Generalised Entropy MDPs and Minimax Regret

Bayesian methods suffer from the problem of how to specify prior beliefs. One interesting idea is to consider worst-case priors. This requires solving a stochastic zero-sum game. In this paper, we extend well-known results from bandit theory in order to discover minimax-Bayes policies and discuss when they are practical.Comment: 7 pages, NIPS workshop "From bad models to good policies

Organ Shape Sensing using Pneumatically Attachable Flexible Rails in Robotic-Assisted Laparoscopic Surgery

In robotic-assisted partial nephrectomy, surgeons remove a part of a kidney often due to the presence of a mass. A drop-in ultrasound probe paired to a surgical robot is deployed to execute multiple swipes over the kidney surface to localise the mass and define the margins of resection. This sub-task is challenging and must be performed by a highly skilled surgeon. Automating this sub-task may reduce cognitive load for the surgeon and improve patient outcomes. The overall goal of this work is to autonomously move the ultrasound probe on the surface of the kidney taking advantage of the use of the Pneumatically Attachable Flexible (PAF) rail system, a soft robotic device used for organ scanning and repositioning. First, we integrate a shape-sensing optical fibre into the PAF rail system to evaluate the curvature of target organs in robotic-assisted laparoscopic surgery. Then, we investigate the impact of the stiffness of the material of the PAF rail on the curvature sensing accuracy, considering that soft targets are present in the surgical field. Finally, we use shape sensing to plan the trajectory of the da Vinci surgical robot paired with a drop-in ultrasound probe and autonomously generate an Ultrasound scan of a kidney phantom.Comment: 9 pages, 11 figure

Specialised Surgical Instruments for Endoscopic and Endoscope-Assisted Neurosurgery: A Systematic Review of Safety, Efficacy and Usability

While there have been great strides in endoscopic and endoscope-assisted neurosurgical approaches, particularly in the treatment of deep-sited brain and skull base tumours, the greatest technical barrier to their adoption has been the availability of suitable surgical instruments. This systematic review seeks to identify specialised instruments for these approaches and evaluate their safety, efficacy and usability. Conducted in accordance with the PRISMA guidelines, Medline, Embase, CENTRAL, SCOPUS and Web of Science were searched. Original research studies that reported the use of specialised mechanical instruments that manipulate tissue in human patients, cadavers or surgical models were included. The results identified 50 specialised instruments over 62 studies. Objective measures of safety were reported in 32 out of 62 studies, and 20 reported objective measures of efficacy. Instruments were broadly safe and effective with one instrument malfunction noted. Measures of usability were reported in 15 studies, with seven reporting on ergonomics and eight on the instruments learning curve. Instruments with reports on usability were generally considered to be ergonomic, though learning curve was often considered a disadvantage. Comparisons to standard instruments were made in eight studies and were generally favourable. While there are many specialised instruments for endoscopic and endoscope-assisted neurosurgery available, the evidence for their safety, efficacy and usability is limited with non-standardised reporting and few comparative studies to standard instruments. Future innovation should be tailored to unmet clinical needs, and evaluation guided by structured development processes

Robotic Handle Prototypes for Endoscopic Endonasal Skull Base Surgery: Pre-clinical Randomised Controlled Trial of Performance and Ergonomics

Endoscopic endonasal skull base surgery is a promising alternative to transcranial approaches. However, standard instruments lack articulation, and thus, could benefit from robotic technologies. The aim of this study was to develop an ergonomic handle for a handheld robotic instrument intended to enhance this procedure. Two different prototypes were developed based on ergonomic guidelines within the literature. The first is a forearm-mounted handle that maps the surgeon’s wrist degrees-of-freedom to that of the robotic end-effector; the second is a joystick-and-trigger handle with a rotating body that places the joystick to the position most comfortable for the surgeon. These handles were incorporated into a custom-designed surgical virtual simulator and were assessed for their performance and ergonomics when compared with a standard neurosurgical grasper. The virtual task was performed by nine novices with all three devices as part of a randomised crossover user-study. Their performance and ergonomics were evaluated both subjectively by themselves and objectively by a validated observational checklist. Both handles outperformed the standard instrument with the rotating joystick-body handle offering the most substantial improvement in terms of balance between performance and ergonomics. Thus, it is deemed the more suitable device to drive instrumentation for endoscopic endonasal skull base surgery

Handheld Robotic Instruments for Endoscopic Neurosurgery

The Endoscopic Endonasal Approach, one of the best examples of endoscopic neurosurgery, allows surgeons to access the pituitary gland through the natural orifice of the nose. Recently, surgeons have introduced the Expanded Endoscopic Endonasal Approach for the treatment of tumours around a broader area at the base of the brain. Operating in this way, however, with standard tools which are lacking articulation, is technically very difficult and not widely adopted. Thus, these operations are only performed by few surgeons, in highly specialised centres, limiting access to most patients. While detection rates have increased due to recent advances in medical imaging, clinical outcome has not improved in the last 20 years. Resultantly, it is widely recognised by patient groups and healthcare institutions that there is an urgent need for surgical innovation to advance clinical outcomes in patients with brain tumours. Robotic-assisted minimally invasive surgery allows for increased instrument articulation and surgeon dexterity in operative workspaces with restricted access. Thus, it could be deemed as a suitable solution for these demanding approaches. This thesis explores the development of novel handheld robotic instruments for endoscopic neurosurgery. Initial work focused on the design of a miniature spherical-joint, robotic end-effector with the aim to expand the surgeon’s operative workspace and enhance their dexterity. To manipulate the end-effector, two concept handle prototypes were developed to cater to a large set of ergonomic literature suggestions. The two novel handles were compared as part of a pre-clinical randomised crossover user-study. This pre-existing work laid the foundation for a robotic system consisting of an ergonomically designed handheld controller, and a series of 3mm detachable end-effectors that was tested in a pre-clinical cadaver study and a multi-surgeon comparison phantom study. Peer-reviewed results on every developmental step suggest that the intended robotic instruments are a promising step towards developing appropriate instruments to drive endoscopic neurosurgery adoption

Handheld robotic device for endoscopic neurosurgery: system integration and pre-clinical evaluation

The Expanded Endoscopic Endonasal Approach, one of the best examples of endoscopic neurosurgery, allows access to the skull base through the natural orifice of the nostril. Current standard instruments lack articulation limiting operative access and surgeon dexterity, and thus, could benefit from robotic articulation. In this study, a handheld robotic system with a series of detachable end-effectors for this approach is presented. This system is comprised of interchangeable articulated 2/3 degrees-of-freedom 3 mm instruments that expand the operative workspace and enhance the surgeon’s dexterity, an ergonomically designed handheld controller with a rotating joystick-body that can be placed at the position most comfortable for the user, and the accompanying control box. The robotic instruments were experimentally evaluated for their workspace, structural integrity, and force-delivery capabilities. The entire system was then tested in a pre-clinical context during a phantom feasibility test, followed up by a cadaveric pilot study by a cohort of surgeons of varied clinical experience. Results from this series of experiments suggested enhanced dexterity and adequate robustness that could be associated with feasibility in a clinical context, as well as improvement over current neurosurgical instruments

Handheld robotic device for endoscopic neurosurgery: system integration and pre-clinical evaluation

The Expanded Endoscopic Endonasal Approach, one of the best examples of endoscopic neurosurgery, allows access to the skull base through the natural orifice of the nostril. Current standard instruments lack articulation limiting operative access and surgeon dexterity, and thus, could benefit from robotic articulation. In this study, a handheld robotic system with a series of detachable end-effectors for this approach is presented. This system is comprised of interchangeable articulated 2/3 degrees-of-freedom 3 mm instruments that expand the operative workspace and enhance the surgeon’s dexterity, an ergonomically designed handheld controller with a rotating joystick-body that can be placed at the position most comfortable for the user, and the accompanying control box. The robotic instruments were experimentally evaluated for their workspace, structural integrity, and force-delivery capabilities. The entire system was then tested in a pre-clinical context during a phantom feasibility test, followed up by a cadaveric pilot study by a cohort of surgeons of varied clinical experience. Results from this series of experiments suggested enhanced dexterity and adequate robustness that could be associated with feasibility in a clinical context, as well as improvement over current neurosurgical instruments

Determination of heavy metals and halogens in plastics from electric and electronic waste

Summarization: The presence of hazardous substances and preparations in small waste electrical and electronic equipment (sWEEE) found in the residual household waste stream of the city of Dresden, Germany has been investigated. The content of sWEEE plastics in heavy metals and halogens is determined using handheld X-ray fluorescence analysis (HXRF), elemental analysis by means of atomic absorption spectrometry (AAS) and ion exchange chromatography (IEC). Mean value of results for heavy metals in samples (n = 51) by AAS are 17.4 mg/kg for Pb, 5.7 mg/kg for Cd, 8.4 mg/kg for Cr. The mass fraction of an additive as shown by HXRF (n = 161) can vary over a wide range. Precise deductions as regards sWEEE plastics content in hazardous substances and preparations cannot be made. Additional research would be expedient regarding the influence of hazardous substances to recycling processes, in particular regarding the contamination of clean fractions in the exit streams of a WEEE treatment plant. Suitable standards for calibrating HXRF for use on EEE plastics or complex electr(on)ic components do not exist and should be developed.Presented on: Waste Managemen

The challenges of planetary mental health in the COVID-19 era

As the focus of the COVID-19 crisis is gradually taken away from emergency healthcare needs, increased attention is warranted on the psychological impact of the pandemic on a global level. Existing guidance on managing the COVID-19 related distress needs to be better informed by upcoming larger-scale research. Applying e-Health can be useful in dealing with the immediate psychological needs, while developing strategies to identify vulnerable populations and shifting the provision of mental health and social care to community services need to be prioritised when looking at the future. Focusing on global mental health during this universal crisis is an opportunity for promoting a more compassionate and less discriminating society