Automatic Construction of Immobilisation Masks for use in Radiotherapy Treatment of Head-and-Neck Cancer

Current clinical practice for immobilisation for patients undergoing brain or head and neck radiotherapy is normally achieved using Perspex or thermoplastic shells that are moulded to patient anatomy during a visit to the mould room. The shells are “made to measure” and the methods currently employed to make them require patients to visit the mould room. The mould room visit can be depressing and some patients find this process particularly unpleasant. In some cases, as treatment progresses, the tumour may shrink and therefore there may be a need for a further mould room visits. With modern manufacturing and rapid prototyping comes the possibility of determining the shape of the shells from the CT-scan of the patient directly, alleviating the need for making physical moulds from the patients’ head. However, extracting such a surface model remains a challenge and is the focus of this thesis. The aim of the work in this thesis is to develop an automatic pipeline capable of creating physical models of immobilisation shells directly from CT scans. The work includes an investigation of a number of image segmentation techniques to segment the skin/air interface from CT images. To enable the developed pipeline to be quantitatively evaluated we compared the 3D model generated from the CT data to ground truth obtained by 3D laser scans of masks produced by the mould room in the frame of a clinical trial. This involved automatically removing image artefacts due to fixations from CT imagery, automatic alignment (registration) between two meshes, measuring the degree of similarity between two 3D volumes, and automatic approach to evaluate the accuracy of segmentation. This thesis has raised and addressed many challenges within this pipeline. We have examined and evaluated each stage of the pipeline separately. The outcomes of the pipeline as a whole are currently being evaluated by a clinical trial (IRAS ID:209119, REC Ref.:16/YH/0485). Early results from the trial indicate that the approach is viable

A data-driven method to reduce excessive contact pressure of hand orthosis using a soft sensor skin

Discomfort under customised hand orthosis has been commonly reported in clinics due to excessive contact pressures, leading to low patient adherence and decreased effectiveness of orthosis. However, the current orthosis adjustment by clinicians to reduce pressures based upon subjective feedback from patients is inefficient and prone to variability. Therefore, a quantitative method to guide orthosis adjustment was proposed here by developing a data-driven method. Firstly, Verbal Protocol Analysis was employed to convert the implicit process of orthosis customisation into working models of clinicians. Relevant data to inform a new solution development to reduce excessive contact pressure were extracted from the working models in terms of time consumption and iterations of tasks. Secondly, a new soft sensor skin with strategically placed sensing units to measure static contact pressures under hand orthoses was developed. Finite element simulations were conducted to reveal the required contact pressure range (0.02 – 0.078 MPa) and the distribution of relatively high pressures in 12 key areas. A new fabrication method was proposed to produce the sensor skin, which was then characterised and tested on the subject. The results show that the sensor unit has a pressure range from 0.01 MPa to 0.1 MPa with the maximum repeatability error of 6.4% at 0.014 MPa, and the maximum measurement error of 8.26% at 0.023 MPa. Thirdly, a new method was proposed to predict contact pressures associated with the moderate level of discomfort at critical spots under hand orthoses. 40 patients were recruited to collect contact pressures under two types of orthoses using the sensor skin, and their discomfort perceptions were measured with a categorical scale. Based on these data, artificial neural networks for five identified critical spots on the hand were built to predict pressure thresholds that clinicians can use to adjust orthoses, thus reducing excessive contact pressures. The neural networks show satisfactory prediction accuracy with R2 values over 0.89 of regression between network outputs and measurements. Collectively, this thesis proposed a novel method for clinicians to adjust orthoses quantitatively and reduce the need for subjective assessment for patients. It provided a platform to further investigate the pressure for patients with other conditions.Open Acces

Anuário científico da Escola Superior de Tecnologia da Saúde de Lisboa - 2019

A 9.ª edição do Anuário da Escola Superior de Tecnologia da Saúde de Lisboa é uma publicação organizada que reafirma o seu compromisso com a divulgação do trabalho científico desenvolvido pelos Professores, Investigadores e Pessoal não Docente. Neste documento encontram-se sintetizados os vários tipos de publicações desenvolvidos no ano 2019, na ESTeSL, nomeadamente, livros, capítulos de livros, artigos publicados em revistas nacionais e internacionais, resumos de comunicações orais e pósteres apresentados em eventos científicos e, ainda, os resultados dos trabalhos de mestrado e de investigação no âmbito da licenciatura, defendidos pelos estudantes da ESTeSL durante o ano em questão. No que respeita à análise do Anuário 2019, comparativamente ao Anuário de 2018, verifica-se uma ligeira diminuição do número de publicações sob a forma de artigos científicos e comunicações; no entanto, comprova-se um aumento do número de artigos indexados nas bases de dados Scopus, Web of Science e MEDLINE/PubMed. A mesma tendência se verifica no que diz respeito ao número de citações de artigos indexados, o que revela, de certa forma, uma crescente aceitação pela comunidade científica e um aumento da relevância dos artigos publicados com afiliação ESTeSL-IPL.info:eu-repo/semantics/publishedVersio

Evaluation of the region-specific risks of accidental radioactive releases from the European Spallation Source

The European Spallation Source (ESS) is a neutron research facility under construction in southern Sweden. The facility will produce a wide range ofradionuclides that could be released into the environment. Some radionuclides are of particular concern such as the rare earth gadolinium-148. In this article, the local environment was investigated in terms of food production and rare earth element concentration in soil. The collected data will later be used to model thetransfer of radioactive contaminations from the ESS

In vivo measurement and objective classification of healthy, injured and pathological shoulder complex function

ysis (MA) techniques have been previously developed at Cardiff University to assess shoulder function following International Society of Biomechanics (ISB) recommendations. However, errors in the system significantly affect shoulder kinematics measurements. Image registration techniques (IRT) were developed to accurately measure GH joint kinematics using dynamic single-plane fluoroscopy. 3D computer bone models of the humerus and scapula were generated from magnetic resonance imaging (MRI) scans using Simpleware Software (Simpleware Ltd). Accurate 3D to two dimensional ( 2D) image registration was performed using Joint- Track software (Banks, S.A.). Full kinematics descriptions of the GH joint and of the scapula were obtained. The pattern of rotation agrees with what other researchers have previously measured. Humeral head translation was measured towards the glenoid centre (3�0.9mm medially, 2.7�0.9mm inferiorly and then superiorly and 6.7�2mm posteriorly) during abduction and (2.8�0.9mm medially, 3.6�0.9mm superiorly and then inferiorly and 5.3�2.1mm anteriorly) during scaption. The centering of the humeral head is believed to provide joint congruency for optimal shoulder function. To investigate the errors commonly associated with MA, a comparison between the kinematics outputs from the MA measuring system and IRT was performed. Greater GH joint elevation was recorded with IRT (54.8� and 82.6� for abduction and scaption respectively) compared to MA (51.1� and 75.2� for abduction and scaption respectively). Furthermore, differences between IRT and MA recordings in GH joint plane of elevation (6.7� and 1.9� abduction and scaption respectively) and axial rotation (24.1� and 23.0� abduction and scaption respectively) were measured. Discrepancies in measured rotations between MA and IRT can be attributed to factors related to differences in the analytical approach as well as the errors commonly associated with the techniques. Additions and improvements to the original Cardiff MA protocol for measuring and analysing shoulder biomechanics were made and healthy and shoulder patient function was subsequently investigated. The glenohumeral (GH) joint centre of rotation (CoR) estimation by means of the instantaneous helical axis (IHA) method was included in the Cardiff model using International Shoulder Group (ISG) routines. With the original protocol, only regression equations (MRE) based on scapula geometry were used to estimate GH joint CoR. Differences between IHA and MRE were investigated by comparing the estimated CoR positions relative to the scapula anatomical coordinate system (ACS). The MRE significantly overestimated the GH joint CoR in the anterior position (by 4 cm) compared to the IHA method and to the work of other research groups. The iii MRE also estimated the GH joint CoR laterally to the scapula ACS although imaging studies identified GH joint CoR medially to the scapula ACS. Trunk contribution to overall arm elevation was assessed between unilateral (UE) and bilateral (BE) arm elevations. BE was found to significantly decrease trunk lateral and axial rotation with respect to UE; however, trunk flexion was significantly greater. This in turn resulted in significantly different scapula rotations between UE and BE with up to 3� difference in scapula retraction during abduction between UE and BE. Consequently in shoulder complex biomechanics studies, particular attention should be made to minimise trunk rotations. Shoulder function asymmetry was investigated between dominant and nondominant shoulders. Significantly greater GH elevation and scapula lateral rotation were measured in dominant arms compared to non-dominant arms, with a difference of up to 7.6� and 7.0� respectively between the two arms. Asymmetry between the two shoulders could be attributed to soft tissue imbalance from more frequent use of the dominant shoulder compared to the non-dominant. Physiological range of motion (during static and dynamic trials) and 15 activities of daily living (ADLs) were recorded with skin markers attached to bony landmarks as well as with the AMC (and the SL for physiological ROMs). Static and dynamic trials measured differences in thorax and scapula rotations which may have arisen from muscle stabilisation. Acromioclavicular (AC) and scapula lateral rotations were underestimated (by up to 8� and 20� respectively) using the skin fixed markers. Joint and segment rotations are comparable to published studies that follow ISB recommendations The kinematics of patients with four different shoulder conditions (clavicle fracture, multidirectional instability, irreparable rotator cuff tear and GH dislocation) was measured. The effect and the extent of the IoP was investigated during physiological ROMs elevation and ADLs recordings by comparing their function to healthy and contralateral shoulders. The results from this study were used to develop a novel application for the Cardiff Dempster Shafer (DS) objective classifier. The classification tool was used to characterise shoulder complex function of 40 participants. Non injured or pathological (NIoP) and IoP shoulder function was characterised with 72.5% accuracy. Eight patients were misclassified as having NIoP shoulder function while two healthy participants were misclassified as having IoP function. A weak correlation between scoring questionnaires with the NIoP and IoP classification indices was found (-0.16298 and 0.180187 respectively). This might be explained by the subjective nature of the scores. The studies described in this thesis contributed towards advancements in shoulder complex kinematics studies at Cardiff University as well as with the international shoulder researcher’s community. An appreciation was gained of the challenges faced when using MA and IRT to measure shoulder motion as well as a better understanding of joint function in healthy and IoP shoulders

Évaluation biomécanique de la marche pour le développement d’orthèses plantaires imprimées en 3D : application à une population ayant les pieds plats

Le pied plat flexible affecte 20-25% de la population adulte. Il est caractérisé par un affaissement anormal de l’arche longitudinale médiale en charge ainsi qu’une pronation excessive du pied. Les orthèses plantaires (OPs) représentent la prise en charge conservatrice la plus fréquemment utilisée au regard de cette pathologie. Toutefois, il existe un manque de consensus quant à leur effet bénéfique, notamment à cause de la variété d’OPs (géométrie et matériaux) utilisée. Ces dernières années, le développement des techniques d’impression 3D a permis d’innover et de faciliter la production d’OPs sur-mesure. Les réalisations actuelles ne se sont cependant limitées qu’à des formes monolithiques reposant sur la forme du pied. L’objectif de cette thèse est d'approfondir les connaissances relatives à l’impact des OPs sur la biomécanique du pied plat, afin d’aider au développement et à l’évaluation d’une OP originale imprimée en 3D. À cet égard, trois objectifs spécifiques ont été définis : (1) investiguer l’effet de la forme géométrique des orthèses plantaires chez des personnes ayant des pieds plats flexibles ; (2) quantifier l’effet de la rigidité d’OPs imprimées en 3D et celle de l’addition d’éléments anti-pronateurs novateurs sur la cinématique du pied ainsi que les pressions plantaires ; (3) évaluer l’impact d’OPs sur-mesure imprimées en 3D sur la biomécanique des membres inférieurs chez des personnes ayant des pieds plats. Par la réalisation d’une revue systématique avec méta-analyse, l’effet de la forme géométrique des OPs sur la cinématique et la cinétique du membre inférieur lors de la marche chez des personnes ayant les pieds plats a pu être déterminé. Seules les études ayant clairement décrit les modifications géométriques des OPs utilisées ont été incluses. Elles ont ensuite été divisées en cinq groupes en fonction de leur forme géométrique : avec stabilisateur d’arrière-pied médial, avec stabilisateur d’avant-pied médial, avec combinaison d’un stabilisateur d’arrière-pied et d’avant-pied médial, avec stabilisateur neutre, et avec support d’arche. La revue a ainsi mis en évidence que l’utilisation de stabilisateur médiaux était la modification géométrique la plus efficace pour réduire l’éversion de l’arrière-pied et ainsi contrôler la pronation excessive. Cependant, l'hétérogénéité dans les protocoles expérimentaux contribue à la faible évidence au regard des effets des OPs sur la biomécanique de la marche chez des personnes ayant les pieds plats. Sur la base des observations tirées de notre revue de la littérature, des stabilisateurs d’arrière-pied innovants (neutre avec extension sous l’arche) ont été développés pour être utilisés avec une OP originale imprimée en 3D. Par conséquent, l’objectif de notre deuxième étude était de quantifier l’effet de ces stabilisateurs mais aussi de déterminer l’impact de la rigidité de notre OP sur la cinématique du pied et les pressions plantaires. Pour se faire, 15 hommes en bonne santé et ayant les pieds neutres (pointure 9.5-10 US) ont été recrutés afin de s’affranchir de l’interaction possible avec une pathologie. Ainsi, il a été mis en évidence qu’une augmentation de la rigidité était associée à une réduction plus importante de l’éversion à l’arrière-pied (Différence Moyenne (DM) = -0.83°). Cette dernière a d’autant plus été réduite par l’ajout de stabilisateurs (DM = -1.15° et -2.43°). Au niveau des pressions plantaires, outre le transfert de la charge vers le médio-pied induit par le port des OPs, l’augmentation de la rigidité a contribué à accentuer les pics de pression sous l’arche et l’arrière-pied (DM de +21.6% à +31.7%). Enfin, notre troisième étude avait pour but d’évaluer l’impact d’OPs personnalisées et imprimées en 3D sur la biomécanique des membres inférieurs chez des personnes ayant des pieds plats. Pour ce faire, 19 patients recrutés par l’intermédiaire de podiatres ont reçu deux paires d’OPs sur-mesure, respectivement flexible et rigide, et ont participé à une évaluation biomécanique (cinématique, cinétique, pressions plantaires). L’augmentation de la rigidité n’a eu que peu d’effets sur la cinématique et les efforts articulaires. Elle a cependant été associée à une augmentation des pressions sous l’arche (DM = +34.4% pour la pression moyenne). L’effet de notre stabilisateur a également été quantifié. Il a été associé à une réduction significative de l'éversion à l’arrière-pied (DM = -2.0°), une réduction du moment interne d'inversion à cheville (DM = -0.03 Nm/kg), et à une légère augmentation du moment interne d’abduction au genou (DM ≈ +0.04 Nm/kg). Dans l’ensemble, le présent travail de thèse a permis de mieux saisir les mécanismes d’action des OPs sur la biomécanique des personnes ayant les pieds plats, de guider le développement d’une OP imprimée en 3D et de stabilisateurs d’arrière-pied innovants, et de confirmer que l’ajout d’éléments anti-pronateurs est essentiel afin d’observer un impact bénéfique des OPs sur le contrôle de la pronation excessive.Flatfoot has been reported to affect around 20–25% of the adult population. It is defined by an abnormally low medial longitudinal arch upon weight bearing and an excessive foot pronation. Foot orthoses (FOs) have commonly been used as a conservative treatment to manage this deformity. However, due to the variety of FOs (geometrical designs and materials) that have been used, there is still low evidence of their beneficial effect. In recent years, the advent of 3D printing techniques has facilitated the production of innovative and customized FOs. Yet, current achievements are limited to monolithic form based on the foot shape. The objective of this thesis was to deepen the knowledge relative to FOs’ impact on flatfoot biomechanics, in order to help the development and the assessment of an original 3D printed FO. Three specific objectives were defined for this purpose: (1) investigate the effect of FOs, based on their geometrical design, in individuals with flexible flatfeet; (2) asses the effect of 3D printed FOs stiffness and newly designed anti-pronator components on foot kinematics and plantar pressures; and (3) evaluate the impact of custom 3D printed FOs on lower extremity biomechanics in individuals with flatfeet. Though a systematic and meta-analysis review, the effects FOs geometrical design on lower limb kinematics and kinetics during walking in people with flatfeet has been determined. Only studies that clearly described FOs geometrical design were included. They were then categorized into five groups based on the geometrical design of FOs: with medial rearfoot posting, with medial forefoot posting, with a combination of forefoot and rearfoot posting, with neutral rearfoot posting, and with arch support. The review highlighted that medial postings are the most effective FO feature to reduce the rearfoot eversion and therefore control excessive foot pronation. However, heterogeneity between study protocols contributes to low evidence of beneficial effects of FOs on flatfeet biomechanics during walking. Based on our literature review, innovative rearfoot postings (neutral with an extension under the medial arch) have been developed for an original 3D printed FO. Hence, our second study aimed to determine the effect of these postings as well as the stiffness of our FO on foot kinematics and plantar pressures. To do so, a study involving 15 healthy men with neutral feet (shoe size 9.5-10 US) was carried out. Healthy people were recruited to avoid any interaction with a pathology. The study showed that increasing FOs stiffness was associated to a greater reduction in rearfoot eversion (Mean Difference (MD) = -0.83°). Rearfoot eversion was further decreased when adding the rearfoot postings (MD = -1.15° and -2.43°). Looking at plantar pressures, besides a shift of the loads to the midfoot region while wearing FOs, higher peak pressures under the rearfoot and the medial arch (MD from +21.6% to +31.7%) were observed when increasing the FOs stiffness. Finally, the third study aimed at evaluating the impact of custom 3D printed FOs on lower extremity biomechanics in individuals with flatfeet. Nineteen patients, recruited by experienced podiatrists, were given two pairs of custom 3D printed FOs and participated in a biomechanical analysis (kinematics, kinetics, plantar pressures). Increasing FOs stiffness had little effects on kinematics and joint moments. However, it resulted in higher plantar pressures under the arch (MD = +34.4% for mean pressures). The addition of our rearfoot posting was associated with notable effects; it significantly reduced the eversion angle (MD = -2.0°) and inversion moment at the ankle (DM = -0.03 Nm/kg), and increased slightly the knee abduction moment (MD ≈ +0.04 Nm/kg). Overall, the present thesis has provided a better understanding on how FOs impact the biomechanics of individuals with flatfeet, helped the development of a 3D printed FO as well as innovative rearfoot postings, and confirmed that anti-pronator components are essential to observe a beneficial impact of FOs on the control of excessive foot pronation

Time for a Nappy Change: controls affecting families’ nappy choices

Lifecycle assessments suggest that modern cloth nappies have fewer environmental impacts than their disposablecounterparts in terms of GHG, plastic and landfill (UNEP 2021). However, despite these apparent environmentalbenefits consumers still use predominantly disposable nappies. This paper will use theories of plannedbehaviour to explore the differences in perceived and actual behaviours between disposable and cloth nappyusers. A self-selecting web-based survey was used to recruit participants with children up to the age of fiveand explore their decision-making in this regard. The findings of the survey reveal that disposable nappy usersare more likely to prioritise convenience and to cite additional laundry loads as the main reasons for not usingcloth nappies. This is despite tending to have the necessary infrastructure (such as disposable income, spaceand washing facilities) to enable them to do so. This indicates that the perceptions of home-laundered clothnappies as inconvenient makes families more likely to opt for disposable nappies. Whilst cloth nappies weregenerally assumed to be more environmentally friendly and aesthetically pleasing by all parents irrespectiveof their choices, this was not enough to overcome the convenience and ease of use for the majority of participants.This study concludes that many disposable nappy users select disposable nappies with the assumptionthat they are easier and more convenient when this may not be the case. The implication of this study is thatinterventions which improve the convenience of cloth nappies and the perception of ease of use will encouragegreater uptake of cloth nappies.References.UNEP. (2021) Recommendations from Life Cycle Assessments Single-use nappies and their alternatives hostedby. United Nations Environment Programme