segment salient objects by bounding-box based approach. The proposed algorithm is ongoing to be ported over a hybrid architecture consisting of a an embedded system with SPC5x Chorus MCU integrated with an automotive-grade system based on STA1295 MCU core. The performances (accuracy of about 90% and correlation coefficient of about 0.49) obtained in the experimental validation phase confirmed the effectiveness of the proposed method.

Affordance Equivalences in Robotics: A Formalism.

Automatic knowledge grounding is still an open problem in cognitive robotics. Recent research in developmental robotics suggests that a robot's interaction with its environment is a valuable source for collecting such knowledge about the effects of robot's actions. A useful concept for this process is that of an affordance, defined as a relationship between an actor, an action performed by this actor, an object on which the action is performed, and the resulting effect. This paper proposes a formalism for defining and identifying affordance equivalence. By comparing the elements of two affordances, we can identify equivalences between affordances, and thus acquire grounded knowledge for the robot. This is useful when changes occur in the set of actions or objects available to the robot, allowing to find alternative paths to reach goals. In the experimental validation phase we verify if the recorded interaction data is coherent with the identified affordance equivalences. This is done by querying a Bayesian Network that serves as container for the collected interaction data, and verifying that both affordances considered equivalent yield the same effect with a high probability.

A three-dimensional FEM model of channel machining by scanning micro electrochemical flow cell and jet electrochemical machining

In this research, a three-dimensional (3D) finite element method (FEM) model based on Faraday’s law and moving mesh technique is proposed to simulate the channel machining process in Scanning Micro Electrochemical Flow Cell (SMEFC) and jet electrochemical machining (jet-ECM). The scarcity of available FEM models for the channel fabrication by electrochemical machining (ECM) with confined electrolyte is identified through a brief review of ECM simulation with moving electrode. The detailed information on the model establishment is then presented, including the fundamental principle, the way to construct the geometrical model of the moving electrolyte droplet during the machining process, the boundary settings and some key assumptions. Thanks to the introduction of the virtual electrolyte layer and the moving mesh technique, confined machining of channels by SMEFC can be simulated. In the experimental validation phase, species of the electrolyte (NaNO3 and NaCl), the dimension of the hollow electrodes and the electrochemical equivalent of the workpiece, the machining voltages and feed rates are compared in terms of the channel cross-sectional profiles and errors. The flow field and heat transfer still need to be considered in order to simulate the case with NaNO3 electrolyte in the future. This proposed 3D simulation model can improve the understanding and applicability of channel machining by SMEFC, since the current density distribution and the change of workpiece shape can be calculated simultaneously. With some modifications, this method can be as well extended to the channel machining by jet-ECM. Two case studies of micro scale and meso scale jet-ECM are simulated respectively. The proposed simulation method is a potential way to understand and improve the channel machining process by ECM with confined electrolyte.

Recent Advances on the Application of Negative Pressure External Volume Expansion in Breast Plastic Surgery

External volume expansion (EVE) has been effectively applied as an assistance to fat transplantation on breast plastic surgery. Many indicators and refinements have been made in clinical practice; meanwhile, the related mechanism and more optimized preclinical model also have been explored in experimental studies. A literature search was conducted using PubMed with the keywords: EVE, negative pressure, breast enlargement, breast augmentation, breast reconstruction, breast plastic surgery and breast aesthetic surgery. Studies dealing with the clinical and preclinical aspects of the subject and also in vitro experiments related to a certain period of negative pressure and adipose-derived cells were selected, and those only focused on negative pressure were excluded. The indications, contraindications, complications and treatments of EVE in clinical practice were summarized. The experimental studies were mainly classified into two groups (mechanical and translational) according to their contents. Mechanical studies were further divided into inference experimental validation phase studies. For the experimental validation phase, EVE was verified to promote angiogenesis, while it still remained controversial whether it would enhance adipogenesis and cell proliferation. Clinically, our experience is on the stage of exploration, and there is a lack of standardized guidelines on its clinical application. Experimentally, the previous studies showed some subtly different views on the functional mechanisms. However, it is not enough to regulate the clinical practice yet. Therefore, related basic studies and long-term clinical follow-up are needed. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Terahertz Reflecting and Transmitting Metasurfaces

Bridging the terahertz gap requires synergism between the microwave and photonic communities. Advances in each of these two communities are often complementary but sometimes overlooked. One example is the manipulation of waves, known as anomalous diffraction via the use of metamaterials. This is achieved by controlling the surface impedance of each pixel at the interface of two different materials or alternately the phase and magnitude of the wave diffracted off the pixel. In this paper, a review of developments in wave manipulation from microwave to optical frequencies is presented, together with our new results in the terahertz regime. Generation of phase curves for pixel design requires a priori information on material properties at terahertz frequencies. Fabrication of terahertz devices entails micromachining in the clean room while their experimental validation demands both amplitude and phase information. Through judicial selection of practices in microwave and photonic communities, we can further the exploration of wave phenomena at terahertz frequencies.

An “all-in-one” solution for simultaneous spoligotyping and drug resistance gene analysis of Mycobacterium tuberculosis: TB-SPRINT and TB-SPRINTplus

The aim of this study is to develop an innovative and alternative nucleic acid-based method for multidrug-resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB) diagnostics, such as the Cepheid GeneXPert or the Hain–Line Probe Assay methods, to simultaneously identify MDR-TB (patient benefit) and to provide clues as to MDR-TB transmission (community benefit) at a reasonable cost to the national public health programs.The DPO (Dual-Priming Oligonucleotide) principle was used to initially develop a 4-Plex multiplexed polymerase chain reaction (PCR) that simultaneously amplifies: (1) the CRISPR; (2) the rpoB hotspot, the katG and the inhA genes. The current maximal version of the assay allows the characterization of up to 68 markers, 59 of which are used routinely in one step (for the Luminex 200) or two-step methods (for the MagPix). Spoligotyping requires 43 markers, and rpoB516, 526, 531, katG315, inhA-8, -15, gyrA94, rrs1401, 1402, 1484 requires 25 markers. For each primer couple, one is biotinylated. Hybridization is performed after a PCR reaction on a microbead-based suspension array device with individually detectable oligonucleotide-coupled beads (Luminex 200 or MagPix systems) and detection proceeds through Streptavidin–Phycoerythrin labelling of the biotinylated-hybridized PCR products.This study shows that this technique provides 100% specificity and sensitivity for rpoB and 100% specificity and 90% sensitivity for isoniazid resistance on DNA extracted from cultures, compared with phenotypic DST. The method was fully validated against sequencing. The method is currently in the experimental validation phase on DNA extracted from biological material and preliminary results will be shown. This technique was recently upgraded to detect fluoroquinolone and aminoglycoside resistance by including 2 new PCR primer couples and 9 more probes on the rrs and gyrA genes. It is suggested that population studies using this laboratory method could provide a simpler and cheaper way to perform national TB-resistance surveys and would also allow to delineate more precisely, without further enquiries, MDR-TB transmission risks.In conclusion, these methods appear to be both economically and technically very innovative. The extension from a Research Use Only to a CE-marked In-Vitro Diagnostics assay is in progress.

Experimental Study on a Laboratory Test Bench for Sea Wave Generation Systems

The paper presents a laboratory test bench specifically designed for sea wave generation systems. In particular a DC Micro Grid is realized to experimentally validate the energy performance of a PM Brushless ball screw actuator, during motor-regenerative operative conditions, which is representative of an oscillating body wave generation system. The proposed architecture is based on a DC bus, which features the integration of renewable energy sources and buffered storage systems, with the aim of smoothing the natural power fluctuations of wave energy generation systems. The wave generation is simulated in laboratory by controlling an electric motor, which is directly coupled with the PM brushless generator. The experimental validation phase is mainly devoted to verify the design criteria of the architecture scheme and the control strategies of the power fluxes related to power converters.

Visually-Guided Balloon Catheter Ablation of Atrial Fibrillation

Electric isolation of the pulmonary veins (PVs) can successfully treat patients with paroxysmal atrial fibrillation. However, it remains technically challenging to identify the left atrial-PV junction and sequentially position the ablation catheter in a point-by-point contiguous fashion to isolate the PVs. In this study, a novel endoscopic ablation system was used to directly visualize and ablate tissue at the left atrial-PV junction with laser energy. This study consisted of 2 phases: a short-term (n=9) and long-term (n=11) canine experimental validation phase and a multicenter clinical feasibility phase (n=30 paroxysmal atrial fibrillation patients). After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and arcs of laser energy (90 degrees to 360 degrees ) were projected onto the target left atrial-PV junction. Electric PV isolation was defined with a circular multielectrode catheter. In the short-term preclinical experimental phase, 15 of 17 targeted PVs (88%) were successfully isolated. Pathological examination revealed well-demarcated circumferential lesions with minimal endothelial disruption. In the long-term experiments, 9 of 10 targeted veins (90%) remained persistently isolated (at 4 to 8 weeks). In the clinical phase, 105 of 116 PVs (91%) were successfully isolated. After a single procedure, the 12-month drug-free rate of freedom from atrial fibrillation was 60% (18 of 30 patients). There were no significant PV stenoses, but adverse events included 1 episode of cardiac tamponade, 1 stroke without residual defect, and 1 asymptomatic phrenic nerve palsy. This study establishes the feasibility of a novel paradigm for AF ablation: direct visualization to guide catheter ablation of the left atrial-PV junction.

View-Synchronized Robotic Image-Guided Therapy for Atrial Fibrillation Ablation

A robotic catheter navigation system has been developed that provides a significant degree of freedom of catheter movement. This study examines the feasibility of synchronizing this robotic navigation system with electroanatomic mapping and 3-dimensional computed tomography imaging to perform view-synchronized left atrial (LA) ablation. This study consisted of a porcine experimental validation phase (9 animals) and a clinical feasibility phase (9 atrial fibrillation patients). Preprocedural computed tomography images were reconstructed to provide 3-dimensional surface models of the LA pulmonary veins and aorta. Aortic electroanatomic mapping was performed manually, followed by registration with the corresponding computed tomography aorta image using custom software. The mapping catheter was remotely manipulated with the robotic navigation system within the registered computed tomography image of the LA pulmonary veins. The point-to-surface error between the LA electroanatomic mapping data and the computed tomography image was 2.1+/-0.7 and 1.6+/-0.1 mm in the preclinical and clinical studies, respectively. The catheter was remotely navigated into all pulmonary veins, the LA appendage, and circumferentially along the mitral valve annulus. In 7 of 9 animals, circumferential radiofrequency ablation lesions were applied periostially to ablate 11 pulmonary veins. In patients, all of the pulmonary veins were remotely electrically isolated in an extraostial fashion. Adjunctive ablation included superior vena cava isolation in 6 patients, cavotricuspid isthmus ablation in 5 patients, and ablation of sites of complex fractionated activity and atypical LA flutters in 3 patients. This study demonstrates the safety and feasibility of an emerging paradigm for atrial fibrillation ablation involving the confluence of 3 technologies: 3-dimensional imaging, electroanatomic mapping, and remote robotic navigation.

SIDESLIP ANGLE MEASUREMENT, EXPERIMENTAL CHARACTERIZATION AND EVALUATION OF THREE DIFFERENT PRINCIPLES

The knowledge of the sideslip angle is fundamental for control of the vehicle's lateral dynamics. In order to measure this angle, there are essentially three different principles: GPS/INS and optical correlation as used by available sensors and model-based techniques like observers. This paper focuses on the two following items. First, as the sensors are too expensive to be mounted on common vehicles, we investigate a low cost solution, based on two different observers, a common bicycle observer and a new observer including roll dynamics. Secondly, as the experimental validation phase of these observers needs the knowledge of reference measurements, we confront GPS/INS measurement principle and optical correlation, by characterization of two sensors: RT3002 and Correvit S400 in order to monitor their advantages and drawbacks. This characterization is carried out with a specific test bench and the different sideslip angle measurement solutions are compared with real tests performed with our laboratory experimental car.

Generalized Multiple Baseline Stereo and Direct Virtual View Synthesis Using Range-Space Search, Match, and Render

A new “range-space” approach is described for synergistic resolution of both stereovision and reflectance (visual) modeling problems simultaneously. This synergistic approach can be applied to arbitrary camera arrangements with different intrinsic and extrinsic parameters, image types, image resolutions, and image number. These images are analyzed in a step-wise manner to extract 3-D range measurements and also to render a customized perspective view. The entire process is fully automatic. An extensive and detailed experimental validation phase supports the basic feasibility and generality of the Range-Space Approach.

A new two-level model for multiclass freeway traffic

A new freeway traffic model is presented, which is made up by two modeling levels. The regular traffic conditions are represented by means of a macroscopic multiclass model, whereas the nonrecurrent situations are described in terms of discrete events. The necessary synchronization mechanisms are sought for the overall model to allow it to be used as a simulation model, and some comments on how to statistically treat the real-world traffic data in order to obtain suitable input functions for the simulator are reported. The comparison between the real and the simulated evolution of some relevant traffic variables is provided to give a feeling of the model experimental validation phase.