Echogenicity of Dupuytren’s nodules is correlated to myofibroblast load and nodule hardness

This study aimed to determine the association between the echogenicity of Dupuytren’s disease nodules and myofibroblast load, and between echogenicity and nodule hardness. Thirty-eight nodules were assessed sonographically. The echogenicity of nodules was measured objectively with Image J (grey-value) and subjectively by visual inspection (hypo-, mixed and hyper-echogenicity). These findings were compared with myofibroblast load measured by histopathological analysis. In a different cohort, 97 nodules were assessed for grey-value and nodule hardness using a tonometer. There was a moderate, significant, negative association between grey-value and myofibroblast load and the subjective visual measurements corresponded to this finding. There was also a moderate, significant, negative association between grey-value and nodule hardness. Ultrasound and tonometry may be useful in the selection of patients for possible future preventive treatments.

Development of a Flexible Dielectric Sensor for Flow Monitoring of the Liquid Resin Infusion Process

The analysis and design of a novel flexible dielectric sensor, which can be integrated into a composite materials manufacturing process to measure the resin frontal flow, is presented in this paper. The proposed sensor consists of two parallel line electrodes and a ground plane covered by a dielectric material. The analytical description and the electrostatic modelling were considered for the design of the sensor and to enhance the understanding of the response of the sensor to the resin impregnation of a carbon fabric during the infusion phase. The optimization of the sensor’s response and the increase of its sensitivity with regards to the geometric characteristics and the materials used were the main objectives of this study. An experimental set-up for the vacuum infusion process which includes the proposed sensor was used to measure the capacitance and validate the derived resin flow against visual measurements. The results indicate that the sensor can provide information on the resin frontal flow within 2% accuracy against visual measurements, which make this technology promising for monitoring the liquid resin infusion processes.

ACK-MSCKF: Tightly-Coupled Ackermann Multi-State Constraint Kalman Filter for Autonomous Vehicle Localization

Visual-Inertial Odometry (VIO) is subjected to additional unobservable directions under the special motions of ground vehicles, resulting in larger pose estimation errors. To address this problem, a tightly-coupled Ackermann visual-inertial odometry (ACK-MSCKF) is proposed to fuse Ackermann error state measurements and the Stereo Multi-State Constraint Kalman Filter (S-MSCKF) with a tightly-coupled filter-based mechanism. In contrast with S-MSCKF, in which the inertial measurement unit (IMU) propagates the vehicle motion and then the propagation is corrected by stereo visual measurements, we successively update the propagation with Ackermann error state measurements and visual measurements after the process model and state augmentation. This way, additional constraints from the Ackermann measurements are exploited to improve the pose estimation accuracy. Both qualitative and quantitative experimental results evaluated under real-world datasets from an Ackermann steering vehicle lead to the following demonstration: ACK-MSCKF can significantly improve the pose estimation accuracy of S-MSCKF under the special motions of autonomous vehicles, and keep accurate and robust pose estimation available under different vehicle driving cycles and environmental conditions. This paper accompanies the source code for the robotics community.

Temporary Tritanopia: Effects of cataract surgery on color

This pilot study made a wide variety of visual measurements before, during, and after bilateral cataract surgery. This article describes the changes in color discrimination and color appearance resulting from cataract implants. It used the F-M 100 Hue Test, color matching of real scenes, and color-balance titration measurements. The pre-surgery data indicated that the previously normal color observers had severe tritanopic anomalies. Lens replacement restored normal color vision.