Microfossil taphonomy in clay-rich rocks in Proterozoic environments analogous to the Noachian on Mars.

peer reviewedSiliciclastic sedimentary rocks are a rich but relatively understudied archive of early life on Earth. In particular, phyllosilicate rich rocks such as mudstones have proven to be effective in the preservation of organic walled microfossils. Understanding the exceptional preservation of organic walled microfossils in mudstones is of particular significance to the search for life on other rocky planets such as Mars. As the presence and composition of phyllosilicates can be determined through remote sensing techniques, this knowledge provides a valuable tool in the search for signs of ancient life in both terrestrial and Martian mudrocks. Several Mars missions are currently focused on the detection of life signatures in mudstones deposited in crater paleolakes (Perseverance) and fluvio-deltaic to basinal settings (Exomars). However, it is currently unknown if the species of phyllosilicates present in the primary sediment affect preservation of organic walled microfossils. Further, effects of depositional settings within a basin on the preservation of organic walled microfossils are also poorly understood. To investigate these questions, we conducted an extensive investigation of the exquisitely preserved ~1.4 Ga Greater McArthur Basin (GMB), northern Australia. The GMB was a long lived stable cratonic basin, partially restricted from the global ocean, and fed by at least one large delta system with sediment derived from the erosion of basaltic hinterlands under an arid climate. Thanks to abundant drill core material, the GMB provides an easily accessible analogue for an early Martian crater lake with deltaic to basinal deposits. We examined an extensive sample set of mudstones extracted from 7 drill cores from the GMB. These cores represent temporally and spatially adjacent depositional settings which provide a proximal to distal transect of contemporaneous depositional environments across the basin. Here we present early fossil, mineralogical, and sedimentological data which illustrate the quantification of clay species, and the abundance, diversity, and preservation quality or taphonomy of organic walled microfossils extracted from those samples. Finally, we present a schematic depositional model for the basin and discuss the possible links between preservation, environment, and clays

WO 2018/046962 A1 - Force sensor plate

The present invention provides a force sensor plate for use in a training apparatus for simulating minimally invasive surgery. The force sensor plate comprises: a frame configured to support a tissue-sheet through which an incision can be made to simulate minimally invasive surgery using at least one surgical tool; and a sensor system configured to sense the force and/or torque applied to the tissue-sheet at the incision by the at least one surgical tool.status: publishe

A mixed-reality surgical trainer with comprehensive sensing for fetal laser minimally invasive surgery

PURPOSE: Smaller incisions and reduced surgical trauma made minimally invasive surgery (MIS) grow in popularity even though long training is required to master the instrument manipulation constraints. While numerous training systems have been developed in the past, very few of them tackled fetal surgery and more specifically the treatment of twin-twin transfusion syndrome (TTTS). To address this lack of training resources, this paper presents a novel mixed-reality surgical trainer equipped with comprehensive sensing for TTTS procedures. The proposed trainer combines the benefits of box trainer technology and virtual reality systems. Face and content validation studies are presented and a use-case highlights the benefits of having embedded sensors. METHODS: Face and content validity of the developed setup was assessed by asking surgeons from the field of fetal MIS to accomplish specific tasks on the trainer. A small use-case investigates whether the trainer sensors are able to distinguish between an easy and difficult scenario. RESULTS: The trainer was deemed sufficiently realistic and its proposed tasks relevant for practicing the required motor skills. The use-case demonstrated that the motion and force sensing capabilities of the trainer were able to analyze surgical skill. CONCLUSION: The developed trainer for fetal laser surgery was validated by surgeons from a specialized center in fetal medicine. Further similar investigations in other centers are of interest, as well as quality improvements which will allow to increase the difficulty of the trainer. The comprehensive sensing appeared to be capable of objectively assessing skill

Motion-based skill analysis in a fetoscopic spina-bifida repair training model

status: publishe

Holocene paleoenvironmental reconstructions from Belgian peatbog

Atmospheric deposition is an important part of the global climate system, and plays a key role in the marine and terrestrial biogeochemical cycles as a source for major and trace nutrient elements. Reconstruction of atmospheric deposition is crucial to understand the effects of the increased atmospheric depositions induced by humans on the environment and to help understanding Holocene climate variability. This study investigated potential paleoenvironmental proxies provided by major and trace elements and stable isotopes compositions of peat bogs. Peat bog cores were collected from Hautes-Fagnes plateau (Misten bog) (SE-Belgium). The analyses of Rare Earth Elements (REE) and lithogenic element concentrations as well as Nd isotopes were performed by HR-ICP-MS and MC-ICP-MS respectively, in a 7 m peat section representing 7300 years, dated by 210Pb and 14C methods. The Misten bog is highly affected by atmospheric supplies (natural and anthropogenic) and can be used to establish the changes in atmospheric dust during the Mid-Late Holocene. Dust fluxes show pronounced increase at 3200-2800BC, 600BC, AD600, 1000AD, 1200AD and from 1700 AD corresponding to local and regional human activities combined with climate change. Peat humification and testate amoebae were used to evaluate hydroclimatic conditions. The Nd values show large variability, between -5 and –13, identifying three major sources of dust: local soils, distal volcanic and desert particles. Our results provide evidence that climate forcing may be detected in ombrotrophic peat, even for the historical period that is characterised by a mixed climate-human control

A mixed-reality surgical simulator for instrument evaluation in fetal minimally invasive surgery

status: publishe

Haptic Guidance Based on All-Optical Ultrasound Distance Sensing for Safer Minimally Invasive Fetal Surgery

By intervening during the early stage of gestation, fetal surgeons aim to correct or minimize the effects of congenital disorders. As compared to postnatal treatment of these disorders, such early interventions can often actually save the life of the fetus and also improve the quality of life of the newborn. However, fetal surgery is considered one of the most challenging disciplines within Minimally Invasive Surgery (MIS), owing to factors such as the fragility of the anatomic features, poor visibility, limited manoeuvrability, and extreme requirements in terms of instrument handling with precise positioning. This work is centered on a fetal laser surgery procedure treating placental disorders. It proposes the use of haptic guidance to enhance the overall safety of this procedure and to simplify instrument handling. A method is described that provides effective guidance by installing a forbidden region virtual fixture over the placenta, thereby safeguarding adequate clearance between the instrument tip and the placenta. With a novel application of all-optical ultrasound distance sensing in which transmission and reception are performed with fibre optics, this method can be used with a sole reliance on intraoperatively acquired data. The added value of the guidance approach, in terms of safety and performance, is demonstrated in a series of experiments with a robotic platform

From a Disposable Ureteroscope to an Active Lightweight Fetoscope

status: publishe

A mixed-reality surgical trainer with comprehensive sensing for fetal laser minimally invasive surgery

PURPOSE: Smaller incisions and reduced surgical trauma made minimally invasive surgery (MIS) grow in popularity even though long training is required to master the instrument manipulation constraints. While numerous training systems have been developed in the past, very few of them tackled fetal surgery and more specifically the treatment of twin-twin transfusion syndrome (TTTS). To address this lack of training resources, this paper presents a novel mixed-reality surgical trainer equipped with comprehensive sensing for TTTS procedures. The proposed trainer combines the benefits of box trainer technology and virtual reality systems. Face and content validation studies are presented and a use-case highlights the benefits of having embedded sensors. METHODS: Face and content validity of the developed setup was assessed by asking surgeons from the field of fetal MIS to accomplish specific tasks on the trainer. A small use-case investigates whether the trainer sensors are able to distinguish between an easy and difficult scenario. RESULTS: The trainer was deemed sufficiently realistic and its proposed tasks relevant for practicing the required motor skills. The use-case demonstrated that the motion and force sensing capabilities of the trainer were able to analyze surgical skill. CONCLUSION: The developed trainer for fetal laser surgery was validated by surgeons from a specialized center in fetal medicine. Further similar investigations in other centers are of interest, as well as quality improvements which will allow to increase the difficulty of the trainer. The comprehensive sensing appeared to be capable of objectively assessing skill.status: publishe

Handheld Active Add-On Control Unit for a Cable-Driven Flexible Endoscope

status: publishe