Robotic simulators for tissue examination training with multimodal sensory feedback

Tissue examination by hand remains an essential technique in clinical practice. The effective application depends on skills in sensorimotor coordination, mainly involving haptic, visual, and auditory feedback. The skills clinicians have to learn can be as subtle as regulating finger pressure with breathing, choosing palpation action, monitoring involuntary facial and vocal expressions in response to palpation, and using pain expressions both as a source of information and as a constraint on physical examination. Patient simulators can provide a safe learning platform to novice physicians before trying real patients. This paper reviews state-of-the-art medical simulators for the training for the first time with a consideration of providing multimodal feedback to learn as many manual examination techniques as possible. The study summarizes current advances in tissue examination training devices simulating different medical conditions and providing different types of feedback modalities. Opportunities with the development of pain expression, tissue modeling, actuation, and sensing are also analyzed to support the future design of effective tissue examination simulators

A reconfigurable tactile display based on polymer MEMS technology

This research focuses on the development of polymer microfabrication technologies for the realization of two major components of a pneumatic tactile display: a microactuator array and a complementary microvalve (control) array. The concept, fabrication, and characterization of a kinematically-stabilized polymeric microbubble actuator (¡°endoskeletal microbubble actuator¡±) were presented. A systematic design and modeling procedure was carried out to generate an optimized geometry of the corrugated diaphragm to satisfy membrane deflection, force, and stability requirements set forth by the tactile display goals. A refreshable Braille cell as a tactile display prototype has been developed based on a 2x3 endoskeletal microbubble array and an array of commercial valves. The prototype can provide both a static display (which meets the displacement and force requirement of a Braille display) and vibratory tactile sensations. Along with the above capabilities, the device was designed to meet the criteria of lightness and compactness to permit portable operation. The design is scalable with respect to the number of tactile actuators while still being simple to fabricate. In order to further reduce the size and cost of the tactile display, a microvalve array can be integrated into the tactile display system to control the pneumatic fluid that actuates the microbubble actuator. A piezoelectrically-driven and hydraulically-amplified polymer microvalve has been designed, fabricated, and tested. An incompressible elastomer was used as a solid hydraulic medium to convert the small axial displacement of a piezoelectric actuator into a large valve head stroke while maintaining a large blocking force. The function of the microvalve as an on-off switch for a pneumatic microbubble tactile actuator was demonstrated. To further reduce the cost of the microvalve, a laterally-stacked multilayer PZT actuator has been fabricated using diced PZT multilayer, high aspect ratio SU-8 photolithography, and molding of electrically conductive polymer composite electrodes.Ph.D.Committee Chair: Allen,Mark; Committee Member: Bucknall,David; Committee Member: Book,Wayne; Committee Member: Griffin,Anselm; Committee Member: Yao,Donggan

Model-based Microfluidic Device Design for Refreshable Braille and Tactile Graphics

A low-cost and reliable technology to support electronic braille displays would significantly increase access to digital media for blind braille readers. Even better, a full-page dense array of refreshable braille-sized dots could be used to display both braille and tactile graphics---a feat not achievable by existing technologies. The work in this dissertation is two-pronged. First, a perceptual study was carried out that motivates and guides the design of a full-page display. Second, a model-based design approach is adopted to develop microfluidic technology to overcome critical challenges in creating a full-page display. A full-page display is made up of thousands of densely-packed dots, each requiring a dedicated actuator. Some design solutions have been proposed which reduce the number of actuators by using a small array that travels along with the reading finger (think: braille cell on a computer mouse), eliminating sliding contact as a consequence. Based on this consideration, a perceptual study was carried out that informs the design of a full-page display. The study quantifies the reduction in braille character recognition imposed by display designs that reduce sliding contact. Microfluidic technology is employed to fabricate tiny channels and chambers in soft silicone that address and raise braille-sized bubble features on a surface. The challenge associated with controlling many individual fluidic features is met by integrating digital fluidic logic networks with the actuators. Each dot is addressed by the combination of a fluid actuator and a basic fluidic memory unit. A memory unit stores high or low pressure as a binary signal that determines whether its corresponding actuator is up or down. Crucially, memory units can be cascaded so the output of one controls the input of another. Pressure-encoded 1s and 0s can be shifted along cascaded memory units, thereby reducing the required number of external valves. To ensure that the design is sufficiently scalable and manufacturable to support the realization of a large dense array of pins at braille spacing, two performance criteria must be attained. The first is ensuring the memory units are cascadable. The second is controlling memory units at speeds suitable for refreshable braille. The work in this dissertation addresses these two performance criteria by developing models of digital fluidic circuits with particular attention to design parameters that affect circuit cascadability and speed.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/138670/1/arussoma_1.pd

Ground Robotic Hand Applications for the Space Program study (GRASP)

This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time

A Soft touch: wearable dielectric elastomer actuated multi-finger soft tactile displays

PhDThe haptic modality in human-computer interfaces is significantly underutilised when compared to that of vision and sound. A potential reason for this is the difficulty in turning computer-generated signals into realistic sensations of touch. Moreover, wearable solutions that can be mounted onto multiple fingertips whilst still allowing for the free dexterous movements of the user’s hand, brings an even higher level of complexity. In order to be wearable, such devices should not only be compact, lightweight and energy efficient; but also, be able to render compelling tactile sensations. Current solutions are unable to meet these criteria, typically due to the actuation mechanisms employed. Aimed at addressing these needs, this work presents research into non-vibratory multi-finger wearable tactile displays, through the use of an improved configuration of a dielectric elastomer actuator. The described displays render forces through a soft bubble-like interface worn on the fingertip. Due to the improved design, forces of up to 1N can be generated in a form factor of 20 x 12 x 23 mm, with a weight of only 6g, demonstrating a significant performance increase in force output and wearability over existing tactile rendering systems. Furthermore, it is shown how these compact wearable devices can be used in conjunction with low-cost commercial optical hand tracking sensors, to cater for simple although accurate tactile interactions within virtual environments, using affordable instrumentation. The whole system makes it possible for users to interact with virtually generated soft body objects with programmable tactile properties. Through a 15-participant study, the system has been validated for three distinct types of touch interaction, including palpation and pinching of virtual deformable objects. Through this investigation, it is believed that this approach could have a significant impact within virtual and augmented reality interaction for purposes of medical simulation, professional training and improved tactile feedback in telerobotic control systems.Engineering and Physical Sciences Research Council (EPSRC) Doctoral Training Centre EP/G03723X/

ReHand - a portable assistive rehabilitation hand exoskeleton

This dissertation presents a synthesis of a novel underactuated exoskeleton (namely ReHand2) thought and designed for a task-oriented rehabilitation and/or for empower the human hand. The first part of this dissertation shows the current context about the robotic rehabilitation with a focus on hand pathologies, which influence the hand capability. The chapter is concluded with the presentation of ReHand2. The second chapter describes the human hand biomechanics. Starting from the definition of human hand anatomy, passing through anthropometric data, to taxonomy on hand grasps and finger constraints, both from static and dynamic point of view. In addition, some information about the hand capability are given. The third chapter analyze the current state of the art in hand exoskeleton for rehabilitation and empower tasks. In particular, the chapter presents exoskeleton technologies, from mechanisms to sensors, passing though transmission and actuators. Finally, the current state of the art in terms of prototype and commercial products is presented. The fourth chapter introduces the concepts of underactuation with the basic explanation and the classical notation used typically in the prosthetic field. In addition, the chapter describe also the most used differential elements in the prosthetic, follow by a statical analysis. Moreover typical transmission tree at inter-finger level as well as the intra- finger underactuation are explained . The fifth chapter presents the prototype called ReHand summarizing the device description and explanation of the working principle. It describes also the kinetostatic analysis for both, inter- and the intra-finger modules. in the last section preliminary results obtained with the exoskeleton are shown and discussed, attention is pointed out on prototype’s problems that have carry out at the second version of the device. The sixth chapter describes the evolution of ReHand, describing the kinematics and dynamics behaviors. In particular, for the mathematical description is introduced the notation used in order to analyze and optimize the geometry of the entire device. The introduced model is also implemented in Matlab Simulink environment. Finally, the chapter presents the new features. The seventh chapter describes the test bench and the methodologies used to evaluate the device statical, and dynamical performances. The chapter presents and discuss the experimental results and compare them with simulated one. Finally in the last chapter the conclusion about the ReHand project are proposed as well as the future development. In particular, the idea to test de device in relevant environments. In addition some preliminary considerations about the thumb and the wrist are introduced, exploiting the possibility to modify the entire layout of the device, for instance changing the actuator location

Investigating the Feasibility of Using Focussed Airborne Ultrasound as Tactile Feedback in Medical Simulators

Novice medical practitioners commonly practice on live patients in real medical procedures. However, due to the inexperience of the practitioner, mistakes are likely which exposes the patient to undue risk. To improve the training of novices, medical simulators create a virtual patient providing a safe environment for the user to practice within. An important clinical skill is palpation, a physical examination technique. The practitioners use their hands to feel the body of the patient to make diagnosis. A virtual patient has a visual representation but as it is virtual, the patient is not physically present. Haptics technology provide additional benefits to the training session by stimulating the physical sense of touch. A novel technique has recently emerged for stimulating tactile sensation called acoustic radiation pressure from focussed airborne ultrasound. Acoustic radiation creates a focal point of concentrated acoustic pressure in a three-dimensional field producing a force in mid-air. Airborne ultrasound has several advantages over conventional technologies. It was also initially theorised that using airborne ultrasound to simulate palpation compared to a previous system called PalpSim which consists of a rubber tube filled with water permanently embedded in a block of silicone, will offer better controllability over the displayed sensation to simulate various tactile sensations. The thesis has investigated the feasibility of using focussed airborne ultrasound as tactile feedback in medical simulators. A tactile device called UltraSendo was completely custom built to simulate an arterial pulse and a thrill sensation. UltraSendo was integrated with an augmented reality simulator displaying a virtual patient for user interaction. The simulator was brought to Ysbyty Glan Clwyd hospital for user feedback. A wide range of user responses were gathered. The majority of responses felt the arterial pulse was not sufficiently realistic whilst there were higher ratings for the thrill sensation which is acceptably realistic. Positive feedback suggests that airborne ultrasound can indeed provide tactile feedback in a medical context and is better at simulating a thrill sensation compared to a pulse sensation

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

Analysis of Product Architectures of Pin Array Technologies for Tactile Displays

Refreshable tactile displays based on pin array technologies have a significant impact on the education of children with visual impairments, but they are prohibitively expensive. To better understand their design and the reason for the high cost, we created a database and analyzed the product architectures of 67 unique pin array technologies from literature and patents. We qualitatively coded their functional elements and analyzed the physical parts that execute the functions. Our findings highlight that pin array surfaces aim to achieve three key functions, i.e., raise and lower pins, lock pins, and create a large array. We also contribute a concise morphological chart that organises the various mechanisms for these three functions. Based on this, we discuss the reasons for the high cost and complexity of these surface haptic technologies and infer why larger displays and more affordable devices are not available. Our findings can be used to design new mechanisms for more affordable and scalable pin array display systems