Design, characterisation and validation of a haptic interface based on twisted string actuation.

This paper presents the design and experimental characterisation of a wrist haptic interface based on a twisted string actuator. The interface is designed for controlled actuation of wrist flexion/extension and is capable of rendering torque feedback through a rotary handle driven by the twisted string actuator and spring-loaded cable mechanisms. The interface was characterised to obtain its static and dynamic haptic feedback rendering capabilities. Compliance in the spring and actuation mechanism makes the interface suitable for smooth rendering of haptic feedback of large magnitudes due to the high motion transmission ratio of the twisted strings. Haptic virtual wall rendering capabilities are demonstrated

Robotic Catheters for Beating Heart Surgery

Compliant and flexible cardiac catheters provide direct access to the inside of the heart via the vascular system without requiring clinicians to stop the heart or open the chest. However, the fast motion of the intracardiac structures makes it difficult to modify and repair the cardiac tissue in a controlled and safe manner. In addition, rigid robotic tools for beating heart surgery require the chest to be opened and the heart exposed, making the procedures highly invasive. The novel robotic catheter system presented here enables minimally invasive repair on the fast-moving structures inside the heart, like the mitral valve annulus, without the invasiveness or risks of stopped heart procedures. In this thesis, I investigate the development of 3D ultrasound-guided robotic catheters for beating heart surgery. First, the force and stiffness values of tissue structures in the left atrium are measured to develop design requirements for the system. This research shows that a catheter will experience contractile forces of 0.5 – 1.0 N and a mean tissue structure stiffness of approximately 0.1 N/mm while interacting with the mitral valve annulus. Next, this thesis presents the catheter system design, including force sensing, tissue resection, and ablation end effectors. In order to operate inside the beating heart, position and force control systems were developed to compensate for the catheter performance limitations of friction and deadzone backlash and evaluated with ex vivo and in vivo experiments. Through the addition of friction and deadzone compensation terms, the system is able to achieve position tracking with less than 1 mm RMS error and force tracking with 0.08 N RMS error under ultrasound image guidance. Finally, this thesis examines how the robotic catheter system enhances beating heart clinical procedures. Specifically, this system improves resection quality while reducing the forces experienced by the tissue by almost 80% and improves ablation performance by reducing contact resistance variations by 97% while applying a constant force on the moving tissue.Engineering and Applied Science

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility

Sistemas interativos tangíveis e processos de mediação tecnológica: hipóteses sobre agência, significação e cognição a partir da investigação do MIT Tangible Media Group

A presente dissertação toma a investigação em sistemas de interação tangível do MIT Tangible Media Group como objeto, a pretexto da sua inclusão na edição de 2016 do Festival Ars Electronica, sob o tema Radical Atoms: The Alchemists of Our Time. Pretende-se compreender quais os pontos de contato da investigação do grupo com os estudos dos media, de forma a localizar a sua relevância para a programação do festival. O enquadramento nos estudos dos media é feito pela localização de um conjunto de termos-chave no trabalho do grupo, os quais evocam questões afetas à fenomenologia, filosofia da tecnologia e mediação tecnológica. Conclui-se que estes sistemas de interação tangível ativam processos particulares de constituição de agência, significação e cognição. Na ausência de outros materiais que explorem estas relações no contexto do festival, a dissertação apresenta-se assim como complemento à leitura do tema Radical Atoms: The Alchemists of Our Time.This dissertation thesis takes the research of the MIT Tangible Media Group as its object, by occasion of its inclusion in the 2016 edition of Ars Electronica Festival under the theme Radical Atoms: The Alchemists of Our Time. The aim is to understand what are the common points between the group's research and media studies, in order to locate this object's relevance to the festival programming scope. The framing within media studies is done by surveying a set of keywords from the group's research, which evoke topics from phenomenology, philosophy of technology and technological mediation. It's concluded that these tangible interactive systems activate specific processes of agency, signification, and cognition. Given the lack of materials which explore these relationships within the context of the festival, the dissertation presents itself as a supplement to the reading of the Radical Atoms: The Alchemists of Our Time theme

Augmenting contact stiffness in passive haptics - preliminary results with twisted string actuation

Haptic feedback is often employed in medical simulators, with the goal to improve user interaction and the training outcome. One option for providing touch sensations is using passive haptics, by including actual physical mock-ups of the anatomical objects in the simulated scene. While this approach has advantages, the usual one-to-one mapping between virtual and physical objects is a fundamental drawback, especially when invasive scene alterations are to be performed, such as cutting or drilling. In this work we propose to alleviate this situation by modifying the mock surgical instruments used for interaction. Twisted string actuation is employed to display variable stiffness while indenting an anatomical model. Quantitative experiments characterizing the performance of a testbed are reported and a prototype system for a surgical bone drill is introduced. Results show that the setup is capable of providing different stiffness augmentations, representing varying bone densities.(VLID)2350048Accepted versio

Physical Diagnosis and Rehabilitation Technologies

The book focuses on the diagnosis, evaluation, and assistance of gait disorders; all the papers have been contributed by research groups related to assistive robotics, instrumentations, and augmentative devices

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version