A Novel Skin-Stretch Haptic Device for Intuitive Control of Robotic Prostheses and Avatars

Without proprioception, i.e., the intrinsic capability of a body to perceive its own limb position, completing daily life activities would require constant visual attention and it would be challenging or even impossible. This situation is similar to the one experienced after limb amputation and in robotic tele-operation, where the natural sensory-motor loop is broken. While some promising solutions based on skin stretch sensory substitution have been proposed to restore tactile properties in these conditions, there is still room for enhancing the intuitiveness of stimulus delivery and integration of haptic feedback devices within user's body. To contribute to this goal, here, we propose a wearable device based on skin stretch stimulation, the Stretch-Pro, which can provide proprioceptive information on artificial hand aperture. This system can be suitably integrated in a prosthetic socket or can be easily worn by a user controlling remote robots. The system can imitate the stretching of the skin that would naturally occur on the intact limb, when it is used to accomplish motor tasks. Two versions of the system are presented, with one and two actuators, respectively, which deliver the stretch stimulus in different ways. Experiments with able-bodied participants and a preliminary test with one prosthesis user are reported. Results suggest that Stretch-Pro could be a viable solution to convey proprioceptive cues to upper limb prosthesis users, opening promising perspectives for tele-robotics applications

A hierarchical sensorimotor control framework for human-in-the-loop robotic hands.

Human manual dexterity relies critically on touch. Robotic and prosthetic hands are much less dexterous and make little use of the many tactile sensors available. We propose a framework modeled on the hierarchical sensorimotor controllers of the nervous system to link sensing to action in human-in-the-loop, haptically enabled, artificial hands

Biomechanically-Consistent Skin Stretch as an Intuitive Mechanism for Sensory Feedback: A Preliminary Investigation in the Lower Limb

The proprioceptive loss accompanied by lower limb amputation can impair function and mobility. We explore a simple, mechanical skin-stretch array configured to generate superficial tissue behaviour that might occur with movement about an intact joint. Four adhesive pads attached around the circumference of the lower leg were connected via cords to a remote “foot” mounted on a ball joint attached to the underside of a fracture boot, such that “foot” reorientation would result in skin stretch. In two discrimination experiments performed with and without the connection, with no view of the mechanism, and with minimal training, unimpaired adults (i) estimated foot orientation following passive foot rotations (eight directions), either with or without contact between the lower leg and boot, and (ii) actively lowered the “foot” to estimate slope orientation (four directions). In (i), 56-60% of responses (depending on contact condition) were correct and 88-94% were either correct or one of the two adjacent choices. In (ii), 56% of responses were correct. In contrast, without the connection, participants performed near or no different to chance. A biomechanically-consistent skin stretch array may be an intuitive means to convey proprioceptive information from an artificial or poorly innervated joint

Diseño e implementación de un dispositivo de estiramiento cutáneo orientado a prótesis mioeléctricas transradiales que proporcione información propioceptiva

La búsqueda de la mejor estrategia y/o mecanismo para transmitir la información sensorial a usuarios de prótesis mioeléctricas es un tema de interés por parte de la comunidad científica debido a que las mismas son rechazadas por la ineficiencia o nulidad de dispositivos hápticos. Así pues, siendo la propiocepción parte de la retroalimentación sensorial perdida, el presente trabajo de investigación tiene como objetivo el diseño e implementación de un dispositivo háptico de estiramiento cutáneo longitudinal orientado a prótesis mioeléctricas transradiales que proporcione información propioceptiva. El diseño mecánico propuesto se desarrolla considerando la norma alemana VDI 2206 y una evaluación técnico-económica basada en la norma VDI 2225. Asimismo, se evalúa la relación a establecerse entre el actuador y el sensor de flexión para evitar el “efecto de aumento”. Más aún, se realiza la evaluación de dos diferentes métodos de fijación a la piel (neopreno y cinta adhesiva de doble cara) a través de dos encuestas cuantitativas subjetivas en base al experimento de la caja de espejo. En cuanto a los resultados con respecto al diseño mecánico, se establece la confiabilidad del mismo dados los parámetros mecánicos obtenidos tras el análisis de elementos finitos. Por otro lado, se establece el empleo del mapeo lineal para relacionar el sensor y el actuador del dispositivo al permitir la distribución correcta de los datos. Finalmente, los resultados de la evaluación del método de fijación a la piel revelan que no existen diferencias estadísticamente significativas al proporcionar información propioceptiva (p = 0.213); análogamente, se destaca la viabilidad de la espuma de neopreno como método de fijación. En síntesis, el diseño planteado puede reducir el rechazo de las prótesis mioeléctricas a través del método de modalidad emparejada expuesto y, dado el diseño planteado, el empleo de la espuma de neopreno se presenta como una solución más viable dada su naturaleza no adhesiva.Campus Lima Centr

Haptic Media Scenes

The aim of this thesis is to apply new media phenomenological and enactive embodied cognition approaches to explain the role of haptic sensitivity and communication in personal computer environments for productivity. Prior theory has given little attention to the role of haptic senses in influencing cognitive processes, and do not frame the richness of haptic communication in interaction design—as haptic interactivity in HCI has historically tended to be designed and analyzed from a perspective on communication as transmissions, sending and receiving haptic signals. The haptic sense may not only mediate contact confirmation and affirmation, but also rich semiotic and affective messages—yet this is a strong contrast between this inherent ability of haptic perception, and current day support for such haptic communication interfaces. I therefore ask: How do the haptic senses (touch and proprioception) impact our cognitive faculty when mediated through digital and sensor technologies? How may these insights be employed in interface design to facilitate rich haptic communication? To answer these questions, I use theoretical close readings that embrace two research fields, new media phenomenology and enactive embodied cognition. The theoretical discussion is supported by neuroscientific evidence, and tested empirically through case studies centered on digital art. I use these insights to develop the concept of the haptic figura, an analytical tool to frame the communicative qualities of haptic media. The concept gauges rich machine- mediated haptic interactivity and communication in systems with a material solution supporting active haptic perception, and the mediation of semiotic and affective messages that are understood and felt. As such the concept may function as a design tool for developers, but also for media critics evaluating haptic media. The tool is used to frame a discussion on opportunities and shortcomings of haptic interfaces for productivity, differentiating between media systems for the hand and the full body. The significance of this investigation is demonstrating that haptic communication is an underutilized element in personal computer environments for productivity and providing an analytical framework for a more nuanced understanding of haptic communication as enabling the mediation of a range of semiotic and affective messages, beyond notification and confirmation interactivity

Down-Conditioning of Soleus Reflex Activity using Mechanical Stimuli and EMG Biofeedback

Spasticity is a common syndrome caused by various brain and neural injuries, which can severely impair walking ability and functional independence. To improve functional independence, conditioning protocols are available aimed at reducing spasticity by facilitating spinal neuroplasticity. This down-conditioning can be performed using different types of stimuli, electrical or mechanical, and reflex activity measures, EMG or impedance, used as biofeedback variable. Still, current results on effectiveness of these conditioning protocols are incomplete, making comparisons difficult. We aimed to show the within-session task- dependent and across-session long-term adaptation of a conditioning protocol based on mechanical stimuli and EMG biofeedback. However, in contrast to literature, preliminary results show that subjects were unable to successfully obtain task-dependent modulation of their soleus short-latency stretch reflex magnitude

Somatic ABC's: A Theoretical Framework for Designing, Developing and Evaluating the Building Blocks of Touch-Based Information Delivery

abstract: Situations of sensory overload are steadily becoming more frequent as the ubiquity of technology approaches reality--particularly with the advent of socio-communicative smartphone applications, and pervasive, high speed wireless networks. Although the ease of accessing information has improved our communication effectiveness and efficiency, our visual and auditory modalities--those modalities that today's computerized devices and displays largely engage--have become overloaded, creating possibilities for distractions, delays and high cognitive load; which in turn can lead to a loss of situational awareness, increasing chances for life threatening situations such as texting while driving. Surprisingly, alternative modalities for information delivery have seen little exploration. Touch, in particular, is a promising candidate given that it is our largest sensory organ with impressive spatial and temporal acuity. Although some approaches have been proposed for touch-based information delivery, they are not without limitations including high learning curves, limited applicability and/or limited expression. This is largely due to the lack of a versatile, comprehensive design theory--specifically, a theory that addresses the design of touch-based building blocks for expandable, efficient, rich and robust touch languages that are easy to learn and use. Moreover, beyond design, there is a lack of implementation and evaluation theories for such languages. To overcome these limitations, a unified, theoretical framework, inspired by natural, spoken language, is proposed called Somatic ABC's for Articulating (designing), Building (developing) and Confirming (evaluating) touch-based languages. To evaluate the usefulness of Somatic ABC's, its design, implementation and evaluation theories were applied to create communication languages for two very unique application areas: audio described movies and motor learning. These applications were chosen as they presented opportunities for complementing communication by offloading information, typically conveyed visually and/or aurally, to the skin. For both studies, it was found that Somatic ABC's aided the design, development and evaluation of rich somatic languages with distinct and natural communication units.Dissertation/ThesisPh.D. Computer Science 201