UrbanFly: Uncertainty-Aware Planning for Navigation Amongst High-Rises with Monocular Visual-Inertial SLAM Maps

We present UrbanFly: an uncertainty-aware real-time planning framework for quadrotor navigation in urban high-rise environments. A core aspect of UrbanFly is its ability to robustly plan directly on the sparse point clouds generated by a Monocular Visual Inertial SLAM (VINS) backend. It achieves this by using the sparse point clouds to build an uncertainty-integrated cuboid representation of the environment through a data-driven monocular plane segmentation network. Our chosen world model provides faster distance queries than the more common voxel-grid representation, and UrbanFly leverages this capability in two different ways leading to as many trajectory optimizers. The first optimizer uses a gradient-free cross-entropy method to compute trajectories that minimize collision probability and smoothness cost. Our second optimizer is a simplified version of the first and uses a sequential convex programming optimizer initialized based on probabilistic safety estimates on a set of randomly drawn trajectories. Both our trajectory optimizers are made computationally tractable and independent of the nature of underlying uncertainty by embedding the distribution of collision violations in Reproducing Kernel Hilbert Space. Empowered by the algorithmic innovation, UrbanFly outperforms competing baselines in metrics such as collision rate, trajectory length, etc., on a high fidelity AirSim simulator augmented with synthetic and real-world dataset scenes.Comment: Submitted to IROS 2022, Code available at https://github.com/sudarshan-s-harithas/UrbanFl

Parachute mitral valve with late presentation: rare case reports

Congenital mitral stenosis involves the annulus, the zone immediately above and contiguous with the annulus, the leaflets, the chordae tendineae, and the papillary muscles. In a parachute mitral valve (PMV), all chordae tendineae which are usually shorter and thicker than normal type, inserted into this single papillary muscle. This condition restricts the motion of leaflets and obstructs the blood flow into the left ventricle during diastole. Here we present two cases of severe congenital mitral stenosis with severe pulmonary hypertension due to parachute mitral valve that allowed survival into adulthood without any specific treatment

FinderNet: A Data Augmentation Free Canonicalization aided Loop Detection and Closure technique for Point clouds in 6-DOF separation

We focus on the problem of LiDAR point cloud based loop detection (or Finding) and closure (LDC) in a multi-agent setting. State-of-the-art (SOTA) techniques directly generate learned embeddings of a given point cloud, require large data transfers, and are not robust to wide variations in 6 Degrees-of-Freedom (DOF) viewpoint. Moreover, absence of strong priors in an unstructured point cloud leads to highly inaccurate LDC. In this original approach, we propose independent roll and pitch canonicalization of the point clouds using a common dominant ground plane. Discretization of the canonicalized point cloud along the axis perpendicular to the ground plane leads to an image similar to Digital Elevation Maps (DEMs), which exposes strong spatial priors in the scene. Our experiments show that LDC based on learnt embeddings of such DEMs is not only data efficient but also significantly more robust, and generalizable than the current SOTA. We report significant performance gain in terms of Average Precision for loop detection and absolute translation/rotation error for relative pose estimation (or loop closure) on Kitti, GPR and Oxford Robot Car over multiple SOTA LDC methods. Our encoder technique allows to compress the original point cloud by over 830 times. To further test the robustness of our technique we create and opensource a custom dataset called Lidar-UrbanFly Dataset (LUF) which consists of point clouds obtained from a LiDAR mounted on a quadrotor

Needle Stick Injuries among health care workers in a tertiary care hospital in District Bathinda, Punjab

Background: Because of the environment in which health care staff works, many they are at an increased risk of accidental needle stick injuries (NSI). NSI has been recognized as one of the potential occupational hazards for healthcare workers which results in transmission of blood borne pathogens such as HBV, HCV, and HIV/AIDS while performing their clinical activities in the Hospital. Aims & Objectives: To study the prevalence of needle stick injuries and knowledge and behavior of health care workers in a tertiary care centre. Material and Methods: A Hospital based cross sectional study was conducted among Health Care workers at a tertiary care hospital in 2016 at District Bathinda, Punjab. Results: A total of two hundred and eight (208) participants took part in the study from various departments. 58 health workers out of 208 i.e. 27% had NSI in the last 12 months. 84.1% of the health care workers were aware of the fact that HIV could transmitted by needle-stick injuries. While 55.8% and 83.2% knew that HBV and HCV respectively be transmitted through NSI. Only 46.6% of the health workers remembered that they had ever received HBV vaccination. Conclusions: The survey found out that the knowledge regarding the risk associated with NSI and use of preventive measures was adequate among the heath care workers but still there was a slight room for improvement in their attitude and practice and the same can be addressed through proper education and trainin

Successful percutaneous balloon dilatation of supravalvular aortic membrane

Supravalvular aortic stenosis is the least common type of left ventricular outflow tract obstruction. Primary balloon dilatation of membranous supravalvular aortic stenosis was performed in a 10-year-old male child with a remarkable reduction in systolic pressure gradient. Balloon dilatation is a feasible treatment modality for membranous supravalvular aortic stenosis. It provides good immediate results and sustained relief of stenosis

Long-term survival and propensity score matched outcomes of bilateral vs. unilateral diaphragm interventions in cytoreductive surgery plus intra-peritoneal chemotherapy

Background/Aim: To assess the impact of short-and long-term outcomes of bilateral vs. unilateral diaphragm interventions in cyto-reductive surgery (CRS) and intraperitoneal chemotherapy (IPC). Patients and Methods: A total of 652 CRS/IPC procedures, between 1996 and 2018, required diaphragm interventions. Among these, 388 underwent bilateral intervention. Preoperative heterogeneity was assessed in 6 parameters and addressed with propensity score matching. The association of each respective analysis was assessed with 11 outcomes. Overall survival was assessed based on histology. Results: CRS/IPC requiring bilateral diaphragmatic interventions illustrated significantly increased operative hours (9.6 vs. 8.6 hours, p<0.001). Postoperatively, there was significantly increased red blood cell (RBC) transfusion (6.37 units vs. 4.47 units, p=0.007) and grade III and IV complications (57.3% vs. 40.6%, p=0.004). No difference was noted in ICU stay, total length of stay, hospital death and return to OT. In terms of respiratory complications, an increased incidence of pneumothorax (16.5% vs. 6.2%, p<0.001) was noted whilst pleural effusions and pneumonia occurrences were non-significant. Overall survival, revealed bilateral interventions in low-grade appendiceal mucinous neoplasm conferred an increased relative risk (p=0.037, RR=2.230, 95%CI=1.052-4.730). They did not have an effect on OS in colorectal cancer and mesothelioma. Conclusion: Despite the increase in short-term morbidity, bilateral diaphragm interventions resulted in similar long-term survival to unilateral interventions

Comparative evaluation of stress levels before, during, and after periodontal surgical procedures with and without nitrous oxide-oxygen inhalation sedation

Context: Periodontal surgical procedures produce varying degree of stress in all patients. Nitrous oxide-oxygen inhalation sedation is very effective for adult patients with mild-to-moderate anxiety due to dental procedures and needle phobia. Aim: The present study was designed to perform periodontal surgical procedures under nitrous oxide-oxygen inhalation sedation and assess whether this technique actually reduces stress physiologically, in comparison to local anesthesia alone (LA) during lengthy periodontal surgical procedures. Settings and Design: This was a randomized, split-mouth, cross-over study. Materials and Methods: A total of 16 patients were selected for this randomized, split-mouth, cross-over study. One surgical session (SS) was performed under local anesthesia aided by nitrous oxide-oxygen inhalation sedation, and the other SS was performed on the contralateral quadrant under LA. For each session, blood samples to measure and evaluate serum cortisol levels were obtained, and vital parameters including blood pressure, heart rate, respiratory rate, and arterial blood oxygen saturation were monitored before, during, and after periodontal surgical procedures. Statistical Analysis Used: Paired t-test and repeated measure ANOVA. Results: The findings of the present study revealed a statistically significant decrease in serum cortisol levels, blood pressure and pulse rate and a statistically significant increase in respiratory rate and arterial blood oxygen saturation during periodontal surgical procedures under nitrous oxide inhalation sedation. Conclusion: Nitrous oxide-oxygen inhalation sedation for periodontal surgical procedures is capable of reducing stress physiologically, in comparison to LA during lengthy periodontal surgical procedures