Twin to twin transfusion syndrome is a rare complication that can develop in monochorionic twin pregnancies where abnormal placental connections lead to hemodynamic imbalance between the two fetuses. The twin receiving the surplus of blood experiences polyhydramnios whereas the twin donating their blood experiences oligohydramnios. Diagnosis of this syndrome is done based off of the Quintero Staging scale, which consists of five categories of criteria ranging from non-critical diagnoses to diagnoses involving demise of one or two fetuses. The gold standard for treatment involves ablating abnormal vessel connections via a laser therapy. This therapy has shown to reduced short term and long term complications within the twins, and be most efficient at ceasing the disproportionate blood supply between the fetuses. Long term outcomes of twin to twin transfusion syndrome mainly involve neurodevelopmental impairment, but cardiovascular and renal complications can also be present. Adverse neurodevelopmental outcomes should be the ones to most closely monitor postnatally in all TTTS survivors. For recipient twin survivors, cardiovascular outcomes should be most closely watched via blood pressure monitoring and routine echocardiograms. For donor twin survivors, creatinine levels should be routinely checked in order to detect signs of chronic kidney disease in early childhood. Long term outcomes of twin to twin transfusion syndrome still need further investigating due to the difficulty of gathering information postnatally. Limitations that further increase the complexity of this research include lack of education and decreased opportunities for underserved communities to access the advanced medical care required to treat and monitor this disease. Shedding light on this disparity can lead mothers to be more aware of the signs and symptoms of this disease, leading to early detection and more positive outcomes.

Twin-to-twin transfusion syndrome (TTTS) is a complication of blood flow among fetuses sharing a single placenta. TTTS is associated with high mortality rates; however there is treatment available which significantly increases the rate of survival. The treatment procedure is although far from perfect. Limited by a narrow field of view, it is a challenging task for the surgeon to mentally visualize the vascular structures of the placenta while trying to navigate across the areas of interest. Previous research within both medical imaging and tracking technologies has been conducted but there is no perfect solution on how to solve these issues. This paper is part of a two-part project attempting to provide an application which can make the surgical procedure easier. The two parts are image stitching and real-time tracking, this paper focusing on the latter. This is done by choosing an appropriate tracking method which can provide location and orientation of a small sensor. The 3D data gathered from the sensor is processed by various transformations so that the bounding box of the camera movement can be mapped directly onto the image generated by the stitching process. The same transformations are applied to data collected from the sensor at a rate of 60 Hz, resulting in a responsive system. By comparing the x-value and y-value of a calculated point to the bounding box, this point can be converted to its corresponding pixel in the image. The system is responsive and by visually comparing the digital position in the image to its corresponding real world position it seems accurate enough, even though a few pixels misalignment will occur. / Tvillingstransfusionssyndrom (TTTS) är en komplikation av blodflöde som kan uppstå hos foster som delar placenta. TTTS associeras medhöga dödstal, emellertid finns det behandlingar som signifikant ökar chanserna för fostrens överlevnad. Behandlingsprocessen är docklångt ifrån perfekt. Begränsad av ett smalt synfält är det en utmanande uppgift för kirurgen att mentalt föreställa sig placentansvaskulärsystem samtidigt som denne försöker att navigera mellan alla intresseområden. Forskning inom både bildbehandling ochspårningsteknologier är inget främmande men det finns ännu ingen självklar lösning på dessa problem. Den här rapporten är en del av etttvåstegsprojekt vars mål är att framställa en applikation som kan underlätta behandlingen. De två delarna är image stitching ochrealtidsspårning, där den här rapporten fokuserar på det sistnämnda. Detta görs genom att välja en lämplig spårningsmetod som kan mätabåde position samt orientering av en sensor. 3D-datan från sensorn behandlas av olika matematiska transformationer så att denomskrivande rektangeln av kamerans rörelser kan placeras på bilden erhållen från stitchingprocessen. På samma sätt behandlas deninformation som hämtas från sensorn i realtid med en frekvens på 60 Hz, vilket resulterar i ett snabbreagerande system. Genom att jämförax-värde och y-värde från en beräknad punkt med den omskrivande rektangeln, kan den här punkten översättas till sin motsvarande pixel ibilden. Systemet reagerar snabbt på indata och genom att visuellt jämföra den digitala positionen i bilden mot den motsvarande positionen iden riktiga världen ger systemet ett tillfredställande resultat, även om punkten kommer att ha ett par pixlars felmarginal.

This is a study exploring how robust one feature descriptors, scale invariant feature transform (SIFT), and one feature detector, feature accelerated segmentation test (FAST), are in terms of handling fetoscopic acquired data when mosaicing. Today’s treatment of severe Twin-to-Twin Transfusion Syndrome at Karolinska University Hospital is fetoscopic guided laser occlusion of chorioangiopagous vessels (FLOC) where intersecting blood vessels causing a transfusion (Anastomoses) in between the fetuses are occluded. These blood vessels are located somewhere on the placenta. The fetoscopy includes navigation of a relatively large area where the field of view (FOV) is limited. The limited FOV during the fetoscopy makes it cumbersome to navigate and identify intersected blood vessels. The motivation of this study is to explore ways of dealing with the complications during FLOC by mosaicing an overview of the placenta that can be used as an assisting map to make the procedure safer by improving navigation of the fetoscope and identification of blood vessels during FLOC. In this study, the steps of mosaicing are defined based on mosaicing frameworks to explore how these methods perform in terms of being able to mosaic a map of the placenta. The methods have been tested on non-fetoscopic acquired data as well as fetoscopic acquired data to create a relative measure in between the two. Three tests on non- fetoscopic data were performed to explore how well the methods handled mosaicing of data with distinctive characteristics. The same methods were then tested on unprocessed fetoscopic data before being tested on preprocessed fetoscopic data to see if the results were affected by external preprocessing. The results showed that there were differences in between the methods. SIFT and FAST showed that they have potential of mosaicing non-fetoscopic data of varying extent. SIFT gave an impression of being more robust during all of the tests. SIFT especially performed better during the tests on data with few potential keypoints which is an advantage when speaking of fetoscopic acquired data. SIFT also managed to mosaic a larger area than FAST when mosaicing preprocessed fetoscopic data. Preprocessing the data improved the mosaicing when using SIFT but further improvements are needed. / Denna studie utforskar hur robust en intressepunktsbeskrivare, scale invariant feature transform (SIFT), och enintressepunktsdetektor, feature accelerated segmentation test (FAST), hanterar digitala bilder insamlade av ett fetoskop med syfte att sy ihop dessa till en översiktskarta. Dagens behandling av tvillingtransfusionsyndrom vid Karolinska Universitetssjukhuset är fetoscopic guided laser occlusion of chorioangiopagous vessels (FLOC). Under denna fetoskopi bränner man och därmed blockerar korsande blodkärl som orsakar en transfusion (anastomoses) och obalans i blodomloppet mellan två tvillingfoster. Dessa blodkärl är lokaliserade på placentan. Fetoskopin omfattar navigering av en relativt stor area med ett begränsat synfält. Det begränsade synfältet under FLOC gör det svårt att orientera fetoskopet och identifiera korsande blodkärl som orsakar transfusionen. Syftet med studien är att utforska ett sätt att hantera komplikationerna med FLOC igenom att utforska sätt att skapa en översiktskarta av placentan under FLOC. Denna översiktskarta kan nyttjas under FLOC och därmed göra proceduren säkrare igenom att kartan underlättar orienteringen av fetoskopet och identifiering av orsakande blodkärl. I denna studie är stegen för att skapa en översiktskarta baserade på olika datorseende ramverk för att se hur dessa tillvägagångssätt presterar när det gäller att skapa en översiktskarta. Metoderna för att skapa en översiktskarta har testats på data insamlad med webkamera och data insamlad med fetoskop för att skapa en relativ uppfattning om hur de står sig beroende på indata. Tre tester på data insamlad med webkamera genomfördes för att utforska hur väl metoderna hanterade data med många potentiella intressepunkter, rörelse orsakad av handhållen enhet/kamera, repetitiva mönster, översiktskartor som resulterande i större upplösning, och liten möjlighet att hitta intressepunkter. Samma metoder testades sedan på icke behandlad data insamlad med fetoskop innan den testades på förbehandlad data insamlad med fetoskop för att se förbehandlingensnödvändighet och prestation. Resultaten visar att det är skillnader mellan de två metoderna använda i denna studie, både när det gäller data insamlad med fetoskop och webkamera. SIFT och FAST visar potential av olika grad när det gäller att skapa en översiktskarta med data insamlad av webkamera. SIFT visade sig vara mer robust under alla tester inklusive data insamlad med fetoskop. SIFT presterade speciellt bättre under testen som omfattade få antal möjliga intressepunkter vilket är en fördel när det gäller data insamlad med fetoskop. SIFT lyckades också skapa översiktskartor med större area än FAST när förbehandlad fetoskopisk data testades. När det gäller SIFT så visade resultaten en förbättring när data insamlad med fetoskop förbehandlades men att ytterligare förbättringar är nödvändiga.

L’objectif principal de cette recherche est de comprendre la place de la vie intra utérine dans le cas de la gémellité compliquée d’un syndrome transfuseur-transfusé (STT). Le second objectif concerne la singularité du deuil périnatal d’un jumeau et son devenir pour les parents et pour le jumeau vivant. Une méthodologie a été construite afin de mettre en perspective le vécu de la grossesse à travers le discours des parents (entretien semi-directif de recherche) et le développement psychique de l’enfant à 6 ans, à travers le bilan psychologique (WISC IV, dessin du bonhomme, dessin de la famille et CAT). Le recueil des données s’est fait à partir de 60 familles. Au sein de cette population, une analyse singulière a été faite à partir du matériel recueilli pour 10 enfants du groupe jumeaux et 10 enfants du groupe singletons. Une analyse transversale a été effectuée pour chacun des groupes et pour la totalité de la population. Mes résultats montrent que l’on retrouve chez l’enfant des traces agissantes d’inscriptions traumatiques pré-psychiques. Au WISC IV, les résultats indiquent que 73% des enfants ont un QI total dans la moyenne. Il existe un état de sidération des processus de pensée et un faible investissement dans les apprentissages. Au CAT, on observe des défenses narcissiques liées à une difficulté de l’élaboration de la position dépressive ainsi qu’une inhibition importante. La confusion et l’indifférenciation des espaces psychiques sont présentes. Dans le dessin de la famille et le CAT, les processus d’identifications se retrouvent d’un jumeau vers l’autre-jumeau, aboutissant à des limites du moi aux contours mal définis. Les identifications aux imagos parentales apparaissent comme secondaires. Cette recherche a montré que la présence du STT contient une potentialité traumatique dans les chaines générationnelles parents/enfants qui s’organise en trois temps. La relation d’objet gémellaire a été décrite comme « le nid prénatal » des relations objectales ultérieures, formées par le trio et le quartet. Ce type de relation inaugure une triadification primaire. Le complexe gémellaire a été décrit selon trois versants : archaïque, oedipianisé et selon l’effet du couple dans la gémellité. Pour les parents qui ont perdu un jumeau durant la grossesse, la perte d’un fœtus jumeau peut devenir un objet de survivance, liée au fonctionnement psychique des parents et au statut du fœtus-jumeau. Chez l’enfant, la place qu’occupe le jumeau décédé pour le vivant est fonction de l’élaboration du deuil des parents. La perte du jumeau peut devenir un objet de survivance, compte tenu de la nature narcissique et pré objectale de la gémellité. Le syndrome du survivant peut se retrouver chez l’enfant. / This thesis explores the phenomenon of twins who develop Twin to twin Transfusion Syndrome (TTTS), and the subsequent metaphyschological effects on both the perinatal and future development of children. The objective of this research is to understand intrauterine life using the context of afterward. Therefore, this research is focused on the link between parents’ experiences of afterward during their pregnancy, and the physical development of 6 year old twins. The second objective of this research concerns the perinatal death of one twin and how life develops in the future for the parents and for the living twin. The methods used are the psychoanalytic and the test method, in a psychodynamic approach. The tools used are the semi-direct research interview and the psychological evaluation of the child. (WISC IV, the drawing of man, the drawing of family and the projective test of the CAT). The collection of data is conducted with more than 60 families who have 6 year old children. At the heart of the population, a single analysis was made from material received for 10 children from a group of twins and 10 single children. A cross sectional analysis was done for each group and for the total of the population. My results show that we can find traces of registered pre-psychic trauma. From the WISC IV test, the results indicate that 73% of children have an average IQ. There is a state of paralysis in thought processes, and little interest in learning. The CAT showed narcissistic defenses related to difficulty in developing the depressive position, as well as significant inhibition. Confusion and lack of differentiation of psychic spaces are present. In the drawing of the family and in the CAT, the identification of one twin with the other twin can be found, resulting in poorly defined boundaries of self. Identification with parental images appears to be secondary. The presence of TTTS has the potential to cause trauma through the generational chain of parent/ child that is organised in three stages. Twin object relations have been described as “the prenatal nest” of subsequent object relations, formed by the trio and the quartet. This type of relationship introduces a primary triadification. Three aspects of the twin complex have been described: archaic, oedipianized and according to the effect of the couple in the twinning. For those parents who have lost a twin during pregnancy, the loss of a twin foetus can become an object of survival, or an object of trauma, linked to the psychic functioning of the parents and the status of the twin foetus. The place the living twin takes, in place of the dead twin, is dependent on the grieving process of the parents. Based on this, the loss of a twin can become an object of survival, taking into account the narcissistic and pre objectal nature of the twinning. Survival Syndrome can be found in children.

Objectifs : Développer un traitement HIFU (High-Intensity Focused Ultrasound) des anomalies placentaires au moyen d’un transducteur torique. Les essais ont été menés à partir d’un modèle ex-vivo, puis la faisabilité, l’efficacité et l’innocuité du traitement a été évaluée sur un modèle de guenons gestantes. Les premières applications thérapeutiques envisagées à l’échelle humaine, concernent le traitement du syndrome transfuseur-transfusé (STT) et les accrétions placentaires pour lesquelles un protocole d’essai clinique a été établi. Matériels et méthodes : Un transducteur torique fonctionnant à 3 MHz et muni d’une cellule d’imagerie échographique intégrée fonctionnant à 7,5 MHz ont été utilisés. Des simulations numériques de séquences de traitement HIFU ont été menées à partir d’une étude préliminaire sur la caractérisation acoustique du tissu placentaire humain. Ces séquences ont été testées au cours d’une étude ex-vivo sur des placentas humains. Deux modèles ex-vivo ont été conçus. Dans un premier temps, un modèle de traitement extracorporis. Dans un second temps, des traitements HIFU ont été réalisés à des distances variables du transducteur, par modification de la taille du ballonnet, afin de simuler un traitement per-césarienne. Le transducteur était placé au contact de la face foetale du placenta afin de simuler la séreuse utérine. A partir des résultats issus de ces essais ex-vivo, un protocole in-vivo sur des guenons gestantes a été mené afin de valider la faisabilité, l’efficacité et l’innocuité de la réalisation de lésions HIFU dans le placenta de guenons gestantes de manière totalement non-invasive. La qualité du monitoring échographique était évaluée au cours des trois études, et corrélée à l’analyse macroscopique. Une étude histologique a également été menée. Résultats : L’atténuation placentaire a été mesurée à partir de 12 échantillons placentaires humains pour un âge gestationnel compris entre 17 et 40 semaines d’aménorrhées (SA). L’atténuation augmentait en fonction de l’âge gestationnel et était compris entre 0,072 et 0,098 Np.cm-1.MHz-1. Lors d’un premier essai ex-vivo, 33 échantillons placentaires humains ont été inclus et soumis à une séquence HIFU, le temps d’insonification était de 55 secondes, la puissance acoustique utilisée était de 90 Watts. Au total, vingt-cinq lésions élémentaires étaient produites pour un diamètre et une profondeur moyens respectifs de 7,1 ± 3,2 et de 8,0 ± 3,1 millimètres. Huit lésions HIFU ont également été produites à partir de la juxtaposition de 6 tirs, pour un diamètre et une profondeur moyenne respectifs de 23,0 ± 5,0 et 11,0 ± 4,7 millimètres. Aucune lésion située en amont de la lésion produite n’a été observée pour une épaisseur de paroi abdominale similaire à celle d’une guenon gestante (10,8 ± 1,7 millimètres). Dans un second temps, 8 placentas humains pour un âge gestationnel compris entre 39 et 40 SA, ont été soumis à une séquence de traitement HIFU sans interposition de paroi abdominale. Le temps d’exposition était de 75 secondes pour une puissance acoustique de 90 Watts. Les lésions placentaires ont été produites à 2 (n=4), 6 (n=4), 7 (n=4) et 8 (n=7) millimètres de la surface du placenta. Au total, 19 lésions placentaires ont été produites, pour un diamètre et une profondeur moyenne respectifs de 14,6 ± 2,1 et de 14,1 ± 2,3 millimètres. Au cours de l’étude in-vivo, 8 guenons ont été incluses pour un âge gestationnel moyen de 72 ± 4 jours. Les puissances acoustiques utilisées étaient de 65, 80, 110 et 120 Watts pour un temps de traitement de 30, 15, 20 et 20 secondes respectivement. Au total 6 lésions placentaires ont été produites à l’issu de 13 insonifications pour des diamètres moyens de 6,4 ± 0,5 mm, 7,8 ± 0,7 mm et une profondeur moyenne de 3,8 ± 1,5 mm [etc…] / Objectives: To develop a High-intensity Focused Ultrasound (HIFU) treatment for placental abnormalities. Trials were first conducted using an ex-vivo model. Then the safety, feasibility and efficacy were demonstrated using a pregnant monkey model. The first therapeutic applications for human concern the treatment of the twin-to-twin transfusion syndrome (TTTS) and placenta accreta, for which, a clinical trial has already been established. Materials and Methods: A toroidal HIFU transducer, with an integrated ultrasound imaging probe was used. Numerical simulations have allowed identifying HIFU treatment parameters based on a preliminary experiment measuring the acoustic attenuation of human placentae. These HIFU parameters were tested during an ex-vivo study on human placentae. Two models were used. First, an extracorporis model of treatment was developed. Second, a percesarean model was developed. HIFU lesions were performed at different distances from the transducer, by adjusting the quantity of water between the transducer and tissues. The transducer was placed in contact with the fetal side of the placenta in order to simulate the uterine serosa. Using the results of these studies, an in-vivo study was conducted in a pregnant monkey model. The aim was to evaluate the feasibility, the efficacy and the harmlessness of the HIFU treatment applied to the placenta non invasively. The ultrasound monitoring was assessed during these three studies, and was correlated to the macroscopic examination. A histological study was also performed. Results: The placental attenuation was measured using 12 placental samples for a gestational age from 17 to 40 weeks of gestation (WG). The attenuation coefficient increased according to the gestational age, and was ranged from 0,072 to 0,098 Np.cm-1.MHz-1. During the first experimental ex-vivo study, 33 human placental samples were included and treated with HIFU. The treatment parameters were an exposure time of 55 seconds and an acoustic power of 90 Watts. Twenty-five HIFU singles lesions were created with an average diameter and depth of 7.1 ± 3.2 and 8.0 ± 3.1 millimeters, respectively. Eight HIFU lesions were also created by juxtaposing 6 single HIFU lesions. The average diameter and depth of these juxtaposed lesions were 23.0 ± 5.0 and 11.0 ± 4.7 millimeters, respectively. No secondary lesion was observed in overlying abdominal tissues. The thickness of these intervening tissues was similar to a pregnant monkey (10.8 ± 1.7 millimeters). In a second set of experiments, 8 human placentae for a gestational age ranging between 39 and 40 weeks were treated without intervening tissues. The time of exposure was 75 seconds and the acoustic power was 90 Watts. The placental lesions were created at 2 (n=4), 6 (n=4), 7 (n=4) and 8 (n=7) millimeters from the surface of the placenta. In total, 19 placental lesions were created with an average diameter and depth of 14.6 ± 2.1 and 14.1 ± 2.3 millimeters, respectively. Eight pregnant monkeys were included in the in-vivo experiments. The average gestational age was 72 ± 4 days. The placenta was treated non-invasively with acoustic powers of 65, 80, 110 and 120 Watts for a time of exposure of 30, 15, 20 and 20 seconds, respectively. In total, 6 placental lesions were created from 13 insonifications. The average diameters and depths of these lesions were 7.8 ± 0.7 and 3.8 ± 1.5 mm, respectively. No significant variation in maternal or fetal parameters was observed. All placental lesions appear hyperechoic in sonograms and well correlated with the macroscopic measurements. The ultrasound monitoring was better invivo when compared with ex-vivo results. The histological examination demonstrated a well delimited lesion of coagulation in all cases