Design & control of precision surgical device for otitis media with effusion

Ph.DDOCTOR OF PHILOSOPH

Control Architectures for Robotic Assistance in Beating Heart Surgery

Tese de doutoramento em Engenharia Electrotécnica e de Computadores, no ramo de especialização em Automação e Robótica, apresentada ao Departamento de Engenharia Electrotécnica e de Computadores da Faculdade de Ciências e Tecnologia da Universidade de CoimbraDoenças cardiovasculares são a primeira causa de morte no mundo. Todos os anos mais de 17 milhões de pessoas morrem, representando 29% do número total de mortes. As doenças coronárias são as mais críticas, atingindo mais de 7.2 milhões de mortes. Para reduzir o risco de morte, o "bypass" coronário é a intervenção cirúrgica mais comum. Atualmente este procedimento envolve uma esternotomia mediana e um "bypass" cardiopulmonar, permitindo que uma máquina externa implemente as funções de oxigenação e bombeamento de sangue. Contudo, esta máquina externa é fonte de muitas complicações pós-operatórias, incluindo a morte de pacientes. Estes problemas motivam o estudo e desenvolvimento de técnicas cirúrgicas sem parar o funcionamento do coração. Nestes casos, os batimentos cardíacos e a respiração representam as principais fontes de perturbação. Foram desenvolvidos estabilizadores mecânicos para diminuir localmente o movimento cardíaco. Colocado numa região de específica (por exemplo, na artéria coronária), estes estabilizadores limitam o movimento por pressão e sucção. Apesar dos melhoramentos feitos ao longo dos anos, ainda existe um movimento residual considerável, e o cirurgião tem que os compensar manualmente. Torna-se então natural incluir dispositivos robóticos para ajudar na prática médica, melhorando a precisão, segurançae conforto de tarefas cirúrgicas. O sistema cirúrgico da Vinci é atualmente o sistema robótico mais avançado para a prática médica, com elevado desempenho em tarefas de destreza, precisão e segurança, apesar de não fornecer soluções de realimentação táctil, nem de compensação automática de movimentos fisiológicos. O trabalho desta tese é na área da robótica para cirurgias cardíacas com o coração a bater. Baseada na realimentação da força, esta tese explora novas arquiteturas de controlo com compensação automática dos movimentos cardíacos. São feitos testes experimentais em cenários muito realistas, sem utilizar seres vivos. Um robô denominado "Heartbox" equipado com um coração real reproduz movimentos cardíacos, enquanto que outro robô manipulador aplica forças cirúrgicas nesse coração com batimento artificial. As forças de interação fornecem realimentação de contacto ao cirurgião. O principal desafio científico deste trabalho é a ligação de técnicas de compensação autónoma de movimentos fisiológicos com controlo de força e realimentação haptica.Cardiovascular diseases are the first cause of mortality in the world. More than 17 million people die every year, representing 29% of all global deaths. Among these, coronary heart diseases are the most critical ones, reaching up to 7.2 million deaths. To reduce the risk of death the coronary artery bypass grafting (CABG) is the most common surgical intervention. Currently, the procedure involves a median sternotomy, an incision in the thorax allowing a direct access to the heart, and a cardiopulmonary bypass (CPB), where heart and lung functionalities are performed by an extracorporal machine. Unfortunately the heart-lung machine is the greatest source of complications and post-operatory mortality for patients. Problems involved have motivated beating heart surgery that circumvent CPB procedure. Heartbeats and respiration represent the two main sources of disturbances during off-pump surgery. Mechanical stabilizers have been conceived for locally decreasing heart motion. Placed around a region of interest (e.g., coronary artery), these stabilizers constraint the motion by suction or pressure. Despite many improvements done over the years, considerable residual motion still remains and the surgeon have to manually compensate them. Robotic assistance has the potential to offer significant improvements to the medical practice in terms of precision, safety and comfort. Theda Vinci surgical system is the most popular and sophisticated. Although it has considerably improved dexterity, precision and safety, no solution for restoring tactile feedback to the surgeon exists and physiological motion compensation still needs to be manually canceled by the surgeon. The work presented in this thesis focus on robotic assistance for beating heart surgery. Based on force feedback, we designed new control architectures providing autonomous physiological motion compensation. Experimental assessments have been performed through a realistic scenario. A Heartbox robot equipped with an \textit{ex vivo} heart reproduces heart motion and a robot arm generates desired surgical forces on the moving heart. Interaction forces provide the haptic feedback for the surgeon. Merging autonomous motion compensation techniques with force control and haptic feedback is a major scientific challenge that we tackle in this work.FCT - SFRH/BD/74278/201

Aerospace medicine and biology. A continuing bibliography (supplement 231)

This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1982

A Fluidic Soft Robot for Needle Guidance and Motion Compensation in Intratympanic Steroid Injections

Intratympanic steroid injections are commonly employed in treating ear diseases, such as sudden sensorineural hearing loss or Meniere's disease through drug delivery via the middle ear. Whilst being an effective treatment, the procedure has to be performed by a trained surgeon to avoid delicate regions in the patient's anatomy and is considered painful despite the use of topical anaesthesia. In this letter we introduce a fluid-driven soft robotic system which aims at increasing patient-comfort during the injection by counteracting unwanted needle motion, reducing the cognitive load of the clinician by autonomously identifying sensitive regions in the ear and de-risking the procedure by steering the needle towards the desired injection site. A design comprising of six embedded fluidic actuators is presented, which allow for translation and rotation of the needle as well as adaptive stiffening in the coupling between needle and ear canal. The system's steering-capabilities are investigated and the differential kinematics derived to demonstrate trajectory tracking in Cartesian space. A vision system is developed which enables tracking of anatomical landmarks on the tympanic membrane and thus locating the desired needle insertion site. The integrated system shows the ability to provide a safe guide for the inserted needle towards a desired target direction while significantly reducing needle motion. The proposed tracking algorithm is able to identify the desired needle insertion site and could be employed to avoid delicate anatomical regions

Estimating and understanding motion : from diagnostic to robotic surgery

Estimating and understanding motion from an image sequence is a central topic in computer vision. The high interest in this topic is because we are living in a world where many events that occur in the environment are dynamic. This makes motion estimation and understanding a natural component and a key factor in a widespread of applications including object recognition , 3D shape reconstruction, autonomous navigation and medica! diagnosis. Particularly, we focus on the medical domain in which understanding the human body for clinical purposes requires retrieving the organs' complex motion patterns, which is in general a hard problem when using only image data. In this thesis, we cope with this problem by posing the question - How to achieve a realistic motion estimation to offer a better clinical understanding? We focus this thesis on answering this question by using a variational formulation as a basis to understand one of the most complex motions in the human's body, the heart motion, through three different applications: (i) cardiac motion estimation for diagnostic, (ii) force estimation and (iii) motion prediction, both for robotic surgery. Firstly, we focus on a central topic in cardiac imaging that is the estimation of the cardiac motion. The main aim is to offer objective and understandable measures to physicians for helping them in the diagnostic of cardiovascular diseases. We employ ultrafast ultrasound data and tools for imaging motion drawn from diverse areas such as low-rank analysis and variational deformation to perform a realistic cardiac motion estimation. The significance is that by taking low-rank data with carefully chosen penalization, synergies in this complex variational problem can be created. We demonstrate how our proposed solution deals with complex deformations through careful numerical experiments using realistic and simulated data. We then move from diagnostic to robotic surgeries where surgeons perform delicate procedures remotely through robotic manipulators without directly interacting with the patients. As a result, they lack force feedback, which is an important primary sense for increasing surgeon-patient transparency and avoiding injuries and high mental workload. To solve this problem, we follow the conservation principies of continuum mechanics in which it is clear that the change in shape of an elastic object is directly proportional to the force applied. Thus, we create a variational framework to acquire the deformation that the tissues undergo due to an applied force. Then, this information is used in a learning system to find the nonlinear relationship between the given data and the applied force. We carried out experiments with in-vivo and ex-vivo data and combined statistical, graphical and perceptual analyses to demonstrate the strength of our solution. Finally, we explore robotic cardiac surgery, which allows carrying out complex procedures including Off-Pump Coronary Artery Bypass Grafting (OPCABG). This procedure avoids the associated complications of using Cardiopulmonary Bypass (CPB) since the heart is not arrested while performing the surgery on a beating heart. Thus, surgeons have to deal with a dynamic target that compromisetheir dexterity and the surgery's precision. To compensate the heart motion, we propase a solution composed of three elements: an energy function to estimate the 3D heart motion, a specular highlight detection strategy and a prediction approach for increasing the robustness of the solution. We conduct evaluation of our solution using phantom and realistic datasets. We conclude the thesis by reporting our findings on these three applications and highlight the dependency between motion estimation and motion understanding at any dynamic event, particularly in clinical scenarios.L’estimació i comprensió del moviment dins d’una seqüència d’imatges és un tema central en la visió per ordinador, el que genera un gran interès perquè vivim en un entorn ple d’esdeveniments dinàmics. Per aquest motiu és considerat com un component natural i factor clau dins d’un ampli ventall d’aplicacions, el qual inclou el reconeixement d’objectes, la reconstrucció de formes tridimensionals, la navegació autònoma i el diagnòstic de malalties. En particular, ens situem en l’àmbit mèdic en el qual la comprensió del cos humà, amb finalitats clíniques, requereix l’obtenció de patrons complexos de moviment dels òrgans. Aquesta és, en general, una tasca difícil quan s’utilitzen només dades de tipus visual. En aquesta tesi afrontem el problema plantejant-nos la pregunta - Com es pot aconseguir una estimació realista del moviment amb l’objectiu d’oferir una millor comprensió clínica? La tesi se centra en la resposta mitjançant l’ús d’una formulació variacional com a base per entendre un dels moviments més complexos del cos humà, el del cor, a través de tres aplicacions: (i) estimació del moviment cardíac per al diagnòstic, (ii) estimació de forces i (iii) predicció del moviment, orientant-se les dues últimes en cirurgia robòtica. En primer lloc, ens centrem en un tema principal en la imatge cardíaca, que és l’estimació del moviment cardíac. L’objectiu principal és oferir als metges mesures objectives i comprensibles per ajudar-los en el diagnòstic de les malalties cardiovasculars. Fem servir dades d’ultrasons ultraràpids i eines per al moviment d’imatges procedents de diverses àrees, com ara l’anàlisi de baix rang i la deformació variacional, per fer una estimació realista del moviment cardíac. La importància rau en que, en prendre les dades de baix rang amb una penalització acurada, es poden crear sinergies en aquest problema variacional complex. Mitjançant acurats experiments numèrics, amb dades realístiques i simulades, hem demostrat com les nostres propostes solucionen deformacions complexes. Després passem del diagnòstic a la cirurgia robòtica, on els cirurgians realitzen procediments delicats remotament, a través de manipuladors robòtics, sense interactuar directament amb els pacients. Com a conseqüència, no tenen la percepció de la força com a resposta, que és un sentit primari important per augmentar la transparència entre el cirurgià i el pacient, per evitar lesions i per reduir la càrrega de treball mental. Resolem aquest problema seguint els principis de conservació de la mecànica del medi continu, en els quals està clar que el canvi en la forma d’un objecte elàstic és directament proporcional a la força aplicada. Per això hem creat un marc variacional que adquireix la deformació que pateixen els teixits per l’aplicació d’una força. Aquesta informació s’utilitza en un sistema d’aprenentatge, per trobar la relació no lineal entre les dades donades i la força aplicada. Hem dut a terme experiments amb dades in-vivo i ex-vivo i hem combinat l’anàlisi estadístic, gràfic i de percepció que demostren la robustesa de la nostra solució. Finalment, explorem la cirurgia cardíaca robòtica, la qual cosa permet realitzar procediments complexos, incloent la cirurgia coronària sense bomba (off-pump coronary artery bypass grafting o OPCAB). Aquest procediment evita les complicacions associades a l’ús de circulació extracorpòria (Cardiopulmonary Bypass o CPB), ja que el cor no s’atura mentre es realitza la cirurgia. Això comporta que els cirurgians han de tractar amb un objectiu dinàmic que compromet la seva destresa i la precisió de la cirurgia. Per compensar el moviment del cor, proposem una solució composta de tres elements: un funcional d’energia per estimar el moviment tridimensional del cor, una estratègia de detecció de les reflexions especulars i una aproximació basada en mètodes de predicció, per tal d’augmentar la robustesa de la solució. L’avaluació de la nostra solució s’ha dut a terme mitjançant conjunts de dades sintètiques i realistes. La tesi conclou informant dels nostres resultats en aquestes tres aplicacions i posant de relleu la dependència entre l’estimació i la comprensió del moviment en qualsevol esdeveniment dinàmic, especialment en escenaris clínics.Postprint (published version

Development of a Novel Handheld Device for Active Compensation of Physiological Tremor

In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation of physiological tremor in the hand. MEMS-based accelerometers and gyroscopes have been used for sensing the motion of the hand in six degrees of freedom (DOF). An augmented state complementary Kalman filter is used to calculate 2 DOF orientation. An adaptive filtering algorithm, band-limited Multiple Fourier linear combiner (BMFLC), is used to calculate the tremor component in the hand in real-time. Ionic Polymer Metallic Composites (IPMCs) have been used as actuators for deflecting the tool-tip to compensate for the tremor

Medical Robotics

The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

Otolith function in human subjects: Perception of motion, reflex eye movements and vision during linear interaural acceleration

The thesis investigates how the otolith organs of the vestibular system, specifically the utricles, assist motion perception and aid visual stabilization, during translational lateral whole-body acceleration. It was found that high gradients of acceleration facilitate the detection of motion and that, for low acceleration gradients, motion perception in normal subjects relies on a 'velocity' threshold detection process. Experiments in patients without vestibular function indicated that, for the stimuli employed, the somatosensory system could be as sensitive to linear motion as the vestibular system. The interaction between the horizontal linear vestibulo-ocular reflex (LVOR) and visual context was characterized in the following experiments. Subjects were accelerated transiently in darkness, or while viewing earth-fixed or head-fixed targets. From onset, the eye velocity response to head translation was enhanced with acceleration level and target proximity, but was only slightly reduced by fixation of head-fixed targets. This suggested that the gain of the LVOR pathway was adjusted before or immediately after motion onset by a parameter depending mainly on viewing distance and less on the knowledge of probable relative target motion. For high relative target velocities, LVORs improved ocular fixation over what would be attained by pursuit alone, although fully compensatory eye movements were not always produced. The LVORs of patients who underwent unilateral vestibular deafferentation suggested that the utricular area generating transaural LVORs is the macular region lateral to the striola. Psychophysical experiments based on a reading task established the functional role of the LVOR for stabilising vision during high-frequency sinusoidal whole-body acceleration. Unlike normal subjects, visual acuity in patients without vestibular function was not better during self-motion than during display oscillation. Finally, the LVOR interaction with canal-ocular reflexes was studied using isolated and combined translational/rotational stimuli. The results showed that, shortly after motion onset, canal stimulation enhances the LVOR evoked by head translation