Towards automated visual flexible endoscope navigation

Background:\ud The design of flexible endoscopes has not changed significantly in the past 50 years. A trend is observed towards a wider application of flexible endoscopes with an increasing role in complex intraluminal therapeutic procedures. The nonintuitive and nonergonomical steering mechanism now forms a barrier in the extension of flexible endoscope applications. Automating the navigation of endoscopes could be a solution for this problem. This paper summarizes the current state of the art in image-based navigation algorithms. The objectives are to find the most promising navigation system(s) to date and to indicate fields for further research.\ud Methods:\ud A systematic literature search was performed using three general search terms in two medical–technological literature databases. Papers were included according to the inclusion criteria. A total of 135 papers were analyzed. Ultimately, 26 were included.\ud Results:\ud Navigation often is based on visual information, which means steering the endoscope using the images that the endoscope produces. Two main techniques are described: lumen centralization and visual odometry. Although the research results are promising, no successful, commercially available automated flexible endoscopy system exists to date.\ud Conclusions:\ud Automated systems that employ conventional flexible endoscopes show the most promising prospects in terms of cost and applicability. To produce such a system, the research focus should lie on finding low-cost mechatronics and technologically robust steering algorithms. Additional functionality and increased efficiency can be obtained through software development. The first priority is to find real-time, robust steering algorithms. These algorithms need to handle bubbles, motion blur, and other image artifacts without disrupting the steering process

Data analysis model selection for estimating local population size of the Risso’s dolphin (Grampus griseus) in the Azores

27th Annual Conference of the European Cetacean Society. Setúbal, Portugal, 8-10 April 2013.Different models estimating cetacean population size require making assumptions about the marking and recapturing of individuals, and on the structure of the population. Crucial in selecting the most appropriate model is a critical assessment of these assumptions. In this study we applied the robust parameterization of the open Jolly-Seber (JS) model (POPAN), using the software program MARK. This model was applied to data collected on the Risso’s dolphin (Grampus griseus). Between 2004 – 2007, photo-identification was used as a Capture-Mark-Recapture technique to identify 670 unique individuals off Pico Island, Azores. For this model, it was assessed what assumptions are supported or violated. The aim of this study was improving our understanding of how to select the most appropriate population size model

The self-perceived palliative care barriers and educational needs of clinicians working in hospital primary care teams and referral patterns: lessons learned from a single-center survey and cohort study

Background: Within the generalist-plus-specialist palliative care model, palliative care is mainly provided by nurses and physicians of hospital primary care teams. Palliative care consultation teams (PCCTs) support these clinicians in adequately caring for patients with advanced illnesses. Our team started in 2012. The aim of this study was to assess the self-perceived barriers, educational needs and awareness of available palliative care support options among our hospital primary care teams. In addition, palliative care referral patterns were evaluated.Methods: Single-center mixed methods study. Outcomes of two surveys of primary care team clinicians (2012 and 2016) on barriers to palliative care, educational needs and awareness of palliative care support options were compared ( chi-square, Mann-Whitney U tests, qualitative analysis). Palliative care referral characteristics were evaluated [2012- 2017], including referral timing (survival since referral) (descriptive statistics, Kaplan-Meier methodology). Predictions of survival at referral were analyzed (weighted Kappa).Results: In 2012 and 2016, the most frequently reported barrier was the late initiation of the palliative care approach. Clinicians reported a need for education on physical symptom management and basic palliative care principles. Awareness of support options increased from 2012 to 2016, including improved familiarity with the PCCT (56% vs. 85%, P= 3 months after referral) (P=0.016). Median survival after referral was 0.9 (range, 0-83.3) months. Referring physicians overestimated survival in 44% of patients (kappa 0.36, 95% CI: 0.30-0.42).Conclusions: Primary care team clinicians persistently reported needing support with basic palliative care skills. PCCTs should continuously focus on educating primary care teams and promoting the use of guidelines. Because physicians tend to overestimate survival and usually referred patients late for specialist palliative care, consultation teams should support primary care teams to identify, treat and refer patients with palliative care needs in a timely manner.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Impact of ongoing centralization of acute stroke care from "drip and ship" into "direct-to-mothership" model in a Dutch urban area

When acute stroke care is organised using a "drip-and-ship" model, patients receive immediate treatment at the nearest primary stroke centre followed by transfer to a comprehensive stroke centre (CSC). When stroke care is further centralised into the "direct-to-mothership" model, patients with stroke symptoms are immediately brought to a CSC to further reduce treatment times and enhance stroke outcomes. We investigated the effects of the ongoing centralization in a Dutch urban setting on treatment times of patients with confirmed ischemic stroke in a 4-year period. Next, in a non-randomized controlled trial, we assessed treatment times of patients with suspected ischemic stroke, and treatment times of patients with neurologic disorders other than suspected ischemic stroke, before and after the intervention in the CSC and the decentralized hospitals, the intervention being the change from "drip and ship" into "direct-to-mothership". Our findings provide support for the ongoing centralization of acute stroke care in urban areas. Treatment times for patients with ischemic stroke decreased significantly, potentially improving functional outcomes. Improvements in treatment times for patients with suspected ischemic stroke were achieved without negative side effects for self-referrals with stroke symptoms and patients with other neurological disorders. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )Paroxysmal Cerebral Disorder

Stable X chromosome reactivation in female human induced pluripotent stem cells

In placental mammals, balanced expression of X-linked genes is accomplished by X chromosome inactivation (XCI) in female cells. In humans, random XCI is initiated early during embryonic development. To investigate whether reprogramming of female human fibroblasts into induced pluripotent stem cells (iPSCs) leads to reactivation of the inactive X chromosome (Xi), we have generated iPSC lines from fibroblasts heterozygous for large X-chromosomal deletions. These fibroblasts show completely skewed XCI of the mutated X chromosome, enabling monitoring of X chromosome reactivation (XCR) and XCI using allele-specific single-cell expression analysis. This approach revealed that XCR is robust under standard culture conditions, but does not prevent reinitiation of XCI, resulting in a mixed population of cells with either two active X chromosomes (Xas) or one Xa and one Xi. This mixed population of XaXa and XaXi cells is stabilized in naive human stem cell medium, allowing expansion of clones with two Xas

Connectivity of larval stages of sedentary marine communities between hard substrates and offshore structures in the North Sea

Man-made structures including rigs, pipelines, cables, renewable energy devices, and ship wrecks, offer hard substrate in the largely soft-sediment environment of the North Sea. These structures become colonised by sedentary organisms and non-migratory reef fish, and form local ecosystems that attract larger predators including seals, birds, and fish. It is possible that these structures form a system of interconnected reef environments through the planktonic dispersal of the pelagic stages of organisms by ocean currents. Changes to the overall arrangement of hard substrate areas through removal or addition of individual man-made structures will affect the interconnectivity and could impact on the ecosystem. Here, we assessed the connectivity of sectors with oil and gas structures, wind farms, wrecks, and natural hard substrate, using a model that simulates the drift of planktonic stages of seven organisms with sedentary adult stages associated with hard substrate, applied to the period 2001–2010. Connectivity was assessed using a classification system designed to address the function of sectors in the network. Results showed a relatively stable overall spatial distribution of sector function but with distinct variations between species and years. The results are discussed in the context of decommissioning of oil and gas infrastructure in the North Sea

Challenges in navigational strategies for flexible endoscopy

Automating flexible endoscope navigation could lead to an increase in patient safety for endoluminal therapeutic procedures. Additionally, it may decrease the costs of diagnostic flexible endoscope procedures by shortening the learning curve and increasing the efficiency of insertion. Earlier attempts at automating the navigation have, to our knowledge, not succeeded yet. We think this is mainly due to false premises about the dynamic interaction between the endoscope and the environment. In the current research, we show that an alternative approach can be used to establish camera motion with respect to the environment. Combining the knowledge of the traveled path with the knowledge of the target location shows potential of solving the navigational problems in automating flexible endoscopy

Feasibility of automated target centralization in colonoscopy

Purpose:\ud Early detection of colorectal cancer is key to full recovery. This urged governments to start population screening programs for colorectal cancer, often using flexible endoscopes. Flexible endoscopy is difficult to learn and time-consuming. Automation of flexible endoscopes may increase the capacity for the screening programs. The goal of this pilot study is to investigate the clinical and technical feasibility of an assisting automated navigation algorithm for a colonoscopy procedure.\ud \ud Methods:\ud Automated navigation (lumen centralization) was implemented in a robotized system designed for conventional flexible endoscopes. Ten novice and eight expert users were asked to perform a diagnostic colonoscopy on a colon model twice: once using the conventional and once using the robotic system. Feasibility was evaluated using time and location data as measures of the system’s added value.\ud \ud Results:\ud Automated target centralization (ATC) was turned on by the novices for a median of 4.2 % of the time during insertion and 0.3 % during retraction. Experts turned ATC on for 4.0 % of the time during insertion and 11.6 % during retraction. Novices and experts showed comparable times to reach the cecum with the conventional or the robotic setup with ATC.\ud \ud Conclusion:\ud The ATC algorithm combined with the robotized endoscope setup works in an experimental setup that closely resembles the clinical environment and is considered feasible, although ATC use was lower than expected. For novices, it was unclear whether the low usage was due to unfamiliarity with the system or because they did not need ATC. Experts used ATC also during the retraction phase of the procedure. This was an unexpected finding and may indicate an added value of the system