Somatic senses required for the emotional design of upper limb prosthesis

Despite the technological advances associated with prostheses, the total embodiment is still the great challenge in the segment of assistive technology. One of the main aspects is that the bionic member’s sensibility is not responsive to the environment that surrounds it. The purpose of this study aims to identify the perceptual modalities of the somatic senses that are required for a more sensible prosthesis. The methodological strategy contemplates literary research and proposes an interrelationship between neuroscience with philosophical/cultural studies, which regards the different concepts of sensory experience. Such data were analyzed quantitatively and qualitatively. The main conclusion points out that it would be important to unite the nine physiological requirements identified in the state of the art, with the ontological image construction of the prosthesis, in order to create a sensory experience that, in addition to the perceptive organs, builds up by the visual areas of the brain.This work is financed by Project “Deus ex Machina”, NORTE-01-0145-FEDER-000026, funded by CCDRN, through Sistema de Apoio à Investigação Científica e Tecnológica (Projetos Estruturados I&D&I) of Programa Operacional Regional do Norte, from Portugal 2020 and byProject UID/CTM/00264/2019 of 2C2T –Centro de Ciência e Tecnologia Têxtil, funded by National Founds through FCT/MCTES

Unpacking Non-Dualistic Design: The Soma Design Case

We report on a somaesthetic design workshop and the subsequent analytical work aiming to demystify what is entailed in a non-dualistic design stance on embodied interaction and why a first-person engagement is crucial to its unfoldings. However, as we will uncover through a detailed account of our process, these first-person engagements are deeply entangled with second- and third-person perspectives, sometimes even overlapping. The analysis furthermore reveals some strategies for bridging the body-mind divide by attending to our inner universe and dissolving or traversing dichotomies between inside and outside; individual and social; body and technology. By detailing the creative process, we show how soma design becomes a process of designing with and through kinesthetic experience, in turn letting us confront several dualisms that run like fault lines through HCI's engagement with embodied interaction

Investigating Phantom Motor Execution as treatment of Phantom Limb Pain

Phantom Limb Pain (PLP) is commonly suffered by people with amputations and even though it has been studied for centuries, it remains a mysterious object of debate among researchers. For one thing, despite the vast number of proposed PLP treatments, no therapy has so far proved to be reliably effective. For another, studies attempting to provide a mechanistic explanation of the condition have produced mixed and inconsistent results, thus providing unreliable guidance for devising new treatment approaches. Phantom Motor Execution (PME) – exertion of voluntary phantom limb movements – aims at restoring control over the phantom limb and the exercise of such control has been hypothesized to reverse neural changes implicated in PLP. Preliminary evidence supporting this hypothesis has been provided by clinical investigations on upper limb amputees. The main purpose of this doctoral thesis was to provide high quality and unbiased evidence for the use of PME as a treatment of PLP, by probing its efficacy with a Randomized Controlled Trial (RCT) on both upper and lower limb amputees. However, the implementation of this clinical investigation required of additional technology development related the extraction of motor volition via Myoelectric Pattern Recognition (MPR). In practice, this doctoral work consisted in the extension of PME technology to lower limb amputations by proposing and validating a new and more user-friendly recording method to acquire myoelectric signals. The use of PME was then shown to be efficacious in relieving PLP even in the lower limb population with a case study.Another necessity for providing unbiased evidence was to ensure that the highest standards were met when designing, conducting, analysing and reporting the results of the RCT. For this reason, the protocol for the RCT and the prospective Statistical Analysis Plan (SAP) were designed and published. The RCT was established as an international, multi-center effort in 2017 and it is expected to reach its conclusion in September 2021. Preliminary results of the RCT regarding the primary outcome showed reduction of PLP above what is considered clinically relevant, and whereas a higher reduction was obtained with PME, this was not statistically significant over the control treatment. The available evidence at this stage indicates that the RCT will not be able to rule out the role of contextual factors other than PME in providing pain relief. Having at hand a way to alleviate PLP provided a unique opportunity to investigate and identify its neural correlates, therefore this became a secondary aim of this thesis. In particular, patients suffering from PLP were followed regarding their pain trajectory through the therapy and brain imaging studies with functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) were performed. The present doctoral thesis reports part of this work by showing the early results of a cross-sectional study on the EEG correlates of PLP. The results show that it is possible to use machine-learning techniques to discriminate EEG recorded from patients with and without PLP. The findings further point to this technique as a promising target for future longitudinal research aiming at elucidating the neural mechanisms underlying PLP

On the use of Phantom Motor Execution for the treatment of Phantom Limb Pain

Phantom limb pain (PLP) is a common complaint among amputees and despite having been studiedfor centuries, it remains a mysterious object of debate among researcher. To date, a vast number ofways to treat PLP has been proposed in the literature, however none of them has proven to beuniversally effective, thus creating uncertainty on how to operate clinically. The uncertainty is largelyattributable to the scarcity of well conducted randomized controlled trials (RCTs) to prove the efficacyof PLP treatments.Phantom Motor Execution (PME) -exertion of voluntary phantom limb movements – aims at restoringthe control over the phantom limb and the exercise of such control has been hypothesized to reverseneural changes implicated in PLP. Preliminary evidence supporting this hypothesis has been providedby clinical investigations on upper limb amputees. The main purpose of this Licentiate thesis was toenable a RCT on the use of PME for the treatment of PLP in order to provide robust and unbiasedevidence for clinical practice. However, the implementation and kick-off of this clinical investigationrequired to complete few preparatory steps. For example, most amputees and PLP patients have lowerlimb amputation, thus PME needed to be adapted and validated for this population. Further, the RCTprotocol needed to be carefully planned and made openly accessible, as per guidelines for conductingand publishing clinical RCT. Finally, a secondary aim of this thesis emerged with the need of providinglong term relief from PLP to patient. Preliminary evidence seemed to indicate that in order to maintainpain relief, periodic rehearsal of the phantom motor skills acquired through PME is necessary. Thisraised the question of whether it is beneficial and possible to translate the technology from clinic tohome use, question that was explored employing both quantitative and qualitative methods fromengineering, medical anthropology, and user interface design.The work conducted within this thesis resulted in the extension of PME to lower limb patients byproposal and validation of a new and more user-friendly recording configuration to record EMG signals.The use of PME was then shown to be efficacious in relieving PLP with a case study on a patient. Theprotocol for the RCT was then designed and published. These two first steps permitted theestablishment of the RCT, which is currently ongoing and expected to close in March 2021. With regardto the secondary aim of this thesis, the work conducted enabled PME to be used by the patients in thecomfort of their home, while it also allowed investigate the benefits and challenges generally faced(not only by PME) in the transition from the clinic to home and its effects on treatment adherence. Thework conducted is presented in the three appended publications.Future work includes the presentation of the results of the RCT. Further, having a way to modulate PLPis an incredibly useful tool to study the neural basis of PLP. By capitalizing on this tool, we are currentlyconducting brain imaging studies using fMRI and electroencephalography that are the main focus ofthe work that lies ahead

The Illusion of Owning a Third Arm

Could it be possible that, in the not-so-distant future, we will be able to reshape the human body so as to have extra limbs? A third arm helping us out with the weekly shopping in the local grocery store, or an extra artificial limb assisting a paralysed person? Here we report a perceptual illusion in which a rubber right hand, placed beside the real hand in full view of the participant, is perceived as a supernumerary limb belonging to the participant's own body. This effect was supported by questionnaire data in conjunction with physiological evidence obtained from skin conductance responses when physically threatening either the rubber hand or the real one. In four well-controlled experiments, we demonstrate the minimal required conditions for the elicitation of this “supernumerary hand illusion”. In the fifth, and final experiment, we show that the illusion reported here is qualitatively different from the traditional rubber hand illusion as it is characterised by less disownership of the real hand and a stronger feeling of having two right hands. These results suggest that the artificial hand ‘borrows’ some of the multisensory processes that represent the real hand, leading to duplication of touch and ownership of two right arms. This work represents a major advance because it challenges the traditional view of the gross morphology of the human body as a fundamental constraint on what we can come to experience as our physical self, by showing that the body representation can easily be updated to incorporate an additional limb

Sensory feedback for supernumerary limbs

Supernumerary robotic limbs (SL) are devices developed to increase human capability. For this to happen, SLs should assist users with minimal cognitive effort and be controlled both independently and in combination with the user’s natural limbs. Despite the development of many SL, their application is limited by a lack of easy-to-use and intuitive controllers. Integrating somatosensory feedback in the control loop could improve this issue. In particular, providing artificial proprioception, a somatosensory modality important for motor control, could help SL users to integrate the SL into their planning and body schema. My objective is to find strategies to deliver intuitive and understandable proprioceptive feedback from a SL. To do so, I investigated possible ways of providing artificial proprioceptive feedback using 2degrees of freedom (DoFs) tactile cues delivered through electrical stimulation and vibration. I designed a set of mappings that provide position cues from a virtual arm for each feedback modality. Two studies, one for each modality, were conducted. In the first study, I observed that the intensity of electrical stimulation affected its perception and comfort. I then found that it was easier to differentiate frequency variations than intensity variations. This study brings new insights into electrical stimulation perception and mapping design, considering comfort is rarely addressed in previous studies. In the second study, I compared two mappings, task space and joint space, for the feedback and control of a virtual arm. Although I did not observe any effect on the performance, I found that the task space mapping was preferred and better understood than the joint space mapping. Furthermore, a novel vibration feedback device was designed and tested to deliver 3DoFs position cues. The study showed that it is possible to transmit feedback at the torso and back, a location that few studies have considered. Moreover, this study proposes a novel strategy to provide 3DoFs feedback using vibration alone.Open Acces

Finding a link in neural correlates of human’s perceptual and illusion

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonWith the ability to feel through artificial limbs, users regain more function and increasingly see the prosthetics as parts of their own bodies. So, main focus of this project was dedicated to recuperating sensation by deception both in sighted and unsighted patients, started with illusionary experiments on healthy volunteers, brain signals were captured with medical EEG headsets during these tests to have a better understanding of how the brain works during body ownership illusions. EEG results suggest that gender difference exists in the perception of body transfer illusion. Visual input can be induced to trick the brain. Using the results, a new device has been designed (sound generator system-SGS) with the principal goal to find ways to include rich sensory feedback in prosthetic devices that would aid their incorporation of the user’s body representation or schema. Studying the brain is fascinating; SGS tested and was found to have an adequate level of dexterity over course of one-month multiple times. After each try, the results were more tolerable than before that proved the idea that brain can learn and understand anything and can be manipulated temporary or lasting due to influences. Different methods used to validate the results, EEG acquisition, mapping subject brain function with EEG and finally interviewing participant after each attempt. Although the results of the illusion shows that when heat applies on rubber hand, subjects behave in similar manner as if their real hand was effected, but main question is still remains. How can the conditioning apply to daily life of amputees so that illusion become permanent? This is a rapidly developing field with advancements in technology and greater interdisciplinary integration of medicine, mechatronics and control engineering with the future looking to have permanent, low power consumption, highly functional devices with a greater intuitive almost natural feel using a variety of body signals including EMG, ultrasound, and Electrocorticography

The Effects of Physiological Arousal on Measures of Upper Extremity Position Sense in Healthy Young Adults

The purpose of this investigation was to examine the effects of physiological arousal on the ability to perceive upper extremity position in healthy young adults. Heart rate measurements and blood pressure measurements were taken at pre-established intervals during data collection. Pre-stressor and post-stressor upper extremity trials were also recorded. Twenty participants, 12 females and 8 males, with a mean age of 22.3 (20 33) years comprised the experimental sample. Participants in the experimental sample underwent a combination of the Stroop color-word task and simple math problems to produce a state of arousal and were pre and post tested for upper extremity position sense. The absolute error score averages were calculated for each subject. The pre-test absolute error scores and post-test absolute error scores were compared. A paired t»test revealed a significant difference (p\u3c .05) between the pre-test trials and the post-test trials. The purpose of this investigation was to examine how arousal effects position sense in healthy young adults. The results suggest under a state of arousal proprioceptive measures decrease. The decrease in perception ability is attributed to changes within the central nervous system, specifically the sympathetic nervous system

Perceptual abnormalities in amputees: phantom pain, mirror-touch synaesthesia and referred tactile sensations

It is often reported that after amputation people experience "a constant or inconstant... sensory ghost... faintly felt at time, but ready to be called up to [their] perception" (Mitchell, 1866). Perceptual abnormalities have been highlighted in amputees, such as sensations in the phantom when being stroked elsewhere (Ramachandran et al., 1992) or when observing someone in pain (Giummarra and Bradshaw, 2008). This thesis explored the perceptual changes that occur following amputation whist focusing on pain, vision and touch. A sample of over 100 amputees were recruited through the National Health Service. Despite finding no difference in phantom pain based on physical amputation details or nonpainful perceptual phenomena, results from Paper 1 indicated that phantom pain may be more intense, with sensations occurring more frequently, in amputees whose pain was triggerinduced. The survey in Paper 2 identified a group of amputees who in losing a limb acquired mirror-touch synaesthesia. Higher levels of empathy found in mirror-touch amputees might mean that some people are predisposed to develop synaesthesia, but that it takes sensory loss to bring dormant cross-sensory interactions into consciousness. Although the mirror-system may reach supra-threshold levels in some amputees, the experiments in Paper 3 suggested a relatively intact mirror-system in amputees overall. Specifically, in a task of apparent biological motion, amputees showed a similar, although weaker, pattern of results to normalbodied participants. The results of Paper 4 showed that tactile spatial acuity on the face was also largely not affected by amputation, as no difference was found between the sides ipsilateral and contralateral to the stump. In Paper 5 cross-modal cuing was used to investigate whether referred tactile sensations could prime a visually presented target in space occupied by the phantom limb. We conclude that perception is only moderately affected in most amputees, but that in some the sensory loss causes normally sub-threshold processing to enhance into conscious awareness