Heterogeneous Sensor Fusion for Accurate State Estimation of Dynamic Legged Robots

In this paper we present a system for the state estimation of a dynamically walking and trotting quadruped. The approach fuses four heterogeneous sensor sources (inertial, kinematic, stereo vision and LIDAR) to maintain an accurate and consistent estimate of the robot’s base link velocity and position in the presence of disturbances such as slips and missteps. We demonstrate the performance of our system, which is robust to changes in the structure and lighting of the environment, as well as the terrain over which the robot crosses. Our approach builds upon a modular inertial-driven Extended Kalman Filter which incorporates a rugged, probabilistic leg odometry component with additional inputs from stereo visual odometry and LIDAR registration. The simultaneous use of both stereo vision and LIDAR helps combat operational issues which occur in real applications. To the best of our knowledge, this paper is the first to discuss the complexity of consistent estimation of pose and velocity states, as well as the fusion of multiple exteroceptive signal sources at largely different frequencies and latencies, in a manner which is acceptable for a quadruped’s feedback controller. A substantial experimental evaluation demonstrates the robustness and accuracy of our system, achieving continuously accurate localization and drift per distance traveled below 1 cm/m

Trajectory and Foothold Optimization using Low-Dimensional Models for Rough Terrain Locomotion

We present a trajectory optimization framework for legged locomotion on rough terrain. We jointly optimize the center of mass motion and the foothold locations, while considering terrain conditions. We use a terrain costmap to quantify the desirability of a foothold location. We increase the gait's adaptability to the terrain by optimizing the step phase duration and modulating the trunk attitude, resulting in motions with guaranteed stability. We show that the combination of parametric models, stochastic-based exploration and receding horizon planning allows us to handle the many local minima associated with different terrain conditions and walking patterns. This combination delivers robust motion plans without the need for warm-starting. Moreover, we use soft-constraints to allow for increased flexibility when searching in the cost landscape of our problem. We showcase the performance of our trajectory optimization framework on multiple terrain conditions and validate our method in realistic simulation scenarios and experimental trials on a hydraulic, torque controlled quadruped robot

Pathological chemotherapy response score is prognostic in tubo-ovarian high-grade serous carcinoma: A systematic review and meta-analysis of individual patient data

There is a need to develop and validate biomarkers for treatment response and survival in tubo-ovarian high-grade serous carcinoma (HGSC). The chemotherapy response score (CRS) stratifies patients into complete/near-complete (CRS3), partial (CRS2), and no/minimal (CRS1) response after neoadjuvant chemotherapy (NACT). Our aim was to review current evidence to determine whether the CRS is prognostic in women with tubo-ovarian HGSC treated with NACT.This article is freely available via Open Access. Click on the Publisher URL to access the full-text via the publisher's site

Nevus composto do colo uterino: relato de caso Compound nevus of the uterine cervix: case report

O nevus composto do colo uterino representa um achado muito raro. Relatos excepcionais de lesões melanocíticas benignas e malignas da endo e exocérvice uterina têm sido publicados. Relatamos o achado ocasional do nevus composto da exocérvice uterina em uma paciente de 47 anos de idade que não apresentava queixas ginecológicas. O diagnóstico foi sugerido pelo exame colposcópico e confirmado à histopatologia. Devido à possibilidade de transformação maligna dessas lesões e à dificuldade de seguimento da paciente, o tratamento foi concluido com a realização de histerectomia total abdominal.<br>Compound nevus of the uterine cervix is very rare. Benign and malignant melanotic lesions of endo and exocervix have been rarely documented. The present case of compound nevus in the uterine exocervix was found in a 47-year-old woman without gynecologic complaints. Diagnosis was suspected by colposcopic evaluation and confirmed trough histopathological examination. The treatment was concluded with total abdominal hysterectomy based on the possible malignant transformation of these lesions and the difficult patient follow-up