57 research outputs found

    A Monolithic Compliant Continuum Manipulator: a Proof-of-Concept Study

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    Continuum robots have the potential to form an effective interface between the patient and surgeon in minimally invasive procedures. Magnetic actuation has the potential for accurate catheter steering, reducing tissue trauma and decreasing radiation exposure. In this paper, a new design of a monolithic metallic compliant continuum manipulator is presented, with flexures for precise motion. Contactless actuation is achieved using time-varying magnetic fields generated by an array of electromagnetic coils. The motion of the manipulator under magnetic actuation for planar deflection is studied. The mean errors of the theoretical model compared to experiments over three designs are found to be 1.9 mm and 5.1degrees in estimating the in-plane position and orientation of the tip of the manipulator, respectively and 1.2 mm for the whole shape of the manipulator. Maneuverability of the manipulator is demonstrated by steering it along a path of known curvature and also through a gelatin phantom which is visualized in real time using ultrasound imaging, substantiating its application as a steerable surgical manipulator

    Do comorbidities influence help-seeking for cancer alarm symptoms? A population-based survey in England

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    Background: We examined associations between different chronic morbidities and help-seeking for possible cancer symptoms. / Methods: Postal survey of individuals aged>50 years in England. Participants could report prior morbidities in respect of 12 pre-defined conditions. Among patients experiencing possible cancer symptoms we examined associations between specific morbidities and self-reported help-seeking (i.e. contacted versus not contacted a GP) for each alarm symptom using regression analyses. / Results: Among 2042 respondents (42% response rate), 936 (46%) recently experienced one of 14 possible cancer symptoms considered in our analysis. Of them, 80% reported one or more morbidities, most frequently hypertension/hypercholesterolemia (40%), osteomuscular (36%) and heart diseases (21%). After adjustment for socio-demographic characteristics, patients with hypertension/hypercholesterolemia were more likely to report help-seeking for possible cancer symptoms, such as unexplained cough (OR=2.0; 95%CI 1.1-3.5), pain (OR=2.2; 95%CI 1.0-4.5) and abdominal bloating (OR=2.3; 95%CI 1.1-4.8). Urinary morbidity was associated with increased help-seeking for abdominal bloating (OR=5.4; 95%CI 1.2-23.7) or rectal bleeding (OR=5.8; 95%CI 1.4-23.8). In contrast, heart problems reduced help-seeking for change in bowel habits (OR=0.4; 95%CI 0.2-1.0). / Conclusions: Comorbidities are common and may facilitate help-seeking for possible cancer symptoms, but associations vary for specific symptom-comorbidity pairs. The findings can contribute to the design of future cancer symptom awareness campaigns

    Comparison of three radiolabelled peptide analogues for CCK-2 receptor scintigraphy in medullary thyroid carcinoma

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    Purpose: Cholecystokinin 2 (CCK-2) receptor overexpression has been demonstrated in a high percentage of medullary thyroid carcinomas (MTC). Analogous to somatostatin receptors, CCK-2 receptors might be viable targets for radionuclide scintigraphy and/or radionuclide therapy. Several CCK-2 receptor-binding radiopeptides have been developed, and some have been carried through into clinical studies. However, these studies are mostly limited and difficult to compare. The aim of this study was to evaluate the diagnostic and therapeutic potential of three promising CCK-2 receptor-binding radiopeptides in patients with MTC. Methods: 111In-DOTA-(D)Asp-Tyr-Nle-Gly-Trp-Nle- Asp-Phe-NH2 (111In-DOTA-CCK), a CCK analogue, and the gastrin-based ligands 99mTc-N4-Gly-(D)Glu-(Glu) 5-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 (99mTc- demogastrin 2) and 111In-DOTA-(D)Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe- NH2 (111In-DOTA-MG11) were each administered to the same group of six patients. Planar images made at 3-5, 7 and 24 h p.i. were used for comparison of tumour visualisation and renal uptake. Results: 99mTc-demogastrin 2 scintigraphy visualised all known lesions and new lesions in four of six patients. 111In-DOTA-CCK and 111In-DOTA-MG11 on the other hand missed several lesions; tumour uptake of these two radiopharmaceuticals was quite low. Comparison of retention of renal activity showed no major differences between the three radiopeptides. Conclusion: 99mTc-demogastrin 2 scintigraphy appeared most promising as a diagnostic tool in patients with MTC. Further studies are required to evaluate its value in patient management. Direct comparisons of the compounds studied strongly suggests that 111In-DOTA-CCK and 111In-DOTA-MG11 have less potential as imaging agents than 99mTc-demogastrin 2. These DOTA-linked compounds are considered unlikely to be useful for radionuclide therapy because of low tumour uptake

    Bilateral transient osteoporosis of the knee during pregnancy

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    Transient osteoporosis is a rare disease, which can affect pregnant women in the third trimester. Bone marrow edema syndrome, transient bone demineralization, hip algodystrophy, regional migratory osteoporosis, and even reflex sympathetic dystrophy all are terms that have been used to describe the condition. Babinsky and Fromen first documented the symptoms of transient osteoporosis in 1916, and in 1959 Curtiss and Kincaid discussed two cases affecting women in the third trimester of pregnancy. The hip joints are most commonly affected in pregnant women, being reported in 76 % of cases

    Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology

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    Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe

    Big Data, Analytics and Education: Challenges, Opportunities and an Example from a Large University Unit

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    The challenge in educational technology (EdTech) is to apply modern analytics to educational data in order to derive information. Information quality (InfoQ) has been proposed by Kenett and Shmueli as a framework for assessing the quality of information generated by empirical studies by using specific empirical methods such as regression models, analysis of variance or predictive analytics. InfoQ is determined by eight dimensions: 1) Data Resolution, 2) Data Structure, 3) Data Integration 4) Temporal Relevance, 5) Chronology of Data and Goal, 6) Generalizability, 7) Operationalization and 8) Communication. The chapter considers, with an example, opportunities and challenges of analytics in education. Among other topics, it discusses how the InfoQ framework can be applied in order to achieve conceptual understanding and other learning outcomes, and applies the framework to an example concerning academic performance of university students pursuing a Bachelor and Master Degree Programme in Education. The rationale is to provide information regarding the students' performance and their actions on the online learning platform. It investigates how the day of assignment submission affect the grade of the students and we predicted the day of the week for assignment submission, by each student. The results revealed that students received highest grades on Wednesdays and Thursdays and lowest grades on Sunday. It is predicted that when students submit assignments on Sunday, their grades are lower. Days with the highest grades were Thursday, for the first assignment, and Tuesday for the second assignment and final score. The results of the case study provided the unit coordinator with feedback to evaluate and review the unit through the lens of best practices

    Surgical Applications of Compliant Mechanisms - A Review

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    Current surgical devices are mostly rigid and are made of stiff materials, even though their predominant use is on soft and wet tissues. With the emergence of compliant mechanisms (CMs), surgical tools can be designed to be flexible and made using soft materials. CMs offer many advantages like monolithic fabrication, high precision, no wear, no friction and no need for lubrication. It is therefore beneficial to consolidate the developments in this field and point to challenges ahead. With this objective, in this paper, we review the application of CMs to surgical interventions. The scope of the review covers five aspects that are important in the development of surgical devices: (i) conceptual design and synthesis, (ii) analysis, (iii) materials, (iv) manufacturing, and (v) actuation. Furthermore, the surgical applications of CMs are assessed by classification into five major groups, namely, (i) grasping and cutting, (ii) reachability and steerability, (iii) transmission, (iv) sensing, (v) implants and deployable devices. The scope and prospects of surgical devices using CMs are also discussed

    Design, Sensing, and Control of a Magnetic Compliant Continuum Manipulator

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    Continuum manipulators coupled with magnetic actuation have great potential as steerable instruments for diverse surgical applications. They can be maneuvered inside the human body to reach difficult-to-access surgical sites with contactless actuation. This paper presents a new design of a compliant continuum manipulator of diameter 3 mm and length 70 mm, capable of spatial bending under magnetic actuation. A quasi-static model is developed to estimate the 3D motion of the manipulator. Experiments report an overall mean error in whole shape estimation of the manipulator between the model and the ground truth of 1.7 mm and 4.8 mm, when suspended vertically and horizontally from its base, respectively. Furthermore, fiber Bragg grating (FBG) sensors are integrated with the manipulator to enable shape sensing. Closed-loop control is demonstrated to trace different trajectories with the tip of the manipulator. A square trajectory and a straight line trajectory are generated with an average error in tip position of 4.1 mm between the desired and estimated positions. The potential of the manipulator as a steerable instrument is validated by maneuvering it inside phantoms of a bifurcating arterial system and a heart with visual guidance from a miniature camera

    Teaching and Assessing with New Methodological Tools (MERLO): A New Pedagogy?

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    The core element of this paper is an innovative didactical and methodological tool, called MERLO (Meaning Equivalence Reusable Learning Objects) used in formative assessment activities. After a general presentation of the MERLO approach, we will focus on the design process of MERLO items for the teaching and learning of mathematics, especially in secondary schools. The paper presents several methodological choices in the setting up and deployment of the MERLO pedagogy. The data, analysis and results come from the research experience gained at the University of Turin in the context of a master's degree of second level for mathematics teacher educators. This is an ongoing research with a current focus on teachers' professional development, with future perspectives on MERLO implementation in the classroom

    Regional Brain Analysis of Modified Amino Acids and Dipeptides during the Sleep/Wake Cycle

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    Sleep is a state in which important restorative and anabolic processes occur. Understanding changes of these metabolic processes during the circadian rhythm in the brain is crucial to elucidate neurophysiological mechanisms important for sleep function. Investigation of amino acid modifications and dipeptides has recently emerged as a valuable approach in the metabolic profiling of the central nervous system. Nonetheless, very little is known about the effects of sleep on the brain levels of amino acid analogues. In the present study, we examined brain regional sleep-induced alterations selective for modified amino acids and dipeptides using Ultra-high performance liquid chromatography-MS/MS (UHPLC-MS/MS) based metabolomics. Our approach enabled the detection and identification of numerous amino acid-containing metabolites in the cortex, the hippocampus, the midbrain, and the cerebellum. In particular, analogues of the aromatic amino acids phenylalanine, tyrosine and tryptophan were significantly altered during sleep in the investigated brain regions. Cortical levels of medium and long chain N-acyl glycines were higher during sleep. Regional specific changes were also detected, especially related to tyrosine analogues in the hippocampus and the cerebellum. Our findings demonstrate a strong correlation between circadian rhythms and amino acid metabolism specific for different brain regions that provide previously unknown insights in brain metabolism
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