Automated assessment of transthoracic echocardiogram image quality using deep neural networks

Background Standard views in two-dimensional echocardiography are well established but the quality of acquired images are highly dependent on operator skills and are assessed subjectively. This study is aimed at providing an objective assessment pipeline for echocardiogram image quality by defining a new set of domain-specific quality indicators. Consequently, image quality assessment can thus be automated to enhance clinical measurements, interpretation, and real-time optimization. Methods We have developed deep neural networks for the automated assessment of echocardiographic frame which were randomly sampled from 11,262 adult patients. The private echocardiography dataset consists of 33,784 frames, previously acquired between 2010 and 2020. Unlike non-medical images where full-reference metrics can be applied for image quality, echocardiogram's data is highly heterogeneous and requires blind-reference (IQA) metrics. Therefore, deep learning approaches were used to extract the spatiotemporal features and the image's quality indicators were evaluated against the mean absolute error. Our quality indicators encapsulate both anatomical and pathological elements to provide multivariate assessment scores for anatomical visibility, clarity, depth-gain and foreshortedness, respectively. Results The model performance accuracy yielded 94.4%, 96.8%, 96.2%, 97.4% for anatomical visibility, clarity, depth-gain and foreshortedness, respectively. The mean model error of 0.375±0.0052 with computational speed of 2.52 ms per frame (real-time performance) was achieved. Conclusion The novel approach offers new insight to objective assessment of transthoracic echocardiogram image quality and clinical quantification in A4C and PLAX views. Also lays stronger foundations for operator's guidance system which can leverage the learning curve for the acquisition of optimum quality images during transthoracic exam

Proximal humerus fractures - Part 1 : conservative management

CITATION: Anley, C. et al. 2019. Proximal humerus fractures. Part 1: Conservative management. South African Orthopaedic Journal, 18(3):63-71. doi:10.17159/2309-8309/2019/v18n3a8The original publication is available at https://www.saoj.org.za/index.php/saoj/indexENGLISH ABSTRACT: Fractures of the proximal humerus are common, especially in osteoporotic females. Despite this, there remains significant debate around their preferred treatment. The difficulties when considering treatment options is the wide array of fracture patterns and multiple patient factors which play an important role in the outcome of the management of these fractures. Fortunately, the vast majority of these fractures can be treated conservatively. The challenge, however, is the 15% of patients in which surgery may be required such as displaced three- and four-part fractures, and fractures in young and active patients. Although various recent studies and review papers show acceptable results with conservative treatment, especially in elderly patients, the decision on when to operate and when to consider conservative treatment remains challenging. The goal of this current concepts paper is to highlight important aspects of the conservative management of patients with proximal humerus fractures, from initial assessment through to treatment, including possible complications. Level of evidence: Level 5https://www.saoj.org.za/index.php/saoj/article/view/343Publisher’s versio

Integral abutment bridges: Investigation of seismic soil-structure interaction effects by shaking table testing

In recent years there has been renewed interest on integral abutment bridges (IABs), mainly due to their low construction and maintenance cost. Owing to the monolithic connection between deck and abutments, there is strong soil-structure interaction between the bridge and the backfill under both thermal action and earthquake shaking. Although some of the regions where IABs are adopted qualify as highly seismic, there is limited knowledge as to their dynamic behaviour and vulnerability under strong ground shaking. To develop a better understanding on the seismic behaviour of IABs, an extensive experimental campaign involving over 75 shaking table tests and 4800 time histories of recorded data, was carried out at EQUALS Laboratory, University of Bristol, under the auspices of EU-sponsored SERA project (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe). The tests were conducted on a 5 m long shear stack mounted on a 3 m × 3 m 6-DOF earthquake simulator, focusing on interaction effects between a scaled bridge model, abutments, foundation piles and backfill soil. The study aims at (a) developing new scaling procedures for physical modelling of IABs, (b) investigating experimentally the potential benefits of adding compressible inclusions (CIs) between the abutment and the backfill and (c) exploring the influence of different types of connection between the abutment and the pile foundation. Results indicate that the CI reduces the accelerations on the bridge deck and the settlements in the backfill, while disconnecting piles from the cap decreases bending near the pile head

The InSight HP^3 mole on Mars: Lessons learned from attempts to penetrate to depth in the Martian soil

The NASA InSight mission payload includes the Heat Flow and Physical Properties Package HP^3 to measure the surface heat flow. The package was designed to use a small penetrator - nicknamed the mole - to implement a string of temperature sensors in the soil to a depth of 5m. The mole itself is equipped with sensors to measure a thermal conductivity as it proceeds to depth. The heat flow would be calculated from the product of the temperature gradient and the thermal conductivity. To avoid the perturbation caused by annual surface temperature variations, the measurements would be taken at a depth between 3 m and 5 m. The mole was designed to penetrate cohesionless soil similar to Quartz sand which was expected to provide a good analogue material for Martian sand. The sand would provide friction to the buried mole hull to balance the remaining recoil of the mole hammer mechanism that drives the mole forward. Unfortunately, the mole did not penetrate more than a mole length of 40 cm. The failure to penetrate deeper was largely due to a few tens of centimeter thick cohesive duricrust that failed to provide the required friction. Although a suppressor mass and spring in the hammer mechanism absorbed much of the recoil, the available mass did not allow a system that would have eliminated the recoil. The mole penetrated to 40 cm depth benefiting from friction provided by springs in the support structure from which it was deployed. It was found in addition that the Martian soil provided unexpected levels of penetration resistance that would have motivated to designing a more powerful mole. It is concluded that more mass would have allowed to design a more robust system with little or no recoil, more energy of the mole hammer mechanism and a more massive support structure.Comment: 34 pages, 15 figures, submitted to Adnaves in Space Researc

Thermal Conductivity of the Martian Soil at the InSight Landing site from HP3 Active Heating Experiments

The heat flow and physical properties package (HP3) of the InSight Mars mission is an instrument package designed to determine the martian planetary heat flow. To this end, the package was designed to emplace sensors into the martian subsurface and measure the thermal conductivity as well as the geothermal gradient in the 0-5 m depth range. After emplacing the probe to a tip depth of 0.37 m, a first reliable measurement of the average soil thermal conductivity in the 0.03 to 0.37 m depth range was performed. Using the HP3 mole as a modified line heat source, we determined a soil thermal conductivity of 0.039 +/- 0.002 W/mK, consistent with the results of orbital and in-situ thermal inertia measurements. This low thermal conductivity implies that 85 to 95% of all particles are smaller than 104-173 micrometer and suggests that any cement contributing to soil cohesion cannot significantly increase grain-to-grain contact areas by forming cementing necks, but could be distributed in the form of grain coatings instead. Soil densities compatible with the measurements are 1211(-113+149) kg/m3, indicating soil porosities of 61

The mechanical properties of the Martian soil at the InSight landing site

The InSight mission is a NASA geophysical mission aimed at better understanding the structure of Mars and of the other rocky plan-ets of the solar system. To do so, various instruments are used, including a very sensitive seismometer (SEIS) and a dynamic self-penetrating heat probe (HP3) that have been placed on the Mars surface by the Instrument Deployment Arm (IDA). Besides geophys-ical data (which have definitely enriched and completed existing knowledge on the structure of Mars), the InSight instruments, togeth-er with orbiter observations and tests carried out on the soil with the IDA, have significantly increased the knowledge of the geologi-cal and geotechnical characteristics of the surface material at the InSight site, which is made up of a basaltic sand. In-situ data were also successfully compared with terrestrial previous estimates from terrestrial lab tests, carried out on various soil simulants. Small strain (elastic) parameters at small strains were derived from wave velocity measurements between the self-penetrating probe and the seismometer. Strength data were derived from both IDA operations and penetration data. The soil includes some pebbles within a somewhat cohesive sandy matrix, limiting the heat probe penetration to only 40 cm length. Thermal data were also obtained, allowing for some thermo-elastic modelling of the effect of the Phobos (one of the “Moons” of Mars) eclipses. Elastic data were also derived from the effects of wind on the ground, detected by SEIS

Mucinous cystic neoplasms of the mesentery: a case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Mucinous cystic neoplasms arise in the ovary and various extra-ovarian sites. While their pathogenesis remains conjectural, their similarities suggest a common pathway of development. There have been rare reports involving the mesentery as a primary tumour site.</p> <p>Case presentation</p> <p>A cystic mass of uncertain origin was demonstrated radiologically in a 22 year old female with chronic abdominal pain. At laparotomy, the mass was fixed within the colonic mesentery. Histology demonstrated a benign mucinous cystadenoma.</p> <p>Methods and results</p> <p>We review the literature on mucinous cystic neoplasms of the mesentery and report on the pathogenesis, biologic behavior, diagnosis and treatment of similar extra-ovarian tumors. We propose an updated classification of mesenteric cysts and cystic tumors.</p> <p>Conclusion</p> <p>Mucinous cystic neoplasms of the mesentery present almost exclusively in women and must be considered in the differential diagnosis of mesenteric tumors. Only full histological examination of a mucinous cystic neoplasm can exclude a borderline or malignant component. An updated classification of mesenteric cysts and cystic tumors is proposed.</p

An Autonomous Lunar Geophysical Experiment Package (ALGEP) for future space missions

Geophysical observations will provide key information about the inner structure of the planets and satellites and understanding the internal structure is a strong constraint on the bulk composition and thermal evolution of these bodies. Thus, geophysical observations are a key to uncovering the origin and evolution of the Moon. In this article, we propose the development of an autonomous lunar geophysical experiment package, composed of a suite of instruments and a central station with standardized interface, which can be installed on various future lunar missions. By fixing the interface between instruments and the central station, it would be possible to easily configure an appropriate experiment package for different missions. We describe here a series of geophysical instruments that may be included as part of the geophysical package: a seismometer, a magnetometer, a heat flow probe, and a laser reflector. These instruments will provide mechanical, thermal, and geodetic parameters of the Moon that are strongly related to the internal structure. We discuss the functionality required for future geophysical observations of the Moon, including the development of the central station that will be used commonly by different payloads

The InSight HP3 Penetrator (Mole) on Mars: Soil Properties Derived from the Penetration Attempts and Related Activities

The NASA InSight Lander on Mars includes the Heat Flow and Physical Properties Package HP3 to measure the surface heat flow of the planet. The package uses temperature sensors that would have been brought to the target depth of 3–5 m by a small penetrator, nicknamed the mole. The mole requiring friction on its hull to balance remaining recoil from its hammer mechanism did not penetrate to the targeted depth. Instead, by precessing about a point midway along its hull, it carved a 7 cm deep and 5–6 cm wide pit and reached a depth of initially 31 cm. The root cause of the failure – as was determined through an extensive, almost two years long campaign – was a lack of friction in an unexpectedly thick cohesive duricrust. During the campaign – described in detail in this paper – the mole penetrated further aided by friction applied using the scoop at the end of the robotic Instrument Deployment Arm and by direct support by the latter. The mole tip finally reached a depth of about 37 cm, bringing the mole back-end 1–2 cm below the surface. It reversed its downward motion twice during attempts to provide friction through pressure on the regolith instead of directly with the scoop to the mole hull. The penetration record of the mole was used to infer mechanical soil parameters such as the penetration resistance of the duricrust of 0.3–0.7 MPa and a penetration resistance of a deeper layer (> 30 cm depth) of 4.9±0.4 MPa. Using the mole’s thermal sensors, thermal conductivity and diffusivity were measured. Applying cone penetration theory, the resistance of the duricrust was used to estimate a cohesion of the latter of 2–15 kPa depending on the internal friction angle of the duricrust. Pushing the scoop with its blade into the surface and chopping off a piece of duricrust provided another estimate of the cohesion of 5.8 kPa. The hammerings of the mole were recorded by the seismometer SEIS and the signals were used to derive P-wave and S-wave velocities representative of the topmost tens of cm of the regolith. Together with the density provided by a thermal conductivity and diffusivity measurement using the mole’s thermal sensors, the elastic moduli were calculated from the seismic velocities. Using empirical correlations from terrestrial soil studies between the shear modulus and cohesion, the previous cohesion estimates were found to be consistent with the elastic moduli. The combined data were used to derive a model of the regolith that has an about 20 cm thick duricrust underneath a 1 cm thick unconsolidated layer of sand mixed with dust and above another 10 cm of unconsolidated sand. Underneath the latter, a layer more resistant to penetration and possibly containing debris from a small impact crater is inferred. The thermal conductivity increases from 14 mW/m K to 34 mW/m K through the 1 cm sand/dust layer, keeps the latter value in the duricrust and the sand layer underneath and then increases to 64 mW/m K in the sand/gravel layer below